From e8bbd303d7de3fb32be1434a5d5ce3e1cb182018 Mon Sep 17 00:00:00 2001 From: Michael Roth Date: Thu, 25 Jan 2024 22:11:09 -0600 Subject: [PATCH] x86/fault: Dump RMP table information when RMP page faults occur 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 Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20240126041126.1927228-10-michael.roth@amd.com --- arch/x86/mm/fault.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 8805e2e20df6e..859adcd123c9c 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -34,6 +34,7 @@ #include /* kvm_handle_async_pf */ #include /* fixup_vdso_exception() */ #include +#include /* snp_dump_hva_rmpentry() */ #define CREATE_TRACE_POINTS #include @@ -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 -- 2.30.2