Re: [PATCH 21/23] KVM: MMU: store shadow_root_level into mmu_role

David Matlack
2022-02-08T01:05:04Z

On Fri, Feb 04, 2022 at 06:57:16AM -0500, Paolo Bonzini wrote:
> mmu_role.level is always the same value as shadow_level:
>
> - kvm_mmu_get_tdp_level(vcpu) when going through init_kvm_tdp_mmu
>
> - the level argument when going through kvm_init_shadow_ept_mmu
>
> - it's assigned directly from new_role.base.level when going
> through shadow_mmu_init_context
>
> Remove the duplication and get the level directly from the role.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

nit: How about the following for the shortlog?

KVM: MMU: Replace shadow_root_level with mmu_role.level

Otherwise,

Reviewed-by: David Matlack <dmatlack@google.com>

> ---
> arch/x86/include/asm/kvm_host.h | 1 -
> arch/x86/kvm/mmu.h | 2 +-
> arch/x86/kvm/mmu/mmu.c | 36 +++++++++++++++------------------
> arch/x86/kvm/mmu/tdp_mmu.c | 2 +-
> arch/x86/kvm/svm/svm.c | 2 +-
> arch/x86/kvm/vmx/vmx.c | 2 +-
> 6 files changed, 20 insertions(+), 25 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index b0085c54786c..867fc82f1de5 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -433,7 +433,6 @@ struct kvm_mmu {
> union kvm_mmu_role cpu_role;
> union kvm_mmu_page_role mmu_role;
> u8 root_level;
> - u8 shadow_root_level;
> bool direct_map;
> struct kvm_mmu_root_info prev_roots[KVM_MMU_NUM_PREV_ROOTS];
>
> diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
> index 51faa2c76ca5..43b99308cb0e 100644
> --- a/arch/x86/kvm/mmu.h
> +++ b/arch/x86/kvm/mmu.h
> @@ -112,7 +112,7 @@ static inline void kvm_mmu_load_pgd(struct kvm_vcpu *vcpu)
> return;
>
> static_call(kvm_x86_load_mmu_pgd)(vcpu, root_hpa,
> - vcpu->arch.mmu->shadow_root_level);
> + vcpu->arch.mmu->mmu_role.level);
> }
>
> struct kvm_page_fault {
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 6f9d876ce429..4d1fa87718f8 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -2143,7 +2143,7 @@ static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterato
> {
> iterator->addr = addr;
> iterator->shadow_addr = root;
> - iterator->level = vcpu->arch.mmu->shadow_root_level;
> + iterator->level = vcpu->arch.mmu->mmu_role.level;
>
> if (iterator->level >= PT64_ROOT_4LEVEL &&
> vcpu->arch.mmu->root_level < PT64_ROOT_4LEVEL &&
> @@ -3254,7 +3254,7 @@ void kvm_mmu_free_roots(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
> &invalid_list);
>
> if (free_active_root) {
> - if (mmu->shadow_root_level >= PT64_ROOT_4LEVEL &&
> + if (mmu->mmu_role.level >= PT64_ROOT_4LEVEL &&
> (mmu->root_level >= PT64_ROOT_4LEVEL || mmu->direct_map)) {
> mmu_free_root_page(kvm, &mmu->root_hpa, &invalid_list);
> } else if (mmu->pae_root) {
> @@ -3329,7 +3329,7 @@ static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, gva_t gva,
> static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
> {
> struct kvm_mmu *mmu = vcpu->arch.mmu;
> - u8 shadow_root_level = mmu->shadow_root_level;
> + u8 shadow_root_level = mmu->mmu_role.level;
> hpa_t root;
> unsigned i;
> int r;
> @@ -3479,7 +3479,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
> */
> if (mmu->root_level >= PT64_ROOT_4LEVEL) {
> root = mmu_alloc_root(vcpu, root_gfn, 0,
> - mmu->shadow_root_level, false);
> + mmu->mmu_role.level, false);
> mmu->root_hpa = root;
> goto set_root_pgd;
> }
> @@ -3495,7 +3495,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
> * the shadow page table may be a PAE or a long mode page table.
> */
> pm_mask = PT_PRESENT_MASK | shadow_me_mask;
> - if (mmu->shadow_root_level >= PT64_ROOT_4LEVEL) {
> + if (mmu->mmu_role.level >= PT64_ROOT_4LEVEL) {
> pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK;
>
> if (WARN_ON_ONCE(!mmu->pml4_root)) {
> @@ -3504,7 +3504,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
> }
> mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask;
>
> - if (mmu->shadow_root_level == PT64_ROOT_5LEVEL) {
> + if (mmu->mmu_role.level == PT64_ROOT_5LEVEL) {
> if (WARN_ON_ONCE(!mmu->pml5_root)) {
> r = -EIO;
> goto out_unlock;
> @@ -3529,9 +3529,9 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
> mmu->pae_root[i] = root | pm_mask;
> }
>
> - if (mmu->shadow_root_level == PT64_ROOT_5LEVEL)
> + if (mmu->mmu_role.level == PT64_ROOT_5LEVEL)
> mmu->root_hpa = __pa(mmu->pml5_root);
> - else if (mmu->shadow_root_level == PT64_ROOT_4LEVEL)
> + else if (mmu->mmu_role.level == PT64_ROOT_4LEVEL)
> mmu->root_hpa = __pa(mmu->pml4_root);
> else
> mmu->root_hpa = __pa(mmu->pae_root);
> @@ -3547,7 +3547,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
> static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu)
> {
> struct kvm_mmu *mmu = vcpu->arch.mmu;
> - bool need_pml5 = mmu->shadow_root_level > PT64_ROOT_4LEVEL;
> + bool need_pml5 = mmu->mmu_role.level > PT64_ROOT_4LEVEL;
