diff options
Diffstat (limited to 'virt/kvm/pfncache.c')
| -rw-r--r-- | virt/kvm/pfncache.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c index 05cb0bcbf662..f610d3945b69 100644 --- a/virt/kvm/pfncache.c +++ b/virt/kvm/pfncache.c @@ -157,6 +157,13 @@ int kvm_gfn_to_pfn_cache_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, if (page_offset + len > PAGE_SIZE) return -EINVAL; + /* + * If another task is refreshing the cache, wait for it to complete. + * There is no guarantee that concurrent refreshes will see the same + * gpa, memslots generation, etc..., so they must be fully serialized. + */ + mutex_lock(&gpc->refresh_lock); + write_lock_irq(&gpc->lock); old_pfn = gpc->pfn; @@ -248,6 +255,8 @@ int kvm_gfn_to_pfn_cache_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, out: write_unlock_irq(&gpc->lock); + mutex_unlock(&gpc->refresh_lock); + gpc_release_pfn_and_khva(kvm, old_pfn, old_khva); return ret; @@ -259,6 +268,7 @@ void kvm_gfn_to_pfn_cache_unmap(struct kvm *kvm, struct gfn_to_pfn_cache *gpc) void *old_khva; kvm_pfn_t old_pfn; + mutex_lock(&gpc->refresh_lock); write_lock_irq(&gpc->lock); gpc->valid = false; @@ -274,6 +284,7 @@ void kvm_gfn_to_pfn_cache_unmap(struct kvm *kvm, struct gfn_to_pfn_cache *gpc) gpc->pfn = KVM_PFN_ERR_FAULT; write_unlock_irq(&gpc->lock); + mutex_unlock(&gpc->refresh_lock); gpc_release_pfn_and_khva(kvm, old_pfn, old_khva); } @@ -288,6 +299,7 @@ int kvm_gfn_to_pfn_cache_init(struct kvm *kvm, struct gfn_to_pfn_cache *gpc, if (!gpc->active) { rwlock_init(&gpc->lock); + mutex_init(&gpc->refresh_lock); gpc->khva = NULL; gpc->pfn = KVM_PFN_ERR_FAULT; |