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Commit Graph

110 Commits

Author SHA1 Message Date
Juergen Gross
b057878b2a xen/pciback: support driver_override
Support the driver_override scheme introduced with commit 782a985d7a
("PCI: Introduce new device binding path using pci_dev.driver_override")

As pcistub_probe() is called for all devices (it has to check for a
match based on the slot address rather than device type) it has to
check for driver_override set to "pciback" itself.

Up to now for assigning a pci device to pciback you need something like:

echo 0000:07:10.0 > /sys/bus/pci/devices/0000\:07\:10.0/driver/unbind
echo 0000:07:10.0 > /sys/bus/pci/drivers/pciback/new_slot
echo 0000:07:10.0 > /sys/bus/pci/drivers_probe

while with the patch you can use the same mechanism as for similar
drivers like pci-stub and vfio-pci:

echo pciback > /sys/bus/pci/devices/0000\:07\:10.0/driver_override
echo 0000:07:10.0 > /sys/bus/pci/devices/0000\:07\:10.0/driver/unbind
echo 0000:07:10.0 > /sys/bus/pci/drivers_probe

So e.g. libvirt doesn't need special handling for pciback.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-09-30 11:49:02 +01:00
Juergen Gross
9f8bee9c98 xen/pciback: avoid multiple entries in slot list
The Xen pciback driver has a list of all pci devices it is ready to
seize. There is no check whether a to be added entry already exists.
While this might be no problem in the common case it might confuse
those which consume the list via sysfs.

Modify the handling of this list by not adding an entry which already
exists. As this will be needed later split out the list handling into
a separate function.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-09-30 11:48:55 +01:00
Juergen Gross
1af916b701 xen/pciback: simplify pcistub device handling
The Xen pciback driver maintains a list of all its seized devices.
There are two functions searching the list for a specific device with
basically the same semantics just returning different structures in
case of a match.

Split out the search function.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-09-30 11:48:33 +01:00
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
Jan Beulich
585203609c xen-pciback: use const and unsigned in bar_init()
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
c8670c22e0 xen-pciback: simplify determination of 64-bit memory resource
Other than for raw BAR values, flags are properly separated in the
internal representation.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-07-06 10:35:37 +01:00
Jan Beulich
6ad2655d87 xen-pciback: fold read_dev_bar() into its now single caller
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-07-06 10:35:37 +01:00
Jan Beulich
664093bb6b xen-pciback: drop rom_init()
It is now identical to bar_init().

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-07-06 10:35:37 +01:00
Jan Beulich
6c6e4caa20 xen-pciback: drop unused function parameter of read_dev_bar()
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-07-06 10:35:37 +01:00
Bhaktipriya Shridhar
429eafe609 xen: xen-pciback: Remove create_workqueue
System workqueues have been able to handle high level of concurrency
for a long time now and there's no reason to use dedicated workqueues
just to gain concurrency.  Replace dedicated xen_pcibk_wq with the
use of system_wq.

Unlike a dedicated per-cpu workqueue created with create_workqueue(),
system_wq allows multiple work items to overlap executions even on
the same CPU; however, a per-cpu workqueue doesn't have any CPU
locality or global ordering guarantees unless the target CPU is
explicitly specified and thus the increase of local concurrency shouldn't
make any difference.

Since the work items could be pending, flush_work() has been used in
xen_pcibk_disconnect(). xen_pcibk_xenbus_remove() calls free_pdev()
which in turn calls xen_pcibk_disconnect() for every pdev to ensure that
there is no pending task while disconnecting the driver.

Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-07-06 10:34:48 +01:00
Jan Beulich
d2bd05d88d xen-pciback: return proper values during BAR sizing
Reads following writes with all address bits set to 1 should return all
changeable address bits as one, not the BAR size (nor, as was the case
for the upper half of 64-bit BARs, the high half of the region's end
address). Presumably this didn't cause any problems so far because
consumers use the value to calculate the size (usually via val & -val),
and do nothing else with it.

But also consider the exception here: Unimplemented BARs should always
return all zeroes.

