Commit Graph

202 Commits

Author SHA1 Message Date
Jeremy Fitzhardinge 667c78afae xen: Provide a variant of __RING_SIZE() that is an integer constant expression
Without this, gcc 4.5 won't compile xen-netfront and xen-blkfront, where
this is being used to specify array sizes.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: David Miller <davem@davemloft.net>
Cc: Stable Kernel <stable@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-15 12:34:28 -08:00
Stefano Stabellini af42b8d12f xen: fix MSI setup and teardown for PV on HVM guests
When remapping MSIs into pirqs for PV on HVM guests, qemu is responsible
for doing the actual mapping and unmapping.
We only give qemu the desired pirq number when we ask to do the mapping
the first time, after that we should be reading back the pirq number
from qemu every time we want to re-enable the MSI.

This fixes a bug in xen_hvm_setup_msi_irqs that manifests itself when
trying to enable the same MSI for the second time: the old MSI to pirq
mapping is still valid at this point but xen_hvm_setup_msi_irqs would
try to assign a new pirq anyway.
A simple way to reproduce this bug is to assign an MSI capable network
card to a PV on HVM guest, if the user brings down the corresponding
ethernet interface and up again, Linux would fail to enable MSIs on the
device.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2010-12-02 14:34:25 +00:00
Stefano Stabellini e5fc734541 xen: use PHYSDEVOP_get_free_pirq to implement find_unbound_pirq
Use the new hypercall PHYSDEVOP_get_free_pirq to ask Xen to allocate a
pirq. Remove the unsupported PHYSDEVOP_get_nr_pirqs hypercall to get the
amount of pirq available.

This fixes find_unbound_pirq that otherwise would return a number
starting from nr_irqs that might very well be out of range in Xen.

The symptom of this bug is that when you passthrough an MSI capable pci
device to a PV on HVM guest, Linux would fail to enable MSIs on the
device.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2010-12-02 14:28:22 +00:00
Jeremy Fitzhardinge 9b8321531a Merge branches 'upstream/core', 'upstream/xenfs' and 'upstream/evtchn' into upstream/for-linus
* upstream/core:
  xen/events: Use PIRQ instead of GSI value when unmapping MSI/MSI-X irqs.
  xen: set IO permission early (before early_cpu_init())
  xen: re-enable boot-time ballooning
  xen/balloon: make sure we only include remaining extra ram
  xen/balloon: the balloon_lock is useless
  xen: add extra pages to balloon
  xen/events: use locked set|clear_bit() for cpu_evtchn_mask
  xen/evtchn: clear secondary CPUs' cpu_evtchn_mask[] after restore
  xen: implement XENMEM_machphys_mapping

* upstream/xenfs:
  Revert "xen/privcmd: create address space to allow writable mmaps"
  xen/xenfs: update xenfs_mount for new prototype
  xen: fix header export to userspace
  xen: set vma flag VM_PFNMAP in the privcmd mmap file_op
  xen: xenfs: privcmd: check put_user() return code

* upstream/evtchn:
  xen: make evtchn's name less generic
  xen/evtchn: the evtchn device is non-seekable
  xen/evtchn: add missing static
  xen/evtchn: Fix name of Xen event-channel device
  xen/evtchn: don't do unbind_from_irqhandler under spinlock
  xen/evtchn: remove spurious barrier
  xen/evtchn: ports start enabled
  xen/evtchn: dynamically allocate port_user array
  xen/evtchn: track enabled state for each port
2010-11-22 12:22:42 -08:00
Jeremy Fitzhardinge 9be4d45759 xen: add extra pages to balloon
Add extra pages in the pseudo-physical address space to the balloon
so we can extend into them later.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-11-19 22:15:59 -08:00
Jeremy Fitzhardinge 20b4755e4f Merge commit 'v2.6.37-rc2' into upstream/xenfs
* commit 'v2.6.37-rc2': (10093 commits)
  Linux 2.6.37-rc2
  capabilities/syslog: open code cap_syslog logic to fix build failure
  i2c: Sanity checks on adapter registration
  i2c: Mark i2c_adapter.id as deprecated
  i2c: Drivers shouldn't include <linux/i2c-id.h>
  i2c: Delete unused adapter IDs
  i2c: Remove obsolete cleanup for clientdata
  include/linux/kernel.h: Move logging bits to include/linux/printk.h
  Fix gcc 4.5.1 miscompiling drivers/char/i8k.c (again)
  hwmon: (w83795) Check for BEEP pin availability
  hwmon: (w83795) Clear intrusion alarm immediately
  hwmon: (w83795) Read the intrusion state properly
  hwmon: (w83795) Print the actual temperature channels as sources
  hwmon: (w83795) List all usable temperature sources
  hwmon: (w83795) Expose fan control method
  hwmon: (w83795) Fix fan control mode attributes
  hwmon: (lm95241) Check validity of input values
  hwmon: Change mail address of Hans J. Koch
  PCI: sysfs: fix printk warnings
  GFS2: Fix inode deallocation race
  ...
2010-11-16 11:06:22 -08:00
Randy Dunlap 744f9f104e xen: fix header export to userspace
scripts/headers_install.pl prevents "__user" from being exported
to userspace headers, so just use compiler.h to make sure that
__user is defined and avoid the error.

unifdef: linux-next-20101112/xx64/usr/include/xen/privcmd.h.tmp: 79: Premature EOF (#if line 33 depth 1)

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc:	Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc:	xen-devel@lists.xensource.com (moderated for non-subscribers)
Cc:	virtualization@lists.osdl.org
Cc:	Tony Finch <dot@dotat.at>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-11-16 10:57:05 -08:00
Ian Campbell 7e77506a59 xen: implement XENMEM_machphys_mapping
This hypercall allows Xen to specify a non-default location for the
machine to physical mapping. This capability is used when running a 32
bit domain 0 on a 64 bit hypervisor to shrink the hypervisor hole to
exactly the size required.

[ Impact: add Xen hypercall definitions ]

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2010-11-12 15:00:06 -08:00
Linus Torvalds 18cb657ca1 Merge branch 'stable/xen-pcifront-0.8.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
and branch 'for-linus' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm

* 'for-linus' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm:
  xen: register xen pci notifier
  xen: initialize cpu masks for pv guests in xen_smp_init
  xen: add a missing #include to arch/x86/pci/xen.c
  xen: mask the MTRR feature from the cpuid
  xen: make hvc_xen console work for dom0.
  xen: add the direct mapping area for ISA bus access
  xen: Initialize xenbus for dom0.
  xen: use vcpu_ops to setup cpu masks
  xen: map a dummy page for local apic and ioapic in xen_set_fixmap
  xen: remap MSIs into pirqs when running as initial domain
  xen: remap GSIs as pirqs when running as initial domain
  xen: introduce XEN_DOM0 as a silent option
  xen: map MSIs into pirqs
  xen: support GSI -> pirq remapping in PV on HVM guests
  xen: add xen hvm acpi_register_gsi variant
  acpi: use indirect call to register gsi in different modes
  xen: implement xen_hvm_register_pirq
  xen: get the maximum number of pirqs from xen
  xen: support pirq != irq

