Coverity complains about "USE_AFTER_FREE" due to how virPCIDeviceSetStubDriver
"could" return either -1, 0, or 1 from the VIR_STRDUP() and then possibly makes
a call to virPCIDeviceDetach().

The only way this could happen is if NULL were passed as the "driver" name
and virStrdup() returned 0.  Since the calling functions check < 0 on the
initial function call, the 0 possibility causes Coverity to complain.

To fix this - enforce that the second parameter is not NULL using
ATTRIBUTE_NONNULL(2) for the function prototype, then in virPCIDeviceDetach
add an sa_assert(dev->stubDriver). This will result in Coverity not complaining
any more.

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Like commit 94a26c7e from Eric Blake, the old fuzzy code should
be replaced by the new array management macros now.

And the type of scsi->count should be changed into "size_t", and
thus virSCSIDeviceListCount should return size_t instead, similar
for vir{PCI,USB}DeviceListCount.

This is a prerequisite to the fix for the fix to:

  https://bugzilla.redhat.com/show_bug.cgi?id=1025397

num_virtual_functions needs to be size_t in order to use the
VIR_APPEND_ELEMENT macro.

Any device which belongs to an "IOMMU group" (used by vfio) will
have links to all devices of its group listed in
/sys/bus/pci/$device/iommu_group/devices;
/sys/bus/pci/$device/iommu_group is actually a link to
/sys/kernel/iommu_groups/$n, where $n is the group number (there
will be a corresponding device node at /dev/vfio/$n once the
devices are bound to the vfio-pci driver)

The following functions are added:

virPCIDeviceGetIOMMUGroupList

  Gets a virPCIDeviceList with one virPCIDeviceList for each device
  in the same IOMMU group as the provided virPCIDevice (a copy of the
  original device object is included in the list.

virPCIDeviceAddressIOMMUGroupIterate

  Calls the function @actor once for each device in the group that
  contains the given virPCIDeviceAddress.

virPCIDeviceAddressGetIOMMUGroupAddresses

  Fills in a virPCIDeviceAddressPtr * with an array of
  virPCIDeviceAddress, one for each device in the iommu group of the
  provided virPCIDeviceAddress (including a copy of the original).

virPCIDeviceAddressGetIOMMUGroupNum

  Returns the group number as an int (a valid group number will always
  be 0 or greater).  If there is no iommu_group link in the device's
  directory (usually indicating that vfio isn't loaded), -2 will be
  returned. On any real error, -1 will be returned.

Make a copy of the device and add the copy to the
list. (virPCIDeviceListAdd() adds the original object to the list
instead).

This function has utility outside of virpci.c, so make it public.

Also the name didn't fit convention, so change it to
virPCIDeviceAddressParse.

I realized after the fact that it's probably better in the long run to
give this function a name that matches the name of the link used in
sysfs to hold the group (iommu_group).

I'm changing it now because I'm about to add several more functions
that deal with iommu groups.

The driver arg to virPCIDeviceDetach is no longer used (the name of the stub driver is now set in the virPCIDevice object, and virPCIDeviceDetach retrieves it from there). Remove it.

* virPCIDeviceFindByIDs - find a device on a list w/o creating an object
    This makes searching for an existing device on a list lighter weight.

* virPCIDeviceCopy - make a copy of an existing virPCIDevice object.

* virPCIDeviceGetDriverPathAndName - construct new strings containing
    1) the name of the driver bound to this device.
    2) the full path to the sysfs config for that driver.
    (This code was lifted from virPCIDeviceUnbindFromStub, and replaced
    there with a call to this new function).

