From: Dominik Dingel <dingel@xxxxxxxxxxxxxxxxxx>
We sometimes need to get/set attributes specific to a virtual machine
and so need something else than ONE_REG.
Let's copy the KVM_DEVICE approach, and define the respective ioctls
for the vm file descriptor.
Signed-off-by: Dominik Dingel <dingel@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
Documentation/virtual/kvm/api.txt | 8 ++---
Documentation/virtual/kvm/devices/vm.txt | 6 ++++
arch/s390/kvm/kvm-s390.c | 54 ++++++++++++++++++++++++++++++++
include/uapi/linux/kvm.h | 1 +
4 files changed, 65 insertions(+), 4 deletions(-)
create mode 100644 Documentation/virtual/kvm/devices/vm.txt
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index c24211d..f69731a 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2314,8 +2314,8 @@ struct kvm_create_device {
4.80 KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR
-Capability: KVM_CAP_DEVICE_CTRL
-Type: device ioctl
+Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device
+Type: device ioctl, vm ioctl
Parameters: struct kvm_device_attr
Returns: 0 on success, -1 on error
Errors:
@@ -2340,8 +2340,8 @@ struct kvm_device_attr {
4.81 KVM_HAS_DEVICE_ATTR
-Capability: KVM_CAP_DEVICE_CTRL
-Type: device ioctl
+Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device
+Type: device ioctl, vm ioctl
Parameters: struct kvm_device_attr
Returns: 0 on success, -1 on error
Errors:
diff --git a/Documentation/virtual/kvm/devices/vm.txt b/Documentation/virtual/kvm/devices/vm.txt
new file mode 100644
index 0000000..4fe1532
--- /dev/null
+++ b/Documentation/virtual/kvm/devices/vm.txt
@@ -0,0 +1,6 @@
+Generic vm interface
+====================================
+
+The interface handles per-vm attributes, such as CMMA status on s390 and is
+similar in way to ONE_REG, but targeting the whole vm instead of one vcpu
+alone. It is available with KVM_CAP_VM_ATTRIBUTES.
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 346a347..c335a2e 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -162,6 +162,7 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_IOEVENTFD:
case KVM_CAP_DEVICE_CTRL:
case KVM_CAP_ENABLE_CAP_VM:
+ case KVM_CAP_VM_ATTRIBUTES:
r = 1;
break;
case KVM_CAP_NR_VCPUS:
@@ -257,11 +258,43 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap)
return r;
}
+static int kvm_s390_vm_set_attr(struct kvm *kvm, struct kvm_device_attr *attr)
+{
+ int ret;
+
+ switch (attr->group) {
+ default:
+ ret = -ENXIO;
+ break;
+ }
+
+ return ret;
+}
+
+static int kvm_s390_vm_get_attr(struct kvm *kvm, struct kvm_device_attr *attr)
+{
+ return -ENXIO;
+}
+
+static int kvm_s390_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr)
+{
+ int ret;
+
+ switch (attr->group) {
+ default:
+ ret = -ENXIO;
+ break;
+ }
+
+ return ret;
+}
+
long kvm_arch_vm_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
struct kvm *kvm = filp->private_data;
void __user *argp = (void __user *)arg;
+ struct kvm_device_attr attr;
int r;
switch (ioctl) {
@@ -294,6 +327,27 @@ long kvm_arch_vm_ioctl(struct file *filp,
}
break;
}
+ case KVM_SET_DEVICE_ATTR: {
+ r = -EFAULT;
+ if (copy_from_user(&attr, (void __user *)arg, sizeof(attr)))
+ break;
+ r = kvm_s390_vm_set_attr(kvm, &attr);
+ break;
+ }
+ case KVM_GET_DEVICE_ATTR: {
+ r = -EFAULT;
+ if (copy_from_user(&attr, (void __user *)arg, sizeof(attr)))
+ break;
+ r = kvm_s390_vm_get_attr(kvm, &attr);
+ break;
+ }
+ case KVM_HAS_DEVICE_ATTR: {
+ r = -EFAULT;
+ if (copy_from_user(&attr, (void __user *)arg, sizeof(attr)))
+ break;
+ r = kvm_s390_vm_has_attr(kvm, &attr);
+ break;
+ }
default:
r = -ENOTTY;
}
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index a8f4ee5..90acfe4 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -743,6 +743,7 @@ struct kvm_ppc_smmu_info {
#define KVM_CAP_IOAPIC_POLARITY_IGNORED 97
#define KVM_CAP_ENABLE_CAP_VM 98
#define KVM_CAP_S390_IRQCHIP 99
+#define KVM_CAP_VM_ATTRIBUTES 100
#ifdef KVM_CAP_IRQ_ROUTING
--
1.8.4.2
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