The following makes 'x86info -r' dump hypervisor leaf cpu ids
(for kvm this is signature+features) when running in a vm.
On the guest we see the signature and the features:
eax in: 0x40000000, eax = 00000000 ebx = 4b4d564b ecx = 564b4d56 edx = 0000004d
eax in: 0x40000001, eax = 0100007b ebx = 00000000 ecx = 00000000 edx = 00000000
Hypervisor flag is checked to avoid output changes when not
running on a VM.
Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
Changes from v1:
Make work on non KVM hypervisors (only KVM was tested).
Avi Kivity said kvm will in the future report
max HV leaf in eax. For now it reports eax = 0
so add a work around for that.
---
diff --git a/identify.c b/identify.c
index 33f35de..a4a3763 100644
--- a/identify.c
+++ b/identify.c
@@ -9,8 +9,8 @@
void get_cpu_info_basics(struct cpudata *cpu)
{
- unsigned int maxi, maxei, vendor, address_bits;
- unsigned int eax;
+ unsigned int maxi, maxei, maxhv, vendor, address_bits;
+ unsigned int eax, ebx, ecx;
cpuid(cpu->number, 0, &maxi, &vendor, NULL, NULL);
maxi &= 0xffff; /* The high-order word is non-zero on some Cyrix CPUs */
@@ -19,7 +19,7 @@ void get_cpu_info_basics(struct cpudata *cpu)
return;
/* Everything that supports cpuid supports these. */
- cpuid(cpu->number, 1, &eax, NULL, NULL, NULL);
+ cpuid(cpu->number, 1, &eax, &ebx, &ecx, NULL);
cpu->stepping = eax & 0xf;
cpu->model = (eax >> 4) & 0xf;
cpu->family = (eax >> 8) & 0xf;
@@ -29,6 +29,19 @@ void get_cpu_info_basics(struct cpudata *cpu)
cpuid(cpu->number, 0xC0000000, &maxei, NULL, NULL, NULL);
cpu->maxei2 = maxei;
+ if (ecx & 0x80000000) {
+ cpuid(cpu->number, 0x40000000, &maxhv, NULL, NULL, NULL);
+ /*
+ * KVM up to linux 3.4 reports 0 as the max hypervisor leaf,
+ * where it really means 0x40000001.
+ * Most (all?) hypervisors have at least one CPUID besides
+ * the vendor ID so assume that.
+ */
+ cpu->maxhv = maxhv ? maxhv : 0x40000001;
+ } else {
+ /* Suppress hypervisor cpuid unless running on a hypervisor */
+ cpu->maxhv = 0;
+ }
cpuid(cpu->number, 0x80000008,&address_bits, NULL, NULL, NULL);
cpu->phyaddr_bits = address_bits & 0xFF;
diff --git a/x86info.c b/x86info.c
index 22c4734..80cae36 100644
--- a/x86info.c
+++ b/x86info.c
@@ -44,6 +44,10 @@ static void display_detailed_info(struct cpudata *cpu)
if (cpu->maxei2 >=0xC0000000)
dump_raw_cpuid(cpu->number, 0xC0000000, cpu->maxei2);
+
+ if (cpu->maxhv >= 0x40000000)
+ dump_raw_cpuid(cpu->number, 0x40000000, cpu->maxhv);
+
}
if (show_cacheinfo) {
diff --git a/x86info.h b/x86info.h
index 7d2a455..c4f5d81 100644
--- a/x86info.h
+++ b/x86info.h
@@ -84,7 +84,7 @@ struct cpudata {
unsigned int cachesize_trace;
unsigned int phyaddr_bits;
unsigned int viraddr_bits;
- unsigned int cpuid_level, maxei, maxei2;
+ unsigned int cpuid_level, maxei, maxei2, maxhv;
char name[CPU_NAME_LEN];
enum connector connector;
unsigned int flags_ecx;
