[PATCH v4 04/10] vfio/fsl-mc: Implement VFIO_DEVICE_GET_REGION_INFO ioctl call

From: Diana Craciun
Date: Wed Aug 26 2020 - 05:34:05 EST


Expose to userspace information about the memory regions.

Signed-off-by: Bharat Bhushan <Bharat.Bhushan@xxxxxxx>
Signed-off-by: Diana Craciun <diana.craciun@xxxxxxxxxxx>
---
drivers/vfio/fsl-mc/vfio_fsl_mc.c | 79 ++++++++++++++++++++++-
drivers/vfio/fsl-mc/vfio_fsl_mc_private.h | 19 ++++++
2 files changed, 97 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
index 5a5460d01f00..093b8d68496c 100644
--- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
+++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
@@ -17,16 +17,72 @@

static struct fsl_mc_driver vfio_fsl_mc_driver;

+static int vfio_fsl_mc_regions_init(struct vfio_fsl_mc_device *vdev)
+{
+ struct fsl_mc_device *mc_dev = vdev->mc_dev;
+ int count = mc_dev->obj_desc.region_count;
+ int i;
+
+ vdev->regions = kcalloc(count, sizeof(struct vfio_fsl_mc_region),
+ GFP_KERNEL);
+ if (!vdev->regions)
+ return -ENOMEM;
+
+ for (i = 0; i < count; i++) {
+ struct resource *res = &mc_dev->regions[i];
+
+ vdev->regions[i].addr = res->start;
+ vdev->regions[i].size = resource_size(res);
+ vdev->regions[i].flags = 0;
+ }
+
+ vdev->num_regions = mc_dev->obj_desc.region_count;
+ return 0;
+}
+
+static void vfio_fsl_mc_regions_cleanup(struct vfio_fsl_mc_device *vdev)
+{
+ vdev->num_regions = 0;
+ kfree(vdev->regions);
+}
+
static int vfio_fsl_mc_open(void *device_data)
{
+ struct vfio_fsl_mc_device *vdev = device_data;
+ int ret;
+
if (!try_module_get(THIS_MODULE))
return -ENODEV;

+ mutex_lock(&vdev->driver_lock);
+ if (!vdev->refcnt) {
+ ret = vfio_fsl_mc_regions_init(vdev);
+ if (ret)
+ goto err_reg_init;
+ }
+ vdev->refcnt++;
+
+ mutex_unlock(&vdev->driver_lock);
+
return 0;
+
+err_reg_init:
+ mutex_unlock(&vdev->driver_lock);
+ module_put(THIS_MODULE);
+ return ret;
}

static void vfio_fsl_mc_release(void *device_data)
{
+ struct vfio_fsl_mc_device *vdev = device_data;
+
+ mutex_lock(&vdev->driver_lock);
+
+ if (!(--vdev->refcnt))
+ vfio_fsl_mc_regions_cleanup(vdev);
+
+ mutex_unlock(&vdev->driver_lock);
+
module_put(THIS_MODULE);
}

@@ -59,7 +115,25 @@ static long vfio_fsl_mc_ioctl(void *device_data, unsigned int cmd,
}
case VFIO_DEVICE_GET_REGION_INFO:
{
- return -ENOTTY;
+ struct vfio_region_info info;
+
+ minsz = offsetofend(struct vfio_region_info, offset);
+
+ if (copy_from_user(&info, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (info.argsz < minsz)
+ return -EINVAL;
+
+ if (info.index >= vdev->num_regions)
+ return -EINVAL;
+
+ /* map offset to the physical address */
+ info.offset = VFIO_FSL_MC_INDEX_TO_OFFSET(info.index);
+ info.size = vdev->regions[info.index].size;
+ info.flags = vdev->regions[info.index].flags;
+
+ return copy_to_user((void __user *)arg, &info, minsz);
}
case VFIO_DEVICE_GET_IRQ_INFO:
{
@@ -204,6 +278,7 @@ static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
vfio_iommu_group_put(group, dev);
return ret;
}
+ mutex_init(&vdev->driver_lock);

return ret;
}
@@ -227,6 +302,8 @@ static int vfio_fsl_mc_remove(struct fsl_mc_device *mc_dev)

mc_dev->mc_io = NULL;

+ mutex_destroy(&vdev->driver_lock);
+
vfio_iommu_group_put(mc_dev->dev.iommu_group, dev);

return 0;
diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
index 37d61eaa58c8..818dfd3df4db 100644
--- a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
+++ b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
@@ -7,9 +7,28 @@
#ifndef VFIO_FSL_MC_PRIVATE_H
#define VFIO_FSL_MC_PRIVATE_H

+#define VFIO_FSL_MC_OFFSET_SHIFT 40
+#define VFIO_FSL_MC_OFFSET_MASK (((u64)(1) << VFIO_FSL_MC_OFFSET_SHIFT) - 1)
+
+#define VFIO_FSL_MC_OFFSET_TO_INDEX(off) ((off) >> VFIO_FSL_MC_OFFSET_SHIFT)
+
+#define VFIO_FSL_MC_INDEX_TO_OFFSET(index) \
+ ((u64)(index) << VFIO_FSL_MC_OFFSET_SHIFT)
+
+struct vfio_fsl_mc_region {
+ u32 flags;
+ u32 type;
+ u64 addr;
+ resource_size_t size;
+};
+
struct vfio_fsl_mc_device {
struct fsl_mc_device *mc_dev;
struct notifier_block nb;
+ int refcnt;
+ u32 num_regions;
+ struct vfio_fsl_mc_region *regions;
+ struct mutex driver_lock;
};

#endif /* VFIO_FSL_MC_PRIVATE_H */
--
2.17.1