Re: [libvirt] [PATCH 4/5] conf: include x86 microcode version in virsh capabilities

On Thu, Jan 04, 2018 at 15:58:11 +0100, Jiri Denemark wrote: > From: Paolo Bonzini <pbonzini(a)redhat.com&gt; > > 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(a)redhat.com&gt; > Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com&gt; > --- > src/conf/cpu_conf.c | 14 ++++++++++++++ > src/conf/cpu_conf.h | 1 + > src/cpu/cpu_x86.c | 9 +++++++++ > 3 files changed, 24 insertions(+) [...] > @@ -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) Hmm, looks like you should add a comment to virHostCPUGetMicrocodeVersion stating that 0 is a special value.