Commit 2fa6e1e1 authored by Radim Krčmář's avatar Radim Krčmář Committed by Christoffer Dall
Browse files

KVM: add kvm_request_pending 



A first step in vcpu->requests encapsulation.  Additionally, we now
use READ_ONCE() when accessing vcpu->requests, which ensures we
always load vcpu->requests when it's accessed.  This is important as
other threads can change it any time.  Also, READ_ONCE() documents
that vcpu->requests is used with other threads, likely requiring
memory barriers, which it does.

Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
[ Documented the new use of READ_ONCE() and converted another check
  in arch/mips/kvm/vz.c ]
Signed-off-by: default avatarAndrew Jones <drjones@redhat.com>
Acked-by: default avatarChristoffer Dall <cdall@linaro.org>
Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
parent 2387149e

arch/mips/kvm/trap_emul.c

+1 −1
Original line number Diff line number Diff line
@@ -1094,7 +1094,7 @@ static void kvm_trap_emul_check_requests(struct kvm_vcpu *vcpu, int cpu, 
	struct mm_struct *mm;

	int i;



	if (likely(!vcpu->requests))

	if (likely(!kvm_request_pending(vcpu)))

		return;



	if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) {

arch/mips/kvm/vz.c

+1 −1
Original line number Diff line number Diff line
@@ -2337,7 +2337,7 @@ static int kvm_vz_check_requests(struct kvm_vcpu *vcpu, int cpu) 
	int ret = 0;

	int i;



	if (!vcpu->requests)

	if (!kvm_request_pending(vcpu))

		return 0;



	if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) {

arch/powerpc/kvm/booke.c

+1 −1
Original line number Diff line number Diff line
@@ -687,7 +687,7 @@ int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu) 


	kvmppc_core_check_exceptions(vcpu);



	if (vcpu->requests) {

	if (kvm_request_pending(vcpu)) {

		/* Exception delivery raised request; start over */

		return 1;

	}

arch/powerpc/kvm/powerpc.c

+2 −3
Original line number Diff line number Diff line
@@ -55,8 +55,7 @@ EXPORT_SYMBOL_GPL(kvmppc_pr_ops); 


int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)

{

	return !!(v->arch.pending_exceptions) ||

	       v->requests;

	return !!(v->arch.pending_exceptions) || kvm_request_pending(v);

}



int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
@@ -108,7 +107,7 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu) 
		 */

		smp_mb();



		if (vcpu->requests) {

		if (kvm_request_pending(vcpu)) {

			/* Make sure we process requests preemptable */

			local_irq_enable();

			trace_kvm_check_requests(vcpu);

arch/s390/kvm/kvm-s390.c

+1 −1
Original line number Diff line number Diff line
@@ -2440,7 +2440,7 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu) 
{

retry:

	kvm_s390_vcpu_request_handled(vcpu);

	if (!vcpu->requests)

	if (!kvm_request_pending(vcpu))

		return 0;

	/*

	 * We use MMU_RELOAD just to re-arm the ipte notifier for the

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