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: Eric 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: Roopa Prabhu <roprabhu@cisco.com>
Signed-off-by: Christian Benvenuti <benve@cisco.com>
Signed-off-by: David Wang <dwang2@cisco.com>
Signed-off-by: Stefan 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: Roopa Prabhu <roprabhu@cisco.com>
Signed-off-by: Christian Benvenuti <benve@cisco.com>
Signed-off-by: David 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: Chris Lalancette <clalance@redhat.com>
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
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: Chris 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: Jiri Denemark <jdenemar@redhat.com>
* src/util/pci.c, src/util/pci.h: Make the pciDeviceList struct
opaque to callers of the API. Add accessor methods for managing
devices in the list
* src/qemu/qemu_driver.c: Update to use APIs instead of directly
accessing pciDeviceList fields
