KVM: x86/mmu: Don't grab CR4.PSE for calculating shadow reserved bits

Unconditionally pass pse=false when calculating reserved bits for shadow
PTEs.  CR4.PSE is only relevant for 32-bit non-PAE paging, which KVM does
not use for shadow paging (including nested NPT).

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622175739.3610207-30-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 f5a55c9..d017352 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4281,19 +4281,22 @@ static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu,
         * MMU contexts.  Note, KVM forces EFER.NX=1 when TDP is disabled.
         */
        bool uses_nx = context->nx || !tdp_enabled;
+
+       /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */
+       bool is_amd = true;
+       /* KVM doesn't use 2-level page tables for the shadow MMU. */
+       bool is_pse = false;
        struct rsvd_bits_validate *shadow_zero_check;
        int i;
 
-       /*
-        * Passing "true" to the last argument is okay; it adds a check
-        * on bit 8 of the SPTEs which KVM doesn't use anyway.
-        */
+       WARN_ON_ONCE(context->shadow_root_level < PT32E_ROOT_LEVEL);
+
        shadow_zero_check = &context->shadow_zero_check;
        __reset_rsvds_bits_mask(vcpu, shadow_zero_check,
                                reserved_hpa_bits(),
                                context->shadow_root_level, uses_nx,
                                guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES),
-                               is_pse(vcpu), true);
+                               is_pse, is_amd);
 
        if (!shadow_me_mask)
                return;
@@ -4329,7 +4332,7 @@ reset_tdp_shadow_zero_bits_mask(struct kvm_vcpu *vcpu,
                                        reserved_hpa_bits(),
                                        context->shadow_root_level, false,
                                        boot_cpu_has(X86_FEATURE_GBPAGES),
-                                       true, true);
+                                       false, true);
        else
                __reset_rsvds_bits_mask_ept(shadow_zero_check,
                                            reserved_hpa_bits(), false);