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authorPaolo Bonzini <pbonzini@redhat.com>2023-01-13 19:27:55 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2023-01-24 14:05:23 +0300
commitdc7c31e922787466957cadf2c0ad21c0f9a4091f (patch)
treeb6c6feeb812282a21d00ae59eaa69033b6c1078a /arch/x86/kvm/xen.c
parentedd731d73221277cb384efeb66da76dae0a68dfa (diff)
parent310bc39546a435c83cc27a0eba878afac0d74714 (diff)
downloadlinux-dc7c31e922787466957cadf2c0ad21c0f9a4091f.tar.xz
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.c90
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);
}