Re: [PATCH v6 5/5] x86/kvm: Avoid dynamic allocation of pvclock data when SEV is active

From: Brijesh Singh
Date: Mon Sep 10 2018 - 12:14:20 EST




On 09/10/2018 10:53 AM, Borislav Petkov wrote:
On Mon, Sep 10, 2018 at 08:15:38AM -0500, Brijesh Singh wrote:
Now, the real question from all this SNAFU is, why can't all those point
to a single struct pvclock_vsyscall_time_info and all CPUs read a single
thing? Why do they have to be per-CPU and thus waste so much memory?

You forgot to answer to the real question - why do we need those things
to be perCPU and why can't we use a single instance to share with *all*
CPUs?

Because if we can, then we're golden!



I did not forgot to answer it. Maybe Paolo or someone more knowledgeable
in that area of code can comment why those are perCpu.

-Brijesh