cpu: Add removedPolicy parameter to virCPUUpdate

virCPUUpdate check the CPU definition for features that were marked as
removed in the specified CPU model and explicitly adds those that were
not mentioned in the definition. So far such features were added with
VIR_CPU_FEATURE_DISABLE policy, but the caller may want to use a
different policy in some situations, which is now possible via the
removedPolicy parameter.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

src/cpu/cpu.c

@@ -560,19 +560,23 @@ virCPUBaseline(virArch arch,
  * @arch: CPU architecture
  * @guest: guest CPU definition to be updated
  * @host: host CPU definition
+ * @removedPolicy: default policy for features removed from the CPU model
  *
  * Updates @guest CPU definition possibly taking @host CPU into account. This
  * is required for maintaining compatibility with older libvirt releases or to
  * support guest CPU definitions specified relatively to host CPU, such as CPUs
  * with VIR_CPU_MODE_CUSTOM and optional features or VIR_CPU_MATCH_MINIMUM, or
- * CPUs with VIR_CPU_MODE_HOST_MODEL.
+ * CPUs with VIR_CPU_MODE_HOST_MODEL. If @guest CPU uses a CPU model which
+ * specifies some features as removed, such features that were not already
+ * present in the @guest CPU definition will be added there with @removedPolicy.
  *
  * Returns 0 on success, -1 on error.
  */
 int
 virCPUUpdate(virArch arch,
              virCPUDef *guest,
-             const virCPUDef *host)
+             const virCPUDef *host,
+             virCPUFeaturePolicy removedPolicy)
 {
     struct cpuArchDriver *driver;
     bool relative;
@@ -622,7 +626,7 @@ virCPUUpdate(virArch arch,
         return -1;
     }
 
-    if (driver->update(guest, host, relative) < 0)
+    if (driver->update(guest, host, relative, removedPolicy) < 0)
         return -1;
 
     VIR_DEBUG("model=%s", NULLSTR(guest->model));

src/cpu/cpu.h

@@ -81,7 +81,8 @@ typedef virCPUDef *
 typedef int
 (*virCPUArchUpdate)(virCPUDef *guest,
                     const virCPUDef *host,
-                    bool relative);
+                    bool relative,
+                    virCPUFeaturePolicy removedPolicy);
 
 typedef int
 (*virCPUArchUpdateLive)(virCPUDef *cpu,
@@ -229,7 +230,8 @@ virCPUBaseline(virArch arch,
 int
 virCPUUpdate(virArch arch,
              virCPUDef *guest,
-             const virCPUDef *host)
+             const virCPUDef *host,
+             virCPUFeaturePolicy removedPolicy)
     ATTRIBUTE_NONNULL(2);
 
 int

src/cpu/cpu_arm.c

@@ -448,7 +448,8 @@ virCPUarmGetMap(void)
 static int
 virCPUarmUpdate(virCPUDef *guest,
                 const virCPUDef *host,
-                bool relative)
+                bool relative,
+                virCPUFeaturePolicy removedPolicy G_GNUC_UNUSED)
 {
     g_autoptr(virCPUDef) updated = virCPUDefCopyWithoutModel(guest);
 

src/cpu/cpu_loongarch.c

@@ -39,7 +39,8 @@ virCPULoongArchCompare(virCPUDef *host G_GNUC_UNUSED,
 static int
 virCPULoongArchUpdate(virCPUDef *guest G_GNUC_UNUSED,
                       const virCPUDef *host G_GNUC_UNUSED,
-                      bool relative G_GNUC_UNUSED)
+                      bool relative G_GNUC_UNUSED,
+                      virCPUFeaturePolicy removedPolicy G_GNUC_UNUSED)
 {
     return 0;
 }

src/cpu/cpu_ppc64.c

@@ -654,7 +654,8 @@ virCPUppc64GetHost(virCPUDef *cpu,
 static int
 virCPUppc64Update(virCPUDef *guest,
                   const virCPUDef *host G_GNUC_UNUSED,
-                  bool relative G_GNUC_UNUSED)
+                  bool relative G_GNUC_UNUSED,
+                  virCPUFeaturePolicy removedPolicy G_GNUC_UNUSED)
 {
     /*
      * - host-passthrough doesn't even get here

src/cpu/cpu_riscv64.c

@@ -49,7 +49,8 @@ virCPURiscv64ValidateFeatures(virCPUDef *cpu G_GNUC_UNUSED)
 static int
 virCPURiscv64Update(virCPUDef *guest,
                     const virCPUDef *host,
-                    bool relative)
+                    bool relative,
+                    virCPUFeaturePolicy removedPolicy G_GNUC_UNUSED)
 {
     g_autoptr(virCPUDef) updated = virCPUDefCopyWithoutModel(guest);
 

src/cpu/cpu_s390.c

@@ -42,7 +42,8 @@ virCPUs390Compare(virCPUDef *host G_GNUC_UNUSED,
 static int
 virCPUs390Update(virCPUDef *guest,
                  const virCPUDef *host,
-                 bool relative)
+                 bool relative,
+                 virCPUFeaturePolicy removedPolicy G_GNUC_UNUSED)
 {
     g_autoptr(virCPUDef) updated = virCPUDefCopyWithoutModel(guest);
     size_t i;

