conf: include x86 microcode version in virsh capabilities

A microcode update can cause the CPUID bits to change; an example
from the past was the update that disabled TSX on several Haswell and
Broadwell machines.

In order to track the x86 microcode version in the QEMU capabilities,
we have to fetch it and store it in the host CPU.  This also makes the
version visible in "virsh capabilities", which is a nice side effect.

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

diff --git a/src/conf/cpu_conf.c b/src/conf/cpu_conf.c
index 603cf0e4711f6b552ee0bc19e013758af9436d65..43a3ab5dcdfa8d7de46b197f7ebaa77e7dd84722 100644 (file)
--- a/src/conf/cpu_conf.c
+++ b/src/conf/cpu_conf.c
@@ -130,6 +130,7 @@ virCPUDefCopyModelFilter(virCPUDefPtr dst,
         VIR_STRDUP(dst->vendor_id, src->vendor_id) < 0 ||
         VIR_ALLOC_N(dst->features, src->nfeatures) < 0)
         return -1;
+    dst->microcodeVersion = src->microcodeVersion;
     dst->nfeatures_max = src->nfeatures;
     dst->nfeatures = 0;
 
@@ -181,6 +182,7 @@ virCPUDefStealModel(virCPUDefPtr dst,
 
     VIR_STEAL_PTR(dst->model, src->model);
     VIR_STEAL_PTR(dst->features, src->features);
+    dst->microcodeVersion = src->microcodeVersion;
     dst->nfeatures_max = src->nfeatures_max;
     src->nfeatures_max = 0;
     dst->nfeatures = src->nfeatures;
@@ -382,6 +384,14 @@ virCPUDefParseXML(xmlXPathContextPtr ctxt,
             goto cleanup;
         }
         VIR_FREE(arch);
+
+        if (virXPathBoolean("boolean(./microcode[1]/@version)", ctxt) > 0 &&
+            virXPathUInt("string(./microcode[1]/@version)", ctxt,
+                         &def->microcodeVersion) < 0) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("invalid microcode version"));
+            goto cleanup;
+        }
     }
 
     if (!(def->model = virXPathString("string(./model[1])", ctxt)) &&
@@ -720,6 +730,10 @@ virCPUDefFormatBuf(virBufferPtr buf,
     if (formatModel && def->vendor)
         virBufferEscapeString(buf, "<vendor>%s</vendor>\n", def->vendor);
 
+    if (def->type == VIR_CPU_TYPE_HOST && def->microcodeVersion)
+        virBufferAsprintf(buf, "<microcode version='%u'/>\n",
+                          def->microcodeVersion);
+
     if (def->sockets && def->cores && def->threads) {
         virBufferAddLit(buf, "<topology");
         virBufferAsprintf(buf, " sockets='%u'", def->sockets);

diff --git a/src/conf/cpu_conf.h b/src/conf/cpu_conf.h
index d1983f5d4f9dd5b4bf4c404d7dd364ecb8e33712..9f2e7ee2649d52d1b9e1a1a317fd75fc08286ce2 100644 (file)
--- a/src/conf/cpu_conf.h
+++ b/src/conf/cpu_conf.h
@@ -133,6 +133,7 @@ struct _virCPUDef {
     char *vendor_id;    /* vendor id returned by CPUID in the guest */
     int fallback;       /* enum virCPUFallback */
     char *vendor;
+    unsigned int microcodeVersion;
     unsigned int sockets;
     unsigned int cores;
     unsigned int threads;

diff --git a/src/cpu/cpu_x86.c b/src/cpu/cpu_x86.c
index fddde64d8cd95f9584980e951082c65c00c20d71..26314a5b3a40bfb617675f82b83fa6a06a95690d 100644 (file)
--- a/src/cpu/cpu_x86.c
+++ b/src/cpu/cpu_x86.c
@@ -33,6 +33,7 @@
 #include "virbuffer.h"
 #include "virendian.h"
 #include "virstring.h"
+#include "virhostcpu.h"
 
 #define VIR_FROM_THIS VIR_FROM_CPU
 
@@ -153,6 +154,8 @@ struct _virCPUx86Map {
 };
 
 static virCPUx86MapPtr cpuMap;
+static unsigned int microcodeVersion;
+
 int virCPUx86DriverOnceInit(void);
 VIR_ONCE_GLOBAL_INIT(virCPUx86Driver);
 
@@ -1409,6 +1412,8 @@ virCPUx86DriverOnceInit(void)
     if (!(cpuMap = virCPUx86LoadMap()))
         return -1;
 
+    microcodeVersion = virHostCPUGetMicrocodeVersion();
+
     return 0;
 }
 
@@ -2424,6 +2429,9 @@ virCPUx86GetHost(virCPUDefPtr cpu,
     virCPUDataPtr cpuData = NULL;
     int ret = -1;
 
+    if (virCPUx86DriverInitialize() < 0)
+        goto cleanup;
+
     if (!(cpuData = virCPUDataNew(archs[0])))
         goto cleanup;
 
@@ -2432,6 +2440,7 @@ virCPUx86GetHost(virCPUDefPtr cpu,
         goto cleanup;
 
     ret = x86DecodeCPUData(cpu, cpuData, models);
+    cpu->microcodeVersion = microcodeVersion;
 
  cleanup:
     virCPUx86DataFree(cpuData);