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

Paolo Bonzini
2022-02-21T16:23:05Z

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(-)

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;
--
2.31.1