Use configured CPU model if possible

Adds ability to provide a preferred CPU model for CPUID data decoding.
Such model would be considered as the best possible model (if it's
supported by hypervisor) regardless on number of features which have to
be added or removed for describing required CPU.

diff --git a/src/cpu/cpu.c b/src/cpu/cpu.c
index 4a1588d0431d2b113966c72488d3bd4a94427d5b..580b767b9afbca99dd133358aea3719b1f2d7b79 100644 (file)
--- a/src/cpu/cpu.c
+++ b/src/cpu/cpu.c
@@ -127,11 +127,13 @@ int
 cpuDecode(virCPUDefPtr cpu,
           const union cpuData *data,
           const char **models,
-          unsigned int nmodels)
+          unsigned int nmodels,
+          const char *preferred)
 {
     struct cpuArchDriver *driver;
 
-    VIR_DEBUG("cpu=%p, data=%p, nmodels=%u", cpu, data, nmodels);
+    VIR_DEBUG("cpu=%p, data=%p, nmodels=%u, preferred=%s",
+              cpu, data, nmodels, NULLSTR(preferred));
     if (models) {
         unsigned int i;
         for (i = 0; i < nmodels; i++)
@@ -160,7 +162,7 @@ cpuDecode(virCPUDefPtr cpu,
         return -1;
     }
 
-    return driver->decode(cpu, data, models, nmodels);
+    return driver->decode(cpu, data, models, nmodels, preferred);
 }
 
 

diff --git a/src/cpu/cpu.h b/src/cpu/cpu.h
index 1494a7f7d4b041bad993794100b8564492e4d8a5..40f2a7d9cf57577ede87b86be7b5843fd34445b4 100644 (file)
--- a/src/cpu/cpu.h
+++ b/src/cpu/cpu.h
@@ -49,7 +49,8 @@ typedef int
 (*cpuArchDecode)    (virCPUDefPtr cpu,
                      const union cpuData *data,
                      const char **models,
-                     unsigned int nmodels);
+                     unsigned int nmodels,
+                     const char *preferred);
 
 typedef int
 (*cpuArchEncode)    (const virCPUDefPtr cpu,
@@ -108,7 +109,8 @@ extern int
 cpuDecode   (virCPUDefPtr cpu,
              const union cpuData *data,
              const char **models,
-             unsigned int nmodels);
+             unsigned int nmodels,
+             const char *preferred);
 
 extern int
 cpuEncode   (const char *arch,

diff --git a/src/cpu/cpu_x86.c b/src/cpu/cpu_x86.c
index b2ca8c831aed19a01d18085d7efd053f0dac806b..633eb69e555d2b7eafa4accca46ca63bfc23ada9 100644 (file)
--- a/src/cpu/cpu_x86.c
+++ b/src/cpu/cpu_x86.c
@@ -1064,7 +1064,8 @@ static int
 x86Decode(virCPUDefPtr cpu,
           const union cpuData *data,
           const char **models,
-          unsigned int nmodels)
+          unsigned int nmodels,
+          const char *preferred)
 {
     int ret = -1;
     struct x86_map *map;
@@ -1109,6 +1110,12 @@ x86Decode(virCPUDefPtr cpu,
             }
         }
 
+        if (preferred && STREQ(cpuCandidate->model, preferred)) {
+            virCPUDefFree(cpuModel);
+            cpuModel = cpuCandidate;
+            break;
+        }
+
         if (cpuModel == NULL
             || cpuModel->nfeatures > cpuCandidate->nfeatures) {
             virCPUDefFree(cpuModel);
@@ -1356,7 +1363,7 @@ x86Baseline(virCPUDefPtr *cpus,
     if (!(data = x86DataFromModel(base_model)))
         goto no_memory;
 
-    if (x86Decode(cpu, data, models, nmodels) < 0)
+    if (x86Decode(cpu, data, models, nmodels, NULL) < 0)
         goto error;
 
 cleanup:

diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c
index 262eb5a8e265460286f91b8a4e671311eb1374e8..2cbcc4fc05557e2623ece824903aea6aaac99591 100644 (file)
--- a/src/qemu/qemu_conf.c
+++ b/src/qemu/qemu_conf.c
@@ -1029,7 +1029,7 @@ qemudCapsInitCPU(virCapsPtr caps,
     cpu->threads = nodeinfo.threads;
 
     if (!(data = cpuNodeData(arch))
-        || cpuDecode(cpu, data, NULL, 0) < 0)
+        || cpuDecode(cpu, data, NULL, 0, NULL) < 0)
         goto error;
 
     caps->host.cpu = cpu;
@@ -3292,6 +3292,7 @@ qemuBuildCpuArgStr(const struct qemud_driver *driver,
 
     if (ncpus > 0 && host) {
         virCPUCompareResult cmp;
+        const char *preferred;
 
         cmp = cpuGuestData(host, def->cpu, &data);
         switch (cmp) {
@@ -3309,8 +3310,13 @@ qemuBuildCpuArgStr(const struct qemud_driver *driver,
         if (VIR_ALLOC(guest) < 0 || !(guest->arch = strdup(ut->machine)))
             goto no_memory;
 
+        if (def->cpu->match == VIR_CPU_MATCH_MINIMUM)
+            preferred = host->model;
+        else
+            preferred = def->cpu->model;
+
         guest->type = VIR_CPU_TYPE_GUEST;
-        if (cpuDecode(guest, data, cpus, ncpus) < 0)
+        if (cpuDecode(guest, data, cpus, ncpus, preferred) < 0)
             goto cleanup;
 
         virBufferVSprintf(&buf, "%s", guest->model);