From: Stefano Garzarella <sgarzare@redhat.com>
To: Jason Wang <jasowang@redhat.com>
Cc: virtualization@lists.linux-foundation.org,
Stefan Hajnoczi <stefanha@redhat.com>,
Laurent Vivier <lvivier@redhat.com>,
linux-kernel@vger.kernel.org, Eli Cohen <elic@nvidia.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
Max Gurtovoy <mgurtovoy@nvidia.com>
Subject: Re: [PATCH RFC 12/12] vdpa_sim_blk: implement ramdisk behaviour
Date: Mon, 16 Nov 2020 12:08:05 +0100 [thread overview]
Message-ID: <20201116110805.efspwzkuw2sdnaca@steredhat> (raw)
In-Reply-To: <56d8c992-44ca-f365-fb92-f5da94896680@redhat.com>
On Mon, Nov 16, 2020 at 01:25:31PM +0800, Jason Wang wrote:
>
>On 2020/11/13 下午9:47, Stefano Garzarella wrote:
>>The previous implementation wrote only the status of each request.
>>This patch implements a more accurate block device simulator,
>>providing a ramdisk-like behavior.
>>
>>Also handle VIRTIO_BLK_T_GET_ID request, always answering the
>>"vdpa_blk_sim" string.
>
>
>Let's use a separate patch for this.
>
Okay, I'll do.
>
>>
>>Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
>>---
>> drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 151 +++++++++++++++++++++++----
>> 1 file changed, 133 insertions(+), 18 deletions(-)
>>
>>diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
>>index 8e41b3ab98d5..68e74383322f 100644
>>--- a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
>>+++ b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
>>@@ -7,6 +7,7 @@
>> */
>> #include <linux/module.h>
>>+#include <linux/blkdev.h>
>> #include <uapi/linux/virtio_blk.h>
>> #include "vdpa_sim.h"
>>@@ -24,10 +25,137 @@
>> static struct vdpasim *vdpasim_blk_dev;
>>+static int vdpasim_blk_handle_req(struct vdpasim *vdpasim,
>>+ struct vdpasim_virtqueue *vq)
>>+{
>>+ size_t wrote = 0, to_read = 0, to_write = 0;
>>+ struct virtio_blk_outhdr hdr;
>>+ uint8_t status;
>>+ uint32_t type;
>>+ ssize_t bytes;
>>+ loff_t offset;
>>+ int i, ret;
>>+
>>+ vringh_kiov_cleanup(&vq->riov);
>>+ vringh_kiov_cleanup(&vq->wiov);
>
>
>It looks to me we should do those after vringh_get_desc_iotlb()? See
>comment above vringh_getdesc_kern().
Do you mean after the last vringh_iov_push_iotlb()?
Because vringh_kiov_cleanup() will free the allocated iov[].
>
>
>>+
>>+ ret = vringh_getdesc_iotlb(&vq->vring, &vq->riov, &vq->wiov,
>>+ &vq->head, GFP_ATOMIC);
>>+ if (ret != 1)
>>+ return ret;
>>+
>>+ for (i = 0; i < vq->wiov.used; i++)
>>+ to_write += vq->wiov.iov[i].iov_len;
>
>
>It's better to introduce a helper for this (or consider to use iov
>iterator).
Okay, I'll try to find the best solution.
>
>
>>+ to_write -= 1; /* last byte is the status */
>>+
>>+ for (i = 0; i < vq->riov.used; i++)
>>+ to_read += vq->riov.iov[i].iov_len;
>>+
>>+ bytes = vringh_iov_pull_iotlb(&vq->vring, &vq->riov, &hdr, sizeof(hdr));
>>+ if (bytes != sizeof(hdr))
>>+ return 0;
>>+
>>+ to_read -= bytes;
>>+
>>+ type = le32_to_cpu(hdr.type);
>>+ offset = le64_to_cpu(hdr.sector) << SECTOR_SHIFT;
>>+ status = VIRTIO_BLK_S_OK;
>>+
>>+ switch (type) {
>>+ case VIRTIO_BLK_T_IN:
>>+ if (offset + to_write > VDPASIM_BLK_CAPACITY <<
>>SECTOR_SHIFT) {
