Re: [PATCH v5 5/5] x86/kvm: Avoid dynamic allocation of pvclock data when SEV is active

From: Borislav Petkov
Date: Thu Sep 06 2018 - 11:19:49 EST


On Thu, Sep 06, 2018 at 07:56:40AM -0700, Sean Christopherson wrote:
> Wouldn't that result in @hv_clock_boot being incorrectly freed in the
> !SEV case?

Ok, maybe I'm missing something but why do we need 4K per CPU? Why can't
we map all those pages which contain the clock variable, decrypted in
all guests' page tables?

Basically

(NR_CPUS * sizeof(struct pvclock_vsyscall_time_info)) / 4096

pages.

For the !SEV case then nothing changes.

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Boris.

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