KVM: arm/arm64: Provide functionality to pause and resume a guest

For some rare corner cases in our VGIC emulation later we have to stop
the guest to make sure the VGIC state is consistent.
Provide the necessary framework to pause and resume a guest.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 385070180c2587df524fed552ac0f36b71cac26b..832be033e654243a461f6b1c99189660209b1d13 100644 (file)
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -41,6 +41,8 @@
 
 #define KVM_MAX_VCPUS VGIC_V2_MAX_CPUS
 
+#define KVM_REQ_VCPU_EXIT      8
+
 u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode);
 int __attribute_const__ kvm_target_cpu(void);
 int kvm_reset_vcpu(struct kvm_vcpu *vcpu);
@@ -225,6 +227,8 @@ static inline void kvm_arch_mmu_notifier_invalidate_page(struct kvm *kvm,
 
 struct kvm_vcpu *kvm_arm_get_running_vcpu(void);
 struct kvm_vcpu __percpu **kvm_get_running_vcpus(void);
+void kvm_arm_halt_guest(struct kvm *kvm);
+void kvm_arm_resume_guest(struct kvm *kvm);
 
 int kvm_arm_copy_coproc_indices(struct kvm_vcpu *vcpu, u64 __user *uindices);
 unsigned long kvm_arm_num_coproc_regs(struct kvm_vcpu *vcpu);

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index ceb9345bcf07283ab5099dc3bc3e8f4b335739e2..e89329d22c18cc4ea38bc4cefaab52c908eb4236 100644 (file)
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -492,30 +492,31 @@ bool kvm_arch_intc_initialized(struct kvm *kvm)
        return vgic_initialized(kvm);
 }
 
-static void kvm_arm_halt_guest(struct kvm *kvm) __maybe_unused;
-static void kvm_arm_resume_guest(struct kvm *kvm) __maybe_unused;
-
-static void kvm_arm_halt_guest(struct kvm *kvm)
+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);
+       kvm_make_all_cpus_request(kvm, KVM_REQ_VCPU_EXIT);
+}
+
+static void kvm_arm_resume_vcpu(struct kvm_vcpu *vcpu)
+{
+       struct swait_queue_head *wq = kvm_arch_vcpu_wq(vcpu);
+
+       vcpu->arch.pause = false;
+       swake_up(wq);
 }
 
-static void kvm_arm_resume_guest(struct kvm *kvm)
+void kvm_arm_resume_guest(struct kvm *kvm)
 {
        int i;
        struct kvm_vcpu *vcpu;
 
-       kvm_for_each_vcpu(i, vcpu, kvm) {
-               struct swait_queue_head *wq = kvm_arch_vcpu_wq(vcpu);
-
-               vcpu->arch.pause = false;
-               swake_up(wq);
-       }
+       kvm_for_each_vcpu(i, vcpu, kvm)
+               kvm_arm_resume_vcpu(vcpu);
 }
 
 static void vcpu_sleep(struct kvm_vcpu *vcpu)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 4cd4196e94a9b8f32158cee453f991424ea53e82..fa94f91812ab1e547491c65cc25ab9212e04f3f8 100644 (file)
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -44,6 +44,8 @@
 
 #define KVM_VCPU_MAX_FEATURES 4
 
+#define KVM_REQ_VCPU_EXIT      8
+
 int __attribute_const__ kvm_target_cpu(void);
 int kvm_reset_vcpu(struct kvm_vcpu *vcpu);
 int kvm_arch_dev_ioctl_check_extension(long ext);
@@ -325,6 +327,8 @@ static inline void kvm_arch_mmu_notifier_invalidate_page(struct kvm *kvm,
 
 struct kvm_vcpu *kvm_arm_get_running_vcpu(void);
 struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void);
+void kvm_arm_halt_guest(struct kvm *kvm);
+void kvm_arm_resume_guest(struct kvm *kvm);
 
 u64 __kvm_call_hyp(void *hypfn, ...);
 #define kvm_call_hyp(f, ...) __kvm_call_hyp(kvm_ksym_ref(f), ##__VA_ARGS__)