From: Pavel Hrdina <phrdina@redhat.com>
In addition to configuring IOMMUFD for each host device add
configuration for the whole VM. This will be extended to add support for
passing FD to libvirt from management applications.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
---
docs/formatdomain.rst | 21 ++++++++++++
src/conf/domain_conf.c | 46 ++++++++++++++++++++++++++
src/conf/domain_conf.h | 2 ++
src/conf/schemas/domaincommon.rng | 12 +++++++
tests/genericxml2xmlindata/iommufd.xml | 18 ++++++++++
tests/genericxml2xmltest.c | 2 ++
6 files changed, 101 insertions(+)
create mode 100644 tests/genericxml2xmlindata/iommufd.xml
diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst
index 9f245293e6..f6096b2b9b 100644
--- a/docs/formatdomain.rst
+++ b/docs/formatdomain.rst
@@ -1382,6 +1382,27 @@ Block I/O Tuning
``write_iops_sec``
Write I/O operations per second limit. :since:`Since 1.2.2`
+Host Device IOMMUFD
+-------------------
+
+::
+
+ <domain>
+ ...
+ <iommufd enabled='yes'/>
+ ...
+ </domain>
+
+``iommufd``
+ :since:`Since 12.2.0 (QEMU/KVM only)` The optional ``iommufd`` element with
+ mandatory ``enabled`` attribute can be used to enable IOMMUFD backned for
+ VFIO host devices. This provides an interface to propagate DMA mappings to
+ kernel for assigned devices. Libvirt will open the /dev/iommu and VFIO device
+ cdev and pass associated file descriptors to QEMU.
+
+ This controls IOMMUFD usage for all host devices, each device can change this
+ global default by setting ``iommufd`` attribute for ``driver`` element.
+
Resource partitioning
---------------------
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 562803ea87..950c755ad9 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -19883,6 +19883,31 @@ virDomainDefControllersParse(virDomainDef *def,
return 0;
}
+static int
+virDomainDefIommufdParse(virDomainDef *def,
+ xmlXPathContextPtr ctxt)
+{
+ int n;
+ g_autofree xmlNodePtr *nodes = NULL;
+
+ if ((n = virXPathNodeSet("./iommufd", ctxt, &nodes)) < 0)
+ return -1;
+
+ if (n > 1) {
+ virReportError(VIR_ERR_XML_ERROR, "%s",
+ _("only one 'iommufd' element is supported"));
+ return -1;
+ }
+
+ if (n == 0)
+ return 0;
+
+ if (virXMLPropTristateBool(nodes[0], "enabled", VIR_XML_PROP_REQUIRED, &def->iommufd) < 0)
+ return -1;
+
+ return 0;
+}
+
static virDomainDef *
virDomainDefParseXML(xmlXPathContextPtr ctxt,
virDomainXMLOption *xmlopt,
@@ -19961,6 +19986,9 @@ virDomainDefParseXML(xmlXPathContextPtr ctxt,
!virDomainIOThreadIDArrayHasPin(def))
def->placement_mode = VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO;
+ if (virDomainDefIommufdParse(def, ctxt) < 0)
+ return NULL;
+
if ((n = virXPathNodeSet("./resource", ctxt, &nodes)) < 0)
return NULL;
@@ -28172,6 +28200,22 @@ virDomainHubDefFormat(virBuffer *buf,
}
+static void
+virDomainDefIommufdFormat(virBuffer *buf,
+ virDomainDef *def)
+{
+ g_auto(virBuffer) attrBuf = VIR_BUFFER_INITIALIZER;
+
+ if (def->iommufd == VIR_TRISTATE_BOOL_ABSENT)
+ return;
+
+ virBufferAsprintf(&attrBuf, " enabled='%s'",
+ virTristateBoolTypeToString(def->iommufd));
+
+ virXMLFormatElement(buf, "iommufd", &attrBuf, NULL);
+}
+
+
static void
virDomainResourceDefFormat(virBuffer *buf,
virDomainResourceDef *def)
@@ -29721,6 +29765,8 @@ virDomainDefFormatInternalSetRootName(virDomainDef *def,
if (virDomainNumatuneFormatXML(buf, def->numa) < 0)
return -1;
+ virDomainDefIommufdFormat(buf, def);
+
virDomainResourceDefFormat(buf, def->resource);
for (i = 0; i < def->nsysinfo; i++) {
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 3b4980394e..f7e2eb6f5e 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -3244,6 +3244,8 @@ struct _virDomainDef {
