[PATCH v1 1/7] qemu: Add capability for CFPC pSeries feature

[Daniel Henrique Barboza]

CFPC (Cache Flush on Privilege Change) is one of the capabilities
added to QEMU to mitigate Spectre vulnerabilities in Power chips.
It was implemented in QEMU 2.12 by commit 6898aed77f46.

This capability is still used today due to differences in how
the host setup (hardware and firmware/kernel) can handle this
mitigation. Its default value also varies with the pseries machine
version of the time. There's also certain OSes, like AIX, that
might not support the default value of the pseries machine the
guest uses.

Exposing this in the Libvirt XML as a feature will allow users to tune
CFPC values in a cleaner way, instead of hacking parameters in
<qemu:commandline> elements.

Signed-off-by: Daniel Henrique Barboza <danielhb413 at gmail.com>
---
 src/qemu/qemu_capabilities.c                     | 2 ++
 src/qemu/qemu_capabilities.h                     | 1 +
 tests/qemucapabilitiesdata/caps_2.12.0.ppc64.xml | 1 +
 tests/qemucapabilitiesdata/caps_3.0.0.ppc64.xml  | 1 +
 tests/qemucapabilitiesdata/caps_3.1.0.ppc64.xml  | 1 +
 tests/qemucapabilitiesdata/caps_4.0.0.ppc64.xml  | 1 +
 tests/qemucapabilitiesdata/caps_4.2.0.ppc64.xml  | 1 +
 tests/qemucapabilitiesdata/caps_5.0.0.ppc64.xml  | 1 +
 8 files changed, 9 insertions(+)

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index fe311048d4..4a262dc71d 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -573,6 +573,7 @@ VIR_ENUM_IMPL(virQEMUCaps,
               "fsdev.multidevs",
               "virtio.packed",
               "pcie-root-port.hotplug",
+              "machine.pseries.cap-cfpc",
     );
 
 
@@ -1615,6 +1616,7 @@ static struct virQEMUCapsStringFlags virQEMUCapsMachinePropsPSeries[] = {
     { "cap-htm", QEMU_CAPS_MACHINE_PSERIES_CAP_HTM },
     { "cap-nested-hv", QEMU_CAPS_MACHINE_PSERIES_CAP_NESTED_HV },
     { "cap-ccf-assist", QEMU_CAPS_MACHINE_PSERIES_CAP_CCF_ASSIST },
+    { "cap-cfpc", QEMU_CAPS_MACHINE_PSERIES_CAP_CFPC },
 };
 
 static struct virQEMUCapsStringFlags virQEMUCapsMachinePropsVirt[] = {
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index 1681fc79a8..81d67d2efe 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -554,6 +554,7 @@ typedef enum { /* virQEMUCapsFlags grouping marker for syntax-check */
     QEMU_CAPS_FSDEV_MULTIDEVS, /* fsdev.multidevs */
     QEMU_CAPS_VIRTIO_PACKED_QUEUES, /* virtio.packed */
     QEMU_CAPS_PCIE_ROOT_PORT_HOTPLUG, /* pcie-root-port.hotplug */
+    QEMU_CAPS_MACHINE_PSERIES_CAP_CFPC, /* -machine pseries.cap-cfpc */
 
     QEMU_CAPS_LAST /* this must always be the last item */
 } virQEMUCapsFlags;
diff --git a/tests/qemucapabilitiesdata/caps_2.12.0.ppc64.xml b/tests/qemucapabilitiesdata/caps_2.12.0.ppc64.xml
index 38a3103c4a..cdd4f26993 100644
--- a/tests/qemucapabilitiesdata/caps_2.12.0.ppc64.xml
+++ b/tests/qemucapabilitiesdata/caps_2.12.0.ppc64.xml
@@ -154,6 +154,7 @@
   <flag name='memory-backend-file.align'/>
   <flag name='drive-nvme'/>
   <flag name='i8042'/>
+  <flag name='machine.pseries.cap-cfpc'/>
   <version>2011090</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>42900289</microcodeVersion>
diff --git a/tests/qemucapabilitiesdata/caps_3.0.0.ppc64.xml b/tests/qemucapabilitiesdata/caps_3.0.0.ppc64.xml
index 9a0b9c05c2..84e9ad2dcc 100644
--- a/tests/qemucapabilitiesdata/caps_3.0.0.ppc64.xml
+++ b/tests/qemucapabilitiesdata/caps_3.0.0.ppc64.xml
@@ -156,6 +156,7 @@
   <flag name='ramfb'/>
   <flag name='drive-nvme'/>
   <flag name='i8042'/>
+  <flag name='machine.pseries.cap-cfpc'/>
   <version>2012050</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>42900239</microcodeVersion>
diff --git a/tests/qemucapabilitiesdata/caps_3.1.0.ppc64.xml b/tests/qemucapabilitiesdata/caps_3.1.0.ppc64.xml
index 6801023208..3d70a67dab 100644
--- a/tests/qemucapabilitiesdata/caps_3.1.0.ppc64.xml
+++ b/tests/qemucapabilitiesdata/caps_3.1.0.ppc64.xml
@@ -161,6 +161,7 @@
   <flag name='drive-nvme'/>
   <flag name='i8042'/>
   <flag name='storage.werror'/>
+  <flag name='machine.pseries.cap-cfpc'/>
   <version>3000091</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>42900240</microcodeVersion>
diff --git a/tests/qemucapabilitiesdata/caps_4.0.0.ppc64.xml b/tests/qemucapabilitiesdata/caps_4.0.0.ppc64.xml
index f7e69fcc97..ce2d470cb2 100644
--- a/tests/qemucapabilitiesdata/caps_4.0.0.ppc64.xml
+++ b/tests/qemucapabilitiesdata/caps_4.0.0.ppc64.xml
@@ -175,6 +175,7 @@
   <flag name='drive-nvme'/>
   <flag name='i8042'/>
   <flag name='storage.werror'/>
+  <flag name='machine.pseries.cap-cfpc'/>
   <version>4000000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>42900240</microcodeVersion>
diff --git a/tests/qemucapabilitiesdata/caps_4.2.0.ppc64.xml b/tests/qemucapabilitiesdata/caps_4.2.0.ppc64.xml
index 99ec98e8cd..a813776660 100644
--- a/tests/qemucapabilitiesdata/caps_4.2.0.ppc64.xml
+++ b/tests/qemucapabilitiesdata/caps_4.2.0.ppc64.xml
@@ -180,6 +180,7 @@
   <flag name='i8042'/>
   <flag name='rng-builtin'/>
   <flag name='storage.werror'/>
+  <flag name='machine.pseries.cap-cfpc'/>
   <version>4001050</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>42900242</microcodeVersion>
diff --git a/tests/qemucapabilitiesdata/caps_5.0.0.ppc64.xml b/tests/qemucapabilitiesdata/caps_5.0.0.ppc64.xml
index b08916132a..c33786b0bf 100644
--- a/tests/qemucapabilitiesdata/caps_5.0.0.ppc64.xml
+++ b/tests/qemucapabilitiesdata/caps_5.0.0.ppc64.xml
@@ -192,6 +192,7 @@
   <flag name='storage.werror'/>
   <flag name='fsdev.multidevs'/>
   <flag name='virtio.packed'/>
+  <flag name='machine.pseries.cap-cfpc'/>
   <version>4002050</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>42900241</microcodeVersion>
-- 
2.25.2