[PATCH v2 2/8] x86/sev-es: Forward page-faults which happen during emulation

Joerg Roedel
Wed, 19 May 2021 13:52:45 -0000

When emulating guest instructions for MMIO or IOIO accesses the #VC
handler might get a page-fault and will not be able to complete. Forward
the page-fault in this case to the correct handler instead of killing
the machine.

Fixes: 0786138c78e7 ("x86/sev-es: Add a Runtime #VC Exception
Handler")
Cc: stable at vger.kernel.org # v5.10+
Signed-off-by: Joerg Roedel <jroedel at suse.de>
---
 arch/x86/kernel/sev.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index 82bced88153b..1f428f401bed 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -1270,6 +1270,10 @@ 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_PF:
+		write_cr2(ctxt->fi.cr2);
+		exc_page_fault(ctxt->regs, error_code);
+		break;
 	case X86_TRAP_AC:
 		exc_alignment_check(ctxt->regs, error_code);
 		break;
--
2.31.1