Re: [PATCH v2 0/3] x86/vdso: Add Hyper-V TSC page clocksource support

On Fri, 17 Feb 2017, Andy Lutomirski wrote: > On Fri, Feb 17, 2017 at 2:14 AM, Vitaly Kuznetsov wrote: > > Not only. As far as I understand (and I *think* K. Y. pointed this out) > > when VM is migrating to another host TSC page clocksource is disabled for > > extended period

Re: [PATCH v2 0/3] x86/vdso: Add Hyper-V TSC page clocksource support

On Fri, Feb 17, 2017 at 2:14 AM, Vitaly Kuznetsov wrote: > Thomas Gleixner writes: > >> On Wed, 15 Feb 2017, Vitaly Kuznetsov wrote: >>> Actually, we already have an implementation of TSC page update in KVM >>> (see arch/x86/kvm/hyperv.c,

Re: [PATCH v2 0/3] x86/vdso: Add Hyper-V TSC page clocksource support

On Fri, 17 Feb 2017, Vitaly Kuznetsov wrote: > Thomas Gleixner writes: > > On Wed, 15 Feb 2017, Vitaly Kuznetsov wrote: > >> Actually, we already have an implementation of TSC page update in KVM > >> (see arch/x86/kvm/hyperv.c, kvm_hv_setup_tsc_page()) and the update does > >>

Re: [PATCH v2 0/3] x86/vdso: Add Hyper-V TSC page clocksource support

Thomas Gleixner writes: > On Wed, 15 Feb 2017, Vitaly Kuznetsov wrote: >> Actually, we already have an implementation of TSC page update in KVM >> (see arch/x86/kvm/hyperv.c, kvm_hv_setup_tsc_page()) and the update does >> the following: >> >> 0) stash seq into seq_prev >>

Re: [PATCH v2 0/3] x86/vdso: Add Hyper-V TSC page clocksource support

On Wed, 15 Feb 2017, Vitaly Kuznetsov wrote: > Actually, we already have an implementation of TSC page update in KVM > (see arch/x86/kvm/hyperv.c, kvm_hv_setup_tsc_page()) and the update does > the following: > > 0) stash seq into seq_prev > 1) seq = 0 making all reads from the page invalid > 2)

Re: [PATCH v2 0/3] x86/vdso: Add Hyper-V TSC page clocksource support

Andy Lutomirski writes: > On Tue, Feb 14, 2017 at 7:50 AM, Vitaly Kuznetsov wrote: >> Thomas Gleixner writes: >> >>> On Tue, 14 Feb 2017, Vitaly Kuznetsov wrote: >>> Hi, while we're still waiting for a definitive ACK

Re: [PATCH v2 0/3] x86/vdso: Add Hyper-V TSC page clocksource support

On Tue, Feb 14, 2017 at 7:50 AM, Vitaly Kuznetsov wrote: > Thomas Gleixner writes: > >> On Tue, 14 Feb 2017, Vitaly Kuznetsov wrote: >> >>> Hi, >>> >>> while we're still waiting for a definitive ACK from Microsoft that the >>> algorithm is good for SMP

Re: [PATCH v2 0/3] x86/vdso: Add Hyper-V TSC page clocksource support

Thomas Gleixner writes: > On Tue, 14 Feb 2017, Vitaly Kuznetsov wrote: > >> Hi, >> >> while we're still waiting for a definitive ACK from Microsoft that the >> algorithm is good for SMP case (as we can't prevent the code in vdso from >> migrating between CPUs) I'd like to

Re: [PATCH v2 0/3] x86/vdso: Add Hyper-V TSC page clocksource support

On Tue, 14 Feb 2017, Vitaly Kuznetsov wrote: > Hi, > > while we're still waiting for a definitive ACK from Microsoft that the > algorithm is good for SMP case (as we can't prevent the code in vdso from > migrating between CPUs) I'd like to send v2 with some modifications to keep > the discussion

RE: [PATCH v2 0/3] x86/vdso: Add Hyper-V TSC page clocksource support

; > virtualizat...@lists.linux-foundation.org > Subject: [PATCH v2 0/3] x86/vdso: Add Hyper-V TSC page clocksource support > > Hi, > > while we're still waiting for a definitive ACK from Microsoft that the > algorithm > is good for SMP case (as we can't prevent

[PATCH v2 0/3] x86/vdso: Add Hyper-V TSC page clocksource support

Hi, while we're still waiting for a definitive ACK from Microsoft that the algorithm is good for SMP case (as we can't prevent the code in vdso from migrating between CPUs) I'd like to send v2 with some modifications to keep the discussion going. Changes since v1: - Document the TSC page reading