Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Paolo Bonzini:
 "These are mostly PPC changes for 3.16-new things.  However, there is
  an x86 change too and it is a regression from 3.14.  As it only
  affects nested virtualization and there were other changes in this
  area in 3.16, I am not nominating it for 3.15-stable"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: Check for nested events if there is an injectable interrupt
  KVM: PPC: RTAS: Do byte swaps explicitly
  KVM: PPC: Book3S PR: Fix ABIv2 on LE
  KVM: PPC: Assembly functions exported to modules need _GLOBAL_TOC()
  PPC: Add _GLOBAL_TOC for 32bit
  KVM: PPC: BOOK3S: HV: Use base page size when comparing against slb value
  KVM: PPC: Book3E: Unlock mmu_lock when setting caching atttribute

1 files changed, 12 insertions, 0 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f644933..ef432f8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5887,6 +5887,18 @@ static int inject_pending_event(struct kvm_vcpu *vcpu, bool req_int_win)
 			kvm_x86_ops->set_nmi(vcpu);
 		}
 	} else if (kvm_cpu_has_injectable_intr(vcpu)) {
+		/*
+		 * Because interrupts can be injected asynchronously, we are
+		 * calling check_nested_events again here to avoid a race condition.
+		 * See https://lkml.org/lkml/2014/7/2/60 for discussion about this
+		 * proposal and current concerns.  Perhaps we should be setting
+		 * KVM_REQ_EVENT only on certain events and not unconditionally?
+		 */
+		if (is_guest_mode(vcpu) && kvm_x86_ops->check_nested_events) {
+			r = kvm_x86_ops->check_nested_events(vcpu, req_int_win);
+			if (r != 0)
+				return r;
+		}
 		if (kvm_x86_ops->interrupt_allowed(vcpu)) {
 			kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu),
 					    false);