* 'stable/xen-pcifront-0.8.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: (27 commits)
  X86/PCI: Remove the dependency on isapnp_disable.
  xen: Update Makefile with CONFIG_BLOCK dependency for biomerge.c
  MAINTAINERS: Add myself to the Xen Hypervisor Interface and remove Chris Wright.
  x86: xen: Sanitse irq handling (part two)
  swiotlb-xen: On x86-32 builts, select SWIOTLB instead of depending on it.
  MAINTAINERS: Add myself for Xen PCI and Xen SWIOTLB maintainer.
  xen/pci: Request ACS when Xen-SWIOTLB is activated.
  xen-pcifront: Xen PCI frontend driver.
  xenbus: prevent warnings on unhandled enumeration values
  xenbus: Xen paravirtualised PCI hotplug support.
  xen/x86/PCI: Add support for the Xen PCI subsystem
  x86: Introduce x86_msi_ops
  msi: Introduce default_[teardown|setup]_msi_irqs with fallback.
  x86/PCI: Export pci_walk_bus function.
  x86/PCI: make sure _PAGE_IOMAP it set on pci mappings
  x86/PCI: Clean up pci_cache_line_size
  xen: fix shared irq device passthrough
  xen: Provide a variant of xen_poll_irq with timeout.
  xen: Find an unbound irq number in reverse order (high to low).
  xen: statically initialize cpu_evtchn_mask_p
  ...

Fix up trivial conflicts in drivers/pci/Makefile
2010-10-28 17:11:17 -07:00
Weidong Han e28c31a96b xen: register xen pci notifier
Register a pci notifier to add (or remove) pci devices to Xen via
hypercalls. Xen needs to know the pci devices present in the system to
handle pci passthrough and even MSI remapping in the initial domain.

Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Qing He <qing.he@intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2010-10-27 18:56:07 +01:00
Linus Torvalds 520045db94 Merge branches 'upstream/xenfs' and 'upstream/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen
* 'upstream/xenfs' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xen/privcmd: make privcmd visible in domU
  xen/privcmd: move remap_domain_mfn_range() to core xen code and export.
  privcmd: MMAPBATCH: Fix error handling/reporting
  xenbus: export xen_store_interface for xenfs
  xen/privcmd: make sure vma is ours before doing anything to it
  xen/privcmd: print SIGBUS faults
  xen/xenfs: set_page_dirty is supposed to return true if it dirties
  xen/privcmd: create address space to allow writable mmaps
  xen: add privcmd driver
  xen: add variable hypercall caller
  xen: add xen_set_domain_pte()
  xen: add /proc/xen/xsd_{kva,port} to xenfs

* 'upstream/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen: (29 commits)
  xen: include xen/xen.h for definition of xen_initial_domain()
  xen: use host E820 map for dom0
  xen: correctly rebuild mfn list list after migration.
  xen: improvements to VIRQ_DEBUG output
  xen: set up IRQ before binding virq to evtchn
  xen: ensure that all event channels start off bound to VCPU 0
  xen/hvc: only notify if we actually sent something
  xen: don't add extra_pages for RAM after mem_end
  xen: add support for PAT
  xen: make sure xen_max_p2m_pfn is up to date
  xen: limit extra memory to a certain ratio of base
  xen: add extra pages for E820 RAM regions, even if beyond mem_end
  xen: make sure xen_extra_mem_start is beyond all non-RAM e820
  xen: implement "extra" memory to reserve space for pages not present at boot
  xen: Use host-provided E820 map
  xen: don't map missing memory
  xen: defer building p2m mfn structures until kernel is mapped
  xen: add return value to set_phys_to_machine()
  xen: convert p2m to a 3 level tree
  xen: make install_p2mtop_page() static
  ...

Fix up trivial conflict in arch/x86/xen/mmu.c, and fix the use of
'reserve_early()' - in the new memblock world order it is now
'memblock_x86_reserve_range()' instead. Pointed out by Jeremy.
2010-10-26 18:20:19 -07:00
Jeremy Fitzhardinge 4fe7d5a708 xen: make hvc_xen console work for dom0.
Use the console hypercalls for dom0 console.

[ Impact: Add Xen dom0 console ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-22 21:26:01 +01:00
Qing He f731e3ef02 xen: remap MSIs into pirqs when running as initial domain
Implement xen_create_msi_irq to create an msi and remap it as pirq.
Use xen_create_msi_irq to implement an initial domain specific version
of setup_msi_irqs.

Signed-off-by: Qing He <qing.he@intel.com>
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-22 21:25:44 +01:00
Jeremy Fitzhardinge 38aa66fcb7 xen: remap GSIs as pirqs when running as initial domain
Implement xen_register_gsi to setup the correct triggering and polarity
properties of a gsi.
Implement xen_register_pirq to register a particular gsi as pirq and
receive interrupts as events.
Call xen_setup_pirqs to register all the legacy ISA irqs as pirqs.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-22 21:25:43 +01:00
Stefano Stabellini 809f9267bb xen: map MSIs into pirqs
Map MSIs into pirqs, writing 0 in the MSI vector data field and the pirq
number in the MSI destination id field.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-22 21:25:43 +01:00
Stefano Stabellini 3942b740e5 xen: support GSI -> pirq remapping in PV on HVM guests
Disable pcifront when running on HVM: it is meant to be used with pv
guests that don't have PCI bus.

Use acpi_register_gsi_xen_hvm to remap GSIs into pirqs.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-22 21:25:42 +01:00
Stefano Stabellini 42a1de56f3 xen: implement xen_hvm_register_pirq
xen_hvm_register_pirq allows the kernel to map a GSI into a Xen pirq and
receive the interrupt as an event channel from that point on.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-22 21:25:41 +01:00
Stefano Stabellini 01557baff6 xen: get the maximum number of pirqs from xen
Use PHYSDEVOP_get_nr_pirqs to get the maximum number of pirqs from xen.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-22 21:25:40 +01:00
Stefano Stabellini 7a043f119c xen: support pirq != irq
PHYSDEVOP_map_pirq might return a pirq different from what we asked if
we are running as an HVM guest, so we need to be able to support pirqs
that are different from linux irqs.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-22 21:25:40 +01:00
Ian Campbell 35ae11fd14 xen: Use host-provided E820 map
Rather than simply using a flat memory map from Xen, use its provided
E820 map.  This allows the domain builder to tell the domain to reserve
space for more pages than those initially provided at domain-build time.

It also allows the host to specify holes in the address space (for
PCI-passthrough, for example).

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-10-22 12:57:27 -07:00
Ian Campbell de1ef2065c xen/privcmd: move remap_domain_mfn_range() to core xen code and export.
This allows xenfs to be built as a module, previously it required flush_tlb_all
and arbitrary_virt_to_machine to be exported.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-10-20 16:22:34 -07:00
Jeremy Fitzhardinge 1c5de1939c xen: add privcmd driver
The privcmd interface in xenfs allows the tool stack in the privileged
domain to get fairly direct access to the hypervisor in order to do
various management things such as domain construction.

[ Impact: new xenfs interface for privileged operations ]

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-10-20 16:22:29 -07:00
Ryan Wilson 956a9202cd xen-pcifront: Xen PCI frontend driver.
This is a port of the 2.6.18 Xen PCI front driver with fixes
to make it build under 2.6.34 and later (for the full list of
changes: git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git
historic/xen-pcifront-0.1). It also includes the fixes
to make it work properly.

