[libvirt] [PATCHv2 6/6] qemu: format caching-mode on iommu command line

[Ján Tomko]

Format the caching-mode option for the intel-iommu device,
based on its <driver caching> attribute value.

https://bugzilla.redhat.com/show_bug.cgi?id=1427005
---
 src/qemu/qemu_capabilities.c                          |  2 ++
 src/qemu/qemu_capabilities.h                          |  1 +
 src/qemu/qemu_command.c                               | 11 +++++++++++
 tests/qemucapabilitiesdata/caps_2.9.0.x86_64.xml      |  1 +
 .../qemuxml2argv-intel-iommu-caching.args             | 19 +++++++++++++++++++
 tests/qemuxml2argvtest.c                              |  5 +++++
 6 files changed, 39 insertions(+)
 create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-intel-iommu-caching.args

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 0c7d7b1..88ea306 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -366,6 +366,7 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST,
               "query-named-block-nodes",
               "kernel-irqchip",
               "intel-iommu-intremap",
+              "intel-iommu-caching",
     );
 
 
@@ -1718,6 +1719,7 @@ static struct virQEMUCapsStringFlags virQEMUCapsObjectPropsUSBNECXHCI[] = {
 
 static struct virQEMUCapsStringFlags virQEMUCapsObjectPropsIntelIOMMU[] = {
     { "intremap", QEMU_CAPS_INTEL_IOMMU_INTREMAP },
+    { "caching-mode", QEMU_CAPS_INTEL_IOMMU_CACHING },
 };
 
 /* see documentation for virQEMUCapsQMPSchemaGetByPath for the query format */
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index 4d19691..2409377 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -403,6 +403,7 @@ typedef enum {
     QEMU_CAPS_QUERY_NAMED_BLOCK_NODES, /* qmp query-named-block-nodes */
     QEMU_CAPS_MACHINE_KERNEL_IRQCHIP, /* -machine kernel_irqchip */
     QEMU_CAPS_INTEL_IOMMU_INTREMAP, /* intel-iommu.intremap */
+    QEMU_CAPS_INTEL_IOMMU_CACHING, /* intel-iommu.caching-mode */
 
     QEMU_CAPS_LAST /* this must always be the last item */
 } virQEMUCapsFlags;
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 1f97bd0..55800c7 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -6690,6 +6690,13 @@ qemuBuildIOMMUCommandLine(virCommandPtr cmd,
                              "with this QEMU binary"));
             return -1;
         }
+        if (iommu->caching != VIR_TRISTATE_SWITCH_ABSENT &&
+            !virQEMUCapsGet(qemuCaps, QEMU_CAPS_INTEL_IOMMU_CACHING))  {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("iommu: caching mode is not supported "
+                             "with this QEMU binary"));
+            return -1;
+        }
         break;
     case VIR_DOMAIN_IOMMU_MODEL_LAST:
         break;
@@ -6719,6 +6726,10 @@ qemuBuildIOMMUCommandLine(virCommandPtr cmd,
             virBufferAsprintf(&opts, ",intremap=%s",
                               virTristateSwitchTypeToString(iommu->intremap));
         }
+        if (iommu->caching != VIR_TRISTATE_SWITCH_ABSENT) {
+            virBufferAsprintf(&opts, ",caching-mode=%s",
+                              virTristateSwitchTypeToString(iommu->caching));
+        }
     case VIR_DOMAIN_IOMMU_MODEL_LAST:
         break;
     }
diff --git a/tests/qemucapabilitiesdata/caps_2.9.0.x86_64.xml b/tests/qemucapabilitiesdata/caps_2.9.0.x86_64.xml
index 799c52a..0193492 100644
--- a/tests/qemucapabilitiesdata/caps_2.9.0.x86_64.xml
+++ b/tests/qemucapabilitiesdata/caps_2.9.0.x86_64.xml
@@ -209,6 +209,7 @@
   <flag name='query-named-block-nodes'/>
   <flag name='kernel-irqchip'/>
   <flag name='intel-iommu-intremap'/>
+  <flag name='intel-iommu-caching'/>
   <version>2008090</version>
   <kvmVersion>0</kvmVersion>
   <package> (v2.9.0-rc0-142-g940a8ce)</package>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-intel-iommu-caching.args b/tests/qemuxml2argvdata/qemuxml2argv-intel-iommu-caching.args
new file mode 100644
index 0000000..dee63f4
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-intel-iommu-caching.args
@@ -0,0 +1,19 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/home/test \
+USER=test \
+LOGNAME=test \
+QEMU_AUDIO_DRV=none \
+/usr/bin/qemu-system-x86_64 \
+-name QEMUGuest1 \
+-S \
+-machine q35,accel=tcg \
+-m 214 \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-nographic \
+-nodefaults \
+-monitor unix:/tmp/lib/domain--1-QEMUGuest1/monitor.sock,server,nowait \
+-no-acpi \
+-boot c \
+-device intel-iommu,intremap=on,caching-mode=on
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 29cd8b5..9950f7f 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -2497,6 +2497,11 @@ mymain(void)
             QEMU_CAPS_MACHINE_KERNEL_IRQCHIP,
             QEMU_CAPS_INTEL_IOMMU_INTREMAP,
             QEMU_CAPS_DEVICE_INTEL_IOMMU);
+    DO_TEST("intel-iommu-caching",
+            QEMU_CAPS_MACHINE_OPT,
+            QEMU_CAPS_DEVICE_INTEL_IOMMU,
+            QEMU_CAPS_INTEL_IOMMU_INTREMAP,
+            QEMU_CAPS_INTEL_IOMMU_CACHING);
 
     DO_TEST("cpu-hotplug-startup", QEMU_CAPS_QUERY_HOTPLUGGABLE_CPUS);
 
-- 
2.10.2