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[v2,09/25] x86/fault: Dump RMP table information when RMP page faults occur

Message ID 20240126041126.1927228-10-michael.roth@amd.com
State Accepted
Commit e8bbd303d7de3fb32be1434a5d5ce3e1cb182018
Headers show
Series Add AMD Secure Nested Paging (SEV-SNP) Initialization Support | expand

Commit Message

Michael Roth Jan. 26, 2024, 4:11 a.m. UTC 
RMP faults on kernel addresses are fatal and should never happen in
practice. They indicate a bug in the host kernel somewhere. Userspace
RMP faults shouldn't occur either, since even for VMs the memory used
for private pages is handled by guest_memfd and by design is not
mappable by userspace.

Dump RMP table information about the PFN corresponding to the faulting
HVA to help diagnose any issues of this sort when show_fault_oops() is
triggered by an RMP fault.

Signed-off-by: Michael Roth <michael.roth@amd.com>
---
 arch/x86/mm/fault.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 8805e2e20df6..859adcd123c9 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -34,6 +34,7 @@ 
 #include <asm/kvm_para.h>		/* kvm_handle_async_pf		*/
 #include <asm/vdso.h>			/* fixup_vdso_exception()	*/
 #include <asm/irq_stack.h>
+#include <asm/sev.h>			/* snp_dump_hva_rmpentry()	*/
 
 #define CREATE_TRACE_POINTS
 #include <asm/trace/exceptions.h>
@@ -580,6 +581,9 @@  show_fault_oops(struct pt_regs *regs, unsigned long error_code, unsigned long ad
 	}
 
 	dump_pagetable(address);
+
+	if (error_code & X86_PF_RMP)
+		snp_dump_hva_rmpentry(address);
 }
 
 static noinline void