And finally, the check for whether to return the sizing address on read
for the ROM BAR should ignore all non-address bits, not just the ROM
Enable one.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-06-24 10:53:03 +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
Linus Torvalds
55fc733c7e xen: features and fixes for 4.6-rc0
- Make earlyprintk=xen work for HVM guests.
 - Remove module support for things never built as modules.
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Merge tag 'for-linus-4.6-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from David Vrabel:
 "Features and fixes for 4.6:

  - Make earlyprintk=xen work for HVM guests

  - Remove module support for things never built as modules"

* tag 'for-linus-4.6-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  drivers/xen: make platform-pci.c explicitly non-modular
  drivers/xen: make sys-hypervisor.c explicitly non-modular
  drivers/xen: make xenbus_dev_[front/back]end explicitly non-modular
  drivers/xen: make [xen-]ballon explicitly non-modular
  xen: audit usages of module.h ; remove unnecessary instances
  xen/x86: Drop mode-selecting ifdefs in startup_xen()
  xen/x86: Zero out .bss for PV guests
  hvc_xen: make early_printk work with HVM guests
  hvc_xen: fix xenboot for DomUs
  hvc_xen: add earlycon support
2016-03-22 12:55:17 -07:00
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
Konrad Rzeszutek Wilk
d159457b84 xen/pciback: Save the number of MSI-X entries to be copied later.
Commit 8135cf8b09 (xen/pciback: Save
xen_pci_op commands before processing it) broke enabling MSI-X because
it would never copy the resulting vectors into the response.  The
number of vectors requested was being overwritten by the return value
(typically zero for success).

Save the number of vectors before processing the op, so the correct
number of vectors are copied afterwards.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <stable@vger.kernel.org>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-02-15 14:21:10 +00:00
Konrad Rzeszutek Wilk
8d47065f7d xen/pciback: Check PF instead of VF for PCI_COMMAND_MEMORY
Commit 408fb0e5aa (xen/pciback: Don't
allow MSI-X ops if PCI_COMMAND_MEMORY is not set) prevented enabling
MSI-X on passed-through virtual functions, because it checked the VF
for PCI_COMMAND_MEMORY but this is not a valid bit for VFs.

Instead, check the physical function for PCI_COMMAND_MEMORY.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <stable@vger.kernel.org>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-02-15 14:00:34 +00:00
Doug Goldstein
584a561a6f xen-pciback: fix up cleanup path when alloc fails
When allocating a pciback device fails, clear the private
field. This could lead to an use-after free, however
the 'really_probe' takes care of setting
dev_set_drvdata(dev, NULL) in its failure path (which we would
exercise if the ->probe function failed), so we we
are OK. However lets be defensive as the code can change.

Going forward we should clean up the pci_set_drvdata(dev, NULL)
in the various code-base. That will be for another day.

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reported-by: Jonathan Creekmore <jonathan.creekmore@gmail.com>
Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-12-18 11:38:48 -05:00
Konrad Rzeszutek Wilk
408fb0e5aa xen/pciback: Don't allow MSI-X ops if PCI_COMMAND_MEMORY is not set.
commit f598282f51 ("PCI: Fix the NIU MSI-X problem in a better way")
teaches us that dealing with MSI-X can be troublesome.

Further checks in the MSI-X architecture shows that if the
PCI_COMMAND_MEMORY bit is turned of in the PCI_COMMAND we
may not be able to access the BAR (since they are memory regions).

Since the MSI-X tables are located in there.. that can lead
to us causing PCIe errors. Inhibit us performing any
operation on the MSI-X unless the MEMORY bit is set.

Note that Xen hypervisor with:
"x86/MSI-X: access MSI-X table only after having enabled MSI-X"
will return:
xen_pciback: 0000:0a:00.1: error -6 enabling MSI-X for guest 3!

When the generic MSI code tries to setup the PIRQ without
MEMORY bit set. Which means with later versions of Xen
(4.6) this patch is not neccessary.

This is part of XSA-157

CC: stable@vger.kernel.org
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-12-18 10:48:39 -05:00
Konrad Rzeszutek Wilk
7cfb905b96 xen/pciback: For XEN_PCI_OP_disable_msi[|x] only disable if device has MSI(X) enabled.
Otherwise just continue on, returning the same values as
previously (return of 0, and op->result has the PIRQ value).

This does not change the behavior of XEN_PCI_OP_disable_msi[|x].

The pci_disable_msi or pci_disable_msix have the checks for
msi_enabled or msix_enabled so they will error out immediately.

However the guest can still call these operations and cause
us to disable the 'ack_intr'. That means the backend IRQ handler
for the legacy interrupt will not respond to interrupts anymore.

This will lead to (if the device is causing an interrupt storm)
for the Linux generic code to disable the interrupt line.

Naturally this will only happen if the device in question
is plugged in on the motherboard on shared level interrupt GSI.

