Re: [PATCH 04/26] vfio: Add struct to hold KVM assets and dedup group vs. iommufd code
On Fri, 15 Sep 2023 17:30:56 -0700
Sean Christopherson wrote:
> Add a struct to hold the KVM assets need to manage and pass along KVM
> references to VFIO devices. Providing a common struct deduplicates the
> group vs. iommufd code, and will make it easier to rework the attachment
> logic so that VFIO doesn't have to do a symbol lookup to retrieve the
> get/put helpers from KVM.
>
> Signed-off-by: Sean Christopherson
> ---
> drivers/vfio/device_cdev.c | 9 +---
> drivers/vfio/group.c | 18 ++--
> drivers/vfio/vfio.h| 22 +--
> drivers/vfio/vfio_main.c | 43 +++---
> 4 files changed, 45 insertions(+), 47 deletions(-)
Reviewed-by: Alex Williamson
> diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c
> index e75da0a70d1f..e484d6d6400a 100644
> --- a/drivers/vfio/device_cdev.c
> +++ b/drivers/vfio/device_cdev.c
> @@ -46,13 +46,6 @@ int vfio_device_fops_cdev_open(struct inode *inode, struct
> file *filep)
> return ret;
> }
>
> -static void vfio_df_get_kvm_safe(struct vfio_device_file *df)
> -{
> - spin_lock(>kvm_ref_lock);
> - vfio_device_get_kvm_safe(df->device, df->kvm);
> - spin_unlock(>kvm_ref_lock);
> -}
> -
> long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df,
> struct vfio_device_bind_iommufd __user *arg)
> {
> @@ -99,7 +92,7 @@ long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df,
>* a reference. This reference is held until device closed.
>* Save the pointer in the device for use by drivers.
>*/
> - vfio_df_get_kvm_safe(df);
> + vfio_device_get_kvm_safe(df->device, >kvm_ref);
>
> ret = vfio_df_open(df);
> if (ret)
> diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
> index 610a429c6191..756e47ff4cf0 100644
> --- a/drivers/vfio/group.c
> +++ b/drivers/vfio/group.c
> @@ -157,13 +157,6 @@ static int vfio_group_ioctl_set_container(struct
> vfio_group *group,
> return ret;
> }
>
> -static void vfio_device_group_get_kvm_safe(struct vfio_device *device)
> -{
> - spin_lock(>group->kvm_ref_lock);
> - vfio_device_get_kvm_safe(device, device->group->kvm);
> - spin_unlock(>group->kvm_ref_lock);
> -}
> -
> static int vfio_df_group_open(struct vfio_device_file *df)
> {
> struct vfio_device *device = df->device;
> @@ -184,7 +177,7 @@ static int vfio_df_group_open(struct vfio_device_file *df)
>* the pointer in the device for use by drivers.
>*/
> if (device->open_count == 0)
> - vfio_device_group_get_kvm_safe(device);
> + vfio_device_get_kvm_safe(device, >group->kvm_ref);
>
> df->iommufd = device->group->iommufd;
> if (df->iommufd && vfio_device_is_noiommu(device) && device->open_count
> == 0) {
> @@ -560,7 +553,7 @@ static struct vfio_group *vfio_group_alloc(struct
> iommu_group *iommu_group,
>
> refcount_set(>drivers, 1);
> mutex_init(>group_lock);
> - spin_lock_init(>kvm_ref_lock);
> + spin_lock_init(>kvm_ref.lock);
> INIT_LIST_HEAD(>device_list);
> mutex_init(>device_lock);
> group->iommu_group = iommu_group;
> @@ -884,13 +877,6 @@ bool vfio_group_enforced_coherent(struct vfio_group
> *group)
> return ret;
> }
>
> -void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
> -{
> - spin_lock(>kvm_ref_lock);
> - group->kvm = kvm;
> - spin_unlock(>kvm_ref_lock);
> -}
> -
> /**
> * vfio_file_has_dev - True if the VFIO file is a handle for device
> * @file: VFIO file to check
> diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
> index c26d1ad68105..a1f741365075 100644
> --- a/drivers/vfio/vfio.h
> +++ b/drivers/vfio/vfio.h
> @@ -12,18 +12,23 @@
> #include
> #include
>
> +struct kvm;
> struct iommufd_ctx;
> struct iommu_group;
> struct vfio_container;
>
> +struct vfio_kvm_reference {
> + struct kvm *kvm;
> + spinlock_t lock;
> +};
> +
> struct vfio_device_file {
> struct vfio_device *device;
> struct vfio_group *group;
>
> u8 access_granted;
> u32 devid; /* only valid when iommufd is valid */
> - spinlock_t kvm_ref_lock; /* protect kvm field */
> - struct kvm *kvm;
> + struct vfio_kvm_reference kvm_ref;
> struct iommufd_ctx *iommufd; /* protected by struct
> vfio_device_set::lock */
> };
>
> @@ -88,11 +93,10 @@ struct vfio_group {
> #endif
> enum vfio_group_typetype;
> struct mutexgroup_lock;
> - struct kvm *kvm;
> + struct vfio_kvm_reference kvm_ref;
> struct file *opened_file;
> struct blocking_notifier_head notifier;
> struct iommufd_ctx *iommufd;
> - spinlock_t kvm_ref_lock;
> unsigned intcdev_device_open_cnt;
> };
>
> @@
[PATCH 04/26] vfio: Add struct to hold KVM assets and dedup group vs. iommufd code
Add a struct to hold the KVM assets need to manage and pass along KVM
references to VFIO devices. Providing a common struct deduplicates the
group vs. iommufd code, and will make it easier to rework the attachment
logic so that VFIO doesn't have to do a symbol lookup to retrieve the
get/put helpers from KVM.
