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| author | chai wen <chaiw.fnst@cn.fujitsu.com> | 2013-10-14 22:22:33 +0800 |
|---|---|---|
| committer | Gleb Natapov <gleb@redhat.com> | 2013-10-15 13:43:37 +0300 |
| commit | f2e106692d5189303997ad7b96de8d8123aa5613 (patch) | |
| tree | be15cad31bc5701570a571b3be04e299bb4ac547 /virt | |
| parent | a7efdf6bec34f1a693a926ebd08de6ba6e700dff (diff) | |
| download | linux-stable-f2e106692d5189303997ad7b96de8d8123aa5613.tar.gz linux-stable-f2e106692d5189303997ad7b96de8d8123aa5613.tar.bz2 linux-stable-f2e106692d5189303997ad7b96de8d8123aa5613.zip | |
KVM: Drop FOLL_GET in GUP when doing async page fault
Page pinning is not mandatory in kvm async page fault processing since
after async page fault event is delivered to a guest it accesses page once
again and does its own GUP. Drop the FOLL_GET flag in GUP in async_pf
code, and do some simplifying in check/clear processing.
Suggested-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Gu zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: chai wen <chaiw.fnst@cn.fujitsu.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/async_pf.c | 17 |
1 files changed, 5 insertions, 12 deletions
diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c index b197950ac4d5..8631d9c14320 100644 --- a/virt/kvm/async_pf.c +++ b/virt/kvm/async_pf.c @@ -56,7 +56,6 @@ void kvm_async_pf_vcpu_init(struct kvm_vcpu *vcpu) static void async_pf_execute(struct work_struct *work) { - struct page *page = NULL; struct kvm_async_pf *apf = container_of(work, struct kvm_async_pf, work); struct mm_struct *mm = apf->mm; @@ -68,13 +67,12 @@ static void async_pf_execute(struct work_struct *work) use_mm(mm); down_read(&mm->mmap_sem); - get_user_pages(current, mm, addr, 1, 1, 0, &page, NULL); + get_user_pages(current, mm, addr, 1, 1, 0, NULL, NULL); up_read(&mm->mmap_sem); unuse_mm(mm); spin_lock(&vcpu->async_pf.lock); list_add_tail(&apf->link, &vcpu->async_pf.done); - apf->page = page; spin_unlock(&vcpu->async_pf.lock); /* @@ -82,7 +80,7 @@ static void async_pf_execute(struct work_struct *work) * this point */ - trace_kvm_async_pf_completed(addr, page, gva); + trace_kvm_async_pf_completed(addr, gva); if (waitqueue_active(&vcpu->wq)) wake_up_interruptible(&vcpu->wq); @@ -112,8 +110,6 @@ void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu) list_entry(vcpu->async_pf.done.next, typeof(*work), link); list_del(&work->link); - if (!is_error_page(work->page)) - kvm_release_page_clean(work->page); kmem_cache_free(async_pf_cache, work); } spin_unlock(&vcpu->async_pf.lock); @@ -133,14 +129,11 @@ void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu) list_del(&work->link); spin_unlock(&vcpu->async_pf.lock); - if (work->page) - kvm_arch_async_page_ready(vcpu, work); + kvm_arch_async_page_ready(vcpu, work); kvm_arch_async_page_present(vcpu, work); list_del(&work->queue); vcpu->async_pf.queued--; - if (!is_error_page(work->page)) - kvm_release_page_clean(work->page); kmem_cache_free(async_pf_cache, work); } } @@ -163,7 +156,7 @@ int kvm_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn, if (!work) return 0; - work->page = NULL; + work->wakeup_all = false; work->vcpu = vcpu; work->gva = gva; work->addr = gfn_to_hva(vcpu->kvm, gfn); @@ -203,7 +196,7 @@ int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu) if (!work) return -ENOMEM; - work->page = KVM_ERR_PTR_BAD_PAGE; + work->wakeup_all = true; INIT_LIST_HEAD(&work->queue); /* for list_del to work */ spin_lock(&vcpu->async_pf.lock); |