This is part of XSA-157

CC: stable@vger.kernel.org
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-12-18 10:48:37 -05:00
Konrad Rzeszutek Wilk
a396f3a210 xen/pciback: Do not install an IRQ handler for MSI interrupts.
Otherwise an guest can subvert the generic MSI code to trigger
an BUG_ON condition during MSI interrupt freeing:

 for (i = 0; i < entry->nvec_used; i++)
        BUG_ON(irq_has_action(entry->irq + i));

Xen PCI backed installs an IRQ handler (request_irq) for
the dev->irq whenever the guest writes PCI_COMMAND_MEMORY
(or PCI_COMMAND_IO) to the PCI_COMMAND register. This is
done in case the device has legacy interrupts the GSI line
is shared by the backend devices.

To subvert the backend the guest needs to make the backend
to change the dev->irq from the GSI to the MSI interrupt line,
make the backend allocate an interrupt handler, and then command
the backend to free the MSI interrupt and hit the BUG_ON.

Since the backend only calls 'request_irq' when the guest
writes to the PCI_COMMAND register the guest needs to call
XEN_PCI_OP_enable_msi before any other operation. This will
cause the generic MSI code to setup an MSI entry and
populate dev->irq with the new PIRQ value.

Then the guest can write to PCI_COMMAND PCI_COMMAND_MEMORY
and cause the backend to setup an IRQ handler for dev->irq
(which instead of the GSI value has the MSI pirq). See
'xen_pcibk_control_isr'.

Then the guest disables the MSI: XEN_PCI_OP_disable_msi
which ends up triggering the BUG_ON condition in 'free_msi_irqs'
as there is an IRQ handler for the entry->irq (dev->irq).

Note that this cannot be done using MSI-X as the generic
code does not over-write dev->irq with the MSI-X PIRQ values.

The patch inhibits setting up the IRQ handler if MSI or
MSI-X (for symmetry reasons) code had been called successfully.

P.S.
Xen PCIBack when it sets up the device for the guest consumption
ends up writting 0 to the PCI_COMMAND (see xen_pcibk_reset_device).
XSA-120 addendum patch removed that - however when upstreaming said
addendum we found that it caused issues with qemu upstream. That
has now been fixed in qemu upstream.

This is part of XSA-157

CC: stable@vger.kernel.org
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-12-18 10:48:34 -05:00
Konrad Rzeszutek Wilk
5e0ce1455c xen/pciback: Return error on XEN_PCI_OP_enable_msix when device has MSI or MSI-X enabled
The guest sequence of:

  a) XEN_PCI_OP_enable_msix
  b) XEN_PCI_OP_enable_msix

results in hitting an NULL pointer due to using freed pointers.

The device passed in the guest MUST have MSI-X capability.

The a) constructs and SysFS representation of MSI and MSI groups.
The b) adds a second set of them but adding in to SysFS fails (duplicate entry).
'populate_msi_sysfs' frees the newly allocated msi_irq_groups (note that
in a) pdev->msi_irq_groups is still set) and also free's ALL of the
MSI-X entries of the device (the ones allocated in step a) and b)).

The unwind code: 'free_msi_irqs' deletes all the entries and tries to
delete the pdev->msi_irq_groups (which hasn't been set to NULL).
However the pointers in the SysFS are already freed and we hit an
NULL pointer further on when 'strlen' is attempted on a freed pointer.

The patch adds a simple check in the XEN_PCI_OP_enable_msix to guard
against that. The check for msi_enabled is not stricly neccessary.

This is part of XSA-157

CC: stable@vger.kernel.org
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-12-18 10:48:29 -05:00
Konrad Rzeszutek Wilk
56441f3c8e xen/pciback: Return error on XEN_PCI_OP_enable_msi when device has MSI or MSI-X enabled
The guest sequence of:

 a) XEN_PCI_OP_enable_msi
 b) XEN_PCI_OP_enable_msi
 c) XEN_PCI_OP_disable_msi

results in hitting an BUG_ON condition in the msi.c code.

The MSI code uses an dev->msi_list to which it adds MSI entries.
Under the above conditions an BUG_ON() can be hit. The device
passed in the guest MUST have MSI capability.

The a) adds the entry to the dev->msi_list and sets msi_enabled.
The b) adds a second entry but adding in to SysFS fails (duplicate entry)
and deletes all of the entries from msi_list and returns (with msi_enabled
is still set).  c) pci_disable_msi passes the msi_enabled checks and hits:

BUG_ON(list_empty(dev_to_msi_list(&dev->dev)));

and blows up.

