Re: [libvirt] [PATCH 3/8] Refuse to reattach from vfio if the iommu group is in use by any domain

It is incorrect to attempt the device reattach of a function, when some other domain is using some functions belonging to the same iommu group. Signed-off-by: Shivaprasad G Bhat <sbhat(a)linux.vnet.ibm.com&gt; --- src/util/virhostdev.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/src/util/virhostdev.c b/src/util/virhostdev.c index de029a0..91f28e9 100644 --- a/src/util/virhostdev.c +++ b/src/util/virhostdev.c @@ -1590,6 +1590,7 @@ virHostdevPCINodeDeviceReAttach(virHostdevManagerPtr hostdev_mgr, virPCIDevicePtr pci) { virPCIDeviceAddressPtr devAddr = NULL; + bool usesVfio = STREQ_NULLABLE(virPCIDeviceGetStubDriver(pci), "vfio-pci"); struct virHostdevIsPCINodeDeviceUsedData data = {hostdev_mgr, NULL, false}; int ret = -1; @@ -1600,8 +1601,16 @@ virHostdevPCINodeDeviceReAttach(virHostdevManagerPtr hostdev_mgr, if (!(devAddr = virPCIDeviceGetAddress(pci))) goto out; - if (virHostdevIsPCINodeDeviceUsed(devAddr, &data)) + if (usesVfio) { + /* Doesn't matter which function. If any domain is actively using the + iommu group, refuse to reattach */

+ if (virPCIDeviceAddressIOMMUGroupIterate(devAddr, + virHostdevIsPCINodeDeviceUsed, + &data) < 0) + goto out; + } else if (virHostdevIsPCINodeDeviceUsed(devAddr, &data)) { goto out; + } virPCIDeviceReattachInit(pci);