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authorAlex Bennée <alex.bennee@linaro.org>2015-03-13 17:02:52 +0000
committerChristoffer Dall <christoffer.dall@linaro.org>2015-03-14 13:44:52 +0100
commitecccf0cc722f40e0dcc97872e7a960765119a256 (patch)
tree85a9d5575976623c9f6ba01081eaa6a0108be722
parentaeda9130c38e2e0e77c1aaa65292c2f5a81107a8 (diff)
downloadkernel-ecccf0cc722f40e0dcc97872e7a960765119a256.tar.gz
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>
-rw-r--r--Documentation/virtual/kvm/api.txt16
-rw-r--r--arch/arm/kvm/arm.c21
2 files changed, 31 insertions, 6 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index b265d8e50be0..71d10d7d141e 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -997,7 +997,7 @@ for vm-wide capabilities.
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 @@ uniprocessor guests).
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 @@ Possible values are:
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 @@ On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an
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 @@ On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an
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 cc96619f10a4..9a5f057a97a3 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -180,6 +180,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
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_set_guest_debug(struct kvm_vcpu *vcpu,
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;
}
/**