| Message ID | 20190313233746.19270-2-sean.j.christopherson@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: fix handling of guest PTE sizes | expand |
Sean Christopherson <sean.j.christopherson@intel.com> writes: > 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@redhat.com> > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> > --- > 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;
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;
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@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- arch/x86/kvm/mmu.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)