Add rcu user eqs exception hooks for async page fault

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / x86 / kernel / kvm.c

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 08b973f64032ba31f5e91a0558e2dc003904531a..9c2bd8bd4b4c1f3cbeb7965b04bb57c3239e41a2 100644 (file)
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -43,6 +43,7 @@
 #include <asm/apicdef.h>
 #include <asm/hypervisor.h>
 #include <asm/kvm_guest.h>
+#include <asm/context_tracking.h>
 
 static int kvmapf = 1;
 
@@ -121,6 +122,8 @@ void kvm_async_pf_task_wait(u32 token)
        struct kvm_task_sleep_node n, *e;
        DEFINE_WAIT(wait);
 
+       rcu_irq_enter();
+
        spin_lock(&b->lock);
        e = _find_apf_task(b, token);
        if (e) {
@@ -128,6 +131,8 @@ void kvm_async_pf_task_wait(u32 token)
                hlist_del(&e->link);
                kfree(e);
                spin_unlock(&b->lock);
+
+               rcu_irq_exit();
                return;
        }
 
@@ -152,13 +157,16 @@ void kvm_async_pf_task_wait(u32 token)
                        /*
                         * We cannot reschedule. So halt.
                         */
+                       rcu_irq_exit();
                        native_safe_halt();
+                       rcu_irq_enter();
                        local_irq_disable();
                }
        }
        if (!n.halted)
                finish_wait(&n.wq, &wait);
 
+       rcu_irq_exit();
        return;
 }
 EXPORT_SYMBOL_GPL(kvm_async_pf_task_wait);
@@ -252,10 +260,10 @@ do_async_page_fault(struct pt_regs *regs, unsigned long error_code)
                break;
        case KVM_PV_REASON_PAGE_NOT_PRESENT:
                /* page is swapped out by the host. */
-               rcu_irq_enter();
+               exception_enter(regs);
                exit_idle();
                kvm_async_pf_task_wait((u32)read_cr2());
-               rcu_irq_exit();
+               exception_exit(regs);
                break;
        case KVM_PV_REASON_PAGE_READY:
                rcu_irq_enter();