Commit Graph

172 Commits

Author SHA1 Message Date
Alexey Dobriyan d43c36dc6b headers: remove sched.h from interrupt.h
After m68k's task_thread_info() doesn't refer to current,
it's possible to remove sched.h from interrupt.h and not break m68k!
Many thanks to Heiko Carstens for allowing this.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-10-11 11:20:58 -07:00
Alexey Dobriyan 828c09509b const: constify remaining file_operations
[akpm@linux-foundation.org: fix KVM]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:11 -07:00
Linus Torvalds 1f0918d03f Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  lguest: don't force VIRTIO_F_NOTIFY_ON_EMPTY
  lguest: cleanup for map_switcher()
  lguest: use PGDIR_SHIFT for PAE code to allow different PAGE_OFFSET
  lguest: use set_pte/set_pmd uniformly for real page table entries
  lguest: move panic notifier registration to its expected place.
  virtio_blk: add support for cache flush
  virtio: add virtio IDs file
  virtio: get rid of redundant VIRTIO_ID_9P definition
  virtio: make add_buf return capacity remaining
  virtio_pci: minor MSI-X cleanups
2009-09-23 09:23:45 -07:00
Xiao Guangrong 6c189d8312 lguest: cleanup for map_switcher()
We can use alloc_page() instead of get_zeroed_page() and virt_to_page()

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-09-23 22:26:47 +09:30
Rusty Russell fb100d78c0 lguest: use PGDIR_SHIFT for PAE code to allow different PAGE_OFFSET
We still assume the Guest and Host have the same PAGE_OFFSET settings,
but now we don't assume 0xC0000000.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Matias Zabaljauregui <zabaljauregui@gmail.com>
2009-09-23 22:26:46 +09:30
Rusty Russell 4c1ea3dd71 lguest: use set_pte/set_pmd uniformly for real page table entries
If we're building a pte, we can use simple assigment; only use set_pte
etc. when we're actually going to use that destination as a PTE.  I
don't know that we'll ever run under Xen, but it's neater.

And use set_pte/set_pmd rather than assuming native_ versions, even
though that's probably true for most people.

(Includes compile fix by Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Matias Zabaljauregui <zabaljauregui@gmail.com>
Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
2009-09-23 22:26:46 +09:30
Anand Gadiyar fd589a8f0a trivial: fix typo "to to" in multiple files
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-09-21 15:14:55 +02:00
Rusty Russell 1842f23c05 lguest and virtio: cleanup struct definitions to Linux style.
I've been doing this for years, and akpm picked me up on it about 12
months ago.  lguest partly serves as example code, so let's do it Right.

Also, remove two unused fields in struct vblk_info in the example launcher.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
2009-07-30 16:03:46 +09:30
Rusty Russell a91d74a3c4 lguest: update commentry
Every so often, after code shuffles, I need to go through and unbitrot
the Lguest Journey (see drivers/lguest/README).  Since we now use RCU in
a simple form in one place I took the opportunity to expand that explanation.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
2009-07-30 16:03:46 +09:30
Rusty Russell 2e04ef7691 lguest: fix comment style
I don't really notice it (except to begrudge the extra vertical
space), but Ingo does.  And he pointed out that one excuse of lguest
is as a teaching tool, it should set a good example.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
2009-07-30 16:03:45 +09:30
Dan Carpenter f294526279 lguest: dereferencing freed mem in add_eventfd()
"new" was freed and then dereferenced.  Also the return value wasn't being
used so I modified the caller as well.

Compile tested only.  Found by smatch (http://repo.or.cz/w/smatch.git).

regards,
dan carpenter

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-07-30 16:03:43 +09:30
Davide Libenzi 27de22d03d lguest: remove unnecessary forward struct declaration
While fixing lg.h to drop the fwd declaration, I noticed
there's another one ;)

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-07-17 21:47:44 +09:30
Davide Libenzi 133890103b eventfd: revised interface and cleanups
Change the eventfd interface to de-couple the eventfd memory context, from
the file pointer instance.

Without such change, there is no clean way to racely free handle the
POLLHUP event sent when the last instance of the file* goes away.  Also,
now the internal eventfd APIs are using the eventfd context instead of the
file*.

