diff options
| author | Junaid Shahid <junaids@google.com> | 2018-06-27 14:59:17 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-08-06 17:58:59 +0200 |
| commit | 08fb59d8a47d5e1f9de08659603a47f117fe60d5 (patch) | |
| tree | 0aca93c0ea3187d9e2d6aaa3258af0d526a2f1e0 /arch/x86/kvm | |
| parent | 7eb77e9f5fcf652a21b2d12bff1cd509b6b14f21 (diff) | |
kvm: x86: Support selectively freeing either current or previous MMU root
kvm_mmu_free_roots() now takes a mask specifying which roots to free, so
that either one of the roots (active/previous) can be individually freed
when needed.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 36 |
1 files changed, 22 insertions, 14 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 6eeca915511e..0f6965ce016a 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -3438,14 +3438,18 @@ static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, *root_hpa = INVALID_PAGE; } -void kvm_mmu_free_roots(struct kvm_vcpu *vcpu, bool free_prev_root) +/* roots_to_free must be some combination of the KVM_MMU_ROOT_* flags */ +void kvm_mmu_free_roots(struct kvm_vcpu *vcpu, ulong roots_to_free) { int i; LIST_HEAD(invalid_list); struct kvm_mmu *mmu = &vcpu->arch.mmu; + bool free_active_root = roots_to_free & KVM_MMU_ROOT_CURRENT; + bool free_prev_root = roots_to_free & KVM_MMU_ROOT_PREVIOUS; - if (!VALID_PAGE(mmu->root_hpa) && - (!VALID_PAGE(mmu->prev_root.hpa) || !free_prev_root)) + /* Before acquiring the MMU lock, see if we need to do any real work. */ + if (!(free_active_root && VALID_PAGE(mmu->root_hpa)) && + !(free_prev_root && VALID_PAGE(mmu->prev_root.hpa))) return; spin_lock(&vcpu->kvm->mmu_lock); @@ -3454,15 +3458,19 @@ void kvm_mmu_free_roots(struct kvm_vcpu *vcpu, bool free_prev_root) mmu_free_root_page(vcpu->kvm, &mmu->prev_root.hpa, &invalid_list); - if (mmu->shadow_root_level >= PT64_ROOT_4LEVEL && - (mmu->root_level >= PT64_ROOT_4LEVEL || mmu->direct_map)) { - mmu_free_root_page(vcpu->kvm, &mmu->root_hpa, &invalid_list); - } else { - for (i = 0; i < 4; ++i) - if (mmu->pae_root[i] != 0) - mmu_free_root_page(vcpu->kvm, &mmu->pae_root[i], - &invalid_list); - mmu->root_hpa = INVALID_PAGE; + if (free_active_root) { + if (mmu->shadow_root_level >= PT64_ROOT_4LEVEL && + (mmu->root_level >= PT64_ROOT_4LEVEL || mmu->direct_map)) { + mmu_free_root_page(vcpu->kvm, &mmu->root_hpa, + &invalid_list); + } else { + for (i = 0; i < 4; ++i) + if (mmu->pae_root[i] != 0) + mmu_free_root_page(vcpu->kvm, + &mmu->pae_root[i], + &invalid_list); + mmu->root_hpa = INVALID_PAGE; + } } kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list); @@ -4109,7 +4117,7 @@ static void __kvm_mmu_new_cr3(struct kvm_vcpu *vcpu, gpa_t new_cr3, bool skip_tlb_flush) { if (!fast_cr3_switch(vcpu, new_cr3, new_role, skip_tlb_flush)) - kvm_mmu_free_roots(vcpu, false); + kvm_mmu_free_roots(vcpu, KVM_MMU_ROOT_CURRENT); } void kvm_mmu_new_cr3(struct kvm_vcpu *vcpu, gpa_t new_cr3, bool skip_tlb_flush) @@ -4885,7 +4893,7 @@ EXPORT_SYMBOL_GPL(kvm_mmu_load); void kvm_mmu_unload(struct kvm_vcpu *vcpu) { - kvm_mmu_free_roots(vcpu, true); + kvm_mmu_free_roots(vcpu, KVM_MMU_ROOTS_ALL); WARN_ON(VALID_PAGE(vcpu->arch.mmu.root_hpa)); } EXPORT_SYMBOL_GPL(kvm_mmu_unload); |