The patch adds a simple check in the XEN_PCI_OP_enable_msi to guard
against that. The check for msix_enabled is not stricly neccessary.

This is part of XSA-157.

CC: stable@vger.kernel.org
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-12-18 10:48:19 -05:00
Konrad Rzeszutek Wilk
8135cf8b09 xen/pciback: Save xen_pci_op commands before processing it
Double fetch vulnerabilities that happen when a variable is
fetched twice from shared memory but a security check is only
performed the first time.

The xen_pcibk_do_op function performs a switch statements on the op->cmd
value which is stored in shared memory. Interestingly this can result
in a double fetch vulnerability depending on the performed compiler
optimization.

This patch fixes it by saving the xen_pci_op command before
processing it. We also use 'barrier' to make sure that the
compiler does not perform any optimization.

This is part of XSA155.

CC: stable@vger.kernel.org
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-12-18 10:00:47 -05:00
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
Wei Liu
ccc9d90a9a xenbus_client: Extend interface to support multi-page ring
Originally Xen PV drivers only use single-page ring to pass along
information. This might limit the throughput between frontend and
backend.

The patch extends Xenbus driver to support multi-page ring, which in
general should improve throughput if ring is the bottleneck. Changes to
various frontend / backend to adapt to the new interface are also
included.

Affected Xen drivers:
* blkfront/back
* netfront/back
* pcifront/back
* scsifront/back
* vtpmfront

The interface is documented, as before, in xenbus_client.c.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Cc: Konrad Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-04-15 10:56:47 +01:00
Jan Beulich
278edfc078 xen-pciback: also support disabling of bus-mastering and memory-write-invalidate
It's not clear to me why only the enabling operation got handled so
far.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-03-16 14:51:35 +00:00
Konrad Rzeszutek Wilk
74beaf6270 xen/pciback: Don't print scary messages when unsupported by hypervisor.
We print at the warninig level messages such as:
pciback 0000:90:00.5: MSI-X preparation failed (-38)

which is due to the hypervisor not supporting this sub-hypercall
(which was added in Xen 4.3).

Instead of having scary messages all the time - only have it
when the hypercall is actually supported.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-03-16 14:49:14 +00:00
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
Jan Beulich
6945c59c77 xen-pciback: drop SR-IOV VFs when PF driver unloads
When a PF driver unloads, it may find it necessary to leave the VFs
around simply because of pciback having marked them as assigned to a
guest. Utilize a suitable notification to let go of the VFs, thus
allowing the PF to go back into the state it was before its driver
loaded (which in particular allows the driver to be loaded again with
it being able to create the VFs anew, but which also allows to then
pass through the PF instead of the VFs).

Don't do this however for any VFs currently in active use by a guest.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
[v2: Removed the switch statement, moved it about]
[v3: Redid it a bit differently]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-04 12:42:03 +00:00
Konrad Rzeszutek Wilk
b1df4a56bf xen/pciback: Restore configuration space when detaching from a guest.
The commit "xen/pciback: Don't deadlock when unbinding." was using
the version of pci_reset_function which would lock the device lock.
That is no good as we can dead-lock. As such we swapped to using
the lock-less version and requiring that the callers
of 'pcistub_put_pci_dev' take the device lock. And as such
this bug got exposed.

Using the lock-less version is  OK, except that we tried to
use 'pci_restore_state' after the lock-less version of
__pci_reset_function_locked - which won't work as 'state_saved'
is set to false. Said 'state_saved' is a toggle boolean that
is to be used by the sequence of a) pci_save_state/pci_restore_state
or b) pci_load_and_free_saved_state/pci_restore_state. We don't
want to use a) as the guest might have messed up the PCI
configuration space and we want it to revert to the state
when the PCI device was binded to us. Therefore we pick
b) to restore the configuration space.

We restore from our 'golden' version of PCI configuration space, when an:
 - Device is unbinded from pciback
 - Device is detached from a guest.

Reported-by:  Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-04 12:42:02 +00:00
Konrad Rzeszutek Wilk
c1a04339e5 xen/pciback: Remove tons of dereferences
A little cleanup. No functional difference.