This patch is required by KVM's IRQfd code, which is still under
development.

Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Gregory Haskins <ghaskins@novell.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-30 18:55:58 -07:00
Linus Torvalds 7f3591cfac Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-lguest: (31 commits)
  lguest: add support for indirect ring entries
  lguest: suppress notifications in example Launcher
  lguest: try to batch interrupts on network receive
  lguest: avoid sending interrupts to Guest when no activity occurs.
  lguest: implement deferred interrupts in example Launcher
  lguest: remove obsolete LHREQ_BREAK call
  lguest: have example Launcher service all devices in separate threads
  lguest: use eventfds for device notification
  eventfd: export eventfd_signal and eventfd_fget for lguest
  lguest: allow any process to send interrupts
  lguest: PAE fixes
  lguest: PAE support
  lguest: Add support for kvm_hypercall4()
  lguest: replace hypercall name LHCALL_SET_PMD with LHCALL_SET_PGD
  lguest: use native_set_* macros, which properly handle 64-bit entries when PAE is activated
  lguest: map switcher with executable page table entries
  lguest: fix writev returning short on console output
  lguest: clean up length-used value in example launcher
  lguest: Segment selectors are 16-bit long. Fix lg_cpu.ss1 definition.
  lguest: beyond ARRAY_SIZE of cpu->arch.gdt
  ...
2009-06-12 09:32:26 -07:00
Rusty Russell 5dac051bc6 lguest: remove obsolete LHREQ_BREAK call
We no longer need an efficient mechanism to force the Guest back into
host userspace, as each device is serviced without bothering the main
Guest process (aka. the Launcher).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:27:11 +09:30
Rusty Russell df60aeef4f lguest: use eventfds for device notification
Currently, when a Guest wants to perform I/O it calls LHCALL_NOTIFY with
an address: the main Launcher process returns with this address, and figures
out what device to run.

A far nicer model is to let processes bind an eventfd to an address: if we
find one, we simply signal the eventfd.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Davide Libenzi <davidel@xmailserver.org>
2009-06-12 22:27:10 +09:30
Rusty Russell 9f155a9b3d lguest: allow any process to send interrupts
We currently only allow the Launcher process to send interrupts, but it
as we already send interrupts from the hrtimer, it's a simple matter of
extracting that code into a common set_interrupt routine.

As we switch to a thread per virtqueue, this avoids a bottleneck through the
main Launcher process.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:27:09 +09:30
Rusty Russell 92b4d8df84 lguest: PAE fixes
1) j wasn't initialized in setup_pagetables, so they weren't set up for me
   causing immediate guest crashes.

2) gpte_addr should not re-read the pmd from the Guest.  Especially
   not BUG_ON() based on the value.  If we ever supported SMP guests,
   they could trigger that.  And the Launcher could also trigger it
   (tho currently root-only).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:27:08 +09:30
Matias Zabaljauregui acdd0b6292 lguest: PAE support
This version requires that host and guest have the same PAE status.
NX cap is not offered to the guest, yet.

Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:27:08 +09:30
Matias Zabaljauregui ebe0ba84f5 lguest: replace hypercall name LHCALL_SET_PMD with LHCALL_SET_PGD
replace LHCALL_SET_PMD with LHCALL_SET_PGD hypercall name
(That's really what it is, and the confusion gets worse with PAE support)

Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reported-by: Jeremy Fitzhardinge <jeremy@goop.org>
2009-06-12 22:27:07 +09:30
Matias Zabaljauregui 90603d15fa lguest: use native_set_* macros, which properly handle 64-bit entries when PAE is activated
Some cleanups and replace direct assignment with native_set_* macros which properly handle 64-bit entries when PAE is activated

Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:27:06 +09:30
Matias Zabaljauregui ed1dc77810 lguest: map switcher with executable page table entries
Map switcher with executable page table entries.
(This bug didn't matter before PAE and hence NX support -- RR)

Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:27:06 +09:30
Matias Zabaljauregui f086122bb6 lguest: Segment selectors are 16-bit long. Fix lg_cpu.ss1 definition.
If GDT_ENTRIES were every > 256, this could become a problem.