virTristateSwitch apic_eoi;
virDomainFeatureTCG *tcg_features;
+ virTristateBool iommufd;
+
bool tseg_specified;
unsigned long long tseg_size;
diff --git a/src/conf/schemas/domaincommon.rng b/src/conf/schemas/domaincommon.rng
index 376218118d..0436ec8edc 100644
--- a/src/conf/schemas/domaincommon.rng
+++ b/src/conf/schemas/domaincommon.rng
@@ -1025,6 +1025,10 @@
<ref name="numatune"/>
</optional>
+ <optional>
+ <ref name="iommufd"/>
+ </optional>
+
<optional>
<ref name="respartition"/>
</optional>
@@ -1368,6 +1372,14 @@
</element>
</define>
+ <define name="iommufd">
+ <element name="iommufd">
+ <attribute name="enabled">
+ <ref name="virYesNo"/>
+ </attribute>
+ </element>
+ </define>
+
<define name="respartition">
<element name="resource">
<optional>
diff --git a/tests/genericxml2xmlindata/iommufd.xml b/tests/genericxml2xmlindata/iommufd.xml
new file mode 100644
index 0000000000..63ea839383
--- /dev/null
+++ b/tests/genericxml2xmlindata/iommufd.xml
@@ -0,0 +1,18 @@
+<domain type='kvm'>
+ <name>foo</name>
+ <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+ <memory unit='KiB'>219136</memory>
+ <currentMemory unit='KiB'>219136</currentMemory>
+ <vcpu placement='static'>1</vcpu>
+ <iommufd enabled='yes'/>
+ <os>
+ <type arch='i686' machine='pc'>hvm</type>
+ <boot dev='hd'/>
+ </os>
+ <clock offset='utc'/>
+ <on_poweroff>destroy</on_poweroff>
+ <on_reboot>restart</on_reboot>
+ <on_crash>destroy</on_crash>
+ <devices>
+ </devices>
+</domain>
diff --git a/tests/genericxml2xmltest.c b/tests/genericxml2xmltest.c
index 6757fc44de..6be694cac5 100644
--- a/tests/genericxml2xmltest.c
+++ b/tests/genericxml2xmltest.c
@@ -263,6 +263,8 @@ mymain(void)
DO_TEST("iothreadids");
+ DO_TEST("iommufd");
+
virObjectUnref(caps);
virObjectUnref(xmlopt);
--
2.53.0On Thu, Mar 19, 2026 at 17:36:53 +0100, Pavel Hrdina via Devel wrote: > From: Pavel Hrdina <phrdina@redhat.com> > > In addition to configuring IOMMUFD for each host device add > configuration for the whole VM. This will be extended to add support for > passing FD to libvirt from management applications. > > Signed-off-by: Pavel Hrdina <phrdina@redhat.com> > --- > docs/formatdomain.rst | 21 ++++++++++++ > src/conf/domain_conf.c | 46 ++++++++++++++++++++++++++ > src/conf/domain_conf.h | 2 ++ > src/conf/schemas/domaincommon.rng | 12 +++++++ > tests/genericxml2xmlindata/iommufd.xml | 18 ++++++++++ > tests/genericxml2xmltest.c | 2 ++ > 6 files changed, 101 insertions(+) > create mode 100644 tests/genericxml2xmlindata/iommufd.xml > > diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst > index 9f245293e6..f6096b2b9b 100644 > --- a/docs/formatdomain.rst > +++ b/docs/formatdomain.rst > @@ -1382,6 +1382,27 @@ Block I/O Tuning > ``write_iops_sec`` > Write I/O operations per second limit. :since:`Since 1.2.2` > > +Host Device IOMMUFD > +------------------- > + > +:: > + > + <domain> > + ... > + <iommufd enabled='yes'/> > + ... > + </domain> > + > +``iommufd`` > + :since:`Since 12.2.0 (QEMU/KVM only)` The optional ``iommufd`` element with > + mandatory ``enabled`` attribute can be used to enable IOMMUFD backned for backend > + VFIO host devices. This provides an interface to propagate DMA mappings to > + kernel for assigned devices. Libvirt will open the /dev/iommu and VFIO device > + cdev and pass associated file descriptors to QEMU. > + > + This controls IOMMUFD usage for all host devices, each device can change this > + global default by setting ``iommufd`` attribute for ``driver`` element. > + > Resource partitioning > --------------------- Reviewed-by: Peter Krempa <pkrempa@redhat.com>
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