Sean Christopherson <[email protected]> writes: > Track the address of the top-level EPT struct, a.k.a. the root HPA, > instead of the EPTP itself for Hyper-V's paravirt TLB flush. The > paravirt API takes only the address, not the full EPTP, and in theory > tracking the EPTP could lead to false negatives, e.g. if the HPA matched > but the attributes in the EPTP do not. In practice, such a mismatch is > extremely unlikely, if not flat out impossible, given how KVM generates > the EPTP. > > Opportunsitically rename the related fields to use the 'root' > nomenclature, and to prefix them with 'hv_' to connect them to Hyper-V's > paravirt TLB flushing. > > Signed-off-by: Sean Christopherson <[email protected]> > --- > arch/x86/kvm/vmx/vmx.c | 83 ++++++++++++++++++++---------------------- > arch/x86/kvm/vmx/vmx.h | 6 +-- > 2 files changed, 42 insertions(+), 47 deletions(-) > > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index 40a67dd45c8c..330d42ac5e02 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -481,18 +481,14 @@ static int kvm_fill_hv_flush_list_func(struct > hv_guest_mapping_flush_list *flush > range->pages); > } > > -static inline int hv_remote_flush_eptp(u64 eptp, struct kvm_tlb_range *range) > +static inline int hv_remote_flush_root_ept(hpa_t root_ept, > + struct kvm_tlb_range *range) > { > - /* > - * FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE hypercall needs address > - * of the base of EPT PML4 table, strip off EPT configuration > - * information. > - */ > if (range) > - return hyperv_flush_guest_mapping_range(eptp & PAGE_MASK, > + return hyperv_flush_guest_mapping_range(root_ept, > kvm_fill_hv_flush_list_func, (void *)range); > else > - return hyperv_flush_guest_mapping(eptp & PAGE_MASK); > + return hyperv_flush_guest_mapping(root_ept); > } > > static int hv_remote_flush_tlb_with_range(struct kvm *kvm, > @@ -500,56 +496,55 @@ static int hv_remote_flush_tlb_with_range(struct kvm > *kvm, > { > struct kvm_vmx *kvm_vmx = to_kvm_vmx(kvm); > struct kvm_vcpu *vcpu; > - int ret = 0, i, nr_unique_valid_eptps; > - u64 tmp_eptp; > + int ret = 0, i, nr_unique_valid_roots; > + hpa_t root; > > - spin_lock(&kvm_vmx->ept_pointer_lock); > + spin_lock(&kvm_vmx->hv_root_ept_lock); > > - if (!VALID_PAGE(kvm_vmx->hv_tlb_eptp)) { > - nr_unique_valid_eptps = 0; > + if (!VALID_PAGE(kvm_vmx->hv_root_ept)) { > + nr_unique_valid_roots = 0; > > /* > - * Flush all valid EPTPs, and see if all vCPUs have converged > - * on a common EPTP, in which case future flushes can skip the > - * loop and flush the common EPTP. > + * Flush all valid roots, and see if all vCPUs have converged > + * on a common root, in which case future flushes can skip the > + * loop and flush the common root. > */ > kvm_for_each_vcpu(i, vcpu, kvm) { > - tmp_eptp = to_vmx(vcpu)->ept_pointer; > - if (!VALID_PAGE(tmp_eptp) || > - tmp_eptp == kvm_vmx->hv_tlb_eptp) > + root = to_vmx(vcpu)->hv_root_ept; > + if (!VALID_PAGE(root) || root == kvm_vmx->hv_root_ept) > continue; > > /* > - * Set the tracked EPTP to the first valid EPTP. Keep > - * this EPTP for the entirety of the loop even if more > - * EPTPs are encountered as a low effort optimization > - * to avoid flushing the same (first) EPTP again. > + * Set the tracked root to the first valid root. Keep > + * this root for the entirety of the loop even if more > + * roots are encountered as a low effort optimization > + * to avoid flushing the same (first) root again. > */ > - if (++nr_unique_valid_eptps == 1) > - kvm_vmx->hv_tlb_eptp = tmp_eptp; > + if (++nr_unique_valid_roots == 