On 04/29/2013 02:28 PM, Laine Stump wrote: > PCIO device assignment using VFIO requires read/write access by the > qemu process to /dev/vfio/vfio, and /dev/vfio/nn, where "nn" is the > VFIO group number that the assigned device belongs to (and can be > found with the function virPCIDeviceGetVFIOGroupDev) > > /dev/vfio/vfio can be accessible to any guest without danger > (according to vfio developers), so it is added to the static ACL. > > The group device must be dynamically added to the cgroup ACL for each > vfio hostdev in two places: > > 1) for any devices in the persistent config when the domain is started > (done during qemuSetupCgroup()) > > 2) at device attach time for any hotplug devices (done in > qemuDomainAttachHostDevice) > > The group device must be removed from the ACL when a device it > "hot-unplugged" (in qemuDomainDetachHostDevice()) > > Note that USB devices are already doing their own cgroup setup and > teardown in the hostdev-usb specific function. I chose to make the new > functions generic and call them in a common location though. We can > then move the USB-specific code (which is duplicated in two locations) > to this single location. I'll be posting a followup patch to do that. > --- > src/qemu/qemu.conf | 2 +- > src/qemu/qemu_cgroup.c | 133 > ++++++++++++++++++++++++++++++++++++- > src/qemu/qemu_cgroup.h | 6 +- > src/qemu/qemu_hotplug.c | 10 ++- > src/qemu/test_libvirtd_qemu.aug.in | 1 + > 5 files changed, 148 insertions(+), 4 deletions(-) >
> @@ -36,6 +36,10 @@ int qemuTeardownDiskCgroup(virDomainObjPtr vm,
> int qemuSetupHostUsbDeviceCgroup(virUSBDevicePtr dev,
> const char *path,
> void *opaque);
> +int qemuSetupHostdevCGroup(virDomainObjPtr vm,
> + virDomainHostdevDefPtr dev)
> ATTRIBUTE_RETURN_CHECK;
> +int qemuTeardownHostdevCgroup(virDomainObjPtr vm,
> + virDomainHostdevDefPtr dev);
A bit odd that setup is ATTRIBUTE_RETURN_CHECK but teardown is not. I'd
rather see both require a use...
> @@ -1257,6 +1260,9 @@ error:
> vm->def, hostdev, NULL) < 0)
> VIR_WARN("Unable to restore host device labelling on hotplug fail");
>
> +teardown_cgroup:
> + qemuTeardownHostdevCgroup(vm, hostdev);
...and here, on cleanup paths after an earlier error, stick a VIR_WARN()
that logs any failure trying to clean up (as we already did on the line
before).
> +
> cleanup:
> virObjectUnref(list);
> if (usb)
> @@ -2499,6 +2505,8 @@ int qemuDomainDetachThisHostDevice(virQEMUDriverPtr
> driver,
> }
>
> if (!ret) {
> + qemuTeardownHostdevCgroup(vm, detach);
> +
> if (virSecurityManagerRestoreHostdevLabel(driver->securityManager,
> vm->def, detach, NULL) <
> 0) {
> VIR_WARN("Failed to restore host device labelling");
...here's another place where a VIR_WARN on failure to clean up is
appropriate.
ACK with that fixed.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
signature.asc
Description: OpenPGP digital signature
-- libvir-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/libvir-list