[v2: Updated Kconfig, removed crud, added Reviewed-by]
[v3: Added 'static', fixed grant table leak, redid Kconfig]
[v4: Added one more 'static' and removed comments]

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Jan Beulich <JBeulich@novell.com>
2010-10-18 10:49:37 -04:00
Yosuke Iwamatsu 89afb6e46a xenbus: Xen paravirtualised PCI hotplug support.
The Xen PCI front driver adds two new states that are utilizez
for PCI hotplug support. This is a patch pulled from the
linux-2.6-xen-sparse tree.

Signed-off-by: Noboru Iwamatsu <n_iwamatsu@jp.fujitsu.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Yosuke Iwamatsu <y-iwamatsu@ab.jp.nec.com>
2010-10-18 10:49:35 -04:00
Alex Nixon b5401a96b5 xen/x86/PCI: Add support for the Xen PCI subsystem
The frontend stub lives in arch/x86/pci/xen.c, alongside other
sub-arch PCI init code (e.g. olpc.c).

It provides a mechanism for Xen PCI frontend to setup/destroy
legacy interrupts, MSI/MSI-X, and PCI configuration operations.

[ Impact: add core of Xen PCI support ]
[ v2: Removed the IOMMU code and only focusing on PCI.]
[ v3: removed usage of pci_scan_all_fns as that does not exist]
[ v4: introduced pci_xen value to fix compile warnings]
[ v5: squished fixes+features in one patch, changed Reviewed-by to Ccs]
[ v7: added Acked-by]
Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Qing He <qing.he@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
2010-10-18 10:49:35 -04:00
Konrad Rzeszutek Wilk 15ebbb82ba xen: fix shared irq device passthrough
In driver/xen/events.c, whether bind_pirq is shareable or not is
determined by desc->action is NULL or not. But in __setup_irq,
startup(irq) is invoked before desc->action is assigned with
new action. So desc->action in startup_irq is always NULL, and
bind_pirq is always not shareable. This results in pt_irq_create_bind
failure when passthrough a device which shares irq to other devices.

This patch doesn't use probing_irq to determine if pirq is shareable
or not, instead set shareable flag in irq_info according to trigger
mode in xen_allocate_pirq. Set level triggered interrupts shareable.
Thus use this flag to set bind_pirq flag accordingly.

[v2: arch/x86/xen/pci.c no more, so file skipped]

Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-18 10:49:29 -04:00
Konrad Rzeszutek Wilk d9a8814f27 xen: Provide a variant of xen_poll_irq with timeout.
The 'xen_poll_irq_timeout' provides a method to pass in
the poll timeout for IRQs if requested. We also export
those two poll functions as Xen PCI fronted uses them.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-10-18 10:49:28 -04:00
Gerd Hoffmann 1a60d05f40 xen: set pirq name to something useful.
Impact: cleanup

Make pirq show useful information in /proc/interrupts

[v2: Removed the parts for arch/x86/xen/pci.c ]

Signed-off-by: Gerd Hoffmann <kraxel@xeni.home.kraxel.org>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-18 10:41:43 -04:00
Jeremy Fitzhardinge d46a78b05c xen: implement pirq type event channels
A privileged PV Xen domain can get direct access to hardware.  In
order for this to be useful, it must be able to get hardware
interrupts.

Being a PV Xen domain, all interrupts are delivered as event channels.
PIRQ event channels are bound to a pirq number and an interrupt
vector.  When a IO APIC raises a hardware interrupt on that vector, it
is delivered as an event channel, which we can deliver to the
appropriate device driver(s).

This patch simply implements the infrastructure for dealing with pirq
event channels.

[ Impact: integrate hardware interrupts into Xen's event scheme ]

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-18 10:40:29 -04:00
Ian Campbell 9c35e90c6f xen: pvhvm: make it clearer that XEN_UNPLUG_* define bits in a bitfield
by defining in terms of (1<<N).

XEN_UNPLUG_UNNECESSARY and XEN_UNPLUG_NEVER are only used within the
kernel and are not defined as a bit on the unplug IO port. Therefore
use a bit which is outside the potentially valid range of the 16 bit
IO port.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>
2010-08-23 12:01:35 +01:00
Ian Campbell 1dc7ce99b0 xen: pvhvm: rename xen_emul_unplug=ignore to =unnnecessary
It is not immediately clear what this option causes to become
ignored. The actual meaning is that it is not necessary to unplug the
emulated devices to safely use the PV ones, even if the platform does
not support the unplug protocol. (pressumably the user will only add
this option if they have ensured that their domain configuration is
safe).

I think xen_emul_unplug=unnecessary better captures this.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>
2010-08-23 11:59:29 +01:00
Ian Campbell c93a4dfb31 xen: pvhvm: allow user to request no emulated device unplug
this allows the user to disable pvhvm and revert to emulated devices
in case of a system misconfiguration (e.g. initramfs with only
emulated drivers in it).

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>
2010-08-23 11:59:28 +01:00
Linus Torvalds 26f0cf9181 Merge branch 'stable/xen-swiotlb-0.8.6' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/xen-swiotlb-0.8.6' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  x86: Detect whether we should use Xen SWIOTLB.
  pci-swiotlb-xen: Add glue code to setup dma_ops utilizing xen_swiotlb_* functions.
  swiotlb-xen: SWIOTLB library for Xen PV guest with PCI passthrough.
  xen/mmu: inhibit vmap aliases rather than trying to clear them out
  vmap: add flag to allow lazy unmap to be disabled at runtime
  xen: Add xen_create_contiguous_region
  xen: Rename the balloon lock
  xen: Allow unprivileged Xen domains to create iomap pages
  xen: use _PAGE_IOMAP in ioremap to do machine mappings

Fix up trivial conflicts (adding both xen swiotlb and xen pci platform
driver setup close to each other) in drivers/xen/{Kconfig,Makefile} and
include/xen/xen-ops.h
2010-08-12 09:09:41 -07:00
Konrad Rzeszutek Wilk b097186fd2 swiotlb-xen: SWIOTLB library for Xen PV guest with PCI passthrough.
This patchset:

PV guests under Xen are running in an non-contiguous memory architecture.

When PCI pass-through is utilized, this necessitates an IOMMU for
translating bus (DMA) to virtual and vice-versa and also providing a
mechanism to have contiguous pages for device drivers operations (say DMA
operations).

Specifically, under Xen the Linux idea of pages is an illusion. It
assumes that pages start at zero and go up to the available memory. To
help with that, the Linux Xen MMU provides a lookup mechanism to
translate the page frame numbers (PFN) to machine frame numbers (MFN)
and vice-versa. The MFN are the "real" frame numbers. Furthermore
memory is not contiguous. Xen hypervisor stitches memory for guests
from different pools, which means there is no guarantee that PFN==MFN
and PFN+1==MFN+1. Lastly with Xen 4.0, pages (in debug mode) are
allocated in descending order (high to low), meaning the guest might
never get any MFN's under the 4GB mark.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Albert Herranz <albert_herranz@yahoo.es>
Cc: Ian Campbell <Ian.Campbell@citrix.com>
2010-07-27 11:51:00 -04:00
Stefano Stabellini 5915100106 x86: Call HVMOP_pagetable_dying on exit_mmap.
When a pagetable is about to be destroyed, we notify Xen so that the
hypervisor can clear the related shadow pagetable.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-26 23:13:26 -07:00
Stefano Stabellini c1c5413ad5 x86: Unplug emulated disks and nics.
Add a xen_emul_unplug command line option to the kernel to unplug
xen emulated disks and nics.

