diff options
| -rw-r--r-- | arch/x86/kvm/x86.c | 10 | ||||
| -rw-r--r-- | include/linux/kvm_host.h | 2 | ||||
| -rw-r--r-- | include/linux/kvm_types.h | 1 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 39 |
4 files changed, 37 insertions, 15 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index b2d5baf..15e79a6 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1448,7 +1448,8 @@ static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data) return 0; } - if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.apf.data, gpa)) + if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.apf.data, gpa, + sizeof(u32))) return 1; vcpu->arch.apf.send_user_only = !(data & KVM_ASYNC_PF_SEND_ALWAYS); @@ -1530,12 +1531,9 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data) gpa_offset = data & ~(PAGE_MASK | 1); - /* Check that the address is 32-byte aligned. */ - if (gpa_offset & (sizeof(struct pvclock_vcpu_time_info) - 1)) - break; - if (kvm_gfn_to_hva_cache_init(vcpu->kvm, - &vcpu->arch.pv_time, data & ~1ULL)) + &vcpu->arch.pv_time, data & ~1ULL, + sizeof(struct pvclock_vcpu_time_info))) vcpu->arch.pv_time_enabled = false; else vcpu->arch.pv_time_enabled = true; diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 8663a26..8cd0f20 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -388,7 +388,7 @@ int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data, int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, void *data, unsigned long len); int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc, - gpa_t gpa); + gpa_t gpa, unsigned long len); int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len); int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len); struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn); diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h index fa7cc72..b0bcce0 100644 --- a/include/linux/kvm_types.h +++ b/include/linux/kvm_types.h @@ -71,6 +71,7 @@ struct gfn_to_hva_cache { u64 generation; gpa_t gpa; unsigned long hva; + unsigned long len; struct kvm_memory_slot *memslot; }; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 88dde44..caa3bb1 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1375,20 +1375,38 @@ int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data, } int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc, - gpa_t gpa) + gpa_t gpa, unsigned long len) { struct kvm_memslots *slots = kvm_memslots(kvm); int offset = offset_in_page(gpa); - gfn_t gfn = gpa >> PAGE_SHIFT; + gfn_t start_gfn = gpa >> PAGE_SHIFT; + gfn_t end_gfn = (gpa + len - 1) >> PAGE_SHIFT; + gfn_t nr_pages_needed = end_gfn - start_gfn + 1; + gfn_t nr_pages_avail; ghc->gpa = gpa; ghc->generation = slots->generation; - ghc->memslot = __gfn_to_memslot(slots, gfn); - ghc->hva = gfn_to_hva_many(ghc->memslot, gfn, NULL); - if (!kvm_is_error_hva(ghc->hva)) + ghc->len = len; + ghc->memslot = gfn_to_memslot(kvm, start_gfn); + ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, &nr_pages_avail); + if (!kvm_is_error_hva(ghc->hva) && nr_pages_avail >= nr_pages_needed) { ghc->hva += offset; - else - return -EFAULT; + } else { + /* + * If the requested region crosses two memslots, we still + * verify that the entire region is valid here. + */ + while (start_gfn <= end_gfn) { + ghc->memslot = gfn_to_memslot(kvm, start_gfn); + ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, + &nr_pages_avail); + if (kvm_is_error_hva(ghc->hva)) + return -EFAULT; + start_gfn += nr_pages_avail; + } + /* Use the slow path for cross page reads and writes. */ + ghc->memslot = NULL; + } return 0; } @@ -1400,8 +1418,13 @@ int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, struct kvm_memslots *slots = kvm_memslots(kvm); int r; + BUG_ON(len > ghc->len); + if (slots->generation != ghc->generation) - kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa); + kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa, ghc->len); + + if (unlikely(!ghc->memslot)) + return kvm_write_guest(kvm, ghc->gpa, data, len); if (kvm_is_error_hva(ghc->hva)) return -EFAULT; |