On Mon, Jan 26, 2026 at 10:50:19 +0100, Michal Privoznik via Devel wrote:
> From: Michal Privoznik <[email protected]>
>
> In PCI assignment scenario the virtio-iommu needs to know the
> guest page size also known as granule. Expose it as an attribute
> to the <driver/> element of a virtio-iommu.
>
> This is possibly interesting only for aarch64 since it supports
> virtio-iommu and also supports running guests with different page
> size than the host.
>
> Signed-off-by: Michal Privoznik <[email protected]>
> ---
> docs/formatdomain.rst | 38 ++++++++-
> src/conf/domain_conf.c | 77 ++++++++++++++++++-
> src/conf/domain_conf.h | 1 +
> src/conf/domain_validate.c | 9 ++-
> src/conf/schemas/domaincommon.rng | 22 ++++++
> src/qemu/qemu_validate.c | 11 +++
> .../virtio-iommu-aarch64.aarch64-latest.xml | 4 +-
> .../qemuxmlconfdata/virtio-iommu-aarch64.xml | 4 +-
> .../virtio-iommu-x86_64.x86_64-latest.xml | 3 +
> tests/qemuxmlconfdata/virtio-iommu-x86_64.xml | 6 +-
> 10 files changed, 166 insertions(+), 9 deletions(-)
[..]
> @@ -14522,6 +14539,41 @@ virDomainIOMMUDefParseXML(virDomainXMLOption *xmlopt,
> if (virXMLPropInt(driver, "pciBus", 10, VIR_XML_PROP_NONE,
> &iommu->pci_bus, -1) < 0)
> return NULL;
> +
> + if ((granule = virXPathNode("./driver/granule", ctxt))) {
> + g_autofree char *mode = virXMLPropString(granule, "mode");
> + unsigned long long size;
> + int rc;
> +
> + rc = virDomainParseMemory("./driver/granule/@size",
> + "./driver/granule/@unit",
> + ctxt, &size, false, false);
> + if (rc < 0) {
> + return NULL;
> + } else if (rc > 0) {
> + if (mode) {
> + virReportError(VIR_ERR_XML_ERROR, "%s",
> + _("'mode' and 'size' can't be specified
> at the same time for 'granule'"));
> + return NULL;
> + }
> +
> + if (size != (int) size) {
Consider using VIR_ASSIGN_IS_OVERFLOW
> + virReportError(VIR_ERR_OVERFLOW, "%s", _("size value too
> large"));
> + return NULL;
> + }
> +
> + iommu->granule = (int)size;
> + } else {
> + if (STREQ_NULLABLE(mode, "host")) {
> + iommu->granule = -1;
> + } else if (mode) {
> + virReportError(VIR_ERR_XML_ERROR,
> + _("Invalid value for attribute '%1$s' in
> element '%2$s': '%3$s'."),
> + "mode", "granule", mode);
> + return NULL;
> + }
> + }
> + }
> }
>
> if (virDomainDeviceInfoParseXML(xmlopt, node, ctxt,
Reviewed-by: Peter Krempa <[email protected]>
