Re: [PATCH 11/23] KVM: MMU: do not recompute root level from kvm_mmu_role_regs

David Matlack
2022-02-07T22:10:47Z

On Fri, Feb 04, 2022 at 06:57:06AM -0500, Paolo Bonzini wrote:
> The root_level can be found in the cpu_role (in fact the field
> is superfluous and could be removed, but one thing at a time).
> Since there is only one usage left of role_regs_to_root_level,
> inline it into kvm_calc_cpu_role.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> arch/x86/kvm/mmu/mmu.c | 23 ++++++++---------------
> 1 file changed, 8 insertions(+), 15 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index f98444e1d834..74789295f922 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -253,19 +253,6 @@ static struct kvm_mmu_role_regs vcpu_to_role_regs(struct kvm_vcpu *vcpu)
> return regs;
> }
>
> -static int role_regs_to_root_level(const struct kvm_mmu_role_regs *regs)
> -{
> - if (!____is_cr0_pg(regs))
> - return 0;
> - else if (____is_efer_lma(regs))
> - return ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL :
> - PT64_ROOT_4LEVEL;
> - else if (____is_cr4_pae(regs))
> - return PT32E_ROOT_LEVEL;
> - else
> - return PT32_ROOT_LEVEL;
> -}
> -
> static inline bool kvm_available_flush_tlb_with_range(void)
> {
> return kvm_x86_ops.tlb_remote_flush_with_range;
> @@ -4673,7 +4660,13 @@ kvm_calc_cpu_role(struct kvm_vcpu *vcpu, const struct kvm_mmu_role_regs *regs)
> role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs);
> role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs);
> role.base.has_4_byte_gpte = !____is_cr4_pae(regs);
> - role.base.level = role_regs_to_root_level(regs);
> +
> + if (____is_efer_lma(regs))
> + role.base.level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL : PT64_ROOT_4LEVEL;
> + else if (____is_cr4_pae(regs))
> + role.base.level = PT32E_ROOT_LEVEL;
> + else
> + role.base.level = PT32_ROOT_LEVEL;

Did you mean to drop the !CR0.PG case?

>
> role.ext.cr0_pg = 1;
> role.ext.cr4_pae = ____is_cr4_pae(regs);
> @@ -4766,7 +4759,7 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu,
> context->get_guest_pgd = get_cr3;
> context->get_pdptr = kvm_pdptr_read;
> context->inject_page_fault = kvm_inject_page_fault;
> - context->root_level = role_regs_to_root_level(regs);
> + context->root_level = cpu_role.base.level;
>
> if (!is_cr0_pg(context))
> context->gva_to_gpa = nonpaging_gva_to_gpa;
> --
> 2.31.1
>
>