Set the default value of xen_emul_unplug depending on whether or
not the Xen PV frontends and the Xen platform PCI driver have
been compiled for this kernel (modules or built-in are both OK).

The user can specify xen_emul_unplug=ignore to enable PV drivers on HVM
even if the host platform doesn't support unplug.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-26 23:13:25 -07:00
Stefano Stabellini 409771d258 x86: Use xen_vcpuop_clockevent, xen_clocksource and xen wallclock.
Use xen_vcpuop_clockevent instead of hpet and APIC timers as main
clockevent device on all vcpus, use the xen wallclock time as wallclock
instead of rtc and use xen_clocksource as clocksource.
The pv clock algorithm needs to work correctly for the xen_clocksource
and xen wallclock to be usable, only modern Xen versions offer a
reliable pv clock in HVM guests (XENFEAT_hvm_safe_pvclock).

Using the hpet as clocksource means a VMEXIT every time we read/write to
the hpet mmio addresses, pvclock give us a better rating without
VMEXITs. Same goes for the xen wallclock and xen_vcpuop_clockevent

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Don Dutile <ddutile@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-26 23:13:25 -07:00
Stefano Stabellini 016b6f5fe8 xen: Add suspend/resume support for PV on HVM guests.
Suspend/resume requires few different things on HVM: the suspend
hypercall is different; we don't need to save/restore memory related
settings; except the shared info page and the callback mechanism.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-22 16:46:21 -07:00
Stefano Stabellini 183d03cc4f xen: Xen PCI platform device driver.
Add the xen pci platform device driver that is responsible
for initializing the grant table and xenbus in PV on HVM mode.
Few changes to xenbus and grant table are necessary to allow the delayed
initialization in HVM mode.
Grant table needs few additional modifications to work in HVM mode.

The Xen PCI platform device raises an irq every time an event has been
delivered to us. However these interrupts are only delivered to vcpu 0.
The Xen PCI platform interrupt handler calls xen_hvm_evtchn_do_upcall
that is a little wrapper around __xen_evtchn_do_upcall, the traditional
Xen upcall handler, the very same used with traditional PV guests.

When running on HVM the event channel upcall is never called while in
progress because it is a normal Linux irq handler (and we cannot switch
the irq chip wholesale to the Xen PV ones as we are running QEMU and
might have passed in PCI devices), therefore we cannot be sure that
evtchn_upcall_pending is 0 when returning.
For this reason if evtchn_upcall_pending is set by Xen we need to loop
again on the event channels set pending otherwise we might loose some
event channel deliveries.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-22 16:46:09 -07:00
Sheng Yang 38e20b07ef x86/xen: event channels delivery on HVM.
Set the callback to receive evtchns from Xen, using the
callback vector delivery mechanism.

The traditional way for receiving event channel notifications from Xen
is via the interrupts from the platform PCI device.
The callback vector is a newer alternative that allow us to receive
notifications on any vcpu and doesn't need any PCI support: we allocate
a vector exclusively to receive events, in the vector handler we don't
need to interact with the vlapic, therefore we avoid a VMEXIT.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-22 16:45:59 -07:00
Jeremy Fitzhardinge 18f19aa62a xen: Add support for HVM hypercalls.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2010-07-22 16:45:31 -07:00
Alex Nixon 08bbc9da92 xen: Add xen_create_contiguous_region
A memory region must be physically contiguous in order to be accessed
through DMA.  This patch adds xen_create_contiguous_region, which
ensures a region of contiguous virtual memory is also physically
contiguous.

Based on Stephen Tweedie's port of the 2.6.18-xen version.

Remove contiguous_bitmap[] as it's no longer needed.

Ported from linux-2.6.18-xen.hg 707:e410857fd83c

[ Impact: add Xen-internal API to make pages phys-contig ]

Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-06-07 15:37:53 -04:00
Alex Nixon 19001c8c5b xen: Rename the balloon lock
* xen_create_contiguous_region needs access to the balloon lock to
  ensure memory doesn't change under its feet, so expose the balloon
  lock
* Change the name of the lock to xen_reservation_lock, to imply it's
  now less-specific usage.

[ Impact: cleanup ]

Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-06-07 14:34:07 -04:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Jeremy Fitzhardinge 1ccbf5344c xen: move Xen-testing predicates to common header
Move xen_domain and related tests out of asm-x86 to xen/xen.h so they
can be included whenever they are necessary.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-11-04 08:47:24 -08:00
Jeremy Fitzhardinge 1943689c47 Merge branches 'for-linus/xen/dev-evtchn', 'for-linus/xen/xenbus', 'for-linus/xen/xenfs' and 'for-linus/xen/sys-hypervisor' into for-linus/xen/master
* for-linus/xen/dev-evtchn:
  xen/dev-evtchn: clean up locking in evtchn
  xen: export ioctl headers to userspace
  xen: add /dev/xen/evtchn driver
  xen: add irq_from_evtchn

* for-linus/xen/xenbus:
  xen/xenbus: export xenbus_dev_changed
  xen: use device model for suspending xenbus devices
  xen: remove suspend_cancel hook

* for-linus/xen/xenfs:
  xen: add "capabilities" file

* for-linus/xen/sys-hypervisor:
  xen: drop kexec bits from /sys/hypervisor since kexec isn't implemented yet
  xen/sys/hypervisor: change writable_pt to features
  xen: add /sys/hypervisor support

Conflicts:
	drivers/xen/Makefile
2009-03-30 10:00:45 -07:00
Jeremy Fitzhardinge cff7e81b3d xen: add /sys/hypervisor support
Adds support for Xen info under /sys/hypervisor.  Taken from Novell 2.6.27
backport tree.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-03-30 09:27:06 -07:00
Ian Campbell de5b31bd47 xen: use device model for suspending xenbus devices
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-03-30 09:26:56 -07:00
Ian Campbell a1ce1be578 xen: remove suspend_cancel hook
Remove suspend_cancel hook from xenbus_driver, in preparation for using
the device model for suspending.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-03-30 09:26:55 -07:00
Ian Campbell c5cfef0f79 xen: export ioctl headers to userspace
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-03-30 09:26:49 -07:00
Ian Campbell f7116284c7 xen: add /dev/xen/evtchn driver
This driver is used by application which wish to receive notifications
from the hypervisor or other guests via Xen's event channel
mechanism. In particular it is used by the xenstore daemon in domain
0.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-03-30 09:26:49 -07:00
Ian Campbell d4c045364d xen: add irq_from_evtchn
Given an evtchn, return the corresponding irq.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-03-30 09:26:49 -07:00
Alex Zeffertt 1107ba885e xen: add xenfs to allow usermode <-> Xen interaction
The xenfs filesystem exports various interfaces to usermode.  Initially
this exports a file to allow usermode to interact with xenbus/xenstore.

Traditionally this appeared in /proc/xen.  Rather than extending procfs,
this patch adds a backward-compat mountpoint on /proc/xen, and provides
a xenfs filesystem which can be mounted there.

