[PATCH 3/5 V4] Add ioctl for KVM_GUEST_STOPPED

[Eric B Munson]

Now that we have a flag that will tell the guest it was suspended, create an
interface for that communication using a KVM ioctl.

Signed-off-by: Eric B Munson <emunson@xxxxxxxxx>

Cc: mingo@xxxxxxxxxx
Cc: hpa@xxxxxxxxx
Cc: arnd@xxxxxxxx
Cc: ryanh@xxxxxxxxxxxxxxxxxx
Cc: aliguori@xxxxxxxxxx
Cc: mtosatti@xxxxxxxxxx
Cc: jeremy.fitzhardinge@xxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: x86@xxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
 arch/x86/include/asm/kvm_host.h |    2 ++
 arch/x86/kvm/x86.c              |   20 ++++++++++++++++++++
 include/linux/kvm.h             |    2 ++
 3 files changed, 24 insertions(+), 0 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index b4973f4..beb94c6 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -672,6 +672,8 @@ int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes,
 		  gpa_t addr, unsigned long *ret);
 u8 kvm_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn);
 
+int kvm_set_guest_paused(struct kvm_vcpu *vcpu);
+
 extern bool tdp_enabled;
 
 u64 vcpu_tsc_khz(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c38efd7..0127617 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3295,6 +3295,10 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
 
 		goto out;
 	}
+	case KVM_GUEST_PAUSED: {
+		r = kvm_set_guest_paused(vcpu);
+		break;
+	}
 	default:
 		r = -EINVAL;
 	}
@@ -6117,6 +6121,22 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason,
 }
 EXPORT_SYMBOL_GPL(kvm_task_switch);
 
+/*
+ * kvm_set_guest_paused() indicates to the guest kernel that it has been
+ * stopped by the hypervisor.  This function will be called from the host only.
+ * EINVAL is returned when the host attempts to set the flag for a guest that
+ * does not support pv clocks.
+ */
+int kvm_set_guest_paused(struct kvm_vcpu *vcpu)
+{
+	struct pvclock_vcpu_time_info *src = &vcpu->arch.hv_clock;
+	if (!vcpu->arch.time_page)
+		return -EINVAL;
+	src->flags |= PVCLOCK_GUEST_STOPPED;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_set_guest_paused);
+
 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 				  struct kvm_sregs *sregs)
 {
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index c3892fc..15578a2 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -762,6 +762,8 @@ struct kvm_clock_data {
 #define KVM_CREATE_SPAPR_TCE	  _IOW(KVMIO,  0xa8, struct kvm_create_spapr_tce)
 /* Available with KVM_CAP_RMA */
 #define KVM_ALLOCATE_RMA	  _IOR(KVMIO,  0xa9, struct kvm_allocate_rma)
+/* VM is being stopped by host */
+#define KVM_GUEST_PAUSED	  _IO(KVMIO,   0xaa)
 
 #define KVM_DEV_ASSIGN_ENABLE_IOMMU	(1 << 0)
 
-- 
1.7.5.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/