On Mon, Apr 30, 2012 at 05:38:35PM +0300, Michael S. Tsirkin wrote:> The following makes 'x86info -r' dump hypervisor leaf cpu ids > (for kvm this is signature+features) when running in a vm. > > On the guest we see the signature and the features: > eax in: 0x40000000, eax = 00000000 ebx = 4b4d564b ecx = 564b4d56 edx = 0000004d > eax in: 0x40000001, eax = 0100007b ebx = 00000000 ecx = 00000000 edx = 00000000 > > Hypervisor flag is checked to avoid output changes when not > running on a VM. > > Signed-off-by: Michael S. Tsirkin <mst at redhat.com> >Looks good to me.> Changes from v1: > Make work on non KVM hypervisors (only KVM was tested). > Avi Kivity said kvm will in the future report > max HV leaf in eax. For now it reports eax = 0 > so add a work around for that. > > --- > > diff --git a/identify.c b/identify.c > index 33f35de..a4a3763 100644 > --- a/identify.c > +++ b/identify.c > @@ -9,8 +9,8 @@ > > void get_cpu_info_basics(struct cpudata *cpu) > { > - unsigned int maxi, maxei, vendor, address_bits; > - unsigned int eax; > + unsigned int maxi, maxei, maxhv, vendor, address_bits; > + unsigned int eax, ebx, ecx; > > cpuid(cpu->number, 0, &maxi, &vendor, NULL, NULL); > maxi &= 0xffff; /* The high-order word is non-zero on some Cyrix CPUs */ > @@ -19,7 +19,7 @@ void get_cpu_info_basics(struct cpudata *cpu) > return; > > /* Everything that supports cpuid supports these. */ > - cpuid(cpu->number, 1, &eax, NULL, NULL, NULL); > + cpuid(cpu->number, 1, &eax, &ebx, &ecx, NULL); > cpu->stepping = eax & 0xf; > cpu->model = (eax >> 4) & 0xf; > cpu->family = (eax >> 8) & 0xf; > @@ -29,6 +29,19 @@ void get_cpu_info_basics(struct cpudata *cpu) > > cpuid(cpu->number, 0xC0000000, &maxei, NULL, NULL, NULL); > cpu->maxei2 = maxei; > + if (ecx & 0x80000000) { > + cpuid(cpu->number, 0x40000000, &maxhv, NULL, NULL, NULL); > + /* > + * KVM up to linux 3.4 reports 0 as the max hypervisor leaf, > + * where it really means 0x40000001. > + * Most (all?) hypervisors have at least one CPUID besides > + * the vendor ID so assume that. > + */ > + cpu->maxhv = maxhv ? maxhv : 0x40000001; > + } else { > + /* Suppress hypervisor cpuid unless running on a hypervisor */ > + cpu->maxhv = 0; > + } > > cpuid(cpu->number, 0x80000008,&address_bits, NULL, NULL, NULL); > cpu->phyaddr_bits = address_bits & 0xFF; > diff --git a/x86info.c b/x86info.c > index 22c4734..80cae36 100644 > --- a/x86info.c > +++ b/x86info.c > @@ -44,6 +44,10 @@ static void display_detailed_info(struct cpudata *cpu) > > if (cpu->maxei2 >=0xC0000000) > dump_raw_cpuid(cpu->number, 0xC0000000, cpu->maxei2); > + > + if (cpu->maxhv >= 0x40000000) > + dump_raw_cpuid(cpu->number, 0x40000000, cpu->maxhv); > + > } > > if (show_cacheinfo) { > diff --git a/x86info.h b/x86info.h > index 7d2a455..c4f5d81 100644 > --- a/x86info.h > +++ b/x86info.h > @@ -84,7 +84,7 @@ struct cpudata { > unsigned int cachesize_trace; > unsigned int phyaddr_bits; > unsigned int viraddr_bits; > - unsigned int cpuid_level, maxei, maxei2; > + unsigned int cpuid_level, maxei, maxei2, maxhv; > char name[CPU_NAME_LEN]; > enum connector connector; > unsigned int flags_ecx;-- Gleb.
