From 45c5eb67da5a668abe79c23a7e64dbc87a600f90 Mon Sep 17 00:00:00 2001 From: Hollis Blanchard Date: Fri, 25 Apr 2008 17:55:49 -0500 Subject: KVM: ppc: Handle guest idle by emulating MSR[WE] writes This reduces host CPU usage when the guest is idle. However, the guest must set MSR[WE] in its idle loop, which Linux did not do until 2.6.26. Signed-off-by: Hollis Blanchard Signed-off-by: Jerone Young Signed-off-by: Avi Kivity --- arch/powerpc/kvm/booke_guest.c | 1 + arch/powerpc/kvm/powerpc.c | 20 +++++++++++++++++--- 2 files changed, 18 insertions(+), 3 deletions(-) (limited to 'arch') diff --git a/arch/powerpc/kvm/booke_guest.c b/arch/powerpc/kvm/booke_guest.c index 6d9884a6884a..b3db6f4576ad 100644 --- a/arch/powerpc/kvm/booke_guest.c +++ b/arch/powerpc/kvm/booke_guest.c @@ -49,6 +49,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { { "inst_emu", VCPU_STAT(emulated_inst_exits) }, { "dec", VCPU_STAT(dec_exits) }, { "ext_intr", VCPU_STAT(ext_intr_exits) }, + { "halt_wakeup", VCPU_STAT(halt_wakeup) }, { NULL } }; diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index bad40bd2d3ac..777e0f34e0ea 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -36,13 +36,12 @@ gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn) int kvm_cpu_has_interrupt(struct kvm_vcpu *v) { - /* XXX implement me */ - return 0; + return !!(v->arch.pending_exceptions); } int kvm_arch_vcpu_runnable(struct kvm_vcpu *v) { - return 1; + return !(v->arch.msr & MSR_WE); } @@ -214,6 +213,11 @@ static void kvmppc_decrementer_func(unsigned long data) struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data; kvmppc_queue_exception(vcpu, BOOKE_INTERRUPT_DECREMENTER); + + if (waitqueue_active(&vcpu->wq)) { + wake_up_interruptible(&vcpu->wq); + vcpu->stat.halt_wakeup++; + } } int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) @@ -339,6 +343,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) int r; sigset_t sigsaved; + vcpu_load(vcpu); + if (vcpu->sigset_active) sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved); @@ -363,12 +369,20 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) if (vcpu->sigset_active) sigprocmask(SIG_SETMASK, &sigsaved, NULL); + vcpu_put(vcpu); + return r; } int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq) { kvmppc_queue_exception(vcpu, BOOKE_INTERRUPT_EXTERNAL); + + if (waitqueue_active(&vcpu->wq)) { + wake_up_interruptible(&vcpu->wq); + vcpu->stat.halt_wakeup++; + } + return 0; } -- cgit v1.2.2