>>+ dev_err(&vdpasim->vdpa.dev,
>>+ "reading over the capacity - offset:
>>0x%llx len: 0x%lx\n",
>>+ offset, to_write);
>>+ status = VIRTIO_BLK_S_IOERR;
>>+ break;
>>+ }
>>+
>>+ bytes = vringh_iov_push_iotlb(&vq->vring, &vq->wiov,
>>+ vdpasim->buffer + offset,
>>+ to_write);
>>+ if (bytes < 0) {
>>+ dev_err(&vdpasim->vdpa.dev,
>>+ "vringh_iov_push_iotlb() error: %ld offset: 0x%llx len: 0x%lx\n",
>>+ bytes, offset, to_write);
>>+ status = VIRTIO_BLK_S_IOERR;
>>+ break;
>>+ }
>>+
>>+ wrote += bytes;
>>+ break;
>>+
>>+ case VIRTIO_BLK_T_OUT:
>>+ if (offset + to_read > VDPASIM_BLK_CAPACITY << SECTOR_SHIFT) {
>>+ dev_err(&vdpasim->vdpa.dev,
>>+ "writing over the capacity - offset: 0x%llx len: 0x%lx\n",
>>+ offset, to_read);
>>+ status = VIRTIO_BLK_S_IOERR;
>>+ break;
>>+ }
>>+
>>+ bytes = vringh_iov_pull_iotlb(&vq->vring, &vq->riov,
>>+ vdpasim->buffer + offset,
>>+ to_read);
>>+ if (bytes < 0) {
>>+ dev_err(&vdpasim->vdpa.dev,
>>+ "vringh_iov_pull_iotlb() error: %ld offset: 0x%llx len: 0x%lx\n",
>>+ bytes, offset, to_read);
>>+ status = VIRTIO_BLK_S_IOERR;
>>+ break;
>>+ }
>>+ break;
>>+
>>+ case VIRTIO_BLK_T_GET_ID: {
>>+ char id[VIRTIO_BLK_ID_BYTES] = "vdpa_blk_sim";
>
>
>Let's use a global static one?
I'll do.
>
>
>>+
>>+ bytes = vringh_iov_push_iotlb(&vq->vring,
>>+ &vq->wiov, id,
>>+ VIRTIO_BLK_ID_BYTES);
>>+ if (bytes < 0) {
>>+ dev_err(&vdpasim->vdpa.dev,
>>+ "vringh_iov_push_iotlb() error: %ld\n", bytes);
>>+ status = VIRTIO_BLK_S_IOERR;
>>+ break;
>>+ }
>>+
>>+ wrote += bytes;
>>+ break;
>>+ }
>>+
>>+ default:
>>+ dev_warn(&vdpasim->vdpa.dev,
>>+ "Unsupported request type %d\n", type);
>>+ status = VIRTIO_BLK_S_IOERR;
>>+ break;
>>+ }
>>+
>>+ /* if VIRTIO_BLK_T_IN or VIRTIO_BLK_T_GET_ID fail, we need to skip
>>+ * the remaining bytes to put the status in the last byte
>>+ */
>>+ if (to_write - wrote > 0) {
>>+ vringh_iov_push_iotlb(&vq->vring, &vq->wiov, NULL,
>>+ to_write - wrote);
>>+ }
>>+
>>+ /* last byte is the status */
>>+ bytes = vringh_iov_push_iotlb(&vq->vring, &vq->wiov, &status, 1);
>>+ if (bytes != 1)
>>+ return 0;
>>+
>>+ wrote += bytes;
>>+
>>+ /* Make sure data is wrote before advancing index */
>>+ smp_wmb();
>>+
>>+ vringh_complete_iotlb(&vq->vring, vq->head, wrote);
>>+
>>+ return ret;
>>+}
>>+
>> 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);
>>@@ -41,21 +169,7 @@ static void vdpasim_blk_work(struct work_struct *work)
>> if (!vq->ready)
>> continue;
>>- while (vringh_getdesc_iotlb(&vq->vring, &vq->riov, &vq->wiov,
>>- &vq->head, GFP_ATOMIC) > 0) {
>>-
>>- int write;
>>-
>>- vq->wiov.i = vq->wiov.used - 1;
>>- write = vringh_iov_push_iotlb(&vq->vring, &vq->wiov, &status, 1);
>>- if (write <= 0)
>>- break;
>>-
>>- /* Make sure data is wrote before advancing
>>index */
>>- smp_wmb();
>>-
>>- vringh_complete_iotlb(&vq->vring, vq->head, write);
>>-
>>+ while (vdpasim_blk_handle_req(vdpasim, vq) > 0) {
>> /* Make sure used is visible before rasing the interrupt. */
>> smp_wmb();
>>@@ -67,6 +181,7 @@ static void vdpasim_blk_work(struct work_struct *work)
>> vq->cb(vq->private);
>> local_bh_enable();
>> }
>>+
>
>
>Unnecessary change.
Removed.
