On 04/27/2012 09:23 PM, Gleb Natapov wrote:
On Fri, Apr 27, 2012 at 04:15:35PM +0530, Raghavendra K T wrote:
On 04/24/2012 03:29 PM, Gleb Natapov wrote:
On Mon, Apr 23, 2012 at 03:29:47PM +0530, Raghavendra K T wrote:
From: Srivatsa Vaddagiri<vatsa@xxxxxxxxxxxxxxxxxx>
KVM_HC_KICK_CPU allows the calling vcpu to kick another vcpu out of halt state.
The presence of these hypercalls is indicated to guest via
KVM_FEATURE_PV_UNHALT/KVM_CAP_PV_UNHALT.
Signed-off-by: Srivatsa Vaddagiri<vatsa@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Suzuki Poulose<suzuki@xxxxxxxxxx>
Signed-off-by: Raghavendra K T<raghavendra.kt@xxxxxxxxxxxxxxxxxx>
---
[...]
+/*
+ * kvm_pv_kick_cpu_op: Kick a vcpu.
+ *
+ * @apicid - apicid of vcpu to be kicked.
+ */
+static void kvm_pv_kick_cpu_op(struct kvm *kvm, int apicid)
+{
+ struct kvm_vcpu *vcpu = NULL;
+ int i;
+
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ if (!kvm_apic_present(vcpu))
+ continue;
+
+ if (kvm_apic_match_dest(vcpu, 0, 0, apicid, 0))
+ break;
+ }
+ if (vcpu) {
+ /*
+ * Setting unhalt flag here can result in spurious runnable
+ * state when unhalt reset does not happen in vcpu_block.
+ * But that is harmless since that should soon result in halt.
+ */
+ vcpu->arch.pv.pv_unhalted = 1;
+ /* We need everybody see unhalt before vcpu unblocks */
+ smp_mb();
+ kvm_vcpu_kick(vcpu);
+ }
+}
This is too similar to kvm_irq_delivery_to_apic(). Why not reuse it. We
can use one of reserved delivery modes as PV delivery mode. We will
disallow guest to trigger it through apic interface, so this will not be
part of ABI and can be changed at will.
[...]
kvm/x86.c
=========
kvm_pv_kick_cpu_op()
{
struct kvm_lapic_irq lapic_irq;
lapic_irq.shorthand = 0;
lapic_irq.dest_mode = 0;
lapic_irq.dest_id = apicid;
lapic_irq.delivery_mode = PV_DELIVERY_MODE;
kvm_irq_delivery_to_apic(kvm, 0,&lapic_irq );
}
kvm/lapic.c
==========
_apic_accept_irq()
{
...
case APIC_DM_REMRD:
result = 1;
vcpu->pv_unhalted = 1
smp_mb();
kvm_make_request(KVM_REQ_EVENT, vcpu);
kvm_vcpu_kick(vcpu);
break;
...
}
here using PV_DELIVERY_MODE = APIC_DM_REMRD, which was unused.
Yes, this is what I mean except that PV_DELIVERY_MODE should be
number defined as reserved by Intel spec.
Hi Gleb, Avi,
This had been TODO in my V8 patches.
I 'll fold this into V9 (while rebasing to
3.5-rc).
Please let me know if it is OK.
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