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author | Paolo Bonzini <pbonzini@redhat.com> | 2023-01-13 11:27:55 -0500 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2023-01-24 06:05:23 -0500 |
commit | dc7c31e922787466957cadf2c0ad21c0f9a4091f (patch) | |
tree | b6c6feeb812282a21d00ae59eaa69033b6c1078a /arch/x86/kvm/xen.c | |
parent | edd731d73221277cb384efeb66da76dae0a68dfa (diff) | |
parent | 310bc39546a435c83cc27a0eba878afac0d74714 (diff) | |
download | linux-dc7c31e922787466957cadf2c0ad21c0f9a4091f.tar.gz linux-dc7c31e922787466957cadf2c0ad21c0f9a4091f.tar.bz2 linux-dc7c31e922787466957cadf2c0ad21c0f9a4091f.zip |
Merge branch 'kvm-v6.2-rc4-fixes' into HEAD
ARM:
* Fix the PMCR_EL0 reset value after the PMU rework
* Correctly handle S2 fault triggered by a S1 page table walk
by not always classifying it as a write, as this breaks on
R/O memslots
* Document why we cannot exit with KVM_EXIT_MMIO when taking
a write fault from a S1 PTW on a R/O memslot
* Put the Apple M2 on the naughty list for not being able to
correctly implement the vgic SEIS feature, just like the M1
before it
* Reviewer updates: Alex is stepping down, replaced by Zenghui
x86:
* Fix various rare locking issues in Xen emulation and teach lockdep
to detect them
* Documentation improvements
* Do not return host topology information from KVM_GET_SUPPORTED_CPUID
Diffstat (limited to 'arch/x86/kvm/xen.c')
-rw-r--r-- | arch/x86/kvm/xen.c | 90 |
1 files changed, 50 insertions, 40 deletions
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c index 0bd5d171df57..2681e2007e39 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -272,7 +272,15 @@ static void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, bool atomic) * Attempt to obtain the GPC lock on *both* (if there are two) * gfn_to_pfn caches that cover the region. */ - read_lock_irqsave(&gpc1->lock, flags); + if (atomic) { + local_irq_save(flags); + if (!read_trylock(&gpc1->lock)) { + local_irq_restore(flags); + return; + } + } else { + read_lock_irqsave(&gpc1->lock, flags); + } while (!kvm_gpc_check(gpc1, user_len1)) { read_unlock_irqrestore(&gpc1->lock, flags); @@ -305,9 +313,18 @@ static void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, bool atomic) * The guest's runstate_info is split across two pages and we * need to hold and validate both GPCs simultaneously. We can * declare a lock ordering GPC1 > GPC2 because nothing else - * takes them more than one at a time. + * takes them more than one at a time. Set a subclass on the + * gpc1 lock to make lockdep shut up about it. */ - read_lock(&gpc2->lock); + lock_set_subclass(&gpc1->lock.dep_map, 1, _THIS_IP_); + if (atomic) { + if (!read_trylock(&gpc2->lock)) { + read_unlock_irqrestore(&gpc1->lock, flags); + return; + } + } else { + read_lock(&gpc2->lock); + } if (!kvm_gpc_check(gpc2, user_len2)) { read_unlock(&gpc2->lock); @@ -591,26 +608,26 @@ int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) if (!IS_ENABLED(CONFIG_64BIT) && data->u.long_mode) { r = -EINVAL; } else { - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.xen.xen_lock); kvm->arch.xen.long_mode = !!data->u.long_mode; - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.xen.xen_lock); r = 0; } break; case KVM_XEN_ATTR_TYPE_SHARED_INFO: - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.xen.xen_lock); r = kvm_xen_shared_info_init(kvm, data->u.shared_info.gfn); - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.xen.xen_lock); break; case KVM_XEN_ATTR_TYPE_UPCALL_VECTOR: if (data->u.vector && data->u.vector < 0x10) r = -EINVAL; else { - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.xen.xen_lock); kvm->arch.xen.upcall_vector = data->u.vector; - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.xen.xen_lock); r = 0; } break; @@ -620,9 +637,9 @@ int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) break; case KVM_XEN_ATTR_TYPE_XEN_VERSION: - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.xen.xen_lock); kvm->arch.xen.xen_version = data->u.xen_version; - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.xen.xen_lock); r = 0; break; @@ -631,9 +648,9 @@ int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) r = -EOPNOTSUPP; break; } - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.xen.xen_lock); kvm->arch.xen.runstate_update_flag = !!data->u.runstate_update_flag; - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.xen.xen_lock); r = 0; break; @@ -648,7 +665,7 @@ int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) { int r = -ENOENT; - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.xen.xen_lock); switch (data->type) { case KVM_XEN_ATTR_TYPE_LONG_MODE: @@ -687,7 +704,7 @@ int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) break; } - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.xen.xen_lock); return r; } @@ -695,7 +712,7 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data) { int idx, r = -ENOENT; - mutex_lock(&vcpu->kvm->lock); + mutex_lock(&vcpu->kvm->arch.xen.xen_lock); idx = srcu_read_lock(&vcpu->kvm->srcu); switch (data->type) { @@ -923,7 +940,7 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data) } srcu_read_unlock(&vcpu->kvm->srcu, idx); - mutex_unlock(&vcpu->kvm->lock); + mutex_unlock(&vcpu->kvm->arch.xen.xen_lock); return r; } @@ -931,7 +948,7 @@ int kvm_xen_vcpu_get_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data) { int r = -ENOENT; - mutex_lock(&vcpu->kvm->lock); + mutex_lock(&vcpu->kvm->arch.xen.xen_lock); switch (data->type) { case KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO: @@ -1014,7 +1031,7 @@ int kvm_xen_vcpu_get_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data) break; } - mutex_unlock(&vcpu->kvm->lock); + mutex_unlock(&vcpu->kvm->arch.xen.xen_lock); return r; } @@ -1107,7 +1124,7 @@ int kvm_xen_hvm_config(struct kvm *kvm, struct kvm_xen_hvm_config *xhc) xhc->blob_size_32 || xhc->blob_size_64)) return -EINVAL; - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.xen.xen_lock); if (xhc->msr && !kvm->arch.xen_hvm_config.msr) static_branch_inc(&kvm_xen_enabled.key); @@ -1116,7 +1133,7 @@ int kvm_xen_hvm_config(struct kvm *kvm, struct kvm_xen_hvm_config *xhc) memcpy(&kvm->arch.xen_hvm_config, xhc, sizeof(*xhc)); - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.xen.xen_lock); return 0; } @@ -1659,15 +1676,7 @@ static int kvm_xen_set_evtchn(struct kvm_xen_evtchn *xe, struct kvm *kvm) mm_borrowed = true; } - /* - * For the irqfd workqueue, using the main kvm->lock mutex is - * fine since this function is invoked from kvm_set_irq() with - * no other lock held, no srcu. In future if it will be called - * directly from a vCPU thread (e.g. on hypercall for an IPI) - * then it may need to switch to using a leaf-node mutex for - * serializing the shared_info mapping. - */ - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.xen.xen_lock); /* * It is theoretically possible for the page to be unmapped @@ -1696,7 +1705,7 @@ static int kvm_xen_set_evtchn(struct kvm_xen_evtchn *xe, struct kvm *kvm) srcu_read_unlock(&kvm->srcu, idx); } while(!rc); - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.xen.xen_lock); if (mm_borrowed) kthread_unuse_mm(kvm->mm); @@ -1812,7 +1821,7 @@ static int kvm_xen_eventfd_update(struct kvm *kvm, int ret; /* Protect writes to evtchnfd as well as the idr lookup. */ - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.xen.xen_lock); evtchnfd = idr_find(&kvm->arch.xen.evtchn_ports, port); ret = -ENOENT; @@ -1843,7 +1852,7 @@ static int kvm_xen_eventfd_update(struct kvm *kvm, } ret = 0; out_unlock: - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.xen.xen_lock); return ret; } @@ -1906,10 +1915,10 @@ static int kvm_xen_eventfd_assign(struct kvm *kvm, evtchnfd->deliver.port.priority = data->u.evtchn.deliver.port.priority; } - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.xen.xen_lock); ret = idr_alloc(&kvm->arch.xen.evtchn_ports, evtchnfd, port, port + 1, GFP_KERNEL); - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.xen.xen_lock); if (ret >= 0) return 0; @@ -1927,9 +1936,9 @@ static int kvm_xen_eventfd_deassign(struct kvm *kvm, u32 port) { struct evtchnfd *evtchnfd; - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.xen.xen_lock); evtchnfd = idr_remove(&kvm->arch.xen.evtchn_ports, port); - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.xen.xen_lock); if (!evtchnfd) return -ENOENT; @@ -1947,7 +1956,7 @@ static int kvm_xen_eventfd_reset(struct kvm *kvm) int i; int n = 0; - mutex_lock(&kvm->lock); + mutex_lock(&kvm->arch.xen.xen_lock); /* * Because synchronize_srcu() cannot be called inside the @@ -1959,7 +1968,7 @@ static int kvm_xen_eventfd_reset(struct kvm *kvm) all_evtchnfds = kmalloc_array(n, sizeof(struct evtchnfd *), GFP_KERNEL); if (!all_evtchnfds) { - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.xen.xen_lock); return -ENOMEM; } @@ -1968,7 +1977,7 @@ static int kvm_xen_eventfd_reset(struct kvm *kvm) all_evtchnfds[n++] = evtchnfd; idr_remove(&kvm->arch.xen.evtchn_ports, evtchnfd->send_port); } - mutex_unlock(&kvm->lock); + mutex_unlock(&kvm->arch.xen.xen_lock); synchronize_srcu(&kvm->srcu); @@ -2070,6 +2079,7 @@ void kvm_xen_destroy_vcpu(struct kvm_vcpu *vcpu) void kvm_xen_init_vm(struct kvm *kvm) { + mutex_init(&kvm->arch.xen.xen_lock); idr_init(&kvm->arch.xen.evtchn_ports); kvm_gpc_init(&kvm->arch.xen.shinfo_cache, kvm, NULL, KVM_HOST_USES_PFN); } |