Re: [PATCH v6 5/5] x86/kvm: Avoid dynamic allocation of pvclock data when SEV is active
From: Paolo Bonzini
Date: Tue Sep 11 2018 - 07:07:13 EST
On 11/09/2018 12:25, Borislav Petkov wrote:
> On Tue, Sep 11, 2018 at 12:19:13PM +0200, Paolo Bonzini wrote:
>> That's exactly what kvmclock is for, it provides a stable and
>> synchronized clock on top of unsynchronized TSCs. But that's also why
>> you need one struct per vCPU, at least in the synchronized case.
> Why can't it be a single pointer to a struct pvclock_vsyscall_time_info
> shared between all vCPUs?
> Or does each vCPU write its own specific stuff into it so it has to be
If the host TSCs are unsynchronized then yes, that's what happens. And
you can do live migration from synchronized to unsynchronized.