[v1] i386/kvm: advertise Hyper-V frequency MSRs

[Qemu-devel] [PATCH 0/3] i386/kvm: advertise Hyper-V frequency MSRs

Ladi Prosek posted 3 patches 6 years, 8 months ago

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target/i386/kvm.c | 130 +++++++++++++++++++++++++++---------------------------
1 file changed, 66 insertions(+), 64 deletions(-)

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[Qemu-devel] [PATCH 0/3] i386/kvm: advertise Hyper-V frequency MSRs

Posted by Ladi Prosek 6 years, 8 months ago

This is the QEMU part of the changes required for nested Hyper-V to read
timestamps with RDTSC + TSC page. Without exposing the frequency MSRs,
Windows with the Hyper-V role enabled use the much slower
HV_X64_MSR_TIME_REF_COUNT (0x40000020) RDMSR to read timestamps.

The new registers are exposed only if the TSC frequency is stable across
migration and known, as suggested by Paolo.

Ladi Prosek (3):
  i386/kvm: use a switch statement for MSR detection
  i386/kvm: set tsc_khz before configuring Hyper-V CPUID
  i386/kvm: advertise Hyper-V frequency MSRs

 target/i386/kvm.c | 130 +++++++++++++++++++++++++++---------------------------
 1 file changed, 66 insertions(+), 64 deletions(-)

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2.9.3