From 8123f265248c85603d55f4e97c68576f45eb1e4d Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Mon, 27 Apr 2020 19:37:14 -0700 Subject: KVM: x86/mmu: Add a helper to consolidate root sp allocation Add a helper, mmu_alloc_root(), to consolidate the allocation of a root shadow page, which has the same basic mechanics for all flavors of TDP and shadow paging. Note, __pa(sp->spt) doesn't need to be protected by mmu_lock, sp->spt points at a kernel page. No functional change intended. Signed-off-by: Sean Christopherson Message-Id: <20200428023714.31923-1-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/mmu.c | 88 ++++++++++++++++++++++---------------------------- 1 file changed, 39 insertions(+), 49 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index fd94668c0f0f..907625fea7b3 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3678,37 +3678,43 @@ static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) return ret; } -static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) +static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, gva_t gva, + u8 level, bool direct) { struct kvm_mmu_page *sp; + + spin_lock(&vcpu->kvm->mmu_lock); + + if (make_mmu_pages_available(vcpu)) { + spin_unlock(&vcpu->kvm->mmu_lock); + return INVALID_PAGE; + } + sp = kvm_mmu_get_page(vcpu, gfn, gva, level, direct, ACC_ALL); + ++sp->root_count; + + spin_unlock(&vcpu->kvm->mmu_lock); + return __pa(sp->spt); +} + +static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) +{ + u8 shadow_root_level = vcpu->arch.mmu->shadow_root_level; + hpa_t root; unsigned i; - if (vcpu->arch.mmu->shadow_root_level >= PT64_ROOT_4LEVEL) { - spin_lock(&vcpu->kvm->mmu_lock); - if(make_mmu_pages_available(vcpu) < 0) { - spin_unlock(&vcpu->kvm->mmu_lock); + if (shadow_root_level >= PT64_ROOT_4LEVEL) { + root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level, true); + if (!VALID_PAGE(root)) return -ENOSPC; - } - sp = kvm_mmu_get_page(vcpu, 0, 0, - vcpu->arch.mmu->shadow_root_level, 1, ACC_ALL); - ++sp->root_count; - spin_unlock(&vcpu->kvm->mmu_lock); - vcpu->arch.mmu->root_hpa = __pa(sp->spt); - } else if (vcpu->arch.mmu->shadow_root_level == PT32E_ROOT_LEVEL) { + vcpu->arch.mmu->root_hpa = root; + } else if (shadow_root_level == PT32E_ROOT_LEVEL) { for (i = 0; i < 4; ++i) { - hpa_t root = vcpu->arch.mmu->pae_root[i]; + MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu->pae_root[i])); - MMU_WARN_ON(VALID_PAGE(root)); - spin_lock(&vcpu->kvm->mmu_lock); - if (make_mmu_pages_available(vcpu) < 0) { - spin_unlock(&vcpu->kvm->mmu_lock); + root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), + i << 30, PT32_ROOT_LEVEL, true); + if (!VALID_PAGE(root)) return -ENOSPC; - } - sp = kvm_mmu_get_page(vcpu, i << (30 - PAGE_SHIFT), - i << 30, PT32_ROOT_LEVEL, 1, ACC_ALL); - root = __pa(sp->spt); - ++sp->root_count; - spin_unlock(&vcpu->kvm->mmu_lock); vcpu->arch.mmu->pae_root[i] = root | PT_PRESENT_MASK; } vcpu->arch.mmu->root_hpa = __pa(vcpu->arch.mmu->pae_root); @@ -3723,9 +3729,9 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) { - struct kvm_mmu_page *sp; u64 pdptr, pm_mask; gfn_t root_gfn, root_pgd; + hpa_t root; int i; root_pgd = vcpu->arch.mmu->get_guest_pgd(vcpu); @@ -3739,20 +3745,12 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) * write-protect the guests page table root. */ if (vcpu->arch.mmu->root_level >= PT64_ROOT_4LEVEL) { - hpa_t root = vcpu->arch.mmu->root_hpa; + MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu->root_hpa)); - MMU_WARN_ON(VALID_PAGE(root)); - - spin_lock(&vcpu->kvm->mmu_lock); - if (make_mmu_pages_available(vcpu) < 0) { - spin_unlock(&vcpu->kvm->mmu_lock); + root = mmu_alloc_root(vcpu, root_gfn, 0, + vcpu->arch.mmu->shadow_root_level, false); + if (!VALID_PAGE(root)) return -ENOSPC; - } - sp = kvm_mmu_get_page(vcpu, root_gfn, 0, - vcpu->arch.mmu->shadow_root_level, 0, ACC_ALL); - root = __pa(sp->spt); - ++sp->root_count; - spin_unlock(&vcpu->kvm->mmu_lock); vcpu->arch.mmu->root_hpa = root; goto set_root_pgd; } @@ -3767,9 +3765,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK; for (i = 0; i < 4; ++i) { - hpa_t root = vcpu->arch.mmu->pae_root[i]; - - MMU_WARN_ON(VALID_PAGE(root)); + MMU_WARN_ON(VALID_PAGE(vcpu->arch.mmu->pae_root[i])); if (vcpu->arch.mmu->root_level == PT32E_ROOT_LEVEL) { pdptr = vcpu->arch.mmu->get_pdptr(vcpu, i); if (!(pdptr & PT_PRESENT_MASK)) { @@ -3780,17 +3776,11 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) if (mmu_check_root(vcpu, root_gfn)) return 1; } - spin_lock(&vcpu->kvm->mmu_lock); - if (make_mmu_pages_available(vcpu) < 0) { - spin_unlock(&vcpu->kvm->mmu_lock); - return -ENOSPC; - } - sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30, PT32_ROOT_LEVEL, - 0, ACC_ALL); - root = __pa(sp->spt); - ++sp->root_count; - spin_unlock(&vcpu->kvm->mmu_lock); + root = mmu_alloc_root(vcpu, root_gfn, i << 30, + PT32_ROOT_LEVEL, false); + if (!VALID_PAGE(root)) + return -ENOSPC; vcpu->arch.mmu->pae_root[i] = root | pm_mask; } vcpu->arch.mmu->root_hpa = __pa(vcpu->arch.mmu->pae_root); -- cgit v1.2.3