1) > + kvm_vmx->hv_root_ept = root; > > if (!ret) > - ret = hv_remote_flush_eptp(tmp_eptp, range); > + ret = hv_remote_flush_root_ept(root, range); > > /* > - * Stop processing EPTPs if a failure occurred and > - * there is already a detected EPTP mismatch. > + * Stop processing roots if a failure occurred and > + * multiple valid roots have already been detected. > */ > - if (ret && nr_unique_valid_eptps > 1) > + if (ret && nr_unique_valid_roots > 1) > break; > } > > /* > - * The optimized flush of a single EPTP can't be used if there > - * are multiple valid EPTPs (obviously). > + * The optimized flush of a single root can't be used if there > + * are multiple valid roots (obviously). > */ > - if (nr_unique_valid_eptps > 1) > - kvm_vmx->hv_tlb_eptp = INVALID_PAGE; > + if (nr_unique_valid_roots > 1) > + kvm_vmx->hv_root_ept = INVALID_PAGE; > } else { > - ret = hv_remote_flush_eptp(kvm_vmx->hv_tlb_eptp, range); > + ret = hv_remote_flush_root_ept(kvm_vmx->hv_root_ept, range); > } > > - spin_unlock(&kvm_vmx->ept_pointer_lock); > + spin_unlock(&kvm_vmx->hv_root_ept_lock); > return ret; > } > static int hv_remote_flush_tlb(struct kvm *kvm) > @@ -584,17 +579,17 @@ static int hv_enable_direct_tlbflush(struct kvm_vcpu > *vcpu) > > #endif /* IS_ENABLED(CONFIG_HYPERV) */ > > -static void hv_load_mmu_eptp(struct kvm_vcpu *vcpu, u64 eptp) > +static void hv_track_root_ept(struct kvm_vcpu *vcpu, hpa_t root_ept) > { > #if IS_ENABLED(CONFIG_HYPERV) > struct kvm_vmx *kvm_vmx = to_kvm_vmx(vcpu->kvm); > > if (kvm_x86_ops.tlb_remote_flush == hv_remote_flush_tlb) { > - spin_lock(&kvm_vmx->ept_pointer_lock); > - to_vmx(vcpu)->ept_pointer = eptp; > - if (eptp != kvm_vmx->hv_tlb_eptp) > - kvm_vmx->hv_tlb_eptp = INVALID_PAGE; > - spin_unlock(&kvm_vmx->ept_pointer_lock); > + spin_lock(&kvm_vmx->hv_root_ept_lock); > + to_vmx(vcpu)->hv_root_ept = root_ept; > + if (root_ept != kvm_vmx->hv_root_ept) > + kvm_vmx->hv_root_ept = INVALID_PAGE; > + spin_unlock(&kvm_vmx->hv_root_ept_lock); > } > #endif > } > @@ -3092,7 +3087,7 @@ static void vmx_load_mmu_pgd(struct kvm_vcpu *vcpu, > hpa_t root_hpa, > eptp = construct_eptp(vcpu, root_hpa, root_level); > vmcs_write64(EPT_POINTER, eptp); > > - hv_load_mmu_eptp(vcpu, eptp); > + hv_track_root_ept(vcpu, root_hpa); > > if (!enable_unrestricted_guest && !is_paging(vcpu)) > guest_cr3 = to_kvm_vmx(kvm)->ept_identity_map_addr; > @@ -6964,7 +6959,7 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu) > vmx->pi_desc.sn = 1; > > #if IS_ENABLED(CONFIG_HYPERV) > - vmx->ept_pointer = INVALID_PAGE; > + vmx->hv_root_ept = INVALID_PAGE; > #endif > return 0; > > @@ -6983,7 +6978,7 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu) > static int vmx_vm_init(struct kvm *kvm) > { > #if IS_ENABLED(CONFIG_HYPERV) > - spin_lock_init(&to_kvm_vmx(kvm)->ept_pointer_lock); > + spin_lock_init(&to_kvm_vmx(kvm)->hv_root_ept_lock); > #endif > > if (!ple_gap) > diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h > index 2bd86d8b2f4b..5c98d16a0c6f 100644 > --- a/arch/x86/kvm/vmx/vmx.h > +++ b/arch/x86/kvm/vmx/vmx.h > @@ -277,7 +277,7 @@ struct vcpu_vmx { > u64 msr_ia32_feature_control; > u64 msr_ia32_feature_control_valid_bits; > #if IS_ENABLED(CONFIG_HYPERV) > - u64 ept_pointer; > + u64 hv_root_ept; > #endif > > struct pt_desc pt_desc; > @@ -298,8 +298,8 @@ struct kvm_vmx { > gpa_t ept_identity_map_addr; > > #if IS_ENABLED(CONFIG_HYPERV) > - hpa_t hv_tlb_eptp; > - spinlock_t ept_pointer_lock; > + hpa_t hv_root_ept; > + spinlock_t hv_root_ept_lock; > #endif > };
Reviewed-by: Vitaly Kuznetsov <[email protected]> -- Vitaly
