KVM: x86/mmu: Dump reserved bits if they're detected on non-MMIO SPTE

Debugging unexpected reserved bit page faults sucks.  Dump the reserved
bits that (likely) caused the page fault to make debugging suck a little
less.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210225204749.1512652-25-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index f15b96c..febe719 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3582,11 +3582,12 @@ static bool get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr, u64 *sptep)
                            __is_rsvd_bits_set(rsvd_check, sptes[level], level);
 
        if (reserved) {
-               pr_err("%s: detect reserved bits on spte, addr 0x%llx, dump hierarchy:\n",
+               pr_err("%s: reserved bits set on MMU-present spte, addr 0x%llx, hierarchy:\n",
                       __func__, addr);
                for (level = root; level >= leaf; level--)
-                       pr_err("------ spte 0x%llx level %d.\n",
-                              sptes[level], level);
+                       pr_err("------ spte = 0x%llx level = %d, rsvd bits = 0x%llx",
+                              sptes[level], level,
+                              rsvd_check->rsvd_bits_mask[(sptes[level] >> 7) & 1][level-1]);
        }
 
        return reserved;