From e221804dad4e6fe3a0cf192ba3c42cd2f328bdac Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Wed, 16 Aug 2023 12:21:22 +1000 Subject: x86/sev: Do not handle #VC for DR7 read/write With MSR_AMD64_SEV_DEBUG_SWAP enabled, the guest is not expected to receive a #VC for reads or writes of DR7. Update the SNP_FEATURES_PRESENT mask with MSR_AMD64_SNP_DEBUG_SWAP so an SNP guest doesn't gracefully terminate during SNP feature negotiation if MSR_AMD64_SEV_DEBUG_SWAP is enabled. Since a guest is not expected to receive a #VC on DR7 accesses when MSR_AMD64_SEV_DEBUG_SWAP is enabled, return an error from the #VC handler in this situation. Signed-off-by: Alexey Kardashevskiy Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Carlos Bilbao Reviewed-by: Tom Lendacky Reviewed-by: Pankaj Gupta Link: https://lore.kernel.org/r/20230816022122.981998-1-aik@amd.com --- arch/x86/boot/compressed/sev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/boot') diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c index c3e343bd4760..e83e71089cf1 100644 --- a/arch/x86/boot/compressed/sev.c +++ b/arch/x86/boot/compressed/sev.c @@ -365,7 +365,7 @@ static void enforce_vmpl0(void) * by the guest kernel. As and when a new feature is implemented in the * guest kernel, a corresponding bit should be added to the mask. */ -#define SNP_FEATURES_PRESENT (0) +#define SNP_FEATURES_PRESENT MSR_AMD64_SNP_DEBUG_SWAP void snp_check_features(void) { -- cgit v1.2.3-58-ga151