On Mon, 2012-04-30 at 17:38 +0300, Michael S. Tsirkin wrote:> The following makes 'x86info -r' dump hypervisor leaf cpu ids > (for kvm this is signature+features) when running in a vm. > > On the guest we see the signature and the features: > eax in: 0x40000000, eax = 00000000 ebx = 4b4d564b ecx = 564b4d56 edx = 0000004d > eax in: 0x40000001, eax = 0100007b ebx = 00000000 ecx = 00000000 edx = 00000000 > > Hypervisor flag is checked to avoid output changes when not > running on a VM. > > Signed-off-by: Michael S. Tsirkin <mst at redhat.com> > > Changes from v1: > Make work on non KVM hypervisors (only KVM was tested). > Avi Kivity said kvm will in the future report > max HV leaf in eax. For now it reports eax = 0 > so add a work around for that. > > --- > > diff --git a/identify.c b/identify.c > index 33f35de..a4a3763 100644 > --- a/identify.c > +++ b/identify.c > @@ -9,8 +9,8 @@ > > void get_cpu_info_basics(struct cpudata *cpu) > { > - unsigned int maxi, maxei, vendor, address_bits; > - unsigned int eax; > + unsigned int maxi, maxei, maxhv, vendor, address_bits; > + unsigned int eax, ebx, ecx; > > cpuid(cpu->number, 0, &maxi, &vendor, NULL, NULL); > maxi &= 0xffff; /* The high-order word is non-zero on some Cyrix CPUs */ > @@ -19,7 +19,7 @@ void get_cpu_info_basics(struct cpudata *cpu) > return; > > /* Everything that supports cpuid supports these. */ > - cpuid(cpu->number, 1, &eax, NULL, NULL, NULL); > + cpuid(cpu->number, 1, &eax, &ebx, &ecx, NULL);You probably want to check ebx, ecx, edx for the signatures of the hypervisor's you are willing to support and which you know do something sane with eax? Also it would be something worth reporting in its own right? BTW, according to arch/x86/include/asm/kvm_para.h unsurprisingly KVM has a signature too 'KVMKVMKVM'.> cpu->stepping = eax & 0xf; > cpu->model = (eax >> 4) & 0xf; > cpu->family = (eax >> 8) & 0xf; > @@ -29,6 +29,19 @@ void get_cpu_info_basics(struct cpudata *cpu) > > cpuid(cpu->number, 0xC0000000, &maxei, NULL, NULL, NULL); > cpu->maxei2 = maxei; > + if (ecx & 0x80000000) { > + cpuid(cpu->number, 0x40000000, &maxhv, NULL, NULL, NULL); > + /* > + * KVM up to linux 3.4 reports 0 as the max hypervisor leaf, > + * where it really means 0x40000001.This is something where I definitely think you want to check the signature first. Ian.> + * Most (all?) hypervisors have at least one CPUID besides > + * the vendor ID so assume that. > + */ > + cpu->maxhv = maxhv ? maxhv : 0x40000001; > + } else { > + /* Suppress hypervisor cpuid unless running on a hypervisor */ > + cpu->maxhv = 0; > + } > > cpuid(cpu->number, 0x80000008,&address_bits, NULL, NULL, NULL); > cpu->phyaddr_bits = address_bits & 0xFF; > diff --git a/x86info.c b/x86info.c > index 22c4734..80cae36 100644 > --- a/x86info.c > +++ b/x86info.c > @@ -44,6 +44,10 @@ static void display_detailed_info(struct cpudata *cpu) > > if (cpu->maxei2 >=0xC0000000) > dump_raw_cpuid(cpu->number, 0xC0000000, cpu->maxei2); > + > + if (cpu->maxhv >= 0x40000000) > + dump_raw_cpuid(cpu->number, 0x40000000, cpu->maxhv); > + > } > > if (show_cacheinfo) { > diff --git a/x86info.h b/x86info.h > index 7d2a455..c4f5d81 100644 > --- a/x86info.h > +++ b/x86info.h > @@ -84,7 +84,7 @@ struct cpudata { > unsigned int cachesize_trace; > unsigned int phyaddr_bits; > unsigned int viraddr_bits; > - unsigned int cpuid_level, maxei, maxei2; > + unsigned int cpuid_level, maxei, maxei2, maxhv; > char name[CPU_NAME_LEN]; > enum connector connector; > unsigned int flags_ecx; > _______________________________________________ > Virtualization mailing list > Virtualization at lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/virtualization >-- Ian Campbell Your own qualities will help prevent your advancement in the world.
