From e8683d5d7e47bdf64117ecd21903e057b6e0233c Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 22 Jun 2021 10:57:11 -0700 Subject: [PATCH] KVM: x86/mmu: Do not set paging-related bits in MMU role if CR0.PG=0 Don't set CR0/CR4/EFER bits in the MMU role if paging is disabled, paging modifiers are irrelevant if there is no paging in the first place. Somewhat arbitrarily clear gpte_is_8_bytes for shadow paging if paging is disabled in the guest. Again, there are no guest PTEs to process, so the size is meaningless. Signed-off-by: Sean Christopherson Message-Id: <20210622175739.3610207-27-seanjc@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/mmu.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 1e5beac6920f9..b109ea16d39eb 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4568,13 +4568,15 @@ static union kvm_mmu_extended_role kvm_calc_mmu_role_ext(struct kvm_vcpu *vcpu, { union kvm_mmu_extended_role ext = {0}; - ext.cr0_pg = ____is_cr0_pg(regs); - ext.cr4_pae = ____is_cr4_pae(regs); - ext.cr4_smep = ____is_cr4_smep(regs); - ext.cr4_smap = ____is_cr4_smap(regs); - ext.cr4_pse = ____is_cr4_pse(regs); - ext.cr4_pke = ____is_cr4_pke(regs); - ext.cr4_la57 = ____is_cr4_la57(regs); + if (____is_cr0_pg(regs)) { + ext.cr0_pg = 1; + ext.cr4_pae = ____is_cr4_pae(regs); + ext.cr4_smep = ____is_cr4_smep(regs); + ext.cr4_smap = ____is_cr4_smap(regs); + ext.cr4_pse = ____is_cr4_pse(regs); + ext.cr4_pke = ____is_cr4_pke(regs); + ext.cr4_la57 = ____is_cr4_la57(regs); + } ext.valid = 1; @@ -4588,8 +4590,10 @@ static union kvm_mmu_role kvm_calc_mmu_role_common(struct kvm_vcpu *vcpu, union kvm_mmu_role role = {0}; role.base.access = ACC_ALL; - role.base.efer_nx = ____is_efer_nx(regs); - role.base.cr0_wp = ____is_cr0_wp(regs); + if (____is_cr0_pg(regs)) { + role.base.efer_nx = ____is_efer_nx(regs); + role.base.cr0_wp = ____is_cr0_wp(regs); + } role.base.smm = is_smm(vcpu); role.base.guest_mode = is_guest_mode(vcpu); @@ -4680,7 +4684,7 @@ kvm_calc_shadow_root_page_role_common(struct kvm_vcpu *vcpu, role.base.smep_andnot_wp = role.ext.cr4_smep && !____is_cr0_wp(regs); role.base.smap_andnot_wp = role.ext.cr4_smap && !____is_cr0_wp(regs); - role.base.gpte_is_8_bytes = ____is_cr4_pae(regs); + role.base.gpte_is_8_bytes = ____is_cr0_pg(regs) && ____is_cr4_pae(regs); return role; } -- 2.39.5