diff options
| author | Tom Lendacky <thomas.lendacky@amd.com> | 2021-02-01 12:26:27 -0600 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-02-02 16:25:05 +0100 |
| commit | 62a08a7193dc9107904aaa51a04ba3ba2959f745 (patch) | |
| tree | c99ef8b81224ce4c1069e93137b45da1a358bd7b | |
| parent | 1048ba83fb1c00cd24172e23e8263972f6b5d9ac (diff) | |
x86/sev-es: Do not unroll string I/O for SEV-ES guests
Under the GHCB specification, SEV-ES guests can support string I/O.
The current #VC handler contains this support, so remove the need to
unroll kernel string I/O operations. This will reduce the number of #VC
exceptions generated as well as the number VM exits for the guest.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/3de04b5b638546ac75d42ba52307fe1a922173d3.1612203987.git.thomas.lendacky@amd.com
| -rw-r--r-- | arch/x86/mm/mem_encrypt.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c index c79e5736ab2b..d55ea77e1ca8 100644 --- a/arch/x86/mm/mem_encrypt.c +++ b/arch/x86/mm/mem_encrypt.c @@ -474,9 +474,10 @@ void __init mem_encrypt_init(void) swiotlb_update_mem_attributes(); /* - * With SEV, we need to unroll the rep string I/O instructions. + * With SEV, we need to unroll the rep string I/O instructions, + * but SEV-ES supports them through the #VC handler. */ - if (sev_active()) + if (sev_active() && !sev_es_active()) static_branch_enable(&sev_enable_key); print_mem_encrypt_feature_info(); |