diff options
| -rw-r--r-- | arch/x86/kvm/xen.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c index bfa9809721b5..651f9c5b873d 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -271,7 +271,15 @@ 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); @@ -308,7 +316,14 @@ static void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, bool atomic) * gpc1 lock to make lockdep shut up about it. */ lock_set_subclass(&gpc1->lock.dep_map, 1, _THIS_IP_); - read_lock(&gpc2->lock); + 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); |