qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PATCH v1] kvm/x86: Hyper-V tsc page setup


From: Paolo Bonzini
Subject: Re: [Qemu-devel] [PATCH v1] kvm/x86: Hyper-V tsc page setup
Date: Fri, 22 Jan 2016 12:53:26 +0100
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.0


On 22/01/2016 12:31, Andrey Smetanin wrote:
>>
>> Sometimes the TSC is detected to be unstable and Linux switches to
>> another clocksource.  At least in that case you can get a write to the
>> TSC page while the guest is running.
> Sorry, now I got it, you mean host TSC is unstable and we should mark
> guest tsc page invalid. Now I understand please ignore my prev. message.

No problem.  Anyhow yes, this is what I meant: a host write to the TSC
page, not a guest write to the TSC page MSR.

Usually it happens only at migration time to update the sequence---which
I believe your patch wasn't doing either.  But if we tie TSC page
updates to kvm_gen_update_masterclock, we get that for free when the
migration destination calls the KVM_SET_CLOCK ioctl.

Paolo



reply via email to

[Prev in Thread] Current Thread [Next in Thread]