On Tue, May 01, 2012 at 01:27:05PM +0100, Ian Campbell wrote:> On Mon, 2012-04-30 at 17:38 +0300, Michael S. Tsirkin wrote: > > The following makes 'x86info -r' dump hypervisor leaf cpu ids > > (for kvm this is signature+features) when running in a vm. > > > > On the guest we see the signature and the features: > > eax in: 0x40000000, eax = 00000000 ebx = 4b4d564b ecx = 564b4d56 edx = 0000004d > > eax in: 0x40000001, eax = 0100007b ebx = 00000000 ecx = 00000000 edx = 00000000 > > > > Hypervisor flag is checked to avoid output changes when not > > running on a VM. > > > > Signed-off-by: Michael S. Tsirkin <mst at redhat.com> > > > > Changes from v1: > > Make work on non KVM hypervisors (only KVM was tested). > > Avi Kivity said kvm will in the future report > > max HV leaf in eax. For now it reports eax = 0 > > so add a work around for that. > > > > --- > > > > diff --git a/identify.c b/identify.c > > index 33f35de..a4a3763 100644 > > --- a/identify.c > > +++ b/identify.c > > @@ -9,8 +9,8 @@ > > > > void get_cpu_info_basics(struct cpudata *cpu) > > { > > - unsigned int maxi, maxei, vendor, address_bits; > > - unsigned int eax; > > + unsigned int maxi, maxei, maxhv, vendor, address_bits; > > + unsigned int eax, ebx, ecx; > > > > cpuid(cpu->number, 0, &maxi, &vendor, NULL, NULL); > > maxi &= 0xffff; /* The high-order word is non-zero on some Cyrix CPUs */ > > @@ -19,7 +19,7 @@ void get_cpu_info_basics(struct cpudata *cpu) > > return; > > > > /* Everything that supports cpuid supports these. */ > > - cpuid(cpu->number, 1, &eax, NULL, NULL, NULL); > > + cpuid(cpu->number, 1, &eax, &ebx, &ecx, NULL); > > You probably want to check ebx, ecx, edx for the signatures of the > hypervisor's you are willing to support and which you know do something > sane with eax?Everyone puts the max leaf in eax - this is what hardware CPUs do. So I think we can just interpret eax as such. If someone wants to put broken info in cpuid, send a patch to blacklist it.> Also it would be something worth reporting in its own > right? > > BTW, according to arch/x86/include/asm/kvm_para.h unsurprisingly KVM has > a signature too 'KVMKVMKVM'. > > > cpu->stepping = eax & 0xf; > > cpu->model = (eax >> 4) & 0xf; > > cpu->family = (eax >> 8) & 0xf; > > @@ -29,6 +29,19 @@ void get_cpu_info_basics(struct cpudata *cpu) > > > > cpuid(cpu->number, 0xC0000000, &maxei, NULL, NULL, NULL); > > cpu->maxei2 = maxei; > > + if (ecx & 0x80000000) { > > + cpuid(cpu->number, 0x40000000, &maxhv, NULL, NULL, NULL); > > + /* > > + * KVM up to linux 3.4 reports 0 as the max hypervisor leaf, > > + * where it really means 0x40000001. > > This is something where I definitely think you want to check the > signature first. > > Ian.kvm lets users change the signature. But worst case we print one useless line. Better than not printing something potentially useful. -- MST
