Patchwork [07/11] KVM: PPC: Book3S HV: Implement H_CONFER

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Submitter Paul Mackerras
Date Sept. 6, 2013, 3:23 a.m.
Message ID <20130906032321.GH29710@iris.ozlabs.ibm.com>
Download mbox | patch
Permalink /patch/273031/
State New
Headers show

Comments

Paul Mackerras - Sept. 6, 2013, 3:23 a.m.
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>
---
 arch/powerpc/kvm/book3s_hv.c | 9 +++++++++
 1 file changed, 9 insertions(+)
Alexander Graf - Sept. 13, 2013, 9:51 p.m.
On 05.09.2013, at 22:23, Paul Mackerras wrote:

> 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>

Thanks, applied to kvm-ppc-queue.


Alex

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Patch

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 1a10afa..0bb23a9 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -567,6 +567,15 @@  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),