> u64 *pml5_root = NULL;
> u64 *pml4_root = NULL;
> u64 *pae_root;
> @@ -3559,7 +3559,7 @@ static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu)
> * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare.
> */
> if (mmu->direct_map || mmu->root_level >= PT64_ROOT_4LEVEL ||
> - mmu->shadow_root_level < PT64_ROOT_4LEVEL)
> + mmu->mmu_role.level < PT64_ROOT_4LEVEL)
> return 0;
>
> /*
> @@ -4145,7 +4145,7 @@ static bool fast_pgd_switch(struct kvm_vcpu *vcpu, gpa_t new_pgd,
> * having to deal with PDPTEs. We may add support for 32-bit hosts/VMs
> * later if necessary.
> */
> - if (mmu->shadow_root_level >= PT64_ROOT_4LEVEL &&
> + if (mmu->mmu_role.level >= PT64_ROOT_4LEVEL &&
> mmu->root_level >= PT64_ROOT_4LEVEL)
> return cached_root_available(vcpu, new_pgd, new_role);
>
> @@ -4408,17 +4408,17 @@ static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu,
> struct rsvd_bits_validate *shadow_zero_check;
> int i;
>
> - WARN_ON_ONCE(context->shadow_root_level < PT32E_ROOT_LEVEL);
> + WARN_ON_ONCE(context->mmu_role.level < PT32E_ROOT_LEVEL);
>
> shadow_zero_check = &context->shadow_zero_check;
> __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(),
> - context->shadow_root_level, uses_nx,
> + context->mmu_role.level, uses_nx,
> guest_can_use_gbpages(vcpu), is_pse, is_amd);
>
> if (!shadow_me_mask)
> return;
>
> - for (i = context->shadow_root_level; --i >= 0;) {
> + for (i = context->mmu_role.level; --i >= 0;) {
> shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask;
> shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask;
> }
> @@ -4445,7 +4445,7 @@ reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context)
>
> if (boot_cpu_is_amd())
> __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(),
> - context->shadow_root_level, false,
> + context->mmu_role.level, false,
> boot_cpu_has(X86_FEATURE_GBPAGES),
> false, true);
> else
> @@ -4456,7 +4456,7 @@ reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context)
> if (!shadow_me_mask)
> return;
>
> - for (i = context->shadow_root_level; --i >= 0;) {
> + for (i = context->mmu_role.level; --i >= 0;) {
> shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask;
> shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask;
> }
> @@ -4735,7 +4735,6 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu, union kvm_mmu_role cpu_role)
> context->page_fault = kvm_tdp_page_fault;
> context->sync_page = nonpaging_sync_page;
> context->invlpg = NULL;
> - context->shadow_root_level = kvm_mmu_get_tdp_level(vcpu);
> context->direct_map = true;
> context->get_guest_pgd = get_cr3;
> context->get_pdptr = kvm_pdptr_read;
> @@ -4773,7 +4772,6 @@ static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *conte
> context->root_level = cpu_role.base.level;
>
> reset_guest_paging_metadata(vcpu, context);
> - context->shadow_root_level = mmu_role.level;
> }
>
> static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu,
> @@ -4852,8 +4850,6 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
> context->cpu_role.as_u64 = new_role.as_u64;
> context->mmu_role.word = new_role.base.word;
>
> - context->shadow_root_level = level;
> -
> context->page_fault = ept_page_fault;
> context->gva_to_gpa = ept_gva_to_gpa;
> context->sync_page = ept_sync_page;
> diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
> index dd4c78833016..9fb6d983bae9 100644
> --- a/arch/x86/kvm/mmu/tdp_mmu.c
> +++ b/arch/x86/kvm/mmu/tdp_mmu.c
> @@ -1697,7 +1697,7 @@ int kvm_tdp_mmu_get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes,
> gfn_t gfn = addr >> PAGE_SHIFT;
> int leaf = -1;
>
> - *root_level = vcpu->arch.mmu->shadow_root_level;
> + *root_level = vcpu->arch.mmu->mmu_role.level;
>
> tdp_mmu_for_each_pte(iter, mmu, gfn, gfn + 1) {
> leaf = iter.level;
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index 7b5345a66117..5a1d552b535b 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -3815,7 +3815,7 @@ static void svm_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa,
> hv_track_root_tdp(vcpu, root_hpa);
>
> cr3 = vcpu->arch.cr3;
> - } else if (vcpu->arch.mmu->shadow_root_level >= PT64_ROOT_4LEVEL) {
> + } else if (vcpu->arch.mmu->mmu_role.level >= PT64_ROOT_4LEVEL) {
> cr3 = __sme_set(root_hpa) | kvm_get_active_pcid(vcpu);
> } else {
> /* PCID in the guest should be impossible with a 32-bit MMU. */
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 8ac5a6fa7720..5e2c865a04ff 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -2965,7 +2965,7 @@ static void vmx_flush_tlb_current(struct kvm_vcpu *vcpu)
>
> if (enable_ept)
> ept_sync_context(construct_eptp(vcpu, root_hpa,
> - mmu->shadow_root_level));
> + mmu->mmu_role.level));
> else
> vpid_sync_context(vmx_get_current_vpid(vcpu));
> }
> --
> 2.31.1
>
>