schedule_work() returns 'false' only when the work is already on the queue and this can't happen as kvm_setup_async_pf() always allocates a new one. Also, to avoid potential race, it makes sense to to schedule_work() at the very end after we've added it to the queue. While on it, do some minor cleanup. gfn_to_pfn_async() mentioned in a comment does not currently exist and, moreover, we can check kvm_is_error_hva() at the very beginning, before we try to allocate work so 'retry_sync' label can go away completely. Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> --- virt/kvm/async_pf.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c index f1e07fae84e9..ba080088da76 100644 --- a/virt/kvm/async_pf.c +++ b/virt/kvm/async_pf.c @@ -164,7 +164,9 @@ int kvm_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, if (vcpu->async_pf.queued >= ASYNC_PF_PER_VCPU) return 0; - /* setup delayed work */ + /* Arch specific code should not do async PF in this case */ + if (unlikely(kvm_is_error_hva(hva))) + return 0; /* * do alloc nowait since if we are going to sleep anyway we @@ -183,24 +185,15 @@ int kvm_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, mmget(work->mm); kvm_get_kvm(work->vcpu->kvm); - /* this can't really happen otherwise gfn_to_pfn_async - would succeed */ - if (unlikely(kvm_is_error_hva(work->addr))) - goto retry_sync; - INIT_WORK(&work->work, async_pf_execute); - if (!schedule_work(&work->work)) - goto retry_sync; list_add_tail(&work->queue, &vcpu->async_pf.queue); vcpu->async_pf.queued++; kvm_arch_async_page_not_present(vcpu, work); + + schedule_work(&work->work); + return 1; -retry_sync: - kvm_put_kvm(work->vcpu->kvm); - mmput(work->mm); - kmem_cache_free(async_pf_cache, work); - return 0; } int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu) -- 2.25.4
