[PATCH V2 1/2] vdpa: Support config interrupt in vhost_vdpa

Zhu Lingshan
2020-04-26T06:13:15Z

This commit implements config interrupt support in
vhost_vdpa layer.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
---
drivers/vhost/vdpa.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++
drivers/vhost/vhost.c | 2 +-
drivers/vhost/vhost.h | 2 ++
include/uapi/linux/vhost.h | 2 ++
4 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 421f02a..b94e349 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -21,6 +21,7 @@
#include <linux/nospec.h>
#include <linux/vhost.h>
#include <linux/virtio_net.h>
+#include <linux/kernel.h>

#include "vhost.h"

@@ -70,6 +71,7 @@ struct vhost_vdpa {
int nvqs;
int virtio_id;
int minor;
+ struct eventfd_ctx *config_ctx;
};

static DEFINE_IDA(vhost_vdpa_ida);
@@ -101,6 +103,17 @@ static irqreturn_t vhost_vdpa_virtqueue_cb(void *private)
return IRQ_HANDLED;
}

+static irqreturn_t vhost_vdpa_config_cb(void *private)
+{
+ struct vhost_vdpa *v = private;
+ struct eventfd_ctx *config_ctx = v->config_ctx;
+
+ if (config_ctx)
+ eventfd_signal(config_ctx, 1);
+
+ return IRQ_HANDLED;
+}
+
static void vhost_vdpa_reset(struct vhost_vdpa *v)
{
struct vdpa_device *vdpa = v->vdpa;
@@ -288,6 +301,36 @@ static long vhost_vdpa_get_vring_num(struct vhost_vdpa *v, u16 __user *argp)
return 0;
}

+static void vhost_vdpa_config_put(struct vhost_vdpa *v)
+{
+ if (v->config_ctx)
+ eventfd_ctx_put(v->config_ctx);
+}
+
+static long vhost_vdpa_set_config_call(struct vhost_vdpa *v, u32 __user *argp)
+{
+ struct vdpa_callback cb;
+ u32 fd;
+ struct eventfd_ctx *ctx;
+
+ cb.callback = vhost_vdpa_config_cb;
+ cb.private = v->vdpa;
+ if (copy_from_user(&fd, argp, sizeof(fd)))
+ return -EFAULT;
+
+ ctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd);
+ swap(ctx, v->config_ctx);
+
+ if (!IS_ERR_OR_NULL(ctx))
+ eventfd_ctx_put(ctx);
+
+ if (IS_ERR(v->config_ctx))
+ return PTR_ERR(v->config_ctx);
+
+ v->vdpa->config->set_config_cb(v->vdpa, &cb);
+
+ return 0;
+}
static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
void __user *argp)
{
@@ -398,6 +441,9 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
case VHOST_SET_LOG_FD:
r = -ENOIOCTLCMD;
break;
+ case VHOST_VDPA_SET_CONFIG_CALL:
+ r = vhost_vdpa_set_config_call(v, argp);
+ break;
default:
r = vhost_dev_ioctl(&v->vdev, cmd, argp);
if (r == -ENOIOCTLCMD)
@@ -734,6 +780,7 @@ static int vhost_vdpa_release(struct inode *inode, struct file *filep)
vhost_dev_stop(&v->vdev);
vhost_vdpa_iotlb_free(v);
vhost_vdpa_free_domain(v);
+ vhost_vdpa_config_put(v);
vhost_dev_cleanup(&v->vdev);
kfree(v->vdev.vqs);
mutex_unlock(&d->mutex);
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index d450e16..e8f5b20 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1590,7 +1590,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg
r = -EFAULT;
break;
}
- ctx = f.fd == -1 ? NULL : eventfd_ctx_fdget(f.fd);
+ ctx = f.fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(f.fd);
if (IS_ERR(ctx)) {
r = PTR_ERR(ctx);
break;
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 1813821..8663139 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -18,6 +18,8 @@
typedef void (*vhost_work_fn_t)(struct vhost_work *work);

#define VHOST_WORK_QUEUED 1
+#define VHOST_FILE_UNBIND -1
+
struct vhost_work {
struct llist_node node;
vhost_work_fn_t fn;
diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
index 9fe72e4..345acb3 100644
--- a/include/uapi/linux/vhost.h
+++ b/include/uapi/linux/vhost.h
@@ -140,4 +140,6 @@
/* Get the max ring size. */
#define VHOST_VDPA_GET_VRING_NUM _IOR(VHOST_VIRTIO, 0x76, __u16)

+/* Set event fd for config interrupt*/
+#define VHOST_VDPA_SET_CONFIG_CALL _IOW(VHOST_VIRTIO, 0x77, u32)
#endif
--
1.8.3.1