Patchwork [PULL,05/51] KVM: PPC: Book3S HV: Implement H_CONFER

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Submitter Alexander Graf
Date Oct. 31, 2013, 9:17 p.m.
Message ID <1383254316-11243-6-git-send-email-agraf@suse.de>
Download mbox | patch
Permalink /patch/287623/
State New
Headers show

Comments

Alexander Graf - Oct. 31, 2013, 9:17 p.m.
From: Paul Mackerras <paulus@samba.org>

The H_CONFER hypercall is used when a guest vcpu is spinning on a lock
held by another vcpu which has been preempted, and the spinning vcpu
wishes to give its timeslice to the lock holder.  We implement this
in the straightforward way using kvm_vcpu_yield_to().

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
 arch/powerpc/kvm/book3s_hv.c | 9 +++++++++
 1 file changed, 9 insertions(+)

Patch

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 56f57af..a010aa4 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -538,6 +538,15 @@  int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 		}
 		break;
 	case H_CONFER:
+		target = kvmppc_get_gpr(vcpu, 4);
+		if (target == -1)
+			break;
+		tvcpu = kvmppc_find_vcpu(vcpu->kvm, target);
+		if (!tvcpu) {
+			ret = H_PARAMETER;
+			break;
+		}
+		kvm_vcpu_yield_to(tvcpu);
 		break;
 	case H_REGISTER_VPA:
 		ret = do_h_register_vpa(vcpu, kvmppc_get_gpr(vcpu, 4),