Thanks,
Stefano
next prev parent reply other threads:[~2020-11-16 12:37 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-13 13:47 [PATCH RFC 00/12] vdpa: generalize vdpa simulator and add block device Stefano Garzarella
2020-11-13 13:47 ` [PATCH RFC 01/12] vhost-vdpa: add support for vDPA blk devices Stefano Garzarella
2020-11-17 10:57 ` Stefan Hajnoczi
2020-11-17 15:05 ` Stefano Garzarella
2020-11-13 13:47 ` [PATCH RFC 02/12] vdpa: split vdpasim to core and net modules Stefano Garzarella
2020-11-16 4:00 ` Jason Wang
2020-11-16 9:39 ` Stefano Garzarella
2020-11-18 13:14 ` Stefano Garzarella
2020-11-19 6:16 ` Jason Wang
2020-11-13 13:47 ` [PATCH RFC 03/12] vdpa_sim: remove hard-coded virtq count Stefano Garzarella
2020-11-16 4:02 ` Jason Wang
2020-11-13 13:47 ` [PATCH RFC 04/12] vdpa: add vdpa simulator for block device Stefano Garzarella
2020-11-16 4:10 ` Jason Wang
2020-11-16 10:17 ` Stefano Garzarella
2020-11-17 11:11 ` Stefan Hajnoczi
2020-11-17 14:16 ` Stefano Garzarella
2020-11-17 16:43 ` Stefan Hajnoczi
2020-11-17 17:38 ` Stefano Garzarella
2020-11-18 11:23 ` Stefan Hajnoczi
2020-11-18 11:39 ` Stefano Garzarella
2020-11-13 13:47 ` [PATCH RFC 05/12] vdpa_sim: remove the limit of IOTLB entries Stefano Garzarella
2020-11-16 4:12 ` Jason Wang
2020-11-16 10:22 ` Stefano Garzarella
2020-11-13 13:47 ` [PATCH RFC 06/12] vdpa_sim: add struct vdpasim_device to store device properties Stefano Garzarella
2020-11-16 4:14 ` Jason Wang
2020-11-16 10:30 ` Stefano Garzarella
2020-11-17 11:23 ` Stefan Hajnoczi
2020-11-17 14:24 ` Stefano Garzarella
2020-11-13 13:47 ` [PATCH RFC 07/12] vdpa_sim: move config management outside of the core Stefano Garzarella
2020-11-16 4:18 ` Jason Wang
2020-11-16 10:42 ` Stefano Garzarella
2020-11-13 13:47 ` [PATCH RFC 08/12] vdpa_sim: use kvmalloc to allocate vdpasim->buffer Stefano Garzarella
2020-11-16 4:19 ` Jason Wang
2020-11-13 13:47 ` [PATCH RFC 09/12] vdpa_sim: make vdpasim->buffer size configurable Stefano Garzarella
2020-11-16 4:19 ` Jason Wang
2020-11-13 13:47 ` [PATCH RFC 10/12] vdpa_sim: split vdpasim_virtqueue's iov field in riov and wiov Stefano Garzarella
2020-11-16 4:21 ` Jason Wang
2020-11-17 11:27 ` Stefan Hajnoczi
2020-11-20 14:41 ` Stefano Garzarella
2020-11-13 13:47 ` [PATCH RFC 11/12] vringh: allow vringh_iov_xfer() to skip bytes when ptr is NULL Stefano Garzarella
2020-11-16 4:32 ` Jason Wang
2020-11-16 11:48 ` Stefano Garzarella
2020-11-13 13:47 ` [PATCH RFC 12/12] vdpa_sim_blk: implement ramdisk behaviour Stefano Garzarella
2020-11-16 5:25 ` Jason Wang
2020-11-16 11:08 ` Stefano Garzarella [this message]
2020-11-16 9:50 ` Michael S. Tsirkin
2020-11-16 11:23 ` Stefano Garzarella
2020-11-17 11:36 ` Stefan Hajnoczi
2020-11-17 14:32 ` Stefano Garzarella
2020-11-16 3:37 ` [PATCH RFC 00/12] vdpa: generalize vdpa simulator and add block device Jason Wang
2020-11-16 8:53 ` Stefano Garzarella
2020-12-18 11:38 ` Stefano Garzarella
2020-12-21 3:16 ` Jason Wang
2020-12-21 11:14 ` Stefano Garzarella
2020-12-22 2:44 ` Jason Wang
2020-12-22 10:57 ` Stefano Garzarella
2020-12-22 12:29 ` Jason Wang
2020-12-22 12:56 ` Jason Wang
2020-12-22 13:23 ` Stefano Garzarella
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201116110805.efspwzkuw2sdnaca@steredhat \
--to=sgarzare@redhat.com \
--cc=elic@nvidia.com \
--cc=jasowang@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=lvivier@redhat.com \
--cc=mgurtovoy@nvidia.com \
--cc=mst@redhat.com \
--cc=stefanha@redhat.com \
--cc=virtualization@lists.linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).