Previously stubDriver was always set from a string literal, so it was
okay to use a const char * that wasn't freed when the virPCIDevice was
freed. This will not be the case in the near future, so it is now a
char* that is allocated in virPCIDeviceSetStubDriver() and freed
during virPCIDeviceFree().

virPCIDeviceReattach and virPCIDeviceUnbindFromStub (called by
virPCIDeviceReattach) had previously required the name of the stub
driver as input. This is unnecessary, because the name of the driver
the device is currently bound to can be found by looking at the link:

  /sys/bus/pci/dddd:bb:ss.ff/driver

Instead of requiring that the name of the expected stub driver name
and only unbinding if that one name is matched, we no longer take a
driver name in the arglist for either of these
functions. virPCIDeviceUnbindFromStub just compares the name of the
currently bound driver to a list of "well known" stubs (right now
contains "pci-stub" and "vfio-pci" for qemu, and "pciback" for xen),
and only performs the unbind if it's one of those devices.

This allows virsh nodedevice-reattach to work properly across a
libvirtd restart, and fixes a couple of cases where we were
erroneously still hard-coding "pci-stub" as the drive name.

For some unknown reason, virPCIDeviceReattach had been calling
modprobe on the stub driver prior to unbinding the device. This was
problematic because we no longer know the name of the stub driver in
that function. However, it is pointless to probe for the stub driver
at that time anyway - because the device is bound to the stub driver,
we are guaranteed that it is already loaded, and so that call to
modprobe has been removed.

Given a virPCIDevice, this function returns the path for the device
that controls the vfio group the device belongs to,
e.g. "/dev/vfio/15".

This can be set when the virPCIDevice is created and placed on a list,
then used later when traversing the list to determine which stub
driver to bind/unbind for managed devices.

The existing Detach and Attach functions' signatures haven't been
changed (they still accept a stub driver name in the arg list), but if
the arg list has NULL for stub driver and one is available in the
device's object, that will be used. (we may later deprecate and remove
the arg from those functions).

Though they are the same thing, mixed use of them is uncomfortable.
"unsigned" is used a lot in old codes, this just tries to change the
ones in utils.

Members of struct virPCIDevice are changed together.

To allow modifications to the lists to be synchronized, convert
virPCIDeviceList and virUSBDeviceList into virObjectLockable
classes. The locking, however, will not be self-contained. The
users of these classes will have to call virObjectLock/Unlock
in the critical regions.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Rename all the pciDeviceXXX and pciXXXDevice APIs to have a
fixed virPCIDevice name prefix

Pass stub driver name directly to pciDettachDevice and pciReAttachDevice to fit
for different libvirt drivers. For example, qemu driver prefers pci-stub, but
Xen prefers pciback.
Signed-off-by: NChunyan Liu <cyliu@suse.com>

In order to be able to steal PCI device by its index in the list.

https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.

* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/;  If/.  If/

Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)

  You should have received a copy of the GNU General Public License
  along with Foobar.  If not, see <http://www.gnu.org/licenses/>.

This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').

Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:

  src/security/security_selinux.h
  src/security/security_driver.h
  src/security/security_selinux.c
  src/security/security_apparmor.h
  src/security/security_apparmor.c
  src/security/security_driver.c

pciDeviceGetVirtualFunctionInfo returns pf netdevice name and virtual
function index for a given vf. This is just a wrapper around existing functions
to return vf's pf and vf_index with one api call

pciConfigAddressToSysfsfile returns the sysfile pci device link
from a 'struct pci_config_address'
Signed-off-by: NRoopa Prabhu <roprabhu@cisco.com>

pciTrySecondaryBusReset checks if there is active device on the
same bus, however, qemu driver doesn't maintain an effective
list for the inactive devices, and it passes meaningless argument
for parameter "inactiveDevs". e.g. (qemuPrepareHostdevPCIDevices)

if (!(pcidevs = qemuGetPciHostDeviceList(hostdevs, nhostdevs)))
    return -1;

..skipped...

if (pciResetDevice(dev, driver->activePciHostdevs, pcidevs) < 0)
    goto reattachdevs;

NB, the "pcidevs" used above are extracted from domain def, and
thus one won't be able to attach a device of which bus has other
device even detached from host (nodedev-detach). To see more
details of the problem:

