Re: [libvirt] [PATCH 2/2] qemu: format eim on intel-iommu command line

This option turns on extended interrupt mode, which allows more than 255 vCPUs.   https://bugzilla.redhat.com/show_bug.cgi?id=1451282 ---   src/qemu/qemu_capabilities.c                         |  2 ++   src/qemu/qemu_capabilities.h                         |  1 +   src/qemu/qemu_command.c                              | 11 +++++++++++   src/qemu/qemu_domain.c                               | 20 ++++++++++++++++++++   tests/qemucapabilitiesdata/caps_2.8.0.x86_64.xml     |  1 +   tests/qemucapabilitiesdata/caps_2.9.0.x86_64.xml     |  1 +   .../qemuxml2argv-intel-iommu-eim.args                | 19 +++++++++++++++++++   tests/qemuxml2argvtest.c                             |  7 +++++++   8 files changed, 62 insertions(+)   create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-intel-iommu-eim.args

@@ -2663,6 +2663,9 @@ qemuDomainRecheckInternalPaths(virDomainDefPtr def,   }       +#define QEMU_MAX_VCPUS_WITHOUT_EIM 255

+ +   static int   qemuDomainDefVcpusPostParse(virDomainDefPtr def)   { @@ -3071,6 +3074,23 @@ qemuDomainDefValidate(const virDomainDef *def,           }       }

+    if (ARCH_IS_X86(def->os.arch) && +        virDomainDefGetVcpusMax(def) > QEMU_MAX_VCPUS_WITHOUT_EIM) { +        if (!qemuDomainIsQ35(def)) { +            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, +                           _("more than %d vCPUs are only supported on " +                             "q35-based machine types"), +                           QEMU_MAX_VCPUS_WITHOUT_EIM); +            goto cleanup; +        } +        if (!def->iommu || def->iommu->eim != VIR_TRISTATE_SWITCH_ON) { +            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, +                           _("more than %d vCPUs require extended interrupt " +                             "mode enabled on the iommu device"), +                           QEMU_MAX_VCPUS_WITHOUT_EIM); +        } +    }