2020-07-16 03:45:05

by Sean Christopherson

Subject: [PATCH 2/9] KVM: x86/mmu: Add separate helper for shadow NPT root page role calc

Refactor the shadow NPT role calculation into a separate helper to
better differentiate it from the non-nested shadow MMU, e.g. the NPT
variant is never direct and derives its root level from the TDP level.

Signed-off-by: Sean Christopherson <[email protected]>
---
arch/x86/kvm/mmu/mmu.c | 30 +++++++++++++++++++++++++-----
1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 678b6209dad50..0fb033ce6cc57 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4908,7 +4908,7 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
}

static union kvm_mmu_role
-kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu, bool base_only)
+kvm_calc_shadow_root_page_role_common(struct kvm_vcpu *vcpu, bool base_only)
{
union kvm_mmu_role role = kvm_calc_mmu_role_common(vcpu, base_only);

@@ -4916,9 +4916,19 @@ kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu, bool base_only)
!is_write_protection(vcpu);
role.base.smap_andnot_wp = role.ext.cr4_smap &&
!is_write_protection(vcpu);
- role.base.direct = !is_paging(vcpu);
role.base.gpte_is_8_bytes = !!is_pae(vcpu);

+ return role;
+}
+
+static union kvm_mmu_role
+kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu, bool base_only)
+{
+ union kvm_mmu_role role =
+ kvm_calc_shadow_root_page_role_common(vcpu, base_only);
+
+ role.base.direct = !is_paging(vcpu);
+
if (!is_long_mode(vcpu))
role.base.level = PT32E_ROOT_LEVEL;
else if (is_la57_mode(vcpu))
@@ -4956,14 +4966,24 @@ static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4, u32 efe
shadow_mmu_init_context(vcpu, context, cr0, cr4, efer, new_role);
}

+static union kvm_mmu_role
+kvm_calc_shadow_npt_root_page_role(struct kvm_vcpu *vcpu)
+{
+ union kvm_mmu_role role =
+ kvm_calc_shadow_root_page_role_common(vcpu, false);
+
+ role.base.direct = false;
+ role.base.level = vcpu->arch.tdp_level;
+
+ return role;
+}
+
void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4, u32 efer,
gpa_t nested_cr3)
{
struct kvm_mmu *context = &vcpu->arch.guest_mmu;
- union kvm_mmu_role new_role =
- kvm_calc_shadow_mmu_root_page_role(vcpu, false);
+ union kvm_mmu_role new_role = kvm_calc_shadow_npt_root_page_role(vcpu);

- new_role.base.level = vcpu->arch.tdp_level;
context->shadow_root_level = new_role.base.level;

__kvm_mmu_new_pgd(vcpu, nested_cr3, new_role.base, false, false);
--
2.26.0

2020-07-22 17:06:40

by Vitaly Kuznetsov

Subject: Re: [PATCH 2/9] KVM: x86/mmu: Add separate helper for shadow NPT root page role calc

Sean Christopherson <[email protected]> writes:

> Refactor the shadow NPT role calculation into a separate helper to
> better differentiate it from the non-nested shadow MMU, e.g. the NPT
> variant is never direct and derives its root level from the TDP level.
>
> Signed-off-by: Sean Christopherson <[email protected]>
> ---
> arch/x86/kvm/mmu/mmu.c | 30 +++++++++++++++++++++++++-----
> 1 file changed, 25 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 678b6209dad50..0fb033ce6cc57 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -4908,7 +4908,7 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
> }
>
> static union kvm_mmu_role
> -kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu, bool base_only)
> +kvm_calc_shadow_root_page_role_common(struct kvm_vcpu *vcpu, bool base_only)
> {
> union kvm_mmu_role role = kvm_calc_mmu_role_common(vcpu, base_only);
>
> @@ -4916,9 +4916,19 @@ kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu, bool base_only)
> !is_write_protection(vcpu);
> role.base.smap_andnot_wp = role.ext.cr4_smap &&
> !is_write_protection(vcpu);
> - role.base.direct = !is_paging(vcpu);
> role.base.gpte_is_8_bytes = !!is_pae(vcpu);
>
> + return role;
> +}
> +
> +static union kvm_mmu_role
> +kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu, bool base_only)
> +{
> + union kvm_mmu_role role =
> + kvm_calc_shadow_root_page_role_common(vcpu, base_only);
> +
> + role.base.direct = !is_paging(vcpu);
> +
> if (!is_long_mode(vcpu))
> role.base.level = PT32E_ROOT_LEVEL;
> else if (is_la57_mode(vcpu))
> @@ -4956,14 +4966,24 @@ static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4, u32 efe
> shadow_mmu_init_context(vcpu, context, cr0, cr4, efer, new_role);
> }
>
> +static union kvm_mmu_role
> +kvm_calc_shadow_npt_root_page_role(struct kvm_vcpu *vcpu)
> +{
> + union kvm_mmu_role role =
> + kvm_calc_shadow_root_page_role_common(vcpu, false);
> +
> + role.base.direct = false;
> + role.base.level = vcpu->arch.tdp_level;
> +
> + return role;
> +}
> +
> void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4, u32 efer,
> gpa_t nested_cr3)
> {
> struct kvm_mmu *context = &vcpu->arch.guest_mmu;
> - union kvm_mmu_role new_role =
> - kvm_calc_shadow_mmu_root_page_role(vcpu, false);
> + union kvm_mmu_role new_role = kvm_calc_shadow_npt_root_page_role(vcpu);
>
> - new_role.base.level = vcpu->arch.tdp_level;
> context->shadow_root_level = new_role.base.level;
>
> __kvm_mmu_new_pgd(vcpu, nested_cr3, new_role.base, false, false);

Reviewed-by: Vitaly Kuznetsov <[email protected]>

--
Vitaly