Signed-off-by: Sean Christopherson
---
drivers/vfio/device_cdev.c | 9 +---
drivers/vfio/group.c | 18 ++--
drivers/vfio/vfio.h| 22 +--
drivers/vfio/vfio_main.c | 43 +++---
4 files changed, 45 insertions(+), 47 deletions(-)
diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c
index e75da0a70d1f..e484d6d6400a 100644
--- a/drivers/vfio/device_cdev.c
+++ b/drivers/vfio/device_cdev.c
@@ -46,13 +46,6 @@ int vfio_device_fops_cdev_open(struct inode *inode, struct
file *filep)
return ret;
}
-static void vfio_df_get_kvm_safe(struct vfio_device_file *df)
-{
- spin_lock(>kvm_ref_lock);
- vfio_device_get_kvm_safe(df->device, df->kvm);
- spin_unlock(>kvm_ref_lock);
-}
-
long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df,
struct vfio_device_bind_iommufd __user *arg)
{
@@ -99,7 +92,7 @@ long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df,
* a reference. This reference is held until device closed.
* Save the pointer in the device for use by drivers.
*/
- vfio_df_get_kvm_safe(df);
+ vfio_device_get_kvm_safe(df->device, >kvm_ref);
ret = vfio_df_open(df);
if (ret)
diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
index 610a429c6191..756e47ff4cf0 100644
--- a/drivers/vfio/group.c
+++ b/drivers/vfio/group.c
@@ -157,13 +157,6 @@ static int vfio_group_ioctl_set_container(struct
vfio_group *group,
return ret;
}
-static void vfio_device_group_get_kvm_safe(struct vfio_device *device)
-{
- spin_lock(>group->kvm_ref_lock);
- vfio_device_get_kvm_safe(device, device->group->kvm);
- spin_unlock(>group->kvm_ref_lock);
-}
-
static int vfio_df_group_open(struct vfio_device_file *df)
{
struct vfio_device *device = df->device;
@@ -184,7 +177,7 @@ static int vfio_df_group_open(struct vfio_device_file *df)
* the pointer in the device for use by drivers.
*/
if (device->open_count == 0)
- vfio_device_group_get_kvm_safe(device);
+ vfio_device_get_kvm_safe(device, >group->kvm_ref);
df->iommufd = device->group->iommufd;
if (df->iommufd && vfio_device_is_noiommu(device) && device->open_count
== 0) {
@@ -560,7 +553,7 @@ static struct vfio_group *vfio_group_alloc(struct
iommu_group *iommu_group,
refcount_set(>drivers, 1);
mutex_init(>group_lock);
- spin_lock_init(>kvm_ref_lock);
+ spin_lock_init(>kvm_ref.lock);
INIT_LIST_HEAD(>device_list);
mutex_init(>device_lock);
group->iommu_group = iommu_group;
@@ -884,13 +877,6 @@ bool vfio_group_enforced_coherent(struct vfio_group *group)
return ret;
}
-void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
-{
- spin_lock(>kvm_ref_lock);
- group->kvm = kvm;
- spin_unlock(>kvm_ref_lock);
-}
-
/**
* vfio_file_has_dev - True if the VFIO file is a handle for device
* @file: VFIO file to check
diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
index c26d1ad68105..a1f741365075 100644
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -12,18 +12,23 @@
#include
#include
+struct kvm;
struct iommufd_ctx;
struct iommu_group;
struct vfio_container;
+struct vfio_kvm_reference {
+ struct kvm *kvm;
+ spinlock_t lock;
+};
+
struct vfio_device_file {
struct vfio_device *device;
struct vfio_group *group;
u8 access_granted;
u32 devid; /* only valid when iommufd is valid */
- spinlock_t kvm_ref_lock; /* protect kvm field */
- struct kvm *kvm;
+ struct vfio_kvm_reference kvm_ref;
struct iommufd_ctx *iommufd; /* protected by struct
vfio_device_set::lock */
};
@@ -88,11 +93,10 @@ struct vfio_group {
#endif
enum vfio_group_typetype;
struct mutexgroup_lock;
- struct kvm *kvm;
+ struct vfio_kvm_reference kvm_ref;
struct file *opened_file;
struct blocking_notifier_head notifier;
struct iommufd_ctx *iommufd;
- spinlock_t kvm_ref_lock;
unsigned intcdev_device_open_cnt;
};
@@ -108,7 +112,6 @@ void vfio_device_group_unuse_iommu(struct vfio_device
*device);
void vfio_df_group_close(struct vfio_device_file *df);
struct vfio_group *vfio_group_from_file(struct file *file);
bool vfio_group_enforced_coherent(struct vfio_group *group);
-void