Signed-off-by: Alex Zeffertt <alex.zeffertt@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:30:59 -08:00
Jeremy Fitzhardinge ecbf29cdb3 xen: clean up asm/xen/hypervisor.h
Impact: cleanup

hypervisor.h had accumulated a lot of crud, including lots of spurious
#includes.  Clean it all up, and go around fixing up everything else
accordingly.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-16 21:50:31 +01:00
Jeremy Fitzhardinge d19c8e516e xen: remove unused balloon.h
The balloon driver doesn't have any externally callable functions at
the moment, so remove the (effectively empty) header.  We can add it
back if we need to.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-03 10:04:10 +02:00
Jeremy Fitzhardinge 168d2f464a xen: save previous spinlock when blocking
A spinlock can be interrupted while spinning, so make sure we preserve
the previous lock of interest if we're taking a lock from within an
interrupt handler.

We also need to deal with the case where the blocking path gets
interrupted between testing to see if the lock is free and actually
blocking.  If we get interrupted there and end up in the state where
the lock is free but the irq isn't pending, then we'll block
indefinitely in the hypervisor.  This fix is to make sure that any
nested lock-takers will always leave the irq pending if there's any
chance the outer lock became free.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-21 13:52:57 +02:00
Jeremy Fitzhardinge 2d9e1e2f58 xen: implement Xen-specific spinlocks
The standard ticket spinlocks are very expensive in a virtual
environment, because their performance depends on Xen's scheduler
giving vcpus time in the order that they're supposed to take the
spinlock.

This implements a Xen-specific spinlock, which should be much more
efficient.

The fast-path is essentially the old Linux-x86 locks, using a single
lock byte.  The locker decrements the byte; if the result is 0, then
they have the lock.  If the lock is negative, then locker must spin
until the lock is positive again.

When there's contention, the locker spin for 2^16[*] iterations waiting
to get the lock.  If it fails to get the lock in that time, it adds
itself to the contention count in the lock and blocks on a per-cpu
event channel.

When unlocking the spinlock, the locker looks to see if there's anyone
blocked waiting for the lock by checking for a non-zero waiter count.
If there's a waiter, it traverses the per-cpu "lock_spinners"
variable, which contains which lock each CPU is waiting on.  It picks
one CPU waiting on the lock and sends it an event to wake it up.

This allows efficient fast-path spinlock operation, while allowing
spinning vcpus to give up their processor time while waiting for a
contended lock.

[*] 2^16 iterations is threshold at which 98% locks have been taken
according to Thomas Friebel's Xen Summit talk "Preventing Guests from
Spinning Around".  Therefore, we'd expect the lock and unlock slow
paths will only be entered 2% of the time.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <clameter@linux-foundation.org>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Virtualization <virtualization@lists.linux-foundation.org>
Cc: Xen devel <xen-devel@lists.xensource.com>
Cc: Thomas Friebel <thomas.friebel@amd.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16 11:15:53 +02:00
Ingo Molnar 9c8a442044 xen64: fix !HVC_XEN build dependency
fix:

arch/x86/xen/built-in.o: In function `set_page_prot':
enlighten.c:(.text+0x111d): undefined reference to `xen_raw_printk'
arch/x86/xen/built-in.o: In function `xen_start_kernel':
: undefined reference to `xen_raw_console_write'
arch/x86/xen/built-in.o: In function `xen_start_kernel':
: undefined reference to `xen_raw_console_write'

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16 11:06:48 +02:00
Jeremy Fitzhardinge 48b5db2062 xen64: define asm/xen/interface for 64-bit
Copy 64-bit definitions of various interface structures into place.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16 10:56:18 +02:00
Isaku Yamahata ad55db9fed xen: add xen_arch_resume()/xen_timer_resume hook for ia64 support
add xen_timer_resume() hook.

Timer resume should be done after event channel is resumed.
add xen_arch_resume() hook when ipi becomes usable after resume.
After resume, some cpu specific resource must be reinitialized
on ia64 that can't be set by another cpu.

However available hooks is run once on only one cpu so that ipi has
to be used.

During stop_machine_run() ipi can't be used because interrupt is masked.
So add another hook after stop_machine_run().
Another approach might be use resume hook which is run by
device_resume(). However device_resume() may be executed on
suspend error recovery path.

So it is necessary to determine whether it is executed on real resume path
or error recovery path.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16 10:55:50 +02:00
Jeremy Fitzhardinge e57778a1e3 xen: implement ptep_modify_prot_start/commit
Xen has a pte update function which will update a pte while preserving
its accessed and dirty bits.  This means that ptep_modify_prot_start() can be
implemented as a simple read of the pte value.  The hardware may
update the pte in the meantime, but ptep_modify_prot_commit() updates it while
preserving any changes that may have happened in the meantime.

The updates in ptep_modify_prot_commit() are batched if we're currently in lazy
mmu mode.

The mmu_update hypercall can take a batch of updates to perform, but
this code doesn't make particular use of that feature, in favour of
using generic multicall batching to get them all into the hypervisor.

The net effect of this is that each mprotect pte update turns from two
expensive trap-and-emulate faults into they hypervisor into a single
hypercall whose cost is amortized in a batched multicall.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-25 15:17:23 +02:00
Ingo Molnar d02859ecb3 Merge commit 'v2.6.26-rc8' into x86/xen
Conflicts:

	arch/x86/xen/enlighten.c
	arch/x86/xen/mmu.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-25 12:16:51 +02:00
Gerd Hoffmann 1c7b67f757 x86: Make xen use the paravirt clocksource structs and functions
This patch updates the xen guest to use the pvclock structs
and helper functions.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24 21:02:32 +03:00
Jeremy Fitzhardinge 7e0edc1bc3 xen: add new Xen elfnote types and use them appropriately
Define recently added XEN_ELFNOTEs, and use them appropriately.
Most significantly, this enables domain checkpointing (xm save -c).

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-02 13:25:51 +02:00
Ingo Molnar 0261ac5f2f xen: fix "xen: implement save/restore"
-tip testing found the following build breakage:

  drivers/built-in.o: In function `xen_suspend':
  manage.c:(.text+0x4390f): undefined reference to `xen_console_resume'

with this config:

  http://redhat.com/~mingo/misc/config-Thu_May_29_09_23_16_CEST_2008.bad

i have bisected it down to:

|  commit 0e91398f2a
|  Author: Jeremy Fitzhardinge <jeremy@goop.org>
|  Date:   Mon May 26 23:31:27 2008 +0100
|
|      xen: implement save/restore

the problem is that drivers/xen/manage.c is built unconditionally if
CONFIG_XEN is enabled and makes use of xen_suspend(), but
drivers/char/hvc_xen.c, where the xen_suspend() method is implemented,
is only build if CONFIG_HVC_XEN=y as well.

i have solved this by providing a NOP implementation for xen_suspend()
in the !CONFIG_HVC_XEN case.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-29 09:31:57 +02:00
Jeremy Fitzhardinge 359cdd3f86 xen: maintain clock offset over save/restore
Hook into the device model to make sure that timekeeping's resume handler
is called.  This deals with our clocksource's non-monotonicity over the
save/restore.  Explicitly call clock_has_changed() to make sure that
all the timers get retriggered properly.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-27 10:11:38 +02:00
Jeremy Fitzhardinge 0e91398f2a xen: implement save/restore
This patch implements Xen save/restore and migration.

