File 9cd03f79-cpu_map-Drop-pconfig-from-Icelake-Serv... of Package libvirt

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File 9cd03f79-cpu_map-Drop-pconfig-from-Icelake-Server-CPU-model.patch of Package libvirt

commit 9cd03f7957e114892ae54e7ccb3758b6fb440644
Author: Jiri Denemark <jdenemar@redhat.com>
Date:   Fri Oct 18 14:33:00 2019 +0200

cpu_map: Drop pconfig from Icelake-Server CPU model
    
    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>

Index: libvirt-5.1.0/src/cpu_map/x86_Icelake-Server.xml
===================================================================
--- libvirt-5.1.0.orig/src/cpu_map/x86_Icelake-Server.xml
+++ libvirt-5.1.0/src/cpu_map/x86_Icelake-Server.xml
@@ -56,7 +56,6 @@
     <feature name='pat'/>
     <feature name='pcid'/>
     <feature name='pclmuldq'/>
-    <feature name='pconfig'/>
     <feature name='pdpe1gb'/>
     <feature name='pge'/>
     <feature name='pku'/>
Index: libvirt-5.1.0/src/qemu/qemu_domain.c
===================================================================
--- libvirt-5.1.0.orig/src/qemu/qemu_domain.c
+++ libvirt-5.1.0/src/qemu/qemu_domain.c
@@ -7735,6 +7735,26 @@ qemuDomainDefCopy(virQEMUDriverPtr drive
 }
 
 
+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,
@@ -7911,6 +7931,9 @@ qemuDomainDefFormatBufInternal(virQEMUDr
             if (!(def->cpu = virCPUDefCopy(origCPU)))
                 goto cleanup;
         }
+
+        if (qemuDomainMakeCPUMigratable(def->cpu) < 0)
+            goto cleanup;
     }
 
  format:
Index: libvirt-5.1.0/src/qemu/qemu_domain.h
===================================================================
--- libvirt-5.1.0.orig/src/qemu/qemu_domain.h
+++ libvirt-5.1.0/src/qemu/qemu_domain.h
@@ -1109,4 +1109,7 @@ qemuDomainIsUsingNoShutdown(qemuDomainOb
 bool
 qemuDomainDiskIsMissingLocalOptional(virDomainDiskDefPtr disk);
 
+int
+qemuDomainMakeCPUMigratable(virCPUDefPtr cpu);
+
 #endif /* LIBVIRT_QEMU_DOMAIN_H */
Index: libvirt-5.1.0/src/qemu/qemu_migration_cookie.c
===================================================================
--- libvirt-5.1.0.orig/src/qemu/qemu_migration_cookie.c
+++ libvirt-5.1.0/src/qemu/qemu_migration_cookie.c
@@ -544,6 +544,9 @@ qemuMigrationCookieAddCPU(qemuMigrationC
     if (!(mig->cpu = virCPUDefCopy(vm->def->cpu)))
         return -1;
 
+    if (qemuDomainMakeCPUMigratable(mig->cpu) < 0)
+        return -1;
+
     mig->flags |= QEMU_MIGRATION_COOKIE_CPU;
 
     return 0;

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File 9cd03f79-cpu_map-Drop-pconfig-from-Icelake-Server-CPU-model.patch of Package libvirt

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