From dcc31ea60b422f9868c39607059d6e37cee6cefa Mon Sep 17 00:00:00 2001 From: Yi Liu Date: Tue, 18 Jul 2023 06:55:30 -0700 Subject: [PATCH] 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 Reviewed-by: Kevin Tian Tested-by: Terrence Xu Tested-by: Nicolin Chen Tested-by: Matthew Rosato Tested-by: Yanting Jiang Tested-by: Shameer Kolothum Tested-by: Zhenzhong Duan Signed-off-by: Yi Liu Link: https://lore.kernel.org/r/20230718135551.6592-6-yi.l.liu@intel.com Signed-off-by: Alex Williamson --- Documentation/virt/kvm/devices/vfio.rst | 45 ++++++++++++++++--------- include/uapi/linux/kvm.h | 13 +++++-- virt/kvm/vfio.c | 12 +++---- 3 files changed, 46 insertions(+), 24 deletions(-) diff --git a/Documentation/virt/kvm/devices/vfio.rst b/Documentation/virt/kvm/devices/vfio.rst index 08b544212638..c549143bb891 100644 --- 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_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 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_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 f089ab290978..13065dd96132 100644 --- 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 8f7fa07e8170..07cb5f44b2a2 100644 --- 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