[RFC v5 11/13] kvm: arm/arm64: implement kvm_arch_halt_guest and kvm_arch_resume_guest

From: Eric Auger
Date: Thu Mar 19 2015 - 10:59:03 EST


This patch defines __KVM_HAVE_ARCH_HALT_GUEST and implements
kvm_arch_halt_guest and kvm_arch_resume_guest for ARM.

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

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

---

v4 -> v5: add arm64 support
- also defines __KVM_HAVE_ARCH_HALT_GUEST for arm64
- add pause field
---
arch/arm/include/asm/kvm_host.h | 4 ++++
arch/arm/kvm/arm.c | 32 +++++++++++++++++++++++++++++---
arch/arm64/include/asm/kvm_host.h | 4 ++++
3 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 79a919c..b829f93 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -28,6 +28,7 @@
#include <kvm/arm_arch_timer.h>

#define __KVM_HAVE_ARCH_INTC_INITIALIZED
+#define __KVM_HAVE_ARCH_HALT_GUEST

#if defined(CONFIG_KVM_ARM_MAX_VCPUS)
#define KVM_MAX_VCPUS CONFIG_KVM_ARM_MAX_VCPUS
@@ -132,6 +133,9 @@ 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 08e12dc..ebc0b55 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -454,11 +454,36 @@ bool kvm_arch_intc_initialized(struct kvm *kvm)
return vgic_initialized(kvm);
}

+void kvm_arch_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);
+}
+
+void kvm_arch_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)
@@ -508,7 +533,7 @@ 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);

kvm_vgic_flush_hwstate(vcpu);
@@ -526,7 +551,8 @@ 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) {
kvm_timer_sync_hwstate(vcpu);
local_irq_enable();
kvm_timer_finish_sync(vcpu);
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index a713b0c..ffcc698 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -29,6 +29,7 @@
#include <asm/kvm_mmio.h>

#define __KVM_HAVE_ARCH_INTC_INITIALIZED
+#define __KVM_HAVE_ARCH_HALT_GUEST

#if defined(CONFIG_KVM_ARM_MAX_VCPUS)
#define KVM_MAX_VCPUS CONFIG_KVM_ARM_MAX_VCPUS
@@ -125,6 +126,9 @@ 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

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