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=773667

This patch is to resolve the problem by introducing an inactive
PCI device list (just like qemu_driver->activePciHostdevs), and
the whole logic is:

  * Add the device to inactive list during nodedev-dettach
  * Remove the device from inactive list during nodedev-reattach
  * Remove the device from inactive list during attach-device
    (for non-managed device)
  * Add the device to inactive list after detach-device, only
    if the device is not managed

With the above, we have a sufficient inactive PCI device list, and thus
we can use it for pciResetDevice. e.g.(qemuPrepareHostdevPCIDevices)

if (pciResetDevice(dev, driver->activePciHostdevs,
                   driver->inactivePciHostdevs) < 0)
    goto reattachdevs;

This functions enables us to get the Virtual Functions attached to
a Physical function given the name of a SR-IOV physical functio.

In order to accomplish the task, added a getter function pciGetDeviceAddrString
to get the BDF of the Virtual Function in a char array.

To support "managed" mode of host PCI device, we record the original
states (unbind_from_stub, remove_slot, and reprobe) so that could
reattach the device to host with original driver. But there is no XML
for theses attrs, and thus after daemon is restarted, we lose the
original states. It's easy to reproduce:

    1) virsh start domain
    2) virsh attach-device dom hostpci.xml (in 'managed' mode)
    3) service libvirtd restart
    4) virsh destroy domain

    You will see the device won't be bound to the original driver
if there was one.

This patch is to solve the problem by introducing internal XML
(won't be dumped to user, only dumped to status XML). The XML is:
    <origstates>
      <unbind/>
      <remove_slot/>
      <reprobe/>
    </origstates>

Which will be child node of <hostdev><source>...</souce></hostdev>.
(only for PCI device).

A new struct "virDomainHostdevOrigStates" is introduced for the XML,
and the according members are updated when preparing the PCI device.
And function "qemuUpdateActivePciHostdevs" is modified to honor
the original states. Use of qemuGetPciHostDeviceList is removed
in function "qemuUpdateActivePciHostdevs", and the "managed" value of
the device config is honored by the change. This fixes another problem
alongside:

    qemuGetPciHostDeviceList set the device as "managed" force
    regardless of whether the device is configured as "managed='yes'"
    or not in XML, which is not right.

When failing on starting a domain, it tries to reattach all the PCI
devices defined in the domain conf, regardless of whether the devices
are still used by other domain. This will cause the devices to be deleted
from the list qemu_driver->activePciHostdevs, thus the devices will be
thought as usable even if it's not true. And following commands
nodedev-{reattach,reset} will be successful.

How to reproduce:
  1) Define two domains with same PCI device defined in the confs.
  2) # virsh start domain1
  3) # virsh start domain2
  4) # virsh nodedev-reattach $pci_device

You will see the device will be reattached to host successfully.
As pciDeviceReattach just check if the device is still used by
other domain via checking if the device is in list driver->activePciHostdevs,
however, the device is deleted from the list by step 2).

This patch is to prohibit the bug by:
  1) Prohibit a domain starting or device attachment right at
     preparation period (qemuPrepareHostdevPCIDevices) if the
     device is in list driver->activePciHostdevs, which means
     it's used by other domain.

  2) Introduces a new field for struct _pciDevice, (const char *used_by),
     it will be set as the domain name at preparation period,
     (qemuPrepareHostdevPCIDevices). Thus we can prohibit deleting
     the device from driver->activePciHostdevs if it's still used by
     other domain when stopping the domain process.

