Commit 2bde9b3e authored by Cédric Le Goater's avatar Cédric Le Goater Committed by Paul Mackerras

KVM: Introduce a 'release' method for KVM devices

When a P9 sPAPR VM boots, the CAS negotiation process determines which
interrupt mode to use (XICS legacy or XIVE native) and invokes a
machine reset to activate the chosen mode.

To be able to switch from one interrupt mode to another, we introduce
the capability to release a KVM device without destroying the VM. The
KVM device interface is extended with a new 'release' method which is
called when the file descriptor of the device is closed.

Once 'release' is called, the 'destroy' method will not be called
anymore as the device is removed from the device list of the VM.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarCédric Le Goater <clg@kaod.org>
Reviewed-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
parent 3fab2d10
...@@ -1240,6 +1240,15 @@ struct kvm_device_ops { ...@@ -1240,6 +1240,15 @@ struct kvm_device_ops {
*/ */
void (*destroy)(struct kvm_device *dev); void (*destroy)(struct kvm_device *dev);
/*
* Release is an alternative method to free the device. It is
* called when the device file descriptor is closed. Once
* release is called, the destroy method will not be called
* anymore as the device is removed from the device list of
* the VM. kvm->lock is held.
*/
void (*release)(struct kvm_device *dev);
int (*set_attr)(struct kvm_device *dev, struct kvm_device_attr *attr); int (*set_attr)(struct kvm_device *dev, struct kvm_device_attr *attr);
int (*get_attr)(struct kvm_device *dev, struct kvm_device_attr *attr); int (*get_attr)(struct kvm_device *dev, struct kvm_device_attr *attr);
int (*has_attr)(struct kvm_device *dev, struct kvm_device_attr *attr); int (*has_attr)(struct kvm_device *dev, struct kvm_device_attr *attr);
......
...@@ -2938,6 +2938,19 @@ static int kvm_device_release(struct inode *inode, struct file *filp) ...@@ -2938,6 +2938,19 @@ static int kvm_device_release(struct inode *inode, struct file *filp)
struct kvm_device *dev = filp->private_data; struct kvm_device *dev = filp->private_data;
struct kvm *kvm = dev->kvm; struct kvm *kvm = dev->kvm;
if (!dev)
return -ENODEV;
if (dev->kvm != kvm)
return -EPERM;
if (dev->ops->release) {
mutex_lock(&kvm->lock);
list_del(&dev->vm_node);
dev->ops->release(dev);
mutex_unlock(&kvm->lock);
}
kvm_put_kvm(kvm); kvm_put_kvm(kvm);
return 0; return 0;
} }
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment