From 059091703401ef3029a1ffdbec8de97d5d5a1fd1 Mon Sep 17 00:00:00 2001

Message-Id: <059091703401ef3029a1ffdbec8de97d5d5a1fd1@dist-git>

From: Jiri Denemark <jdenemar@redhat.com>

Date: Fri, 15 Nov 2019 17:52:36 +0100

Subject: [PATCH] cpu_map: Drop pconfig from Icelake-Server CPU model

MIME-Version: 1.0

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The pconfig feature was enabled in QEMU by accident in 3.1.0. All other

newer versions do not support it and it was removed from the

Icelake-Server CPU model in QEMU.

We don't normally change our CPU models even when QEMU does so to avoid

breaking migrations between different versions of libvirt. But we can

safely do so in this specific case. QEMU never supported enabling

pconfig so any domain which was able to start has pconfig disabled.

With a small compatibility hack which explicitly disables pconfig when

CPU model equals Icelake-Server in migratable domain definition, only

one migration scenario stays broken (and there's nothing we can do about

it): from any host to a host with libvirt < 5.10.0 and QEMU > 3.1.0.

https://bugzilla.redhat.com/show_bug.cgi?id=1749672

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

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

(cherry picked from commit 9cd03f7957e114892ae54e7ccb3758b6fb440644)

https://bugzilla.redhat.com/show_bug.cgi?id=1756156

https://bugzilla.redhat.com/show_bug.cgi?id=1721608

Conflicts:

	src/cpu_map/x86_Icelake-Server.xml

            - still monolithic cpu_map.xml downstream

	src/qemu/qemu_domain.h

            - context

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

Message-Id: <6c06dac67da208e6ba8c07798c31405644acfb16.1573836581.git.jdenemar@redhat.com>

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

---

 src/cpu/cpu_map.xml                           |  1 -

 src/qemu/qemu_domain.c                        | 23 +++++++++++++++++++

 src/qemu/qemu_domain.h                        |  3 +++

 src/qemu/qemu_migration_cookie.c              |  3 +++

 .../x86_64-cpuid-Ice-Lake-Server-guest.xml    |  1 -

 .../x86_64-cpuid-Ice-Lake-Server-host.xml     | 11 +--------

 .../x86_64-cpuid-Ice-Lake-Server-json.xml     |  1 -

 7 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/src/cpu/cpu_map.xml b/src/cpu/cpu_map.xml

index acd9dad7dc..7b9f8bb452 100644

--- a/src/cpu/cpu_map.xml

+++ b/src/cpu/cpu_map.xml

@@ -2176,7 +2176,6 @@

       <feature name='pat'/>

       <feature name='pcid'/>

       <feature name='pclmuldq'/>

-      <feature name='pconfig'/>

       <feature name='pdpe1gb'/>

       <feature name='pge'/>

       <feature name='pku'/>

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

index c9899b9e6d..f45d7d427e 100644

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

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

@@ -7348,6 +7348,26 @@ qemuDomainDefCopy(virQEMUDriverPtr driver,

 }

+int

+qemuDomainMakeCPUMigratable(virCPUDefPtr cpu)

+{

+    if (cpu->mode == VIR_CPU_MODE_CUSTOM &&

+        STREQ_NULLABLE(cpu->model, "Icelake-Server")) {

+        /* Originally Icelake-Server CPU model contained pconfig CPU feature.

+         * It was never actually enabled and thus it was removed. To enable

+         * migration to QEMU 3.1.0 (with both new and old libvirt), we

+         * explicitly disable pconfig in migration XML (otherwise old libvirt

+         * would think it was implicitly enabled on the source). New libvirt

+         * will drop it from the XML before starting the domain on new QEMU.

+         */

+        if (virCPUDefUpdateFeature(cpu, "pconfig", VIR_CPU_FEATURE_DISABLE) < 0)

+            return -1;

+    }

+

+    return 0;

+}

+

+

 static int

 qemuDomainDefFormatBufInternal(virQEMUDriverPtr driver,

                                virDomainDefPtr def,

@@ -7522,6 +7542,9 @@ qemuDomainDefFormatBufInternal(virQEMUDriverPtr driver,

             if (!(def->cpu = virCPUDefCopy(origCPU)))

                 goto cleanup;

         }

+

+        if (qemuDomainMakeCPUMigratable(def->cpu) < 0)

+            goto cleanup;

     }

  format:

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

index 8463a8b706..a29a678771 100644

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

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

@@ -1072,4 +1072,7 @@ char * qemuDomainGetManagedPRSocketPath(qemuDomainObjPrivatePtr priv);

 virDomainEventResumedDetailType

 qemuDomainRunningReasonToResumeEvent(virDomainRunningReason reason);

+int

+qemuDomainMakeCPUMigratable(virCPUDefPtr cpu);

+

 #endif /* __QEMU_DOMAIN_H__ */

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

index 60df449d53..c270896944 100644

--- a/src/qemu/qemu_migration_cookie.c

+++ b/src/qemu/qemu_migration_cookie.c

@@ -543,6 +543,9 @@ qemuMigrationCookieAddCPU(qemuMigrationCookiePtr mig,

     if (!(mig->cpu = virCPUDefCopy(vm->def->cpu)))

         return -1;

+    if (qemuDomainMakeCPUMigratable(mig->cpu) < 0)

+        return -1;

+

     mig->flags |= QEMU_MIGRATION_COOKIE_CPU;

     return 0;

diff --git a/tests/cputestdata/x86_64-cpuid-Ice-Lake-Server-guest.xml b/tests/cputestdata/x86_64-cpuid-Ice-Lake-Server-guest.xml

index 6ca2099b33..4676f3aa7d 100644

--- a/tests/cputestdata/x86_64-cpuid-Ice-Lake-Server-guest.xml

+++ b/tests/cputestdata/x86_64-cpuid-Ice-Lake-Server-guest.xml

@@ -32,5 +32,4 @@

   <feature policy='require' name='rdctl-no'/>

   <feature policy='require' name='ibrs-all'/>

   <feature policy='require' name='skip-l1dfl-vmentry'/>

-  <feature policy='disable' name='pconfig'/>

 </cpu>

diff --git a/tests/cputestdata/x86_64-cpuid-Ice-Lake-Server-host.xml b/tests/cputestdata/x86_64-cpuid-Ice-Lake-Server-host.xml

index 31af20bc85..35b9e39629 100644

--- a/tests/cputestdata/x86_64-cpuid-Ice-Lake-Server-host.xml

+++ b/tests/cputestdata/x86_64-cpuid-Ice-Lake-Server-host.xml

@@ -1,6 +1,6 @@

 <cpu>

   <arch>x86_64</arch>

-  <model>Icelake-Client</model>

+  <model>Icelake-Server</model>

   <vendor>Intel</vendor>

   <feature name='ds'/>

   <feature name='acpi'/>

@@ -21,23 +21,14 @@

   <feature name='osxsave'/>

   <feature name='tsc_adjust'/>

   <feature name='cmt'/>

-  <feature name='avx512f'/>

-  <feature name='avx512dq'/>

   <feature name='avx512ifma'/>

-  <feature name='clflushopt'/>

-  <feature name='clwb'/>

-  <feature name='avx512cd'/>

   <feature name='sha-ni'/>

-  <feature name='avx512bw'/>

-  <feature name='avx512vl'/>

   <feature name='ospke'/>

-  <feature name='la57'/>

   <feature name='stibp'/>

   <feature name='arch-capabilities'/>

   <feature name='xsaves'/>

   <feature name='mbm_total'/>

   <feature name='mbm_local'/>

-  <feature name='pdpe1gb'/>

   <feature name='invtsc'/>

   <feature name='rdctl-no'/>

   <feature name='ibrs-all'/>

diff --git a/tests/cputestdata/x86_64-cpuid-Ice-Lake-Server-json.xml b/tests/cputestdata/x86_64-cpuid-Ice-Lake-Server-json.xml

index b043db58d7..ada11d2608 100644

--- a/tests/cputestdata/x86_64-cpuid-Ice-Lake-Server-json.xml

+++ b/tests/cputestdata/x86_64-cpuid-Ice-Lake-Server-json.xml

@@ -13,5 +13,4 @@

   <feature policy='require' name='ibrs-all'/>

   <feature policy='require' name='skip-l1dfl-vmentry'/>

   <feature policy='disable' name='intel-pt'/>

-  <feature policy='disable' name='pconfig'/>

 </cpu>

-- 

2.24.0