[libvirt] [PATCH] Allow vfio hotplug of a device to the domain which owns the iommu

[Shivaprasad bhat]

Ping!

Thanks,
Shivaprasad

On Tue, Jul 14, 2015 at 5:26 PM, Shivaprasad G Bhat
<shivaprasadbhat at gmail.com> wrote:
> The commit 7e72de4 didn't consider the hotplug scenarios. The patch addresses
> the hotplug case whereby if atleast one of the pci function is owned by a
> guest, the hotplug of other functions/devices in the same iommu group to the
> same guest goes through successfully.
>
> Signed-off-by: Shivaprasad G Bhat <sbhat at linux.vnet.ibm.com>
> ---
>  src/util/virhostdev.c |   34 +++++++++++++++++++++++++++-------
>  1 file changed, 27 insertions(+), 7 deletions(-)
>
> diff --git a/src/util/virhostdev.c b/src/util/virhostdev.c
> index 809caed..529753c 100644
> --- a/src/util/virhostdev.c
> +++ b/src/util/virhostdev.c
> @@ -54,23 +54,35 @@ static virClassPtr virHostdevManagerClass;
>  static void virHostdevManagerDispose(void *obj);
>  static virHostdevManagerPtr virHostdevManagerNew(void);
>
> +struct virHostdevIsPCINodeDeviceUsedData {
> +    virHostdevManagerPtr hostdev_mgr;
> +    const char *domainName;
> +    const bool usesVfio;
> +};
> +
>  static int virHostdevIsPCINodeDeviceUsed(virPCIDeviceAddressPtr devAddr, void *opaque)
>  {
>      virPCIDevicePtr other;
>      int ret = -1;
>      virPCIDevicePtr pci = NULL;
> -    virHostdevManagerPtr hostdev_mgr = opaque;
> +    struct virHostdevIsPCINodeDeviceUsedData *helperData = opaque;
>
>      if (!(pci = virPCIDeviceNew(devAddr->domain, devAddr->bus,
>                                  devAddr->slot, devAddr->function)))
>          goto cleanup;
>
> -    other = virPCIDeviceListFind(hostdev_mgr->activePCIHostdevs, pci);
> +    other = virPCIDeviceListFind(helperData->hostdev_mgr->activePCIHostdevs,
> +                                 pci);
>      if (other) {
>          const char *other_drvname = NULL;
>          const char *other_domname = NULL;
>          virPCIDeviceGetUsedBy(other, &other_drvname, &other_domname);
>
> +        if (helperData->usesVfio &&
> +            (other_domname && helperData->domainName) &&
> +            (STREQ(other_domname, helperData->domainName)))
> +            goto iommu_owner;
> +
>          if (other_drvname && other_domname)
>              virReportError(VIR_ERR_OPERATION_INVALID,
>                             _("PCI device %s is in use by "
> @@ -83,6 +95,7 @@ static int virHostdevIsPCINodeDeviceUsed(virPCIDeviceAddressPtr devAddr, void *o
>                             virPCIDeviceGetName(pci));
>          goto cleanup;
>      }
> + iommu_owner:
>      ret = 0;
>   cleanup:
>      virPCIDeviceFree(pci);
> @@ -562,6 +575,9 @@ virHostdevPreparePCIDevices(virHostdevManagerPtr hostdev_mgr,
>      for (i = 0; i < virPCIDeviceListCount(pcidevs); i++) {
>          virPCIDevicePtr dev = virPCIDeviceListGet(pcidevs, i);
>          bool strict_acs_check = !!(flags & VIR_HOSTDEV_STRICT_ACS_CHECK);
> +        bool usesVfio = STREQ(virPCIDeviceGetStubDriver(dev), "vfio-pci");
> +        struct virHostdevIsPCINodeDeviceUsedData data = {hostdev_mgr, dom_name,
> +                                                         usesVfio};
>
>          if (!virPCIDeviceIsAssignable(dev, strict_acs_check)) {
>              virReportError(VIR_ERR_OPERATION_INVALID,
> @@ -579,12 +595,12 @@ virHostdevPreparePCIDevices(virHostdevManagerPtr hostdev_mgr,
>           * belonging to same iommu group can't be shared
>           * across guests.
>           */
> -        if (STREQ(virPCIDeviceGetStubDriver(dev), "vfio-pci")) {
> +        if (usesVfio) {
>              if (virPCIDeviceAddressIOMMUGroupIterate(devAddr,
>                                                       virHostdevIsPCINodeDeviceUsed,
> -                                                     hostdev_mgr) < 0)
> +                                                     &data) < 0)
>                  goto cleanup;
> -        } else if (virHostdevIsPCINodeDeviceUsed(devAddr, hostdev_mgr)) {
> +        } else if (virHostdevIsPCINodeDeviceUsed(devAddr, &data)) {
>              goto cleanup;
>          }
>      }
> @@ -1544,6 +1560,8 @@ virHostdevPCINodeDeviceDetach(virHostdevManagerPtr hostdev_mgr,
>                                virPCIDevicePtr pci)
>  {
>      virPCIDeviceAddressPtr devAddr = NULL;
> +    struct virHostdevIsPCINodeDeviceUsedData data = { hostdev_mgr, NULL,
> +                                                     false };
>      int ret = -1;
>
>      virObjectLock(hostdev_mgr->activePCIHostdevs);
> @@ -1552,7 +1570,7 @@ virHostdevPCINodeDeviceDetach(virHostdevManagerPtr hostdev_mgr,
>      if (!(devAddr = virPCIDeviceGetAddress(pci)))
>          goto out;
>
> -    if (virHostdevIsPCINodeDeviceUsed(devAddr, hostdev_mgr))
> +    if (virHostdevIsPCINodeDeviceUsed(devAddr, &data))
>          goto out;
>
>      if (virPCIDeviceDetach(pci, hostdev_mgr->activePCIHostdevs,
> @@ -1573,6 +1591,8 @@ virHostdevPCINodeDeviceReAttach(virHostdevManagerPtr hostdev_mgr,
>                                  virPCIDevicePtr pci)
>  {
>      virPCIDeviceAddressPtr devAddr = NULL;
> +    struct virHostdevIsPCINodeDeviceUsedData data = {hostdev_mgr, NULL,
> +                                                     false};
>      int ret = -1;
>
>      virObjectLock(hostdev_mgr->activePCIHostdevs);
> @@ -1581,7 +1601,7 @@ virHostdevPCINodeDeviceReAttach(virHostdevManagerPtr hostdev_mgr,
>      if (!(devAddr = virPCIDeviceGetAddress(pci)))
>          goto out;
>
> -    if (virHostdevIsPCINodeDeviceUsed(devAddr, hostdev_mgr))
> +    if (virHostdevIsPCINodeDeviceUsed(devAddr, &data))
>          goto out;
>
>      virPCIDeviceReattachInit(pci);
>
> --
> libvir-list mailing list
> libvir-list at redhat.com
> https://www.redhat.com/mailman/listinfo/libvir-list