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authorXiao Guangrong <xiaoguangrong@cn.fujitsu.com>2010-11-01 17:03:44 +0800
committerAvi Kivity <avi@redhat.com>2011-01-12 11:29:03 +0200
commit64f638c7c44fa87e65f51eaf0f8302b9cba2d696 (patch)
tree8aff59c0397f9231f5889d21b682a7a76e7dc66d /virt
parent15096ffceabb9693306982127348890886384aaa (diff)
downloadlinux-stericsson-64f638c7c44fa87e65f51eaf0f8302b9cba2d696.tar.gz
KVM: fix the race while wakeup all pv guest
In kvm_async_pf_wakeup_all(), we add a dummy apf to vcpu->async_pf.done without holding vcpu->async_pf.lock, it will break if we are handling apfs at this time. Also use 'list_empty_careful()' instead of 'list_empty()' Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Acked-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/async_pf.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c
index 100c66ee0220..74268b4c2ee1 100644
--- a/virt/kvm/async_pf.c
+++ b/virt/kvm/async_pf.c
@@ -196,7 +196,7 @@ int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu)
{
struct kvm_async_pf *work;
- if (!list_empty(&vcpu->async_pf.done))
+ if (!list_empty_careful(&vcpu->async_pf.done))
return 0;
work = kmem_cache_zalloc(async_pf_cache, GFP_ATOMIC);
@@ -207,7 +207,10 @@ int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu)
get_page(bad_page);
INIT_LIST_HEAD(&work->queue); /* for list_del to work */
+ spin_lock(&vcpu->async_pf.lock);
list_add_tail(&work->link, &vcpu->async_pf.done);
+ spin_unlock(&vcpu->async_pf.lock);
+
vcpu->async_pf.queued++;
return 0;
}