On 04/23/2012 12:59 PM, 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.
>
> #endif
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index e216ba0..dad475b 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -481,6 +481,10 @@ struct kvm_vcpu_arch {
> u64 length;
> u64 status;
> } osvw;
> + /* pv related host specific info */
> + struct {
> + int pv_unhalted;
> + } pv;
> };
'bool'. Or maybe push into vcpu->requests.
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 4044ce0..7fc9be6 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -2147,6 +2147,7 @@ int kvm_dev_ioctl_check_extension(long ext)
> case KVM_CAP_ASYNC_PF:
> case KVM_CAP_GET_TSC_KHZ:
> case KVM_CAP_PCI_2_3:
> + case KVM_CAP_PV_UNHALT:
> r = 1;
> break;
> case KVM_CAP_COALESCED_MMIO:
Redundant, since we can infer this from KVM_GET_SUPPORTED_CPUID. But
please indicate this in the documentation.
>
> +/*
> + * 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();
smp_wmb().
> + kvm_vcpu_kick(vcpu);
> + }
> +}
> +
>
> /*
> * hypercalls use architecture specific
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 42b7393..edf56d4 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -1500,6 +1500,14 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
> prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
>
> if (kvm_arch_vcpu_runnable(vcpu)) {
> + /*
> + * This is the only safe place to reset unhalt flag.
> + * otherwise it results in loosing the notification
> + * which eventually can result in vcpu hangs.
> + */
> + kvm_arch_vcpu_reset_pv_unhalted(vcpu);
> + /* preventing reordering should be enough here */
> + barrier();
> kvm_make_request(KVM_REQ_UNHALT, vcpu);
> break;
> }
>
Hm, what about reusing KVM_REQ_UNHALT?
--
error compiling committee.c: too many arguments to function
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