KVM: Resolve RCU vs. async page fault problem
"Page ready" async PF can kick vcpu out of idle state much like IRQ.
We need to tell RCU about this.
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 694d801..b8ba6e4 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -38,6 +38,7 @@
#include <asm/traps.h>
#include <asm/desc.h>
#include <asm/tlbflush.h>
+#include <asm/idle.h>
static int kvmapf = 1;
@@ -253,7 +254,10 @@
kvm_async_pf_task_wait((u32)read_cr2());
break;
case KVM_PV_REASON_PAGE_READY:
+ rcu_irq_enter();
+ exit_idle();
kvm_async_pf_task_wake((u32)read_cr2());
+ rcu_irq_exit();
break;
}
}