On Mon, Apr 30, 2012 at 05:38:35PM +0300, Michael S. Tsirkin wrote:> The following makes 'x86info -r' dump hypervisor leaf cpu ids > (for kvm this is signature+features) when running in a vm. > > On the guest we see the signature and the features: > eax in: 0x40000000, eax = 00000000 ebx = 4b4d564b ecx = 564b4d56 edx = 0000004d > eax in: 0x40000001, eax = 0100007b ebx = 00000000 ecx = 00000000 edx = 00000000 > > Hypervisor flag is checked to avoid output changes when not > running on a VM. > > Signed-off-by: Michael S. Tsirkin <mst at redhat.com> > > Changes from v1: > Make work on non KVM hypervisors (only KVM was tested). > Avi Kivity said kvm will in the future report > max HV leaf in eax. For now it reports eax = 0 > so add a work around for that.Ping. Davej, any comments? Would be nice to have this in.> --- > > diff --git a/identify.c b/identify.c > index 33f35de..a4a3763 100644 > --- a/identify.c > +++ b/identify.c > @@ -9,8 +9,8 @@ > > void get_cpu_info_basics(struct cpudata *cpu) > { > - unsigned int maxi, maxei, vendor, address_bits; > - unsigned int eax; > + unsigned int maxi, maxei, maxhv, vendor, address_bits; > + unsigned int eax, ebx, ecx; > > cpuid(cpu->number, 0, &maxi, &vendor, NULL, NULL); > maxi &= 0xffff; /* The high-order word is non-zero on some Cyrix CPUs */ > @@ -19,7 +19,7 @@ void get_cpu_info_basics(struct cpudata *cpu) > return; > > /* Everything that supports cpuid supports these. */ > - cpuid(cpu->number, 1, &eax, NULL, NULL, NULL); > + cpuid(cpu->number, 1, &eax, &ebx, &ecx, NULL); > cpu->stepping = eax & 0xf; > cpu->model = (eax >> 4) & 0xf; > cpu->family = (eax >> 8) & 0xf; > @@ -29,6 +29,19 @@ void get_cpu_info_basics(struct cpudata *cpu) > > cpuid(cpu->number, 0xC0000000, &maxei, NULL, NULL, NULL); > cpu->maxei2 = maxei; > + if (ecx & 0x80000000) { > + cpuid(cpu->number, 0x40000000, &maxhv, NULL, NULL, NULL); > + /* > + * KVM up to linux 3.4 reports 0 as the max hypervisor leaf, > + * where it really means 0x40000001. > + * Most (all?) hypervisors have at least one CPUID besides > + * the vendor ID so assume that. > + */ > + cpu->maxhv = maxhv ? maxhv : 0x40000001; > + } else { > + /* Suppress hypervisor cpuid unless running on a hypervisor */ > + cpu->maxhv = 0; > + } > > cpuid(cpu->number, 0x80000008,&address_bits, NULL, NULL, NULL); > cpu->phyaddr_bits = address_bits & 0xFF; > diff --git a/x86info.c b/x86info.c > index 22c4734..80cae36 100644 > --- a/x86info.c > +++ b/x86info.c > @@ -44,6 +44,10 @@ static void display_detailed_info(struct cpudata *cpu) > > if (cpu->maxei2 >=0xC0000000) > dump_raw_cpuid(cpu->number, 0xC0000000, cpu->maxei2); > + > + if (cpu->maxhv >= 0x40000000) > + dump_raw_cpuid(cpu->number, 0x40000000, cpu->maxhv); > + > } > > if (show_cacheinfo) { > diff --git a/x86info.h b/x86info.h > index 7d2a455..c4f5d81 100644 > --- a/x86info.h > +++ b/x86info.h > @@ -84,7 +84,7 @@ struct cpudata { > unsigned int cachesize_trace; > unsigned int phyaddr_bits; > unsigned int viraddr_bits; > - unsigned int cpuid_level, maxei, maxei2; > + unsigned int cpuid_level, maxei, maxei2, maxhv; > char name[CPU_NAME_LEN]; > enum connector connector; > unsigned int flags_ecx;