[RFC 08/17] kvm: arm/arm64: implement kvm_arm_[halt,resume]_guest

Eric Auger
2015-07-02T13:24:10Z

On halt, the guest is forced to exit and prevented from being
re-entered. This is synchronous.

Those two operations will be needed for IRQ forwarding setting.

Signed-off-by: Eric Auger <eric.auger@linaro.org>

---

RFC:
- rename the function and this latter becomes static
- remove __KVM_HAVE_ARCH_HALT_GUEST

v4 -> v5: add arm64 support
- also defines __KVM_HAVE_ARCH_HALT_GUEST for arm64
- add pause field
---
arch/arm/include/asm/kvm_host.h | 3 +++
arch/arm/kvm/arm.c | 32 +++++++++++++++++++++++++++++---
arch/arm64/include/asm/kvm_host.h | 3 +++
3 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 304004d..899ae27 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -132,6 +132,9 @@ struct kvm_vcpu_arch {
/* vcpu power-off state */
bool power_off;

+ /* Don't run the guest */
+ bool pause;
+
/* IO related fields */
struct kvm_decode mmio_decode;

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 7537e68..4be6715 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -471,11 +471,36 @@ bool kvm_arch_intc_initialized(struct kvm *kvm)
return vgic_initialized(kvm);
}

+static void kvm_arm_halt_guest(struct kvm *kvm)
+{
+ int i;
+ struct kvm_vcpu *vcpu;
+
+ kvm_for_each_vcpu(i, vcpu, kvm)
+ vcpu->arch.pause = true;
+ force_vm_exit(cpu_all_mask);
+}
+
+static void kvm_arm_resume_guest(struct kvm *kvm)
+{
+ int i;
+ struct kvm_vcpu *vcpu;
+
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
+
+ vcpu->arch.pause = false;
+ wake_up_interruptible(wq);
+ }
+}
+
+
static void vcpu_pause(struct kvm_vcpu *vcpu)
{
wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);

- wait_event_interruptible(*wq, !vcpu->arch.power_off);
+ wait_event_interruptible(*wq, ((!vcpu->arch.power_off) &&
+ (!vcpu->arch.pause)));
}

static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
@@ -525,7 +550,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)

update_vttbr(vcpu->kvm);

- if (vcpu->arch.power_off)
+ if (vcpu->arch.power_off || vcpu->arch.pause)
vcpu_pause(vcpu);

/*
@@ -551,7 +576,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
run->exit_reason = KVM_EXIT_INTR;
}

- if (ret <= 0 || need_new_vmid_gen(vcpu->kvm)) {
+ if (ret <= 0 || need_new_vmid_gen(vcpu->kvm) ||
+ vcpu->arch.pause) {
local_irq_enable();
preempt_enable();
kvm_vgic_sync_hwstate(vcpu);
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 009da6b..69e3785 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -125,6 +125,9 @@ struct kvm_vcpu_arch {
/* vcpu power-off state */
bool power_off;

+ /* Don't run the guest */
+ bool pause;
+
/* IO related fields */
struct kvm_decode mmio_decode;

--
1.9.1