From 21a5e5cd2a5c8030453eed7ad3e84d244429d403 Mon Sep 17 00:00:00 2001 Message-ID: <21a5e5cd2a5c8030453eed7ad3e84d244429d403.1733398772.git.jdenemar@redhat.com> From: Michal Privoznik Date: Wed, 6 Nov 2024 12:57:21 +0100 Subject: [PATCH] qemu_domain: Automagically add IOMMU if needed MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If a Q35 domain has huge number of vCPUS (over 255, currently), then it needs IOMMU with Extended Interrupt Mode enabled (see check in qemuValidateDomainVCpuTopology()). Well, we already add some devices and to other tricks when parsing new domain XML. Might as well add IOMMU device if above condition is met. Resolves: https://issues.redhat.com/browse/RHEL-65844 Signed-off-by: Michal Privoznik Reviewed-by: Ján Tomko (cherry picked from commit 844d1036eb734b6c80397a0c69f491645c682313) Resolves: https://issues.redhat.com/browse/RHEL-69725 Signed-off-by: Michal Privoznik --- src/qemu/qemu_domain.c | 20 +++++++++++++++++++ .../intel-iommu-eim-autoadd.xml | 1 - 2 files changed, 20 insertions(+), 1 deletion(-) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 97e7ca5139..16fcdefbf0 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -4176,6 +4176,7 @@ qemuDomainDefAddDefaultDevices(virQEMUDriver *driver, bool addDefaultUSBMouse = false; bool addPanicDevice = false; bool addITCOWatchdog = false; + bool addIOMMU = false; /* add implicit input devices */ if (qemuDomainDefAddImplicitInputDevice(def) < 0) @@ -4198,6 +4199,10 @@ qemuDomainDefAddDefaultDevices(virQEMUDriver *driver, addImplicitSATA = true; addITCOWatchdog = true; + if (virDomainDefGetVcpusMax(def) > QEMU_MAX_VCPUS_WITHOUT_EIM) { + addIOMMU = true; + } + /* Prefer adding a USB3 controller if supported, fall back * to USB2 if there is no USB3 available, and if that's * unavailable don't add anything. @@ -4444,6 +4449,21 @@ qemuDomainDefAddDefaultDevices(virQEMUDriver *driver, } } + if (addIOMMU && !def->iommu && + virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_INTEL_IOMMU) && + virQEMUCapsGet(qemuCaps, QEMU_CAPS_INTEL_IOMMU_INTREMAP) && + virQEMUCapsGet(qemuCaps, QEMU_CAPS_INTEL_IOMMU_EIM)) { + g_autoptr(virDomainIOMMUDef) iommu = NULL; + + iommu = virDomainIOMMUDefNew(); + iommu->model = VIR_DOMAIN_IOMMU_MODEL_INTEL; + /* eim requires intremap. */ + iommu->intremap = VIR_TRISTATE_SWITCH_ON; + iommu->eim = VIR_TRISTATE_SWITCH_ON; + + def->iommu = g_steal_pointer(&iommu); + } + if (qemuDomainDefAddDefaultAudioBackend(driver, def) < 0) return -1; diff --git a/tests/qemuxmlconfdata/intel-iommu-eim-autoadd.xml b/tests/qemuxmlconfdata/intel-iommu-eim-autoadd.xml index 7c294fe2f9..fa3aaf0d44 100644 --- a/tests/qemuxmlconfdata/intel-iommu-eim-autoadd.xml +++ b/tests/qemuxmlconfdata/intel-iommu-eim-autoadd.xml @@ -30,6 +30,5 @@