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>
(cherry picked from commit f2e106692d5189303997ad7b96de8d8123aa5613)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 96765c1..e4985fc 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7118,7 +7118,7 @@
int r;
if ((vcpu->arch.mmu.direct_map != work->arch.direct_map) ||
- is_error_page(work->page))
+ work->wakeup_all)
return;
r = kvm_mmu_reload(vcpu);
@@ -7228,7 +7228,7 @@
struct x86_exception fault;
trace_kvm_async_pf_ready(work->arch.token, work->gva);
- if (is_error_page(work->page))
+ if (work->wakeup_all)
work->arch.token = ~0; /* broadcast wakeup */
else
kvm_del_async_pf_gfn(vcpu, work->arch.gfn);