// SPDX-License-Identifier: GPL-2.0-only /* * KVM L1 hypervisor optimizations on Hyper-V. */ #include <linux/kvm_host.h> #include <asm/mshyperv.h> #include "hyperv.h" #include "kvm_onhyperv.h" static int kvm_fill_hv_flush_list_func(struct hv_guest_mapping_flush_list *flush, void *data) { struct kvm_tlb_range *range = data; return hyperv_fill_flush_guest_mapping_list(flush, range->start_gfn, range->pages); } static inline int hv_remote_flush_root_tdp(hpa_t root_tdp, struct kvm_tlb_range *range) { if (range) return hyperv_flush_guest_mapping_range(root_tdp, kvm_fill_hv_flush_list_func, (void *)range); else return hyperv_flush_guest_mapping(root_tdp); } int hv_remote_flush_tlb_with_range(struct kvm *kvm, struct kvm_tlb_range *range) { struct kvm_arch *kvm_arch = &kvm->arch; struct kvm_vcpu *vcpu; int ret = 0, nr_unique_valid_roots; unsigned long i; hpa_t root; spin_lock(&kvm_arch->hv_root_tdp_lock); if (!VALID_PAGE(kvm_arch->hv_root_tdp)) { nr_unique_valid_roots = 0; /* * 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) { root = vcpu->arch.hv_root_tdp; if (!VALID_PAGE(root) || root == kvm_arch->hv_root_tdp) continue; /* * 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_roots == 1) kvm_arch->hv_root_tdp = root; if (!ret) ret = hv_remote_flush_root_tdp(root, range); /* * Stop processing roots if a failure occurred and * multiple valid roots have already been detected. */ if (ret && nr_unique_valid_roots > 1) break; } /* * The optimized flush of a single root can't be used if there * are multiple valid roots (obviously). */ if (nr_unique_valid_roots > 1) kvm_arch->hv_root_tdp = INVALID_PAGE; } else { ret = hv_remote_flush_root_tdp(kvm_arch->hv_root_tdp, range); } spin_unlock(&kvm_arch->hv_root_tdp_lock); return ret; } EXPORT_SYMBOL_GPL(hv_remote_flush_tlb_with_range); int hv_remote_flush_tlb(struct kvm *kvm) { return hv_remote_flush_tlb_with_range(kvm, NULL); } EXPORT_SYMBOL_GPL(hv_remote_flush_tlb); void hv_track_root_tdp(struct kvm_vcpu *vcpu, hpa_t root_tdp) { struct kvm_arch *kvm_arch = &vcpu->kvm->arch; if (kvm_x86_ops.tlb_remote_flush == hv_remote_flush_tlb) { spin_lock(&kvm_arch->hv_root_tdp_lock); vcpu->arch.hv_root_tdp = root_tdp; if (root_tdp != kvm_arch->hv_root_tdp) kvm_arch->hv_root_tdp = INVALID_PAGE; spin_unlock(&kvm_arch->hv_root_tdp_lock); } } EXPORT_SYMBOL_GPL(hv_track_root_tdp);