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[v2,02/25] KVM: x86/mmu: nested EPT cannot be used in SMM

Message ID	20220221162243.683208-3-pbonzini@redhat.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <kvm-owner@kernel.org> From: Paolo Bonzini <pbonzini@redhat.com> To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: dmatlack@google.com, seanjc@google.com Subject: [PATCH v2 02/25] KVM: x86/mmu: nested EPT cannot be used in SMM Date: Mon, 21 Feb 2022 11:22:20 -0500 Message-Id: <20220221162243.683208-3-pbonzini@redhat.com> In-Reply-To: <20220221162243.683208-1-pbonzini@redhat.com> References: <20220221162243.683208-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	KVM MMU refactoring part 2: role changes \| expand [v2,00/25] KVM MMU refactoring part 2: role changes [v2,01/25] KVM: x86/mmu: avoid indirect call for get_cr3 [v2,02/25] KVM: x86/mmu: nested EPT cannot be used in SMM [v2,03/25] KVM: x86/mmu: constify uses of struct kvm_mmu_role_regs [v2,04/25] KVM: x86/mmu: pull computation of kvm_mmu_role_regs to kvm_init_mmu [v2,05/25] KVM: x86/mmu: rephrase unclear comment [v2,06/25] KVM: nVMX/nSVM: do not monkey-patch inject_page_fault callback [v2,07/25] KVM: x86/mmu: remove "bool base_only" arguments [v2,08/25] KVM: x86/mmu: split cpu_mode from mmu_role [v2,09/25] KVM: x86/mmu: do not recompute root level from kvm_mmu_role_regs [v2,10/25] KVM: x86/mmu: remove ept_ad field [v2,11/25] KVM: x86/mmu: remove kvm_calc_shadow_root_page_role_common [v2,12/25] KVM: x86/mmu: cleanup computation of MMU roles for two-dimensional paging [v2,13/25] KVM: x86/mmu: cleanup computation of MMU roles for shadow paging [v2,14/25] KVM: x86/mmu: store shadow EFER.NX in the MMU role [v2,15/25] KVM: x86/mmu: remove extended bits from mmu_role, rename field [v2,16/25] KVM: x86/mmu: rename kvm_mmu_role union [v2,17/25] KVM: x86/mmu: remove redundant bits from extended role [v2,18/25] KVM: x86/mmu: remove valid from extended role [v2,19/25] KVM: x86/mmu: simplify and/or inline computation of shadow MMU roles [v2,20/25] KVM: x86/mmu: pull CPU mode computation to kvm_init_mmu [v2,21/25] KVM: x86/mmu: replace shadow_root_level with root_role.level [v2,22/25] KVM: x86/mmu: replace root_level with cpu_mode.base.level [v2,23/25] KVM: x86/mmu: replace direct_map with root_role.direct [v2,24/25] KVM: x86/mmu: initialize constant-value fields just once [v2,25/25] KVM: x86/mmu: extract initialization of the page walking data

Commit Message

Paolo Bonzini Feb. 21, 2022, 4:22 p.m. UTC

The role.base.smm flag is always zero when setting up shadow EPT,
do not bother copying it over from vcpu->arch.root_mmu.

Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/mmu/mmu.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

Comments

Sean Christopherson March 8, 2022, 4:18 p.m. UTC | #1

On Mon, Feb 21, 2022, Paolo Bonzini wrote:
> The role.base.smm flag is always zero when setting up shadow EPT,
> do not bother copying it over from vcpu->arch.root_mmu.
> 
> Reviewed-by: David Matlack <dmatlack@google.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---

Reviewed-by: Sean Christopherson <seanjc@google.com>

diff mbox series

Patch

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 7051040e15b3..4f9bbd02fb8b 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4886,9 +4886,11 @@  kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty,
 {
 	union kvm_mmu_role role = {0};
 
-	/* SMM flag is inherited from root_mmu */
-	role.base.smm = vcpu->arch.root_mmu.mmu_role.base.smm;
-
+	/*
+	 * KVM does not support SMM transfer monitors, and consequently does not
+	 * support the "entry to SMM" control either.  role.base.smm is always 0.
+	 */
+	WARN_ON_ONCE(is_smm(vcpu));
 	role.base.level = level;
 	role.base.has_4_byte_gpte = false;
 	role.base.direct = false;