Signed-off-by: Matias Zabaljauregui <zabaljauregui at gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:27:04 +09:30
Roel Kluin 81b79b01d0 lguest: beyond ARRAY_SIZE of cpu->arch.gdt
Do not go beyond ARRAY_SIZE of cpu->arch.gdt

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:27:04 +09:30
Rusty Russell a32a8813d0 lguest: improve interrupt handling, speed up stream networking
lguest never checked for pending interrupts when enabling interrupts, and
things still worked.  However, it makes a significant difference to TCP
performance, so it's time we fixed it by introducing a pending_irq flag
and checking it on irq_restore and irq_enable.

These two routines are now too big to patch into the 8/10 bytes
patch space, so we drop that code.

Note: The high latency on interrupt delivery had a very curious
effect: once everything else was optimized, networking without GSO was
faster than networking with GSO, since more interrupts were sent and
hence a greater chance of one getting through to the Guest!

Note2: (Almost) Closing the same loophole for iret doesn't have any
measurable effect, so I'm leaving that patch for the moment.

Before:
	1GB tcpblast Guest->Host:		30.7 seconds
	1GB tcpblast Guest->Host (no GSO):	76.0 seconds

After:
	1GB tcpblast Guest->Host:		6.8 seconds
	1GB tcpblast Guest->Host (no GSO):	27.8 seconds

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:27:03 +09:30
Rusty Russell abd41f037e lguest: fix race in halt code
When the Guest does the LHCALL_HALT hypercall, we go to sleep, expecting
that a timer or the Waker will wake_up_process() us.

But we do it in a stupid way, leaving a classic missing wakeup race.

So split maybe_do_interrupt() into interrupt_pending() and
try_deliver_interrupt(), and check maybe_do_interrupt() and the
"break_out" flag before calling schedule.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:27:02 +09:30
Rusty Russell a6c372de6e lguest: fix lguest wake on guest clock tick, or fd activity
The Launcher could be inside the Guest on another CPU; wake_up_process
will do nothing because it is "running".  kick_process will knock it
back into our kernel in this case, otherwise we'll miss it until the
next guest exit.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:27:01 +09:30
Michael S. Tsirkin d2a7ddda9f virtio: find_vqs/del_vqs virtio operations
This replaces find_vq/del_vq with find_vqs/del_vqs virtio operations,
and updates all drivers. This is needed for MSI support, because MSI
needs to know the total number of vectors upfront.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ lguest/9p compile fixes)
2009-06-12 22:16:36 +09:30
Rusty Russell 9499f5e7ed virtio: add names to virtqueue struct, mapping from devices to queues.
Add a linked list of all virtqueues for a virtio device: this helps for
debugging and is also needed for upcoming interface change.

Also, add a "name" field for clearer debug messages.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:16:36 +09:30
Rusty Russell 564346224d lguest: fix on Intel when KVM loaded (unhandled trap 13)
When KVM is loaded, and hence VT set up, the vmcall instruction in an
lguest guest causes a #GP, not #UD.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-26 12:13:11 -07:00
Rusty Russell a489f0b555 lguest: fix guest crash on non-linear addresses in gdt pvops
Fixes guest crash 'lguest: bad read address 0x4800000 len 256'

The new per-cpu allocator ends up handing a non-linear address to
write_gdt_entry.  We do __pa() on it, and hand it to the host, which
kills us.

I've long wanted to make the hypercall "LOAD_GDT_ENTRY" to match the IDT
code, but had no pressing reason until now.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: lguest@ozlabs.org
2009-04-19 23:14:01 +09:30
Matias Zabaljauregui 88df781afb lguest: fix crash on vmlinux images
Typical message: 'lguest: unhandled trap 6 at 0x418726 (0x0)'

vmlinux guests were broken by 4cd8b5e2a1
'lguest: use KVM hypercalls', which rewrites guest text from kvm hypercalls
to trap 31.

