From f4038af76b0b8b4f8fb7b4ea7e957a6eb0614ea5 Mon Sep 17 00:00:00 2001

Message-Id: <f4038af76b0b8b4f8fb7b4ea7e957a6eb0614ea5@dist-git>

From: Jiri Denemark <jdenemar@redhat.com>

Date: Tue, 16 May 2017 13:26:54 +0200

Subject: [PATCH] qemu: Remember CPU def from domain start

When starting a domain we update the guest CPU definition to match what

QEMU actually provided (since it is allowed to add or removed some

features unless check='full' is specified). Let's store the original CPU

in domain private data so that we can use it to provide a backward

compatible domain XML.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>

(cherry picked from commit ea6d89831198ae1854dca15b2bcf081df2d866a2)

https://bugzilla.redhat.com/show_bug.cgi?id=1441662

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

---

 src/libvirt_private.syms |  2 ++

 src/qemu/qemu_domain.c   |  7 +++++++

 src/qemu/qemu_domain.h   |  4 ++++

 src/qemu/qemu_process.c  | 13 +++++++++++--

 4 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms

index 88e3f4b8ac..8c088316c4 100644

--- a/src/libvirt_private.syms

+++ b/src/libvirt_private.syms

@@ -76,9 +76,11 @@ virCPUDefCopyModelFilter;

 virCPUDefCopyWithoutModel;

 virCPUDefFormat;

 virCPUDefFormatBuf;

+virCPUDefFormatBufFull;

 virCPUDefFree;

 virCPUDefFreeFeatures;

 virCPUDefFreeModel;

+virCPUDefIsEqual;

 virCPUDefParseXML;

 virCPUDefStealModel;

 virCPUDefUpdateFeature;

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c

index 63fcde8024..89fd9f9abc 100644

--- a/src/qemu/qemu_domain.c

+++ b/src/qemu/qemu_domain.c

@@ -1705,6 +1705,8 @@ qemuDomainObjPrivateFree(void *data)

     VIR_FREE(priv->migTLSAlias);

     qemuDomainMasterKeyFree(priv);

+    virCPUDefFree(priv->origCPU);

+

     VIR_FREE(priv);

 }

@@ -1860,6 +1862,8 @@ qemuDomainObjPrivateXMLFormat(virBufferPtr buf,

     virBufferEscapeString(buf, "<channelTargetDir path='%s'/>\n",

                           priv->channelTargetDir);

+    virCPUDefFormatBufFull(buf, priv->origCPU, NULL, false);

+

     return 0;

 }

@@ -2128,6 +2132,9 @@ qemuDomainObjPrivateXMLParse(xmlXPathContextPtr ctxt,

     if (qemuDomainSetPrivatePathsOld(driver, vm) < 0)

         goto error;

+    if (virCPUDefParseXML(ctxt, "./cpu", VIR_CPU_TYPE_GUEST, &priv->origCPU) < 0)

+        goto error;

+

     return 0;

  error:

diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h

index 80d80e4554..0c5dad60e1 100644

--- a/src/qemu/qemu_domain.h

+++ b/src/qemu/qemu_domain.h

@@ -293,6 +293,10 @@ struct _qemuDomainObjPrivate {

     /* Used when fetching/storing the current 'tls-creds' migration setting */

     /* (not to be saved in our private XML). */

     char *migTLSAlias;

+

+    /* CPU def used to start the domain when it differs from the one actually

+     * provided by QEMU. */

+    virCPUDefPtr origCPU;

 };

 # define QEMU_DOMAIN_PRIVATE(vm)	\

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c

index 7e51ca819a..79f780ed46 100644

--- a/src/qemu/qemu_process.c

+++ b/src/qemu/qemu_process.c

@@ -3915,6 +3915,7 @@ qemuProcessUpdateLiveGuestCPU(virQEMUDriverPtr driver,

     qemuDomainObjPrivatePtr priv = vm->privateData;

     int rc;

     int ret = -1;

+    virCPUDefPtr orig = NULL;

     if (ARCH_IS_X86(def->os.arch)) {

         if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)

@@ -3945,10 +3946,17 @@ qemuProcessUpdateLiveGuestCPU(virQEMUDriverPtr driver,

         if (qemuProcessVerifyCPUFeatures(def, cpu) < 0)

             goto cleanup;

-        if ((rc = virCPUUpdateLive(def->os.arch, def->cpu, cpu, disabled)) < 0)

+        if (!(orig = virCPUDefCopy(def->cpu)))

             goto cleanup;

-        else if (rc == 0)

+

+        if ((rc = virCPUUpdateLive(def->os.arch, def->cpu, cpu, disabled)) < 0) {

+            goto cleanup;

+        } else if (rc == 0) {

+            if (!virCPUDefIsEqual(def->cpu, orig, false))

+                VIR_STEAL_PTR(priv->origCPU, orig);

+

             def->cpu->check = VIR_CPU_CHECK_FULL;

+        }

     }

     ret = 0;

@@ -3956,6 +3964,7 @@ qemuProcessUpdateLiveGuestCPU(virQEMUDriverPtr driver,

  cleanup:

     virCPUDataFree(cpu);

     virCPUDataFree(disabled);

+    virCPUDefFree(orig);

     return ret;

 }

-- 

2.13.1