Commit Graph

13 Commits

Author SHA1 Message Date
Jan Beulich 1ad6344acf xen-pciback: drop superfluous variables
req_start is simply an alias of the "offset" function parameter, and
req_end is being used just once in each function. (And both variables
were loop invariant anyway, so should at least have got initialized
outside the loop.)

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-07-06 10:35:38 +01:00
Jan Beulich ee87d6d0d3 xen-pciback: short-circuit read path used for merging write values
There's no point calling xen_pcibk_config_read() here - all it'll do is
return whatever conf_space_read() returns for the field which was found
here (and which would be found there again). Also there's no point
clearing tmp_val before the call.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-07-06 10:35:38 +01:00
Andrey Grodzovsky 02ef871eca xen/pciback: Fix conf_space read/write overlap check.
Current overlap check is evaluating to false a case where a filter
field is fully contained (proper subset) of a r/w request.  This
change applies classical overlap check instead to include all the
scenarios.

More specifically, for (Hilscher GmbH CIFX 50E-DP(M/S)) device driver
the logic is such that the entire confspace is read and written in 4
byte chunks. In this case as an example, CACHE_LINE_SIZE,
LATENCY_TIMER and PCI_BIST are arriving together in one call to
xen_pcibk_config_write() with offset == 0xc and size == 4.  With the
exsisting overlap check the LATENCY_TIMER field (offset == 0xd, length
== 1) is fully contained in the write request and hence is excluded
from write, which is incorrect.

Signed-off-by: Andrey Grodzovsky <andrey2805@gmail.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Jan Beulich <JBeulich@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-06-23 11:36:15 +01:00
Paul Gortmaker 59aa56bf2a xen: audit usages of module.h ; remove unnecessary instances
Code that uses no modular facilities whatsoever should not be
sourcing module.h at all, since that header drags in a bunch
of other headers with it.

Similarly, code that is not explicitly using modular facilities
like module_init() but only is declaring module_param setup
variables should be using moduleparam.h and not the larger
module.h file for that.

In making this change, we also uncover an implicit use of BUG()
in inline fcns within arch/arm/include/asm/xen/hypercall.h so
we explicitly source <linux/bug.h> for that file now.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-03-21 15:13:32 +00:00
Ben Hutchings 8014bcc86e xen-pciback: Add name prefix to global 'permissive' variable
The variable for the 'permissive' module parameter used to be static
but was recently changed to be extern.  This puts it in the kernel
global namespace if the driver is built-in, so its name should begin
with a prefix identifying the driver.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Fixes: af6fc858a3 ("xen-pciback: limit guest control of command register")
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-04-29 17:34:50 +01:00
Jan Beulich af6fc858a3 xen-pciback: limit guest control of command register
Otherwise the guest can abuse that control to cause e.g. PCIe
Unsupported Request responses by disabling memory and/or I/O decoding
and subsequently causing (CPU side) accesses to the respective address
ranges, which (depending on system configuration) may be fatal to the
host.

Note that to alter any of the bits collected together as
PCI_COMMAND_GUEST permissive mode is now required to be enabled
globally or on the specific device.

This is CVE-2015-2150 / XSA-120.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-03-11 14:34:40 +00:00
Alex Williamson a696165140 PCI: create common pcibios_err_to_errno
For returning errors out to non-PCI code.  Re-name xen's version.

Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-06-12 09:21:42 -06:00
Rusty Russell 90ab5ee941 module_param: make bool parameters really bool (drivers & misc)
module_param(bool) used to counter-intuitively take an int.  In
fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy
trick.

It's time to remove the int/unsigned int option.  For this version
it'll simply give a warning, but it'll break next kernel version.

Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-13 09:32:20 +10:30
Paul Gortmaker 72ee5112a0 xen: Add module.h to modular drivers/xen users.
Previously these drivers just got module.h implicitly, but we
are cleaning that up and it will be no longer.  Call out the
real users of it.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:32:11 -04:00
Jan Beulich 402c5e15b4 xen/pciback: miscellaneous adjustments
This is a minor bugfix and a set of small cleanups; as it is not clear
whether this needs splitting into pieces (and if so, at what
granularity), it is a single combined patch.
- add a missing return statement to an error path in
  kill_domain_by_device()
- use pci_is_enabled() rather than raw atomic_read()
- remove a bogus attempt to zero-terminate an already zero-terminated
  string
- #define DRV_NAME once uniformly in the shared local header
- make DRIVER_ATTR() variables static
- eliminate a pointless use of list_for_each_entry_safe()
- add MODULE_ALIAS()
- a little bit of constification
- adjust a few messages
- remove stray semicolons from inline function definitions

Signed-off-by: Jan Beulich <jbeulich@suse.com>
[v1: Dropped the resource_size fix, altered the description]
[v2: Fixed cleanpatch.pl comments]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-21 18:17:59 -04:00
Konrad Rzeszutek Wilk a92336a117 xen/pciback: Drop two backends, squash and cleanup some code.
- Remove the slot and controller controller backend as they
   are not used.
 - Document the find pciback_[read|write]_config_[byte|word|dword]
   to make it easier to find.
 - Collapse the code from conf_space_capability_msi into pciback_ops.c
 - Collapse conf_space_capability_[pm|vpd].c in conf_space_capability.c
   [and remove the conf_space_capability.h file]
 - Rename all visible functions from pciback to xen_pcibk.
 - Rename all the printk/pr_info, etc that use the "pciback" to say
   "xen-pciback".
 - Convert functions that are not referenced outside the code to be
   static to save on name space.
 - Do the same thing for structures that are internal to the driver.
 - Run checkpatch.pl after the renames and fixup its warnings and
   fix any compile errors caused by the variable rename
 - Cleanup any structs that checkpath.pl commented about or just
   look odd.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-07-19 20:58:35 -04:00
Konrad Rzeszutek Wilk 8bfd4e023f xen/pciback: Cleanup the driver based on checkpatch warnings and errors.
Checkpatch found some extra warnings and errors. This mega
patch fixes them all in one big swoop. We also spruce
up the pcistub_ids to use DEFINE_PCI_DEVICE_TABLE macro
(suggested by Jan Beulich).

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-07-19 20:58:28 -04:00
Konrad Rzeszutek Wilk 30edc14bf3 xen/pciback: xen pci backend driver.
This is the host side counterpart to the frontend driver in
drivers/pci/xen-pcifront.c. The PV protocol is also implemented by
frontend drivers in other OSes too, such as the BSDs.

The PV protocol is rather simple. There is page shared with the guest,
which has the 'struct xen_pci_sharedinfo' embossed in it. The backend
has a thread that is kicked every-time the structure is changed and
based on the operation field it performs specific tasks:

 XEN_PCI_OP_conf_[read|write]:
   Read/Write 0xCF8/0xCFC filtered data. (conf_space*.c)
   Based on which field is probed, we either enable/disable the PCI
   device, change power state, read VPD, etc. The major goal of this
   call is to provide a Physical IRQ (PIRQ) to the guest.

   The PIRQ is Xen hypervisor global IRQ value irrespective of the IRQ
   is tied in to the IO-APIC, or is a vector. For GSI type
   interrupts, the PIRQ==GSI holds. For MSI/MSI-X the
   PIRQ value != Linux IRQ number (thought PIRQ==vector).

   Please note, that with Xen, all interrupts (except those level shared ones)
   are injected directly to the guest - there is no host interaction.

 XEN_PCI_OP_[enable|disable]_msi[|x] (pciback_ops.c)
   Enables/disables the MSI/MSI-X capability of the device. These operations
   setup the MSI/MSI-X vectors for the guest and pass them to the frontend.

   When the device is activated, the interrupts are directly injected in the
   guest without involving the host.

 XEN_PCI_OP_aer_[detected|resume|mmio|slotreset]: In case of failure,
  perform the appropriate AER commands on the guest. Right now that is
  a cop-out - we just kill the guest.

Besides implementing those commands, it can also

 - hide a PCI device from the host. When booting up, the user can specify
   xen-pciback.hide=(1:0:0)(BDF..) so that host does not try to use the
   device.

The driver was lifted from linux-2.6.18.hg tree and fixed up
so that it could compile under v3.0. Per suggestion from Jesse Barnes
moved the driver to drivers/xen/xen-pciback.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2011-07-19 20:58:01 -04:00