[PATCH v2] i386: Make migration fail when Hyper-V reenlightenment was enabled but 'user_tsc_khz' is unset

2021-03-19 Thread Vitaly Kuznetsov
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 succeeds, it is unsafe to proceed wi

Re: [PATCH v2] i386: Make migration fail when Hyper-V reenlightenment was enabled but 'user_tsc_khz' is unset

2021-03-29 Thread Dr. David Alan Gilbert
* Vitaly Kuznetsov (vkuzn...@redhat.com) wrote: > 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

Re: [PATCH v2] i386: Make migration fail when Hyper-V reenlightenment was enabled but 'user_tsc_khz' is unset

2021-03-29 Thread Vitaly Kuznetsov
"Dr. David Alan Gilbert" writes: > * Vitaly Kuznetsov (vkuzn...@redhat.com) wrote: >> 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

Re: [PATCH v2] i386: Make migration fail when Hyper-V reenlightenment was enabled but 'user_tsc_khz' is unset

2021-03-29 Thread Dr. David Alan Gilbert
* Vitaly Kuznetsov (vkuzn...@redhat.com) wrote: > "Dr. David Alan Gilbert" writes: > > > * Vitaly Kuznetsov (vkuzn...@redhat.com) wrote: > >> KVM doesn't fully support Hyper-V reenlightenment notifications on > >> migration. In particular, it doesn't support emulating TSC frequency > >> of the so

Re: [PATCH v2] i386: Make migration fail when Hyper-V reenlightenment was enabled but 'user_tsc_khz' is unset

2021-03-30 Thread Vitaly Kuznetsov
"Dr. David Alan Gilbert" writes: > * Vitaly Kuznetsov (vkuzn...@redhat.com) wrote: >> "Dr. David Alan Gilbert" writes: >> >> > * Vitaly Kuznetsov (vkuzn...@redhat.com) wrote: >> >> KVM doesn't fully support Hyper-V reenlightenment notifications on >> >> migration. In particular, it doesn't supp