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authorCédric Le Goater <clg@kaod.org>2019-04-18 12:39:41 +0200
committerPaul Mackerras <paulus@ozlabs.org>2019-04-30 19:35:16 +1000
commit2bde9b3ec8bdf60788e9e2ce8c07a2f8d6003dbd (patch)
treed4998665dc62f3c003fbd7e8c28a65651c7ad7ff /virt/kvm
parent3fab2d10588e09abd4bd7b9bacce5e4e435993f6 (diff)
downloadlinux-2bde9b3ec8bdf60788e9e2ce8c07a2f8d6003dbd.tar.gz
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: Cédric Le Goater <clg@kaod.org> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Diffstat (limited to 'virt/kvm')
-rw-r--r--virt/kvm/kvm_main.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index ea2018ae1cd7..ea2619d5ca98 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2938,6 +2938,19 @@ static int kvm_device_release(struct inode *inode, struct file *filp)
struct kvm_device *dev = filp->private_data;
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);
return 0;
}