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-04 12:42:01 +00:00
Konrad Rzeszutek Wilk
15390613b6 xen/pciback: Print out the domain owning the device.
We had been printing it only if the device was built with
debug enabled. But this information is useful in the field
to troubleshoot.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-04 12:42:00 +00:00
Konrad Rzeszutek Wilk
b5d512147a xen/pciback: Include the domain id if removing the device whilst still in use
Cleanup the function a bit - also include the id of the
domain that is using the device.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-04 12:41:59 +00:00
Konrad Rzeszutek Wilk
ac8010221d driver core: Provide an wrapper around the mutex to do lockdep warnings
Instead of open-coding it in drivers that want to double check
that their functions are indeed holding the device lock.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Suggested-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-04 12:41:59 +00:00
Konrad Rzeszutek Wilk
e8801a7418 xen/pciback: Don't deadlock when unbinding.
As commit 0a9fd01529
'xen/pciback: Document the entry points for 'pcistub_put_pci_dev''
explained there are four entry points in this function.
Two of them are when the user fiddles in the SysFS to
unbind a device which might be in use by a guest or not.

Both 'unbind' states will cause a deadlock as the the PCI lock has
already been taken, which then pci_device_reset tries to take.

We can simplify this by requiring that all callers of
pcistub_put_pci_dev MUST hold the device lock. And then
we can just call the lockless version of pci_device_reset.

To make it even simpler we will modify xen_pcibk_release_pci_dev
to quality whether it should take a lock or not - as it ends
up calling xen_pcibk_release_pci_dev and needs to hold the lock.

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-12-04 12:41:58 +00:00
Linus Torvalds
81ae31d782 xen: features and fixes for 3.18-rc0
- Add pvscsi frontend and backend drivers.
 - Remove _PAGE_IOMAP PTE flag, freeing it for alternate uses.
 - Try and keep memory contiguous during PV memory setup (reduces
   SWIOTLB usage).
 - Allow front/back drivers to use threaded irqs.
 - Support large initrds in PV guests.
 - Fix PVH guests in preparation for Xen 4.5
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Merge tag 'stable/for-linus-3.18-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen updates from David Vrabel:
 "Features and fixes:

   - Add pvscsi frontend and backend drivers.
   - Remove _PAGE_IOMAP PTE flag, freeing it for alternate uses.
   - Try and keep memory contiguous during PV memory setup (reduces
     SWIOTLB usage).
   - Allow front/back drivers to use threaded irqs.
   - Support large initrds in PV guests.
   - Fix PVH guests in preparation for Xen 4.5"

* tag 'stable/for-linus-3.18-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (22 commits)
  xen: remove DEFINE_XENBUS_DRIVER() macro
  xen/xenbus: Remove BUG_ON() when error string trucated
  xen/xenbus: Correct the comments for xenbus_grant_ring()
  x86/xen: Set EFER.NX and EFER.SCE in PVH guests
  xen: eliminate scalability issues from initrd handling
  xen: sync some headers with xen tree
  xen: make pvscsi frontend dependant on xenbus frontend
  arm{,64}/xen: Remove "EXPERIMENTAL" in the description of the Xen options
  xen-scsifront: don't deadlock if the ring becomes full
  x86: remove the Xen-specific _PAGE_IOMAP PTE flag
  x86/xen: do not use _PAGE_IOMAP PTE flag for I/O mappings
  x86: skip check for spurious faults for non-present faults
  xen/efi: Directly include needed headers
  xen-scsiback: clean up a type issue in scsiback_make_tpg()
  xen-scsifront: use GFP_ATOMIC under spin_lock
  MAINTAINERS: Add xen pvscsi maintainer
  xen-scsiback: Add Xen PV SCSI backend driver
  xen-scsifront: Add Xen PV SCSI frontend driver
  xen: Add Xen pvSCSI protocol description
  xen/events: support threaded irqs for interdomain event channels
  ...
2014-10-11 20:29:01 -04:00
David Vrabel
95afae4814 xen: remove DEFINE_XENBUS_DRIVER() macro
The DEFINE_XENBUS_DRIVER() macro looks a bit weird and causes sparse
errors.

Replace the uses with standard structure definitions instead.  This is
similar to pci and usb device registration.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-10-06 10:27:57 +01:00
Ethan Zhao
be507fd090 xen/pciback: Use PCI device flag helper functions
Use PCI device flag helper functions when assigning or releasing device.
No functional change.

Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: David Vrabel <david.vrabel@citrix.com>
2014-09-16 16:19:17 -06:00
Benoit Taine
9baa3c34ac PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use
We should prefer `struct pci_device_id` over `DEFINE_PCI_DEVICE_TABLE` to
meet kernel coding style guidelines.  This issue was reported by checkpatch.

