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authorJoerg Roedel <jroedel@suse.de>2020-09-07 15:16:01 +0200
committerBorislav Petkov <bp@suse.de>2020-09-09 11:33:20 +0200
commita2d0171a9cf59637411281a929900fde80e6c1cb (patch)
tree5aba35e4a0bacc056d6671c445e97e71d818e364 /arch
parent2eb7dcf0ccc40ad3f39b000becf16661abf98102 (diff)
x86/sev-es: Handle #AC Events
Implement a handler for #VC exceptions caused by #AC exceptions. The #AC exception is just forwarded to do_alignment_check() and not pushed down to the hypervisor, as requested by the SEV-ES GHCB Standardization Specification. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-61-joro@8bytes.org
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/sev-es.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c
index 86cb4c5a7ad2..8867c481e3e2 100644
--- a/arch/x86/kernel/sev-es.c
+++ b/arch/x86/kernel/sev-es.c
@@ -909,6 +909,19 @@ static enum es_result vc_handle_vmmcall(struct ghcb *ghcb,
return ES_OK;
}
+static enum es_result vc_handle_trap_ac(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ /*
+ * Calling ecx_alignment_check() directly does not work, because it
+ * enables IRQs and the GHCB is active. Forward the exception and call
+ * it later from vc_forward_exception().
+ */
+ ctxt->fi.vector = X86_TRAP_AC;
+ ctxt->fi.error_code = 0;
+ return ES_EXCEPTION;
+}
+
static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
struct ghcb *ghcb,
unsigned long exit_code)
@@ -922,6 +935,9 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
case SVM_EXIT_WRITE_DR7:
result = vc_handle_dr7_write(ghcb, ctxt);
break;
+ case SVM_EXIT_EXCP_BASE + X86_TRAP_AC:
+ result = vc_handle_trap_ac(ghcb, ctxt);
+ break;
case SVM_EXIT_RDTSC:
case SVM_EXIT_RDTSCP:
result = vc_handle_rdtsc(ghcb, ctxt, exit_code);
@@ -981,6 +997,9 @@ static __always_inline void vc_forward_exception(struct es_em_ctxt *ctxt)
case X86_TRAP_UD:
exc_invalid_op(ctxt->regs);
break;
+ case X86_TRAP_AC:
+ exc_alignment_check(ctxt->regs, error_code);
+ break;
default:
pr_emerg("Unsupported exception in #VC instruction emulation - can't continue\n");
BUG();