| Message ID | 20210318160249.1084178-1-vkuznets@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | i386: Make sure TSC frequency is preserved across migration when Hyper-V reenlightenment is in use | expand |
On 18/03/21 17:02, Vitaly Kuznetsov wrote: > Currently, Hyper-V enlightenments are only implemented by KVM so there's no > need to have corresponding vmstate_x86_cpu sections when !CONFIG_KVM. > > Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> I expect WHPX may implement at least some, so I'll leave this out. Paolo > --- > target/i386/machine.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/target/i386/machine.c b/target/i386/machine.c > index 3967dfc25763..a4777a73b0a9 100644 > --- a/target/i386/machine.c > +++ b/target/i386/machine.c > @@ -697,6 +697,7 @@ static const VMStateDescription vmstate_mpx = { > } > }; > > +#ifdef CONFIG_KVM > static bool hyperv_hypercall_enable_needed(void *opaque) > { > X86CPU *cpu = opaque; > @@ -895,6 +896,7 @@ static const VMStateDescription vmstate_msr_hyperv_reenlightenment = { > VMSTATE_END_OF_LIST() > } > }; > +#endif > > static bool avx512_needed(void *opaque) > { > @@ -1484,6 +1486,7 @@ VMStateDescription vmstate_x86_cpu = { > &vmstate_msr_ia32_feature_control, > &vmstate_msr_architectural_pmu, > &vmstate_mpx, > +#ifdef CONFIG_KVM > &vmstate_msr_hypercall_hypercall, > &vmstate_msr_hyperv_vapic, > &vmstate_msr_hyperv_time, > @@ -1492,6 +1495,7 @@ VMStateDescription vmstate_x86_cpu = { > &vmstate_msr_hyperv_synic, > &vmstate_msr_hyperv_stimer, > &vmstate_msr_hyperv_reenlightenment, > +#endif > &vmstate_avx512, > &vmstate_xss, > &vmstate_umwait, >
KVM doesn't fully support Hyper-V reenlightenment notifications on migration. In particular, it doesn't support emulating TSC frequency of the source host by trapping all TSC accesses so unless TSC scaling is supported on the destination host and KVM_SET_TSC_KHZ succeeded, it is unsafe to proceed with migration. Vitaly Kuznetsov (3): i386: Make Hyper-V related sections KVM only i386: Fix 'hypercall_hypercall' typo i386: Make sure kvm_arch_set_tsc_khz() succeeds on migration when 'hv-reenlightenment' was exposed target/i386/kvm/hyperv.h | 1 + target/i386/kvm/kvm.c | 11 ++++++++++ target/i386/machine.c | 45 ++++++++++++++++++++++++++++++++++++++-- 3 files changed, 55 insertions(+), 2 deletions(-)