A simplified version of the semantic patch that makes this change is as
follows (http://coccinelle.lip6.fr/):

// <smpl>

@@
identifier i;
declarer name DEFINE_PCI_DEVICE_TABLE;
initializer z;
@@

- DEFINE_PCI_DEVICE_TABLE(i)
+ const struct pci_device_id i[]
= z;

// </smpl>

[bhelgaas: add semantic patch]
Signed-off-by: Benoit Taine <benoit.taine@lip6.fr>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-08-12 12:15:14 -06:00
Wei Yongjun
2ef760323a xen/pciback: Fix error return code in xen_pcibk_attach()
Fix to return -EFAULT from the error handling case instead of 0 when
version mismatch with pcifront.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Reviewed-by Jan Beulich <jbeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-08-01 15:44:46 +01:00
Linus Torvalds
776edb5931 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next
Pull core locking updates from Ingo Molnar:
 "The main changes in this cycle were:

   - reduced/streamlined smp_mb__*() interface that allows more usecases
     and makes the existing ones less buggy, especially in rarer
     architectures

   - add rwsem implementation comments

   - bump up lockdep limits"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  rwsem: Add comments to explain the meaning of the rwsem's count field
  lockdep: Increase static allocations
  arch: Mass conversion of smp_mb__*()
  arch,doc: Convert smp_mb__*()
  arch,xtensa: Convert smp_mb__*()
  arch,x86: Convert smp_mb__*()
  arch,tile: Convert smp_mb__*()
  arch,sparc: Convert smp_mb__*()
  arch,sh: Convert smp_mb__*()
  arch,score: Convert smp_mb__*()
  arch,s390: Convert smp_mb__*()
  arch,powerpc: Convert smp_mb__*()
  arch,parisc: Convert smp_mb__*()
  arch,openrisc: Convert smp_mb__*()
  arch,mn10300: Convert smp_mb__*()
  arch,mips: Convert smp_mb__*()
  arch,metag: Convert smp_mb__*()
  arch,m68k: Convert smp_mb__*()
  arch,m32r: Convert smp_mb__*()
  arch,ia64: Convert smp_mb__*()
  ...
2014-06-03 12:57:53 -07:00
Konrad Rzeszutek Wilk
0a9fd01529 xen/pciback: Document the entry points for 'pcistub_put_pci_dev'
which are quite a few. It should be evident that dealing with that
many options is a bit complex.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
2014-05-23 12:33:55 -04:00
Konrad Rzeszutek Wilk
24d8bf1b0a xen/pciback: Document when the 'unbind' and 'bind' functions are called.
And also mention that you cannot do any pci_reset_function,
pci_reset_slot, or such calls. This is because they take the same
lock as SysFS does - and we would end up with a dead-lock if
we call those functions.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
2014-05-23 12:33:50 -04:00
Konrad Rzeszutek Wilk
8be9df6d4b xen-pciback: Document when we FLR an PCI device.
When the toolstack wants us to drop or add an PCI device it
changes the XenBus state to Configuring - and as result of that
we find out which devices we should still be exporting out and
which ones not. For the ones we don't need anymore we need to
do an PCI reset so that it is ready for the next guest.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
2014-05-23 12:33:43 -04:00
Konrad Rzeszutek Wilk
fcb8ce968f xen-pciback: First reset, then free.
We were doing the operations of freeing and reset in the wrong
order. Granted nothing broke because the reset functions just
set bar->which = 0.

But nonethless this was incorrect.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
2014-05-23 12:33:36 -04:00
Konrad Rzeszutek Wilk
8899035eec xen-pciback: Cleanup up pcistub_put_pci_dev
We are using 'psdev->dev','found_psdev->dev', and 'dev' at the
same time - and they all point to the same structure.

To keep it straight lets just use one - 'dev'.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
2014-05-23 12:33:30 -04:00
Peter Zijlstra
4e857c58ef arch: Mass conversion of smp_mb__*()
Mostly scripted conversion of the smp_mb__* barriers.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-18 14:20:48 +02:00
Dan Carpenter
c0914e6166 xen-pciback: silence an unwanted debug printk
There is a missing curly brace here so we might print some extra debug
information.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-04-15 17:41:12 +01:00
Daeseok Youn
cea37f8751 xen: fix memory leak in __xen_pcibk_add_pci_dev()
It need to free dev_entry when it failed to assign to a new
slot on the virtual PCI bus.

smatch says:
 drivers/xen/xen-pciback/vpci.c:142 __xen_pcibk_add_pci_dev() warn:
possible memory leak of 'dev_entry'

Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-04-15 17:32:30 +01:00