Saving is triggered via xenbus, which is polled in
drivers/xen/manage.c.  When a suspend request comes in, the kernel
prepares itself for saving by:

1 - Freeze all processes.  This is primarily to prevent any
    partially-completed pagetable updates from confusing the suspend
    process.  If CONFIG_PREEMPT isn't defined, then this isn't necessary.

2 - Suspend xenbus and other devices

3 - Stop_machine, to make sure all the other vcpus are quiescent.  The
    Xen tools require the domain to run its save off vcpu0.

4 - Within the stop_machine state, it pins any unpinned pgds (under
    construction or destruction), performs canonicalizes various other
    pieces of state (mostly converting mfns to pfns), and finally

5 - Suspend the domain

Restore reverses the steps used to save the domain, ending when all
the frozen processes are thawed.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-27 10:11:38 +02:00
Jeremy Fitzhardinge 6b9b732d0e xen-console: add save/restore
Add code to:

 1. Deal with the console page being canonicalized.  During save, the
    console's mfn in the start_info structure is canonicalized to a pfn.
    In order to deal with that, we always use a copy of the pfn and
    indirect off that all the time.  However, we fall back to using the
    mfn if the pfn hasn't been initialized yet.

 2. Restore the console event channel, and rebind it to the existing irq.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-27 10:11:37 +02:00
Jeremy Fitzhardinge eb1e305f4e xen: add rebind_evtchn_irq
Add rebind_evtchn_irq(), which will rebind an device driver's existing
irq to a new event channel on restore.  Since the new event channel
will be masked and bound to vcpu0, we update the state accordingly and
unmask the irq once everything is set up.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-27 10:11:37 +02:00
Isaku Yamahata bfdab126cf xen: add missing definitions in include/xen/interface/memory.h which ia64/xen needs
Add xen handles realted definitions for xen memory which ia64/xen needs.
Pointer argumsnts for ia64/xen hypercall are passed in pseudo physical
address (guest physical address) so that it is required to convert
guest kernel virtual address into pseudo physical address.
The xen guest handle represents such arguments.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-27 10:11:36 +02:00
Markus Armbruster e4dcff1f6e xen pvfb: Dynamic mode support (screen resizing)
The pvfb backend indicates dynamic mode support by creating node
feature_resize with a non-zero value in its xenstore directory.
xen-fbfront sends a resize notification event on mode change.  Fully
backwards compatible both ways.

Framebuffer size and initial resolution can be controlled through
kernel parameter xen_fbfront.video.  The backend enforces a separate
size limit, which it advertises in node videoram in its xenstore
directory.

xen-kbdfront gets the maximum screen resolution from nodes width and
height in the backend's xenstore directory instead of hardcoding it.

Additional goodie: support for larger framebuffers (512M on a 64-bit
system with 4K pages).

Changing the number of bits per pixels dynamically is not supported,
yet.

Ported from
http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/92f7b3144f41
http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/bfc040135633

Signed-off-by: Pat Campbell <plc@novell.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-27 10:11:36 +02:00
Markus Armbruster 6ba0e7b36c xen pvfb: Pointer z-axis (mouse wheel) support
Add z-axis motion to pointer events.  Backward compatible, because
there's space for the z-axis in union xenkbd_in_event, and old
backends zero it.

Derived from
http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/57dfe0098000
http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/1edfea26a2a9
http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/c3ff0b26f664

Signed-off-by: Pat Campbell <plc@novell.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-27 10:11:36 +02:00
Jeremy Fitzhardinge 0acf10d8fb xen: add raw console write functions for debug
Add a couple of functions which can write directly to the Xen console
for debugging.  This output ends up on the host's dom0 console
(assuming it allows the domain to write there).

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-27 10:11:35 +02:00
Jeremy Fitzhardinge 1775826cee xen: add balloon driver
The balloon driver allows memory to be dynamically added or removed from the domain,
in order to allow host memory to be balanced between multiple domains.

This patch introduces the Xen balloon driver, though it currently only
allows a domain to be shrunk from its initial size (and re-grown back to
that size).  A later patch will add the ability to grow a domain beyond
its initial size.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:33 +02:00
Markus Armbruster 4ee36dc08e xen pvfb: Para-virtual framebuffer, keyboard and pointer driver
This is a pair of Xen para-virtual frontend device drivers:
drivers/video/xen-fbfront.c provides a framebuffer, and
drivers/input/xen-kbdfront provides keyboard and mouse.

The backends run in dom0 user space.

The two drivers are not in two separate patches, because the
intermediate step (one driver, not the other) is somewhat problematic:
the backend in dom0 needs both drivers, and will refuse to complete
device initialization unless they're both present.

Signed-off-by: Markus Armbruster <armbru@redhat.com>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:33 +02:00
Christian Limpach 1d78d70556 xen blkfront: Delay wait for block devices until after the disk is added
When the xen block frontend driver is built as a module the module load
is only synchronous up to the point where the frontend and the backend
become connected rather than when the disk is added.

This means that there can be a race on boot between loading the module and
loading the dm-* modules and doing the scan for LVM physical volumes (all
in the initrd). In the failure case the disk is not present until after the
scan for physical volumes is complete.

Taken from:

  http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/11483a00c017

Signed-off-by: Christian Limpach <Christian.Limpach@xensource.com>
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:33 +02:00
Markus Armbruster 3e334239d8 xen: Make xen-blkfront write its protocol ABI to xenstore
Frontends are expected to write their protocol ABI to xenstore.  Since
the protocol ABI defaults to the backend's native ABI, things work
fine without that as long as the frontend's native ABI is identical to
the backend's native ABI.  This is not the case for xen-blkfront
running 32-on-64, because its ABI differs between 32 and 64 bit, and
thus needs this fix.

Based on http://xenbits.xensource.com/xen-unstable.hg?rev/c545932a18f3
and http://xenbits.xensource.com/xen-unstable.hg?rev/ffe52263b430 by
Gerd Hoffmann <kraxel@suse.de>

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <Jeremy.Fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:32 +02:00
Isaku Yamahata b15993fcc1 xen: import arch generic part of xencomm
On xen/ia64 and xen/powerpc hypercall arguments are passed by pseudo
physical address (guest physical address) so that it's necessary to
convert from virtual address into pseudo physical address. The frame
work is called xencomm.
Import arch generic part of xencomm.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:32 +02:00
Isaku Yamahata 8d3d2106c1 xen: make grant table arch portable
split out x86 specific part from grant-table.c and
allow ia64/xen specific initialization.
ia64/xen grant table is based on pseudo physical address
(guest physical address) unlike x86/xen. On ia64 init_mm
doesn't map identity straight mapped area.
ia64/xen specific grant table initialization is necessary.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:32 +02:00
Isaku Yamahata 5f0ababbf4 xen: replace callers of alloc_vm_area()/free_vm_area() with xen_ prefixed one
Don't use alloc_vm_area()/free_vm_area() directly, instead define
xen_alloc_vm_area()/xen_free_vm_area() and use them.

