Sean Christopherson <sean.j.christopherson@xxxxxxxxx> writes:
> Move the initialization of shadow NPT MMU's shadow_root_level into
> kvm_init_shadow_npt_mmu() and explicitly set the level in the shadow NPT
> MMU's role to be the TDP level. This ensures the role and MMU levels
> are synchronized and also initialized before __kvm_mmu_new_pgd(), which
> consumes the level when attempting a fast PGD switch.
>
> Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> Fixes: 9fa72119b24db ("kvm: x86: Introduce kvm_mmu_calc_root_page_role()")
> Fixes: a506fdd223426 ("KVM: nSVM: implement nested_svm_load_cr3() and use it for host->guest switch")
> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> ---
> arch/x86/kvm/mmu/mmu.c | 3 +++
> arch/x86/kvm/svm/nested.c | 1 -
> 2 files changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 77810ce66bdb4..678b6209dad50 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -4963,6 +4963,9 @@ void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, u32 cr0, u32 cr4, u32 efer,
> union kvm_mmu_role new_role =
> kvm_calc_shadow_mmu_root_page_role(vcpu, false);
>
> + 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);
>
> if (new_role.as_u64 != context->mmu_role.as_u64)
> diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
> index 61378a3c2ce44..fb68467e60496 100644
> --- a/arch/x86/kvm/svm/nested.c
> +++ b/arch/x86/kvm/svm/nested.c
> @@ -85,7 +85,6 @@ static void nested_svm_init_mmu_context(struct kvm_vcpu *vcpu)
> vcpu->arch.mmu->get_guest_pgd = nested_svm_get_tdp_cr3;
> vcpu->arch.mmu->get_pdptr = nested_svm_get_tdp_pdptr;
> vcpu->arch.mmu->inject_page_fault = nested_svm_inject_npf_exit;
> - vcpu->arch.mmu->shadow_root_level = vcpu->arch.tdp_level;
> reset_shadow_zero_bits_mask(vcpu, vcpu->arch.mmu);
> vcpu->arch.walk_mmu = &vcpu->arch.nested_mmu;
> }
FWIW,
Reviewed-and-tested-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
--
Vitaly