src/cpu/cpu_x86.c

@@ -829,6 +829,22 @@ x86DataAddSignature(virCPUx86Data *data,
 }
 
 
+/*
+ * Adds features removed from the CPU @model to @cpu with a specified @policy
+ * unless the features were already explicitly mentioned in @cpu.
+ */
+static void
+virCPUx86AddRemovedFeatures(virCPUDef *cpu,
+                            virCPUx86Model *model,
+                            virCPUFeaturePolicy policy)
+{
+    char **feat;
+
+    for (feat = model->removedFeatures; feat && *feat; feat++)
+        virCPUDefAddFeatureIfMissing(cpu, *feat, policy);
+}
+
+
 /*
  * Disables features removed from the CPU @model unless they are already
  * mentioned in @cpu to make sure these features will always be explicitly
@@ -838,15 +854,7 @@ static void
 virCPUx86DisableRemovedFeatures(virCPUDef *cpu,
                                 virCPUx86Model *model)
 {
-    char **feat = model->removedFeatures;
+    virCPUx86AddRemovedFeatures(cpu, model, VIR_CPU_FEATURE_DISABLE);
-
-    if (!feat)
-        return;
-
-    while (*feat) {
-        virCPUDefAddFeatureIfMissing(cpu, *feat, VIR_CPU_FEATURE_DISABLE);
-        feat++;
-    }
 }
 
 
@@ -2940,7 +2948,8 @@ x86UpdateHostModel(virCPUDef *guest,
 static int
 virCPUx86Update(virCPUDef *guest,
                 const virCPUDef *host,
-                bool relative)
+                bool relative,
+                virCPUFeaturePolicy removedPolicy)
 {
     g_autoptr(virCPUx86Model) model = NULL;
     virCPUx86Model *guestModel;
@@ -2985,7 +2994,7 @@ virCPUx86Update(virCPUDef *guest,
         return -1;
     }
 
-    virCPUx86DisableRemovedFeatures(guest, guestModel);
+    virCPUx86AddRemovedFeatures(guest, guestModel, removedPolicy);
 
     return 0;
 }

src/qemu/qemu_domain.c

@@ -6763,7 +6763,8 @@ qemuDomainDefFormatBufInternal(virQEMUDriver *driver,
 
         if (virCPUUpdate(def->os.arch, def->cpu,
                          virQEMUCapsGetHostModel(qCaps, def->virtType,
-                                                 VIR_QEMU_CAPS_HOST_CPU_MIGRATABLE)) < 0)
+                                                 VIR_QEMU_CAPS_HOST_CPU_MIGRATABLE),
+                         VIR_CPU_FEATURE_DISABLE) < 0)
             return -1;
     }
 

src/qemu/qemu_process.c

@@ -6281,7 +6281,8 @@ qemuProcessUpdateGuestCPU(virDomainDef *def,
 
         if (virCPUUpdate(def->os.arch, def->cpu,
                          virQEMUCapsGetHostModel(qemuCaps, def->virtType,
-                                                 VIR_QEMU_CAPS_HOST_CPU_MIGRATABLE)) < 0)
+                                                 VIR_QEMU_CAPS_HOST_CPU_MIGRATABLE),
+                         VIR_CPU_FEATURE_DISABLE) < 0)
             return -1;
 
         cpuModels = virQEMUCapsGetCPUModels(qemuCaps, def->virtType, NULL, NULL);
@@ -8914,7 +8915,8 @@ qemuProcessRefreshCPU(virQEMUDriver *driver,
         virCPUDefCopyModelFilter(cpu, hostmig, false, virQEMUCapsCPUFilterFeatures,
                                  &host->arch);
 
-        if (virCPUUpdate(vm->def->os.arch, vm->def->cpu, cpu) < 0)
+        if (virCPUUpdate(vm->def->os.arch, vm->def->cpu, cpu,
+                         VIR_CPU_FEATURE_DISABLE) < 0)
             return -1;
 
         if (qemuProcessUpdateCPU(vm, VIR_ASYNC_JOB_NONE) < 0)

tests/cputest.c

@@ -236,7 +236,7 @@ cpuTestGuestCPU(const void *arg)
         goto cleanup;
     }
 
-    if (virCPUUpdate(host->arch, cpu, host) < 0 ||
+    if (virCPUUpdate(host->arch, cpu, host, VIR_CPU_FEATURE_DISABLE) < 0 ||
         virCPUTranslate(host->arch, cpu, data->models) < 0) {
         ret = -1;
         goto cleanup;
@@ -363,7 +363,7 @@ cpuTestUpdate(const void *arg)
     if (!(migHost = virCPUCopyMigratable(data->arch, host)))
         return -1;
 
-    if (virCPUUpdate(host->arch, cpu, migHost) < 0)
+    if (virCPUUpdate(host->arch, cpu, migHost, VIR_CPU_FEATURE_DISABLE) < 0)
         return -1;
 
     result = g_strdup_printf("%s+%s", data->host, data->name);