alloc_vm_area()/free_vm_area() are used to allocate/free area which
are for grant table mapping. Xen/x86 grant table is based on virtual
address so that alloc_vm_area()/free_vm_area() are suitable.
On the other hand Xen/ia64 (and Xen/powerpc) grant table is based on
pseudo physical address (guest physical address) so that allocation
should be done differently.
The original version of xenified Linux/IA64 have its own
allocate_vm_area()/free_vm_area() definitions which don't allocate vm area
contradictory to those names.
Now vanilla Linux already has its definitions so that it's impossible
to have IA64 definitions of allocate_vm_area()/free_vm_area().
Instead introduce xen_allocate_vm_area()/xen_free_vm_area() and use them.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:32 +02:00
Isaku Yamahata 20e71f2edb xen: make include/xen/page.h portable moving those definitions under asm dir
The definitions in include/asm/xen/page.h are arch specific.
ia64/xen wants to define its own version. So move them to arch specific
directory and keep include/xen/page.h in order not to break compilation.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:32 +02:00
Isaku Yamahata 642e0c882c xen: add resend_irq_on_evtchn() definition into events.c
Define resend_irq_on_evtchn() which ia64/xen uses.
Although it isn't used by current x86/xen code, it's arch generic
so that put it into common code.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:32 +02:00
Isaku Yamahata e849c3e9e0 Xen: make events.c portable for ia64/xen support
Remove x86 dependency in drivers/xen/events.c for ia64/xen support
introducing include/asm/xen/events.h.
Introduce xen_irqs_disabled() to hide regs->flags
Introduce xen_do_IRQ() to hide regs->orig_ax.
make enum ipi_vector definition arch specific. ia64/xen needs four vectors.
Add one rmb() because on ia64 xchg() isn't barrier.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:32 +02:00
Isaku Yamahata e04d0d0767 xen: move events.c to drivers/xen for IA64/Xen support
move arch/x86/xen/events.c undedr drivers/xen to share codes
with x86 and ia64. And minor adjustment to compile.
ia64/xen also uses events.c

Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:32 +02:00
Isaku Yamahata 2724426924 xen: add missing definitions in include/xen/interface/vcpu.h which ia64/xen needs
Add xen handles realted definitions for xen vcpu which ia64/xen needs.
Pointer argumsnts for ia64/xen hypercall are passed in pseudo physical
address (guest physical address) so that it is required to convert
guest kernel virtual address into pseudo physical address.
The xen guest handle represents such arguments.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:32 +02:00
Isaku Yamahata 87e27cf628 xen: add missing definitions for xen grant table which ia64/xen needs
Add xen handles realted definitions for grant table which ia64/xen
needs.
Pointer argumsnts for ia64/xen hypercall are passed in pseudo physical
address (guest physical address) so that it is required to convert
guest kernel virtual address into pseudo physical address right before
issuing hypercall.
The xen guest handle represents such arguments.
Define necessary handles and helper functions.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:32 +02:00
Isaku Yamahata 2eb6d5eb48 xen: definitions which ia64/xen needs
Add xen VIRQ numbers defined for arch specific use.
ia64/xen domU uses VIRQ_ARCH_0 for virtual itc timer.
Although all those constants aren't used yet by ia64
at this moment, add all arch specific VIRQ numbers.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:32 +02:00
Isaku Yamahata 9a9db275b0 xen: definisions which ia64 needs
Add xen hypercall numbers defined for arch specific use.
ia64/xen domU uses __HYPERVISOR_arch_1 to manipulate paravirtualized
IOSAPIC. Although all those constants aren't used yet by IA64 at this
moment, add all arch specific hypercall numbers.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:32 +02:00
Jeremy Fitzhardinge aa380c82b8 xen: add support for callbackops hypercall
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:31 +02:00
Jeremy Fitzhardinge 9666e9d44b xen: unify pte operations on machine frames
Xen's pte operations on mfns can be unified like the kernel's pfn operations.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:31 +02:00
Jeremy Fitzhardinge 3b4724b0e6 xen: use phys_addr_t when referring to physical addresses
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:57:31 +02:00
Jeremy Fitzhardinge c8e5393ab3 x86: page.h: make pte_t a union to always include
Make sure pte_t, whatever its definition, has a pte element with type
pteval_t.  This allows common code to access it without needing to be
specifically parameterised on what pagetable mode we're compiling for.
For 32-bit, this means that pte_t becomes a union with "pte" and "{
pte_low, pte_high }" (PAE) or just "pte_low" (non-PAE).

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:32:57 +01:00
Jeremy Fitzhardinge e3d2697669 xen: fix incorrect vcpu_register_vcpu_info hypercall argument
The kernel's copy of struct vcpu_register_vcpu_info was out of date,
at best causing the hypercall to fail and the guest kernel to fall
back to the old mechanism, or worse, causing random memory corruption.

[ Stable folks: applies to 2.6.23 ]

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Stable Kernel <stable@kernel.org>
Cc: Morten =?utf-8?q?B=C3=B8geskov?= <xen-users@morten.bogeskov.dk>
Cc: Mark Williamson <mark.williamson@cl.cam.ac.uk>
2007-10-16 11:51:31 -07:00
Jeremy Fitzhardinge dfb68689bf xen: xen/page.h compile fix
Fix:
linux/include/xen/page.h: In function mfn_pte:
linux/include/xen/page.h:149: error: __supported_pte_mask undeclared (first use in this function)
linux/include/xen/page.h:149: error: (Each undeclared identifier is reported only once
linux/include/xen/page.h:149: error: for each function it appears in.)

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-26 11:35:16 -07:00
Jeremy Fitzhardinge 60223a326f xen: Place vcpu_info structure into per-cpu memory
An experimental patch for Xen allows guests to place their vcpu_info
structs anywhere.  We try to use this to place the vcpu_info into the
PDA, which allows direct access.

If this works, then switch to using direct access operations for
irq_enable, disable, save_fl and restore_fl.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Keir Fraser <keir@xensource.com>
2007-07-18 08:47:45 -07:00
Jeremy Fitzhardinge 4bac07c993 xen: add the Xenbus sysfs and virtual device hotplug driver
This communicates with the machine control software via a registry
residing in a controlling virtual machine. This allows dynamic
creation, destruction and modification of virtual device
configurations (network devices, block devices and CPUS, to name some
examples).

[ Greg, would you mind giving this a review?  Thanks -J ]

Signed-off-by: Ian Pratt <ian.pratt@xensource.com>
Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Greg KH <greg@kroah.com>
2007-07-18 08:47:45 -07:00
Jeremy Fitzhardinge ad9a86121f xen: Add grant table support
Add Xen 'grant table' driver which allows granting of access to
selected local memory pages by other virtual machines and,
symmetrically, the mapping of remote memory pages which other virtual
machines have granted access to.

This driver is a prerequisite for many of the Xen virtual device
drivers, which grant the 'device driver domain' restricted and
temporary access to only those memory pages that are currently
involved in I/O operations.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Ian Pratt <ian.pratt@xensource.com>
Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
2007-07-18 08:47:44 -07:00
Jeremy Fitzhardinge b536b4b962 xen: use the hvc console infrastructure for Xen console
Implement a Xen back-end for hvc console.

* * *
Add early printk support via hvc console, enable using
"earlyprintk=xen" on the kernel command line.

From: Gerd Hoffmann <kraxel@suse.de>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Olof Johansson <olof@lixom.net>
2007-07-18 08:47:44 -07:00
Jeremy Fitzhardinge f87e4cac4f xen: SMP guest support
This is a fairly straightforward Xen implementation of smp_ops.

