Fix race condition that can cause a crash at startup.

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Merge tag 'for-upstream' of https://gitlab.com/bonzini/qemu into staging

Fix race condition that can cause a crash at startup.

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# gpg: Signature made Tue 04 Apr 2023 17:47:22 BST
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* tag 'for-upstream' of https://gitlab.com/bonzini/qemu:
  kvm: dirty-ring: Fix race with vcpu creation

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Peter Maydell 2023-04-04 19:50:22 +01:00
commit b5fba99ec7

View File

@ -685,6 +685,15 @@ static uint32_t kvm_dirty_ring_reap_one(KVMState *s, CPUState *cpu)
uint32_t ring_size = s->kvm_dirty_ring_size;
uint32_t count = 0, fetch = cpu->kvm_fetch_index;
/*
* It's possible that we race with vcpu creation code where the vcpu is
* put onto the vcpus list but not yet initialized the dirty ring
* structures. If so, skip it.
*/
if (!cpu->created) {
return 0;
}
assert(dirty_gfns && ring_size);
trace_kvm_dirty_ring_reap_vcpu(cpu->cpu_index);