[libvirt] [PATCH 8/8] qemu: Tweak Intel IOMMU command line generation

Mostly add comments explaining why there are two capabilites for the same feature and how they interact. Signed-off-by: Andrea Bolognani <abologna(a)redhat.com&gt; --- src/qemu/qemu_command.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index e16c748d31..73f570c419 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -6935,8 +6935,12 @@ qemuBuildIOMMUCommandLine(virCommandPtr cmd, if (!iommu) return 0; - if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_MACHINE_IOMMU)) - return 0; /* Already handled via -machine */ + /* qemuDomainDeviceDefValidate() already made sure we have one of + * QEMU_CAPS_DEVICE_INTEL_IOMMU or QEMU_CAPS_MACHINE_IOMMU: here we + * handle the former case, while the latter is taken care of in + * qemuBuildMachineCommandLine() */ + if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_INTEL_IOMMU)) + return 0; switch (iommu->model) { case VIR_DOMAIN_IOMMU_MODEL_INTEL: @@ -7594,7 +7598,10 @@ qemuBuildMachineCommandLine(virCommandPtr cmd, } } - /* We don't report errors on missing cap here - -device code will do that */ + /* qemuDomainDeviceDefValidate() already made sure we have one of + * QEMU_CAPS_DEVICE_INTEL_IOMMU or QEMU_CAPS_MACHINE_IOMMU: here we + * handle the latter case, while the former is taken care of in + * qemuBuildIOMMUCommandLine() */ if (def->iommu && virQEMUCapsGet(qemuCaps, QEMU_CAPS_MACHINE_IOMMU)) { switch (def->iommu->model) { -- 2.21.0