Re: [PATCH kvm-unit-tests] x86: tsc: add test for RDTSCP

[Paolo Bonzini]

On 13/11/2015 02:48, Wanpeng Li wrote:
> > diff --git a/x86/unittests.cfg b/x86/unittests.cfg
> > index ac652fc..fd7e9b2 100644
> > --- a/x86/unittests.cfg
> > +++ b/x86/unittests.cfg
> > @@ -114,6 +114,7 @@ file = sieve.flat
> >
> >  [tsc]
> >  file = tsc.flat
> > +extra_params = -cpu kvm64,+rdtscp
> >
> >  [tsc_adjust]
> >  file = tsc_adjust.flat
>
> When I run cpuid tool in a real linux guest, the rdtscp, tsc_adjust,
> tsc deadline timer are present, however, kvm-unit-tests always report
> these features are not detected, what is the issue here?

Your guest is probably run with some "-cpu" option, while
kvm-unit-tests' x86/run script doesn't add any.  This is why I needed
the extra_params line above.

Paolo
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Re: [PATCH kvm-unit-tests] x86: tsc: add test for RDTSCP

[Wanpeng Li]

2015-11-12 19:12 GMT+08:00 Paolo Bonzini :
> Signed-off-by: Paolo Bonzini 
> ---
>  lib/x86/processor.h | 16 
>  x86/tsc.c   | 23 +++
>  x86/unittests.cfg   |  1 +
>  3 files changed, 40 insertions(+)
>
> diff --git a/lib/x86/processor.h b/lib/x86/processor.h
> index 7973879..b9cb753 100644
> --- a/lib/x86/processor.h
> +++ b/lib/x86/processor.h
> @@ -2,6 +2,7 @@
>  #define LIBCFLAT_PROCESSOR_H
>
>  #include "libcflat.h"
> +#include "msr.h"
>  #include 
>
>  #ifdef __x86_64__
> @@ -340,6 +341,21 @@ static inline unsigned long long rdtsc()
> return r;
>  }
>
> +static inline unsigned long long rdtscp(u32 *aux)
> +{
> +   long long r;
> +
> +#ifdef __x86_64__
> +   unsigned a, d;
> +
> +   asm volatile ("rdtscp" : "=a"(a), "=d"(d), "=c"(*aux));
> +   r = a | ((long long)d << 32);
> +#else
> +   asm volatile ("rdtscp" : "=A"(r), "=c"(*aux));
> +#endif
> +   return r;
> +}
> +
>  static inline void wrtsc(u64 tsc)
>  {
> unsigned a = tsc, d = tsc >> 32;
> diff --git a/x86/tsc.c b/x86/tsc.c
> index 58f332d..c71dc2a 100644
> --- a/x86/tsc.c
> +++ b/x86/tsc.c
> @@ -1,6 +1,13 @@
>  #include "libcflat.h"
>  #include "processor.h"
>
> +#define CPUID_8001_EDX_RDTSCP  (1 << 27)
> +int check_cpuid_8001_edx(unsigned int bit)
> +{
> +return (cpuid(0x8001).d & bit) != 0;
> +}
> +
> +
>  void test_wrtsc(u64 t1)
>  {
> u64 t2;
> @@ -10,6 +17,15 @@ void test_wrtsc(u64 t1)
> printf("rdtsc after wrtsc(%lld): %lld\n", t1, t2);
>  }
>
> +void test_rdtscp(u64 aux)
> +{
> +   u32 ecx;
> +
> +   wrmsr(MSR_TSC_AUX, aux);
> +   rdtscp();
> +   report("Test RDTSCP %d", ecx == aux, aux);
> +}
> +
>  int main()
>  {
> u64 t1, t2;
> @@ -20,5 +36,12 @@ int main()
>
> test_wrtsc(0);
> test_wrtsc(1000ull);
> +
> +   if (check_cpuid_8001_edx(CPUID_8001_EDX_RDTSCP)) {
> +   test_rdtscp(0);
> +   test_rdtscp(10);
> +   test_rdtscp(0x100);
> +   } else
> +   printf("rdtscp not supported\n");
> return 0;
>  }
> diff --git a/x86/unittests.cfg b/x86/unittests.cfg
> index ac652fc..fd7e9b2 100644
> --- a/x86/unittests.cfg
> +++ b/x86/unittests.cfg
> @@ -114,6 +114,7 @@ file = sieve.flat
>
>  [tsc]
>  file = tsc.flat
> +extra_params = -cpu kvm64,+rdtscp
>
>  [tsc_adjust]
>  file = tsc_adjust.flat

When I run cpuid tool in a real linux guest, the rdtscp, tsc_adjust,
tsc deadline timer are present, however, kvm-unit-tests always report
these features are not detected, what is the issue here?

