Commit a2d0171a authored by Joerg Roedel's avatar Joerg Roedel Committed by Borislav Petkov

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: default avatarJoerg Roedel <jroedel@suse.de>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200907131613.12703-61-joro@8bytes.org
parent 2eb7dcf0
...@@ -909,6 +909,19 @@ static enum es_result vc_handle_vmmcall(struct ghcb *ghcb, ...@@ -909,6 +909,19 @@ static enum es_result vc_handle_vmmcall(struct ghcb *ghcb,
return ES_OK; 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, static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
struct ghcb *ghcb, struct ghcb *ghcb,
unsigned long exit_code) unsigned long exit_code)
...@@ -922,6 +935,9 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt, ...@@ -922,6 +935,9 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
case SVM_EXIT_WRITE_DR7: case SVM_EXIT_WRITE_DR7:
result = vc_handle_dr7_write(ghcb, ctxt); result = vc_handle_dr7_write(ghcb, ctxt);
break; break;
case SVM_EXIT_EXCP_BASE + X86_TRAP_AC:
result = vc_handle_trap_ac(ghcb, ctxt);
break;
case SVM_EXIT_RDTSC: case SVM_EXIT_RDTSC:
case SVM_EXIT_RDTSCP: case SVM_EXIT_RDTSCP:
result = vc_handle_rdtsc(ghcb, ctxt, exit_code); result = vc_handle_rdtsc(ghcb, ctxt, exit_code);
...@@ -981,6 +997,9 @@ static __always_inline void vc_forward_exception(struct es_em_ctxt *ctxt) ...@@ -981,6 +997,9 @@ static __always_inline void vc_forward_exception(struct es_em_ctxt *ctxt)
case X86_TRAP_UD: case X86_TRAP_UD:
exc_invalid_op(ctxt->regs); exc_invalid_op(ctxt->regs);
break; break;
case X86_TRAP_AC:
exc_alignment_check(ctxt->regs, error_code);
break;
default: default:
pr_emerg("Unsupported exception in #VC instruction emulation - can't continue\n"); pr_emerg("Unsupported exception in #VC instruction emulation - can't continue\n");
BUG(); BUG();
......
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