diff options
| author | Alexey Kardashevskiy <aik@amd.com> | 2023-08-16 12:21:22 +1000 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2023-08-16 10:13:42 +0200 |
| commit | e221804dad4e6fe3a0cf192ba3c42cd2f328bdac (patch) | |
| tree | 4df33e1361e3a024c6e3a99db4d75646a8fb09f5 /arch/x86 | |
| parent | 2ccdd1b13c591d306f0401d98dedc4bdcd02b421 (diff) | |
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 <aik@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Carlos Bilbao <carlos.bilbao@amd.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Link: https://lore.kernel.org/r/20230816022122.981998-1-aik@amd.com
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/boot/compressed/sev.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/sev.c | 6 |
2 files changed, 7 insertions, 1 deletions
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) { diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index 1ee7bed453de..d380c9399480 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -1575,6 +1575,9 @@ static enum es_result vc_handle_dr7_write(struct ghcb *ghcb, long val, *reg = vc_insn_get_rm(ctxt); enum es_result ret; + if (sev_status & MSR_AMD64_SNP_DEBUG_SWAP) + return ES_VMM_ERROR; + if (!reg) return ES_DECODE_FAILED; @@ -1612,6 +1615,9 @@ static enum es_result vc_handle_dr7_read(struct ghcb *ghcb, struct sev_es_runtime_data *data = this_cpu_read(runtime_data); long *reg = vc_insn_get_rm(ctxt); + if (sev_status & MSR_AMD64_SNP_DEBUG_SWAP) + return ES_VMM_ERROR; + if (!reg) return ES_DECODE_FAILED; |