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authorMarcelo Tosatti <mtosatti@redhat.com>2009-06-17 10:53:47 -0300
committerAvi Kivity <avi@redhat.com>2009-06-28 14:10:29 +0300
commit84261923d3dddb766736023bead6fa07b7e218d5 (patch)
tree23a0c4af14dd9c548c5bcb457c74fdd980e2312e /include/linux
parent29a4b9333bf9ffef12b3dd7cbf2e3dbe01152968 (diff)
KVM: protect concurrent make_all_cpus_request
make_all_cpus_request contains a race condition which can trigger false request completed status, as follows: CPU0 CPU1 if (test_and_set_bit(req,&vcpu->requests)) .... if (test_and_set_bit(req,&vcpu->requests)) .. return proceed to smp_call_function_many(wait=1) Use a spinlock to serialize concurrent CPUs. Cc: stable@kernel.org Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/kvm_host.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index aacc5449f58..16713dc672e 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -125,6 +125,7 @@ struct kvm_kernel_irq_routing_entry {
struct kvm {
struct mutex lock; /* protects the vcpus array and APIC accesses */
spinlock_t mmu_lock;
+ spinlock_t requests_lock;
struct rw_semaphore slots_lock;
struct mm_struct *mm; /* userspace tied to this vm */
int nmemslots;