On Tue, Aug 11, 2026 at 11:50:45AM -0700, Nathan Chen via Devel wrote:
From: Nathan Chen <nathanc@nvidia.com>
Introduce support for "cmdqv" IOMMU attribute, which enables NVIDIA Tegra241 CMDQV, an extension for ARM SMMUv3. It supports passthroughs of physical SMMU-CMDQ linked command queue from host space to a VM.
Signed-off-by: Nathan Chen <nathanc@nvidia.com> --- docs/formatdomain.rst | 6 ++++++ src/conf/domain_conf.c | 15 +++++++++++++++ src/conf/domain_conf.h | 1 + src/conf/domain_validate.c | 6 +++++- src/conf/schemas/domaincommon.rng | 5 +++++ src/qemu/qemu_command.c | 1 + src/qemu/qemu_validate.c | 1 - 7 files changed, 33 insertions(+), 2 deletions(-)
diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst index 0b346a0952..2d5a34cb35 100644 --- a/docs/formatdomain.rst +++ b/docs/formatdomain.rst @@ -9436,6 +9436,12 @@ Examples: devices. :since:`Since 12.7.0` (QEMU/KVM and ``smmuv3`` model only)
+ ``cmdqv`` + The ``cmdqv`` attribute with possible values ``on`` and ``off`` can be used + to enable NVIDIA Tegra241 CMDQV, an extension for ARM SMMUv3 that supports + passthrough of physical SMMU-CMDQ linked command queue from host space to VM. + :since:`Since 12.7.0` (QEMU/KVM and ``smmuv3`` model only) +
It should mention the default value if accel is enabled like the other attributes.
``ats`` The ``ats`` attribute with possible values ``on`` and ``off`` can be used to enable reporting Address Translation Services capability to diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 9880339e42..42a0faca88 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -14758,6 +14758,10 @@ virDomainIOMMUDefParseXML(virDomainXMLOption *xmlopt, &iommu->accel) < 0) return NULL;
+ if (virXMLPropTristateSwitch(driver, "cmdqv", VIR_XML_PROP_NONE, + &iommu->cmdqv) < 0) + return NULL; + if (virXMLPropTristateSwitch(driver, "ats", VIR_XML_PROP_NONE, &iommu->ats) < 0) return NULL; @@ -16879,6 +16883,7 @@ virDomainIOMMUDefEquals(const virDomainIOMMUDef *a, a->dma_translation != b->dma_translation || a->pci_bus != b->pci_bus || a->accel != b->accel || + a->cmdqv != b->cmdqv || a->ats != b->ats || a->ril != b->ril || a->ssid_size != b->ssid_size || @@ -22773,6 +22778,12 @@ virDomainIOMMUDefCheckABIStability(virDomainIOMMUDef *src, dst->accel, src->accel); return false; } + if (src->cmdqv != dst->cmdqv) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("Target domain IOMMU device cmdqv value '%1$d' does not match source '%2$d'"), + dst->cmdqv, src->cmdqv); + return false; + } if (src->ats != dst->ats) { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, _("Target domain IOMMU device ATS value '%1$d' does not match source '%2$d'"), @@ -29271,6 +29282,10 @@ virDomainIOMMUDefFormat(virBuffer *buf, virBufferAsprintf(&driverAttrBuf, " accel='%s'", virTristateSwitchTypeToString(iommu->accel)); } + if (iommu->cmdqv != VIR_TRISTATE_SWITCH_ABSENT) { + virBufferAsprintf(&driverAttrBuf, " cmdqv='%s'", + virTristateSwitchTypeToString(iommu->cmdqv)); + } if (iommu->ats != VIR_TRISTATE_SWITCH_ABSENT) { virBufferAsprintf(&driverAttrBuf, " ats='%s'", virTristateSwitchTypeToString(iommu->ats)); diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index 2c017738e3..0c79bea015 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -3106,6 +3106,7 @@ struct _virDomainIOMMUDef { virTristateSwitch pt; int granule; /* -1 means 'host', 0 unset, page size in KiB otherwise */ virTristateSwitch accel; + virTristateSwitch cmdqv; virTristateSwitch ats; virTristateSwitch ril; int ssid_size; diff --git a/src/conf/domain_validate.c b/src/conf/domain_validate.c index 710a891904..59b6c5f6d7 100644 --- a/src/conf/domain_validate.c +++ b/src/conf/domain_validate.c @@ -3207,7 +3207,8 @@ virDomainIOMMUDefValidate(const virDomainIOMMUDef *iommu) (iommu->ats != VIR_TRISTATE_SWITCH_ABSENT || iommu->ril != VIR_TRISTATE_SWITCH_ABSENT || iommu->ssid_size >= 0 || - iommu->oas >= 0)) { + iommu->oas >= 0 || + iommu->cmdqv != VIR_TRISTATE_SWITCH_ABSENT)) {
For consistency with the other conditions I would move the check between accel and ats. Otherwise looks good. Pavel