[libvirt] [PATCH 4/5] qemu: Check if PCI passhtrough is available in the host when starting
Check the presence of the selected PCI passthrough option when starting
a VM.
---
src/qemu/qemu_process.c | 41 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 41 insertions(+)
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index dd16f6c..e36ab99 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -3481,6 +3481,8 @@ int qemuProcessStart(virConnectPtr conn,
unsigned int stop_flags;
virQEMUDriverConfigPtr cfg;
virCapsPtr caps = NULL;
+ int supportsPassthroughKVM = -1;
+ int supportsPassthroughVFIO = -1;
/* Okay, these are just internal flags,
* but doesn't hurt to check */
@@ -3713,6 +3715,45 @@ int qemuProcessStart(virConnectPtr conn,
goto cleanup;
}
+ /* assign defaults for hostdev passthrough */
+ for (i = 0; i < vm->def->nhostdevs; i++) {
+ virDomainHostdevDefPtr hostdev = vm->def->hostdevs[i];
+
+ if (hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS &&
+ hostdev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI) {
+ int *backend = &hostdev->source.subsys.u.pci.backend;
+
+ /* cache host state of passthrough support */
+ if (supportsPassthroughKVM == -1 || supportsPassthroughVFIO == -1) {
+ supportsPassthroughKVM = qemuHostdevHostSupportsPassthroughLegacy();
+ supportsPassthroughVFIO = qemuHostdevHostSupportsPassthroughVFIO();
+ }
+
+ switch ((virDomainHostdevSubsysPciBackendType) *backend) {
+ case VIR_DOMAIN_HOSTDEV_PCI_BACKEND_VFIO:
+ if (!supportsPassthroughVFIO) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("host doesn't support VFIO PCI
passthrough"));
+ goto cleanup;
+ }
+ break;
+
+ case VIR_DOMAIN_HOSTDEV_PCI_BACKEND_DEFAULT:
+ case VIR_DOMAIN_HOSTDEV_PCI_BACKEND_KVM:
+ if (!supportsPassthroughKVM) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("host doesn't support legacy PCI
passthrough"));
+ goto cleanup;
+ }
+
+ break;
+
+ case VIR_DOMAIN_HOSTDEV_PCI_BACKEND_TYPE_LAST:
+ break;
+ }
+ }
+ }
+
/*
* Normally PCI addresses are assigned in the virDomainCreate
* or virDomainDefine methods. We might still need to assign
--
1.8.3.2