arm/arm64: KVM: export VCPU power state via MP_STATE ioctl
To cleanly restore an SMP VM we need to ensure that the current pause
state of each vcpu is correctly recorded. Things could get confused if
the CPU starts running after migration restore completes when it was
paused before it state was captured.
We use the existing KVM_GET/SET_MP_STATE ioctl to do this. The arm/arm64
interface is a lot simpler as the only valid states are
KVM_MP_STATE_RUNNABLE and KVM_MP_STATE_STOPPED.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index b265d8e..71d10d7 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -997,7 +997,7 @@
4.38 KVM_GET_MP_STATE
Capability: KVM_CAP_MP_STATE
-Architectures: x86, s390
+Architectures: x86, s390, arm, arm64
Type: vcpu ioctl
Parameters: struct kvm_mp_state (out)
Returns: 0 on success; -1 on error
@@ -1011,7 +1011,7 @@
Possible values are:
- - KVM_MP_STATE_RUNNABLE: the vcpu is currently running [x86]
+ - KVM_MP_STATE_RUNNABLE: the vcpu is currently running [x86,arm/arm64]
- KVM_MP_STATE_UNINITIALIZED: the vcpu is an application processor (AP)
which has not yet received an INIT signal [x86]
- KVM_MP_STATE_INIT_RECEIVED: the vcpu has received an INIT signal, and is
@@ -1020,7 +1020,7 @@
is waiting for an interrupt [x86]
- KVM_MP_STATE_SIPI_RECEIVED: the vcpu has just received a SIPI (vector
accessible via KVM_GET_VCPU_EVENTS) [x86]
- - KVM_MP_STATE_STOPPED: the vcpu is stopped [s390]
+ - KVM_MP_STATE_STOPPED: the vcpu is stopped [s390,arm/arm64]
- KVM_MP_STATE_CHECK_STOP: the vcpu is in a special error state [s390]
- KVM_MP_STATE_OPERATING: the vcpu is operating (running or halted)
[s390]
@@ -1031,11 +1031,15 @@
in-kernel irqchip, the multiprocessing state must be maintained by userspace on
these architectures.
+For arm/arm64:
+
+The only states that are valid are KVM_MP_STATE_STOPPED and
+KVM_MP_STATE_RUNNABLE which reflect if the vcpu is paused or not.
4.39 KVM_SET_MP_STATE
Capability: KVM_CAP_MP_STATE
-Architectures: x86, s390
+Architectures: x86, s390, arm, arm64
Type: vcpu ioctl
Parameters: struct kvm_mp_state (in)
Returns: 0 on success; -1 on error
@@ -1047,6 +1051,10 @@
in-kernel irqchip, the multiprocessing state must be maintained by userspace on
these architectures.
+For arm/arm64:
+
+The only states that are valid are KVM_MP_STATE_STOPPED and
+KVM_MP_STATE_RUNNABLE which reflect if the vcpu should be paused or not.
4.40 KVM_SET_IDENTITY_MAP_ADDR
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index cc96619..9a5f057 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -180,6 +180,7 @@
case KVM_CAP_ARM_PSCI:
case KVM_CAP_ARM_PSCI_0_2:
case KVM_CAP_READONLY_MEM:
+ case KVM_CAP_MP_STATE:
r = 1;
break;
case KVM_CAP_COALESCED_MMIO:
@@ -310,13 +311,29 @@
int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state)
{
- return -EINVAL;
+ if (vcpu->arch.pause)
+ mp_state->mp_state = KVM_MP_STATE_STOPPED;
+ else
+ mp_state->mp_state = KVM_MP_STATE_RUNNABLE;
+
+ return 0;
}
int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state)
{
- return -EINVAL;
+ switch (mp_state->mp_state) {
+ case KVM_MP_STATE_RUNNABLE:
+ vcpu->arch.pause = false;
+ break;
+ case KVM_MP_STATE_STOPPED:
+ vcpu->arch.pause = true;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
}
/**