* src/pci.h (define two internal functions, pciDeviceSetUsedBy and
    pciDevceGetUsedBy)
* src/pci.c (new field "const char *used_by" for struct _pciDevice,
    implementations for the two new functions)
* src/libvirt_private.syms (Add the two new internal functions)
* src/qemu_hostdev.h (Modify the definition of functions
    qemuPrepareHostdevPCIDevices, and qemuDomainReAttachHostdevDevices)
* src/qemu_hostdev.c (Prohibit preparation and don't delete the
    device from activePciHostdevs list if it's still used by other domain)
* src/qemu_hotplug.c (Update function usage, as the definitions are
    changed)
Signed-off-by: NEric Blake <eblake@redhat.com>

This patch adds the following helper functions:
pciDeviceIsVirtualFunction: Function to check if a pci device is a sriov VF
pciGetVirtualFunctionIndex: Function to get the VF index of a sriov VF
pciDeviceNetName: Function to get the network device name of a pci device
pciConfigAddressCompare: Function to compare pci config addresses
Signed-off-by: NRoopa Prabhu <roprabhu@cisco.com>
Signed-off-by: NChristian Benvenuti <benve@cisco.com>
Signed-off-by: NDavid Wang <dwang2@cisco.com>
Signed-off-by: NStefan Berger <stefanb@linux.vnet.ibm.com>

This patch moves some of the sriov related pci code from node_device driver
to src/util/pci.[ch]. Some functions had to go thru name and argument list
change to accommodate the move.
Signed-off-by: NRoopa Prabhu <roprabhu@cisco.com>
Signed-off-by: NChristian Benvenuti <benve@cisco.com>
Signed-off-by: NDavid Wang <dwang2@cisco.com>

add a new API pciDeviceReAttachInit() in pci.c to initialize state values for nodedev reattach

Initialize three state value of device driver to 1. This is just for a new call to
qemudNodeDeviceReAttach()

When doing a PCI secondary bus reset, we must be sure that there are no
active devices on the same bus segment.  The active device tracking is
designed to only track host devices that are active in use by guests.
This ignores host devices that are actively in use by the host.  So the
current logic will reset host devices.

Switch this logic around and allow sbus reset when we are assigning all
devices behind a bridge to the same guest at guest startup or as a result
of a single attach-device command.

* src/util/pci.h: change signature of pciResetDevice to add an
  inactive devices list
* src/qemu/qemu_driver.c src/xen/xen_driver.c: use (or not) the new
  functionality of pciResetDevice() depending on the place of use
* src/util/pci.c: implement the interface and logic changes

In the current libvirt PCI code, there is no checking whether
a PCI device is in use by a guest when doing node device
detach or reattach.  This causes problems when a device is
assigned to a guest, and the administrator starts issuing
nodedevice commands.  Make it so that we check the list
of active devices when trying to detach/reattach, and only
allow the operation if the device is not assigned to a guest.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

* global: patch created by running:
for f in $(git ls-files '*.[ch]') ; do
    cppi $f > $f.t && mv $f.t $f
done

All callers now pass a NULL virConnectPtr into the USB/PCi device
iterator functions. Therefore the virConnectPtr arg can now be
removed from these functions

* src/util/hostusb.h, src/util/hostusb.c: Remove virConnectPtr
  from usbDeviceFileIterate
* src/util/pci.c, src/util/pci.h: Remove virConnectPtr arg from
  pciDeviceFileIterate
* src/qemu/qemu_security_dac.c, src/security/security_selinux.c: Update
  to drop redundant virConnectPtr arg

It was used for error reporting only.

Certain hypervisors (like qemu/kvm) map the PCI bar(s) on
the host when doing device passthrough.  This can lead to a race
condition where the hypervisor is still cleaning up the device while
libvirt is trying to re-attach it to the host device driver.  To avoid
this situation, we look through /proc/iomem, and if the hypervisor is
still holding onto the bar (denoted by the string in the matcher variable),
then we can wait around a bit for that to clear up.

v2: Thanks to review by DV, make sure we wait the full timeout per-device
Signed-off-by: NChris Lalancette <clalance@redhat.com>

New pciDeviceIsAssignable() function for checking whether a given PCI
device can be assigned to a guest was added. Currently it only checks
for ACS being enabled on all PCIe switches between root and the PCI
device. In the future, it could be the right place to check whether a
device is unbound or bound to a stub driver.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>