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>

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;