util: introduce virHostCPUGetMicrocodeVersion

This new API reads host's CPU microcode version from /proc/cpuinfo.

Unfortunately, there is no other way of reading microcode version which
would be usable from both system and session daemon.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
This commit is contained in:
Paolo Bonzini 2017-12-12 16:23:41 +01:00 committed by Jiri Denemark
parent 40fc85e796
commit 04502fd54f
3 changed files with 50 additions and 0 deletions

View File

@ -1869,6 +1869,7 @@ virHostCPUGetCount;
virHostCPUGetInfo;
virHostCPUGetKVMMaxVCPUs;
virHostCPUGetMap;
virHostCPUGetMicrocodeVersion;
virHostCPUGetOnline;
virHostCPUGetOnlineBitmap;
virHostCPUGetPresentBitmap;

View File

@ -1206,3 +1206,50 @@ virHostCPUGetKVMMaxVCPUs(void)
return -1;
}
#endif /* HAVE_LINUX_KVM_H */
#ifdef __linux__
/*
* Returns 0 if the microcode version is unknown or cannot be read for
* some reason.
*/
unsigned int
virHostCPUGetMicrocodeVersion(void)
{
char *outbuf = NULL;
char *cur;
unsigned int version = 0;
if (virFileReadHeaderQuiet(CPUINFO_PATH, 4096, &outbuf) < 0) {
char ebuf[1024];
VIR_DEBUG("Failed to read microcode version from %s: %s",
CPUINFO_PATH, virStrerror(errno, ebuf, sizeof(ebuf)));
return 0;
}
/* Account for format 'microcode : XXXX'*/
if (!(cur = strstr(outbuf, "microcode")) ||
!(cur = strchr(cur, ':')))
goto cleanup;
cur++;
/* Linux places the microcode revision in a 32-bit integer, so
* ui is fine for us too. */
if (virStrToLong_ui(cur, &cur, 0, &version) < 0)
goto cleanup;
cleanup:
VIR_FREE(outbuf);
return version;
}
#else
unsigned int
virHostCPUGetMicrocodeVersion(void)
{
return 0;
}
#endif /* __linux__ */

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@ -66,4 +66,6 @@ virBitmapPtr virHostCPUGetSiblingsList(unsigned int cpu);
int virHostCPUGetOnline(unsigned int cpu, bool *online);
unsigned int virHostCPUGetMicrocodeVersion(void);
#endif /* __VIR_HOSTCPU_H__*/