From a1cd3f0883f435e5f9ae6530d7e62b361c87a91a Mon Sep 17 00:00:00 2001 From: Cédric Le Goater Date: Thu, 18 Apr 2019 12:39:36 +0200 Subject: KVM: Introduce a 'mmap' method for KVM devices MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Some KVM devices will want to handle special mappings related to the underlying HW. For instance, the XIVE interrupt controller of the POWER9 processor has MMIO pages for thread interrupt management and for interrupt source control that need to be exposed to the guest when the OS has the required support. Cc: Paolo Bonzini Signed-off-by: Cédric Le Goater Reviewed-by: David Gibson Signed-off-by: Paul Mackerras --- virt/kvm/kvm_main.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'virt') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 55fe8e20d8fd..ea2018ae1cd7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2884,6 +2884,16 @@ out: } #endif +static int kvm_device_mmap(struct file *filp, struct vm_area_struct *vma) +{ + struct kvm_device *dev = filp->private_data; + + if (dev->ops->mmap) + return dev->ops->mmap(dev, vma); + + return -ENODEV; +} + static int kvm_device_ioctl_attr(struct kvm_device *dev, int (*accessor)(struct kvm_device *dev, struct kvm_device_attr *attr), @@ -2936,6 +2946,7 @@ static const struct file_operations kvm_device_fops = { .unlocked_ioctl = kvm_device_ioctl, .release = kvm_device_release, KVM_COMPAT(kvm_device_ioctl), + .mmap = kvm_device_mmap, }; struct kvm_device *kvm_device_from_filp(struct file *filp) -- cgit v1.2.3-58-ga151 From 2bde9b3ec8bdf60788e9e2ce8c07a2f8d6003dbd Mon Sep 17 00:00:00 2001 From: Cédric Le Goater Date: Thu, 18 Apr 2019 12:39:41 +0200 Subject: KVM: Introduce a 'release' method for KVM devices MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Cédric Le Goater Reviewed-by: David Gibson Signed-off-by: Paul Mackerras --- include/linux/kvm_host.h | 9 +++++++++ virt/kvm/kvm_main.c | 13 +++++++++++++ 2 files changed, 22 insertions(+) (limited to 'virt') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 831d963451d8..722692e2f745 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1240,6 +1240,15 @@ struct kvm_device_ops { */ 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 (*get_attr)(struct kvm_device *dev, struct kvm_device_attr *attr); int (*has_attr)(struct kvm_device *dev, struct kvm_device_attr *attr); 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; } -- cgit v1.2.3-58-ga151 From 4894fbcce856635c9ab79f44e50826e86bb92110 Mon Sep 17 00:00:00 2001 From: Cédric Le Goater Date: Thu, 9 May 2019 14:33:44 +0200 Subject: KVM: PPC: Book3S: Remove useless checks in 'release' method of KVM device MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There is no need to test for the device pointer validity when releasing a KVM device. The file descriptor should identify it safely. Fixes: 2bde9b3ec8bd ("KVM: Introduce a 'release' method for KVM devices") Signed-off-by: Cédric Le Goater Reviewed-by: Alexey Kardashevskiy Signed-off-by: Paul Mackerras --- virt/kvm/kvm_main.c | 6 ------ 1 file changed, 6 deletions(-) (limited to 'virt') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index ea2619d5ca98..37149433c07a 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2938,12 +2938,6 @@ 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); -- cgit v1.2.3-58-ga151