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Re: [Xen-devel] [V0 PATCH 5/6] AMD-PVH: Support TSC_MODE_NEVER_EMULATE for PVH

On 08/15/2014 09:53 PM, Mukesh Rathor wrote:
On AMD, MSR_AMD64_TSC_RATIO must be set for rdtsc instruction in guest
to properly read the cpu tsc. To that end, set tsc_khz in struct domain.

Signed-off-by: Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>
  xen/arch/x86/time.c | 1 +
  1 file changed, 1 insertion(+)

diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c
index bd89219..7512aa4 100644
--- a/xen/arch/x86/time.c
+++ b/xen/arch/x86/time.c
@@ -1908,6 +1908,7 @@ void tsc_set_info(struct domain *d,
           * but "always_emulate" does not for some reason.  Figure out
           * why.
+        d->arch.tsc_khz = cpu_khz;
          switch ( tsc_mode )
          case TSC_MODE_NEVER_EMULATE:

I suspect that TSC_MODE DEFAULT may actually work for PVH: since we don't support migration it should be equivalent to NEVER_EMULATE.

If you replace in tsc_set_info() is_hvm_domain() with is_hvm_container_domain() and allow TSC_MODE_DEFAULT along with TSC_MODE_NEVER_EMULATE under 'if (is_pvh_domain())' then it seems to me that things should be fine.


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