The Launcher mmaps the kernel image.  The Guest executes and
immediately faults in the first text page (read-only).  Then it hits a
hypercall, and we rewrite that hypercall, causing a copy-on-write.
But the Guest pagetables still refer to the old page: we fault again,
but as Host we see the hypercall already rewritten, and pass the fault
back to the Guest.  The Guest hasn't set up an IDT yet, so we kill it.

This doesn't happen with bzImages: they unpack themselves and so the
text pages are already read-write.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Patrick McHardy <kaber@trash.net>
2009-04-19 23:14:00 +09:30
Matias Zabaljauregui df1693abc4 lguest: use bool instead of int
Impact: clean up

Rusty told me, some time ago, that he had become a fan of "bool".
So, here are some replacements.

Signed-off-by: Matias Zabaljauregui <zabaljauregui at gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-03-30 21:55:25 +10:30
Matias Zabaljauregui 4cd8b5e2a1 lguest: use KVM hypercalls
Impact: cleanup

This patch allow us to use KVM hypercalls

Signed-off-by: Matias Zabaljauregui <zabaljauregui at gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-03-30 21:55:24 +10:30
Rusty Russell 6afbdd059c lguest: fix spurious BUG_ON() on invalid guest stack.
Impact: fix crash on misbehaving guest

gpte_addr() contains a BUG_ON(), insisting that the present flag is
set.  We need to return before we call it if that isn't the case.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
2009-03-30 21:55:23 +10:30
Ingo Molnar 6e15cf0486 Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2
Conflicts:
	arch/parisc/kernel/irq.c
	arch/x86/include/asm/fixmap_64.h
	arch/x86/include/asm/setup.h
	kernel/irq/handle.c

Semantic merge:
        arch/x86/include/asm/fixmap.h

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-27 17:28:43 +01:00
Rusty Russell 6db6a5f3ae lguest: fix for CONFIG_SPARSE_IRQ=y
Impact: remove lots of lguest boot WARN_ON() when CONFIG_SPARSE_IRQ=y

We now need to call irq_to_desc_alloc_cpu() before
set_irq_chip_and_handler_name(), but we can't do that from init_IRQ (no
kmalloc available).

So do it as we use interrupts instead.  Also means we only alloc for
irqs we use, which was the intent of CONFIG_SPARSE_IRQ anyway.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
2009-03-09 10:06:29 +10:30
Ingo Molnar 965c7ecaf2 x86: remove the Voyager 32-bit subarch
Impact: remove unused/broken code

The Voyager subarch last built successfully on the v2.6.26 kernel
and has been stale since then and does not build on the v2.6.27,
v2.6.28 and v2.6.29-rc5 kernels.

No actual users beyond the maintainer reported this breakage.
Patches were sent and most of the fixes were accepted but the
discussion around how to do a few remaining issues cleanly
fizzled out with no resolution and the code remained broken.

In the v2.6.30 x86 tree development cycle 32-bit subarch support
has been reworked and removed - and the Voyager code, beyond the
build problems already known, needs serious and significant
changes and probably a rewrite to support it.

CONFIG_X86_VOYAGER has been marked BROKEN then. The maintainer has
been notified but no patches have been sent so far to fix it.

While all other subarchs have been converted to the new scheme,
voyager is still broken. We'd prefer to receive patches which
clean up the current situation in a constructive way, but even in
case of removal there is no obstacle to add that support back
after the issues have been sorted out in a mutually acceptable
fashion.

So remove this inactive code for now.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-23 00:54:01 +01:00
Mark Wallis 05dfdbbd67 lguest: Fix a memory leak with the lg object during launcher close
Fix a memory leak identified by Rusty Russell during LCA09 by
kfree'ing the lg object instead of just clearing it when the
launcher closes.

Signed-off-by: Mark Wallis <mwallis@serialmonkey.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-01-30 11:34:11 +10:30
Atsushi SAKAI 72410af921 lguest: typos fix
3 points

lguest_asm.S => i386_head.S
LHCALL_BREAK => LHREQ_BREAK
perferred    => preferred

Signed-off-by: Atsushi SAKAI <sakaia@jp.fujitsu.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-01-30 11:34:10 +10:30
Mark McLoughlin ff8561c4ad lguest: do not statically allocate root device
We shouldn't be statically allocating the root device object,
so dynamically allocate it using root_device_register()
instead.

