kvm/vfio: Accept vfio device file from userspace

This defines KVM_DEV_VFIO_FILE* and make alias with KVM_DEV_VFIO_GROUP*.
Old userspace uses KVM_DEV_VFIO_GROUP* works as well.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-6-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/Documentation/virt/kvm/devices/vfio.rst b/Documentation/virt/kvm/devices/vfio.rst
index 08b544212638c1b960f9d9943652aea74822dc1d..c549143bb89152850833bf59f274c218fd71c629 100644 (file)
--- a/Documentation/virt/kvm/devices/vfio.rst
+++ b/Documentation/virt/kvm/devices/vfio.rst
@@ -9,22 +9,34 @@ Device types supported:
   - KVM_DEV_TYPE_VFIO
 
 Only one VFIO instance may be created per VM.  The created device
-tracks VFIO groups in use by the VM and features of those groups
-important to the correctness and acceleration of the VM.  As groups
-are enabled and disabled for use by the VM, KVM should be updated
-about their presence.  When registered with KVM, a reference to the
-VFIO-group is held by KVM.
+tracks VFIO files (group or device) in use by the VM and features
+of those groups/devices important to the correctness and acceleration
+of the VM.  As groups/devices are enabled and disabled for use by the
+VM, KVM should be updated about their presence.  When registered with
+KVM, a reference to the VFIO file is held by KVM.
 
 Groups:
-  KVM_DEV_VFIO_GROUP
-
-KVM_DEV_VFIO_GROUP attributes:
-  KVM_DEV_VFIO_GROUP_ADD: Add a VFIO group to VFIO-KVM device tracking
-       kvm_device_attr.addr points to an int32_t file descriptor
-       for the VFIO group.
-  KVM_DEV_VFIO_GROUP_DEL: Remove a VFIO group from VFIO-KVM device tracking
-       kvm_device_attr.addr points to an int32_t file descriptor
-       for the VFIO group.
+  KVM_DEV_VFIO_FILE
+       alias: KVM_DEV_VFIO_GROUP
+
+KVM_DEV_VFIO_FILE attributes:
+  KVM_DEV_VFIO_FILE_ADD: Add a VFIO file (group/device) to VFIO-KVM device
+       tracking
+
+       kvm_device_attr.addr points to an int32_t file descriptor for the
+       VFIO file.
+
+  KVM_DEV_VFIO_FILE_DEL: Remove a VFIO file (group/device) from VFIO-KVM
+       device tracking
+
+       kvm_device_attr.addr points to an int32_t file descriptor for the
+       VFIO file.
+
+KVM_DEV_VFIO_GROUP (legacy kvm device group restricted to the handling of VFIO group fd):
+  KVM_DEV_VFIO_GROUP_ADD: same as KVM_DEV_VFIO_FILE_ADD for group fd only
+
+  KVM_DEV_VFIO_GROUP_DEL: same as KVM_DEV_VFIO_FILE_DEL for group fd only
+
   KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE: attaches a guest visible TCE table
        allocated by sPAPR KVM.
        kvm_device_attr.addr points to a struct::
@@ -40,7 +52,10 @@ KVM_DEV_VFIO_GROUP attributes:
        - @tablefd is a file descriptor for a TCE table allocated via
          KVM_CREATE_SPAPR_TCE.
 
-The GROUP_ADD operation above should be invoked prior to accessing the
+The FILE/GROUP_ADD operation above should be invoked prior to accessing the
 device file descriptor via VFIO_GROUP_GET_DEVICE_FD in order to support
 drivers which require a kvm pointer to be set in their .open_device()
-callback.
+callback.  It is the same for device file descriptor via character device
+open which gets device access via VFIO_DEVICE_BIND_IOMMUFD.  For such file
+descriptors, FILE_ADD should be invoked before VFIO_DEVICE_BIND_IOMMUFD
+to support the drivers mentioned in prior sentence as well.

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index f089ab290978450eced8a4fb705fc2d299a6d5e7..13065dd96132da65beb99f9455659c9b75ed109d 100644 (file)
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1418,9 +1418,16 @@ struct kvm_device_attr {
        __u64   addr;           /* userspace address of attr data */
 };
 
-#define  KVM_DEV_VFIO_GROUP                    1
-#define   KVM_DEV_VFIO_GROUP_ADD                       1
-#define   KVM_DEV_VFIO_GROUP_DEL                       2
+#define  KVM_DEV_VFIO_FILE                     1
+
+#define   KVM_DEV_VFIO_FILE_ADD                        1
+#define   KVM_DEV_VFIO_FILE_DEL                        2
+
+/* KVM_DEV_VFIO_GROUP aliases are for compile time uapi compatibility */
+#define  KVM_DEV_VFIO_GROUP    KVM_DEV_VFIO_FILE
+
+#define   KVM_DEV_VFIO_GROUP_ADD       KVM_DEV_VFIO_FILE_ADD
+#define   KVM_DEV_VFIO_GROUP_DEL       KVM_DEV_VFIO_FILE_DEL
 #define   KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE             3
 
 enum kvm_device_type {

diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index 8f7fa07e8170f9f69ba4cd13eb76341db52d9e43..07cb5f44b2a24a2ee96b4ca4dc8b7a8a76d7e263 100644 (file)
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -286,12 +286,12 @@ static int kvm_vfio_set_file(struct kvm_device *dev, long attr,
        int32_t fd;
 
        switch (attr) {
-       case KVM_DEV_VFIO_GROUP_ADD:
+       case KVM_DEV_VFIO_FILE_ADD:
                if (get_user(fd, argp))
                        return -EFAULT;
                return kvm_vfio_file_add(dev, fd);
 
-       case KVM_DEV_VFIO_GROUP_DEL:
+       case KVM_DEV_VFIO_FILE_DEL:
                if (get_user(fd, argp))
                        return -EFAULT;
                return kvm_vfio_file_del(dev, fd);
@@ -309,7 +309,7 @@ static int kvm_vfio_set_attr(struct kvm_device *dev,
                             struct kvm_device_attr *attr)
 {
        switch (attr->group) {
-       case KVM_DEV_VFIO_GROUP:
+       case KVM_DEV_VFIO_FILE:
                return kvm_vfio_set_file(dev, attr->attr,
                                         u64_to_user_ptr(attr->addr));
        }
@@ -321,10 +321,10 @@ static int kvm_vfio_has_attr(struct kvm_device *dev,
                             struct kvm_device_attr *attr)
 {
        switch (attr->group) {
-       case KVM_DEV_VFIO_GROUP:
+       case KVM_DEV_VFIO_FILE:
                switch (attr->attr) {
-               case KVM_DEV_VFIO_GROUP_ADD:
-               case KVM_DEV_VFIO_GROUP_DEL:
+               case KVM_DEV_VFIO_FILE_ADD:
+               case KVM_DEV_VFIO_FILE_DEL:
 #ifdef CONFIG_SPAPR_TCE_IOMMU
                case KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE:
 #endif