On Mon, Nov 16, 2020 at 12:10:19PM +0800, Jason Wang wrote:
On 2020/11/13 下午9:47, Stefano Garzarella wrote:
From: Max Gurtovoy <mgurtovoy@xxxxxxxxxx>
This will allow running vDPA for virtio block protocol.
Signed-off-by: Max Gurtovoy <mgurtovoy@xxxxxxxxxx>
[sgarzare: various cleanups/fixes]
Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
---
v1:
- Removed unused headers
- Used cpu_to_vdpasim*() to store config fields
- Replaced 'select VDPA_SIM' with 'depends on VDPA_SIM' since selected
option can not depend on other [Jason]
- Start with a single queue for now [Jason]
- Add comments to memory barriers
---
drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 124 +++++++++++++++++++++++++++
drivers/vdpa/Kconfig | 9 ++
drivers/vdpa/vdpa_sim/Makefile | 1 +
3 files changed, 134 insertions(+)
create mode 100644 drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
new file mode 100644
index 000000000000..386dbb2f7138
--- /dev/null
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * VDPA simulator for block device.
+ *
+ * Copyright (c) 2020, Mellanox Technologies. All rights reserved.
+ *
+ */
+
+#include <linux/module.h>
+
+#include "vdpa_sim.h"
+
+#define VDPASIM_BLK_FEATURES ((1ULL << VIRTIO_BLK_F_SIZE_MAX) | \
+ (1ULL << VIRTIO_BLK_F_SEG_MAX) | \
+ (1ULL << VIRTIO_BLK_F_BLK_SIZE) | \
+ (1ULL << VIRTIO_BLK_F_TOPOLOGY) | \
+ (1ULL << VIRTIO_BLK_F_MQ))
+
+#define VDPASIM_BLK_CAPACITY 0x40000
+#define VDPASIM_BLK_SIZE_MAX 0x1000
+#define VDPASIM_BLK_SEG_MAX 32
+#define VDPASIM_BLK_VQ_NUM 1
+
+static struct vdpasim *vdpasim_blk_dev;
+
+static void vdpasim_blk_work(struct work_struct *work)
+{
+ struct vdpasim *vdpasim = container_of(work, struct vdpasim, work);
+ u8 status = VIRTIO_BLK_S_OK;
+ int i;
+
+ spin_lock(&vdpasim->lock);
+
+ if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
+ goto out;
+
+ for (i = 0; i < VDPASIM_BLK_VQ_NUM; i++) {
+ struct vdpasim_virtqueue *vq = &vdpasim->vqs[i];
+
+ if (!vq->ready)
+ continue;
+
+ while (vringh_getdesc_iotlb(&vq->vring, &vq->iov, &vq->iov,
+ &vq->head, GFP_ATOMIC) > 0) {
+
+ int write;
+
+ vq->iov.i = vq->iov.used - 1;
+ write = vringh_iov_push_iotlb(&vq->vring, &vq->iov, &status, 1);
+ if (write <= 0)
+ break;
+
+ /* Make sure data is wrote before advancing index */
+ smp_wmb();
+
+ vringh_complete_iotlb(&vq->vring, vq->head, write);
+
+ /* Make sure used is visible before rasing the interrupt. */
+ smp_wmb();
+
+ if (vringh_need_notify_iotlb(&vq->vring) > 0)
+ vringh_notify(&vq->vring);
Do we initialize vrh->notify anywhere? And This seems duplicated with
the following vq->cb.
I think the correct way is to initialize vrh->notify and use
vringh_need_notify_iotlb()/vringh_notify() instead of the vq->cb here.
Okay, so I'll set vrh->notify in the vdpasim core with a function that
calls vq->cb() (the callback set through .set_vq_cb).
And while at it, it's better to convert net simulator to do the same.
Sure.
Thanks,
Stefano
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