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-06 10:44:34 -08:00
Linus Torvalds b840d79631 Merge branch 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (66 commits)
  x86: export vector_used_by_percpu_irq
  x86: use logical apicid in x2apic_cluster's x2apic_cpu_mask_to_apicid_and()
  sched: nominate preferred wakeup cpu, fix
  x86: fix lguest used_vectors breakage, -v2
  x86: fix warning in arch/x86/kernel/io_apic.c
  sched: fix warning in kernel/sched.c
  sched: move test_sd_parent() to an SMP section of sched.h
  sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0
  sched: activate active load balancing in new idle cpus
  sched: bias task wakeups to preferred semi-idle packages
  sched: nominate preferred wakeup cpu
  sched: favour lower logical cpu number for sched_mc balance
  sched: framework for sched_mc/smt_power_savings=N
  sched: convert BALANCE_FOR_xx_POWER to inline functions
  x86: use possible_cpus=NUM to extend the possible cpus allowed
  x86: fix cpu_mask_to_apicid_and to include cpu_online_mask
  x86: update io_apic.c to the new cpumask code
  x86: Introduce topology_core_cpumask()/topology_thread_cpumask()
  x86: xen: use smp_call_function_many()
  x86: use work_on_cpu in x86/kernel/cpu/mcheck/mce_amd_64.c
  ...

Fixed up trivial conflict in kernel/time/tick-sched.c manually
2009-01-02 11:44:09 -08:00
Mark McLoughlin bda53cd510 lguest: struct device - replace bus_id with dev_name()
bus_id is gradually being removed, so use dev_name() instead.

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-12-30 09:26:12 +10:30
Matias Zabaljauregui 58a2456644 lguest: move the initial guest page table creation code to the host
This patch moves the initial guest page table creation code to the host,
so the launcher keeps working with PAE enabled configs.

Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-12-30 09:26:11 +10:30
Rusty Russell 87c7d57c17 virtio: hand virtio ring alignment as argument to vring_new_virtqueue
This allows each virtio user to hand in the alignment appropriate to
their virtio_ring structures.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
2008-12-30 09:26:03 +10:30
Rusty Russell 2966af73e7 virtio: use LGUEST_VRING_ALIGN instead of relying on pagesize
This doesn't really matter, since lguest is i386 only at the moment,
but we could actually choose a different value.  (lguest doesn't have
a guarenteed ABI).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-12-30 09:26:02 +10:30
Yinghai Lu b77b881f21 x86: fix lguest used_vectors breakage, -v2
Impact: fix lguest, clean up

32-bit lguest used used_vectors to record vectors, but that model of
allocating vectors changed and got broken, after we changed vector
allocation to a per_cpu array.

Try enable that for 64bit, and the array is used for all vectors that
are not managed by vector_irq per_cpu array.

Also kill system_vectors[], that is now a duplication of the
used_vectors bitmap.

[ merged in cpus4096 due to io_apic.c cpumask changes. ]
[ -v2, fix build failure ]

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-23 22:37:28 +01:00
Rusty Russell 1dc3e3bcbf lguest: update commentry
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-08-26 00:19:28 +10:00
Rusty Russell 71a3f4edc1 lguest: use get_user_pages_fast() instead of get_user_pages()
Using a simple page table thrashing program I measure a slight
improvement.  The program creates five processes.  Each touches 1000
pages then schedules the next process.  We repeat this 1000 times.  As
lguest only caches 4 cr3 values, this rebuilds a lot of shadow page
tables requiring virt->phys mappings.

	Before: 5.93 seconds
	After: 5.40 seconds

(Counts of slow vs fastpath in this usage are 6092 and 2852462 respectively.)

And more importantly for lguest, the code is simpler.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-08-12 17:52:53 +10:00
Andrew Morton cf485e566b lguest: use cpu capability accessors
To support my little make-x86-bitops-use-proper-typechecking projectlet.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrea Arcangeli <andrea@qumranet.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29 09:58:34 +10:00