From: Shannon Zhao <shannon.zhao at linaro.org>
In some cases it needs to get/set attributes specific to a vcpu and so
needs something else than ONE_REG.
Let's copy the KVM_DEVICE approach, and define the respective ioctls
for the vcpu file descriptor.
Signed-off-by: Shannon Zhao <shannon.zhao at linaro.org>
Reviewed-by: Andrew Jones <drjones at redhat.com>
Acked-by: Peter Maydell <peter.maydell at linaro.org>
---
CC: Peter Maydell <peter.maydell at linaro.org>
---
Documentation/virtual/kvm/api.txt | 10 +++---
Documentation/virtual/kvm/devices/vcpu.txt | 8 +++++
arch/arm/kvm/arm.c | 55 ++++++++++++++++++++++++++++++
arch/arm64/kvm/reset.c | 1 +
include/uapi/linux/kvm.h | 1 +
5 files changed, 71 insertions(+), 4 deletions(-)
create mode 100644 Documentation/virtual/kvm/devices/vcpu.txt
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 9684f8d..cb2ef0b 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2507,8 +2507,9 @@ struct kvm_create_device {
4.80 KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR
-Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device
-Type: device ioctl, vm ioctl
+Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device,
+ KVM_CAP_VCPU_ATTRIBUTES for vcpu device
+Type: device ioctl, vm ioctl, vcpu ioctl
Parameters: struct kvm_device_attr
Returns: 0 on success, -1 on error
Errors:
@@ -2533,8 +2534,9 @@ struct kvm_device_attr {
4.81 KVM_HAS_DEVICE_ATTR
-Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device
-Type: device ioctl, vm ioctl
+Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device,
+ KVM_CAP_VCPU_ATTRIBUTES for vcpu device
+Type: device ioctl, vm ioctl, vcpu ioctl
Parameters: struct kvm_device_attr
Returns: 0 on success, -1 on error
Errors:
diff --git a/Documentation/virtual/kvm/devices/vcpu.txt b/Documentation/virtual/kvm/devices/vcpu.txt
new file mode 100644
index 0000000..3cc59c5
--- /dev/null
+++ b/Documentation/virtual/kvm/devices/vcpu.txt
@@ -0,0 +1,8 @@
+Generic vcpu interface
+====================================
+
+The virtual cpu "device" also accepts the ioctls KVM_SET_DEVICE_ATTR,
+KVM_GET_DEVICE_ATTR, and KVM_HAS_DEVICE_ATTR. The interface uses the same struct
+kvm_device_attr as other devices, but targets VCPU-wide settings and controls.
+
+The groups and attributes per virtual cpu, if any, are architecture specific.
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index d2c2cc3..34d7395 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -826,11 +826,51 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
return 0;
}
+static int kvm_arm_vcpu_set_attr(struct kvm_vcpu *vcpu,
+ struct kvm_device_attr *attr)
+{
+ int ret = -ENXIO;
+
+ switch (attr->group) {
+ default:
+ break;
+ }
+
+ return ret;
+}
+
+static int kvm_arm_vcpu_get_attr(struct kvm_vcpu *vcpu,
+ struct kvm_device_attr *attr)
+{
+ int ret = -ENXIO;
+
+ switch (attr->group) {
+ default:
+ break;
+ }
+
+ return ret;
+}
+
+static int kvm_arm_vcpu_has_attr(struct kvm_vcpu *vcpu,
+ struct kvm_device_attr *attr)
+{
+ int ret = -ENXIO;
+
+ switch (attr->group) {
+ default:
+ break;
+ }
+
+ return ret;
+}
+
long kvm_arch_vcpu_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
struct kvm_vcpu *vcpu = filp->private_data;
void __user *argp = (void __user *)arg;
+ struct kvm_device_attr attr;
switch (ioctl) {
case KVM_ARM_VCPU_INIT: {
@@ -873,6 +913,21 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
return -E2BIG;
return kvm_arm_copy_reg_indices(vcpu, user_list->reg);
}
+ case KVM_SET_DEVICE_ATTR: {
+ if (copy_from_user(&attr, argp, sizeof(attr)))
+ return -EFAULT;
+ return kvm_arm_vcpu_set_attr(vcpu, &attr);
+ }
+ case KVM_GET_DEVICE_ATTR: {
+ if (copy_from_user(&attr, argp, sizeof(attr)))
+ return -EFAULT;
+ return kvm_arm_vcpu_get_attr(vcpu, &attr);
+ }
+ case KVM_HAS_DEVICE_ATTR: {
+ if (copy_from_user(&attr, argp, sizeof(attr)))
+ return -EFAULT;
+ return kvm_arm_vcpu_has_attr(vcpu, &attr);
+ }
default:
return -EINVAL;
}
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index cf4f28a..9677bf0 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -81,6 +81,7 @@ int kvm_arch_dev_ioctl_check_extension(long ext)
r = kvm_arm_support_pmu_v3();
break;
case KVM_CAP_SET_GUEST_DEBUG:
+ case KVM_CAP_VCPU_ATTRIBUTES:
r = 1;
break;
default:
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index dc16d30..50f44a2 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -851,6 +851,7 @@ struct kvm_ppc_smmu_info {
#define KVM_CAP_HYPERV_SYNIC 123
#define KVM_CAP_S390_RI 124
#define KVM_CAP_ARM_PMU_V3 125
+#define KVM_CAP_VCPU_ATTRIBUTES 126
#ifdef KVM_CAP_IRQ_ROUTING
--
2.0.4