Explicitly zero out quadrant and invalid instead of inheriting them from
the root_mmu. Functionally, this patch is a nop as we (should) never
set quadrant for a direct mapped (EPT) root_mmu and nested EPT is only
allowed if EPT is used for L1, and the root_mmu will never be invalid at
this point.
Explicitly setting flags sets the stage for repurposing the legacy
paging bits in role, e.g. nxe, cr0_wp, and sm{a,e}p_andnot_wp, at which
point 'smm' would be the only flag to be inherited from root_mmu.
Tested-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
arch/x86/kvm/mmu.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index e55cebbe7918..71098f2ae870 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4917,11 +4917,15 @@ static union kvm_mmu_role
kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty,
bool execonly)
{
- union kvm_mmu_role role;
+ union kvm_mmu_role role = {0};
+ union kvm_mmu_page_role root_base = vcpu->arch.root_mmu.mmu_role.base;
- /* Base role is inherited from root_mmu */
- role.base.word = vcpu->arch.root_mmu.mmu_role.base.word;
- role.ext = kvm_calc_mmu_role_ext(vcpu);
+ /* Legacy paging and SMM flags are inherited from root_mmu */
+ role.base.smm = root_base.smm;
+ role.base.nxe = root_base.nxe;
+ role.base.cr0_wp = root_base.cr0_wp;
+ role.base.smep_andnot_wp = root_base.smep_andnot_wp;
+ role.base.smap_andnot_wp = root_base.smap_andnot_wp;
role.base.level = PT64_ROOT_4LEVEL;
role.base.direct = false;
@@ -4929,6 +4933,7 @@ kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty,
role.base.guest_mode = true;
role.base.access = ACC_ALL;
+ role.ext = kvm_calc_mmu_role_ext(vcpu);
role.ext.execonly = execonly;
return role;
--
2.21.0
