Re: [PATCH v3 64/75] x86/sev-es: Cache CPUID results for improved performance

Joerg Roedel
2020-06-12T09:12:19Z

On Tue, Apr 28, 2020 at 05:17:14PM +0200, Joerg Roedel wrote:
> From: Mike Stunes <mstunes@vmware.com>
>
> To avoid a future VMEXIT for a subsequent CPUID function, cache the
> results returned by CPUID into an xarray.
>
> [tl: coding standard changes, register zero extension]
>
> Signed-off-by: Mike Stunes <mstunes@vmware.com>
> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
> [ jroedel@suse.de: - Wrapped cache handling into vc_handle_cpuid_cached()
> - Used lower_32_bits() where applicable
> - Moved cache_index out of struct es_em_ctxt ]
> Co-developed-by: Joerg Roedel <jroedel@suse.de>
> Signed-off-by: Joerg Roedel <jroedel@suse.de>
> ---
> arch/x86/kernel/sev-es-shared.c | 12 ++--
> arch/x86/kernel/sev-es.c | 119 +++++++++++++++++++++++++++++++-
> 2 files changed, 124 insertions(+), 7 deletions(-)

Okay, following the discussion, I am dropping this patch for now. We can
revisit CPUID caching later when we have a better justification.

Regards,

Joerg