Regards,
Wanpeng Li
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Re: [PATCH kvm-unit-tests] x86: tsc: add test for RDTSCP

[Wanpeng Li]

2015-11-12 19:12 GMT+08:00 Paolo Bonzini :
>
> Signed-off-by: Paolo Bonzini 
> ---
>  lib/x86/processor.h | 16 
>  x86/tsc.c   | 23 +++
>  x86/unittests.cfg   |  1 +
>  3 files changed, 40 insertions(+)
>
> diff --git a/lib/x86/processor.h b/lib/x86/processor.h
> index 7973879..b9cb753 100644
> --- a/lib/x86/processor.h
> +++ b/lib/x86/processor.h
> @@ -2,6 +2,7 @@
>  #define LIBCFLAT_PROCESSOR_H
>
>  #include "libcflat.h"
> +#include "msr.h"
>  #include 
>
>  #ifdef __x86_64__
> @@ -340,6 +341,21 @@ static inline unsigned long long rdtsc()
> return r;
>  }
>
> +static inline unsigned long long rdtscp(u32 *aux)
> +{
> +   long long r;
> +
> +#ifdef __x86_64__
> +   unsigned a, d;
> +
> +   asm volatile ("rdtscp" : "=a"(a), "=d"(d), "=c"(*aux));
> +   r = a | ((long long)d << 32);
> +#else
> +   asm volatile ("rdtscp" : "=A"(r), "=c"(*aux));
> +#endif
> +   return r;
> +}
> +
>  static inline void wrtsc(u64 tsc)
>  {
> unsigned a = tsc, d = tsc >> 32;
> diff --git a/x86/tsc.c b/x86/tsc.c
> index 58f332d..c71dc2a 100644
> --- a/x86/tsc.c
> +++ b/x86/tsc.c
> @@ -1,6 +1,13 @@
>  #include "libcflat.h"
>  #include "processor.h"
>
> +#define CPUID_8001_EDX_RDTSCP  (1 << 27)
> +int check_cpuid_8001_edx(unsigned int bit)
> +{
> +return (cpuid(0x8001).d & bit) != 0;
> +}
> +
> +
>  void test_wrtsc(u64 t1)
>  {
> u64 t2;
> @@ -10,6 +17,15 @@ void test_wrtsc(u64 t1)
> printf("rdtsc after wrtsc(%lld): %lld\n", t1, t2);
>  }
>
> +void test_rdtscp(u64 aux)
> +{
> +   u32 ecx;
> +
> +   wrmsr(MSR_TSC_AUX, aux);
> +   rdtscp();
> +   report("Test RDTSCP %d", ecx == aux, aux);
> +}
> +
>  int main()
>  {
> u64 t1, t2;
> @@ -20,5 +36,12 @@ int main()
>
> test_wrtsc(0);
> test_wrtsc(1000ull);
> +
> +   if (check_cpuid_8001_edx(CPUID_8001_EDX_RDTSCP)) {
> +   test_rdtscp(0);
> +   test_rdtscp(10);
> +   test_rdtscp(0x100);
> +   } else
> +   printf("rdtscp not supported\n");
> return 0;
>  }
> diff --git a/x86/unittests.cfg b/x86/unittests.cfg
> index ac652fc..fd7e9b2 100644
> --- a/x86/unittests.cfg
> +++ b/x86/unittests.cfg
> @@ -114,6 +114,7 @@ file = sieve.flat
>
>  [tsc]
>  file = tsc.flat
> +extra_params = -cpu kvm64,+rdtscp
>
>  [tsc_adjust]
>  file = tsc_adjust.flat

When I run cpuid tool in a real linux guest, the rdtscp, tsc_adjust,
tsc deadline timer are
present, however, kvm-unit-tests always report these features are not
detected, what is
the issue here?

Regards,
Wanpeng Li
--
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the body of a message to majord...@vger.kernel.org
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