Xen has its own IPI mechanisms, and has no dependency on any
APIC-based IPI.  The smp_ops hooks and the flush_tlb_others pv_op
allow a Xen guest to avoid all APIC code in arch/i386 (the only apic
operation is a single apic_read for the apic version number).

One subtle point which needs to be addressed is unpinning pagetables
when another cpu may have a lazy tlb reference to the pagetable. Xen
will not allow an in-use pagetable to be unpinned, so we must find any
other cpus with a reference to the pagetable and get them to shoot
down their references.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andi Kleen <ak@suse.de>
2007-07-18 08:47:44 -07:00
Jeremy Fitzhardinge e46cdb66c8 xen: event channels
Xen implements interrupts in terms of event channels.  Each guest
domain gets 1024 event channels which can be used for a variety of
purposes, such as Xen timer events, inter-domain events,
inter-processor events (IPI) or for real hardware IRQs.

Within the kernel, we map the event channels to IRQs, and implement
the whole interrupt handling using a Xen irq_chip.

Rather than setting NR_IRQ to 1024 under PARAVIRT in order to
accomodate Xen, we create a dynamic mapping between event channels and
IRQs.  Ideally, Linux will eventually move towards dynamically
allocating per-irq structures, and we can use a 1:1 mapping between
event channels and irqs.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Eric W. Biederman <ebiederm@xmission.com>
2007-07-18 08:47:42 -07:00
Jeremy Fitzhardinge 5ead97c84f xen: Core Xen implementation
This patch is a rollup of all the core pieces of the Xen
implementation, including:
 - booting and setup
 - pagetable setup
 - privileged instructions
 - segmentation
 - interrupt flags
 - upcalls
 - multicall batching

BOOTING AND SETUP

The vmlinux image is decorated with ELF notes which tell the Xen
domain builder what the kernel's requirements are; the domain builder
then constructs the address space accordingly and starts the kernel.

Xen has its own entrypoint for the kernel (contained in an ELF note).
The ELF notes are set up by xen-head.S, which is included into head.S.
In principle it could be linked separately, but it seems to provoke
lots of binutils bugs.

Because the domain builder starts the kernel in a fairly sane state
(32-bit protected mode, paging enabled, flat segments set up), there's
not a lot of setup needed before starting the kernel proper.  The main
steps are:
  1. Install the Xen paravirt_ops, which is simply a matter of a
     structure assignment.
  2. Set init_mm to use the Xen-supplied pagetables (analogous to the
     head.S generated pagetables in a native boot).
  3. Reserve address space for Xen, since it takes a chunk at the top
     of the address space for its own use.
  4. Call start_kernel()

PAGETABLE SETUP

Once we hit the main kernel boot sequence, it will end up calling back
via paravirt_ops to set up various pieces of Xen specific state.  One
of the critical things which requires a bit of extra care is the
construction of the initial init_mm pagetable.  Because Xen places
tight constraints on pagetables (an active pagetable must always be
valid, and must always be mapped read-only to the guest domain), we
need to be careful when constructing the new pagetable to keep these
constraints in mind.  It turns out that the easiest way to do this is
use the initial Xen-provided pagetable as a template, and then just
insert new mappings for memory where a mapping doesn't already exist.

This means that during pagetable setup, it uses a special version of
xen_set_pte which ignores any attempt to remap a read-only page as
read-write (since Xen will map its own initial pagetable as RO), but
lets other changes to the ptes happen, so that things like NX are set
properly.

PRIVILEGED INSTRUCTIONS AND SEGMENTATION

When the kernel runs under Xen, it runs in ring 1 rather than ring 0.
This means that it is more privileged than user-mode in ring 3, but it
still can't run privileged instructions directly.  Non-performance
critical instructions are dealt with by taking a privilege exception
and trapping into the hypervisor and emulating the instruction, but
more performance-critical instructions have their own specific
paravirt_ops.  In many cases we can avoid having to do any hypercalls
for these instructions, or the Xen implementation is quite different
from the normal native version.

The privileged instructions fall into the broad classes of:
  Segmentation: setting up the GDT and the GDT entries, LDT,
     TLS and so on.  Xen doesn't allow the GDT to be directly
     modified; all GDT updates are done via hypercalls where the new
     entries can be validated.  This is important because Xen uses
     segment limits to prevent the guest kernel from damaging the
     hypervisor itself.
  Traps and exceptions: Xen uses a special format for trap entrypoints,
     so when the kernel wants to set an IDT entry, it needs to be
     converted to the form Xen expects.  Xen sets int 0x80 up specially
     so that the trap goes straight from userspace into the guest kernel
     without going via the hypervisor.  sysenter isn't supported.
  Kernel stack: The esp0 entry is extracted from the tss and provided to
     Xen.
  TLB operations: the various TLB calls are mapped into corresponding
     Xen hypercalls.
  Control registers: all the control registers are privileged.  The most
     important is cr3, which points to the base of the current pagetable,
     and we handle it specially.

Another instruction we treat specially is CPUID, even though its not
privileged.  We want to control what CPU features are visible to the
rest of the kernel, and so CPUID ends up going into a paravirt_op.
Xen implements this mainly to disable the ACPI and APIC subsystems.

INTERRUPT FLAGS

Xen maintains its own separate flag for masking events, which is
contained within the per-cpu vcpu_info structure.  Because the guest
kernel runs in ring 1 and not 0, the IF flag in EFLAGS is completely
ignored (and must be, because even if a guest domain disables
interrupts for itself, it can't disable them overall).

(A note on terminology: "events" and interrupts are effectively
synonymous.  However, rather than using an "enable flag", Xen uses a
"mask flag", which blocks event delivery when it is non-zero.)

There are paravirt_ops for each of cli/sti/save_fl/restore_fl, which
are implemented to manage the Xen event mask state.  The only thing
worth noting is that when events are unmasked, we need to explicitly
see if there's a pending event and call into the hypervisor to make
sure it gets delivered.

UPCALLS

Xen needs a couple of upcall (or callback) functions to be implemented
by each guest.  One is the event upcalls, which is how events
(interrupts, effectively) are delivered to the guests.  The other is
the failsafe callback, which is used to report errors in either
reloading a segment register, or caused by iret.  These are
implemented in i386/kernel/entry.S so they can jump into the normal
iret_exc path when necessary.

MULTICALL BATCHING

Xen provides a multicall mechanism, which allows multiple hypercalls
to be issued at once in order to mitigate the cost of trapping into
the hypervisor.  This is particularly useful for context switches,
since the 4-5 hypercalls they would normally need (reload cr3, update
TLS, maybe update LDT) can be reduced to one.  This patch implements a
generic batching mechanism for hypercalls, which gets used in many
places in the Xen code.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Ian Pratt <ian.pratt@xensource.com>
Cc: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
Cc: Adrian Bunk <bunk@stusta.de>
2007-07-18 08:47:42 -07:00
Jeremy Fitzhardinge a42089dd35 xen: Add Xen interface header files
Add Xen interface header files. These are taken fairly directly from
the Xen tree, but somewhat rearranged to suit the kernel's conventions.

Define macros and inline functions for doing hypercalls into the
hypervisor.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Ian Pratt <ian.pratt@xensource.com>
Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
2007-07-18 08:47:42 -07:00