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From: shuah <shuah@kernel.org>
To: Suwan Kim <suwan.kim027@gmail.com>,
	valentina.manea.m@gmail.com, gregkh@linuxfoundation.org,
	stern@rowland.harvard.edu
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	shuah <shuah@kernel.org>
Subject: Re: [PATCH v5 2/2] usbip: Implement SG support to vhci-hcd and stub driver
Date: Tue, 13 Aug 2019 12:36:22 -0600
Message-ID: <c4beef01-f321-fed1-f56c-b484c67a1056@kernel.org> (raw)
In-Reply-To: <d7377b4f-b5c7-13e4-2107-c9170f312ddf@kernel.org>

On 8/8/19 10:21 AM, shuah wrote:
> On 8/8/19 9:54 AM, Suwan Kim wrote:
>> There are bugs on vhci with usb 3.0 storage device. In USB, each SG
>> list entry buffer should be divisible by the bulk max packet size.
>> But with native SG support, this problem doesn't matter because the
>> SG buffer is treated as contiguous buffer. But without native SG
>> support, USB storage driver breaks SG list into several URBs and the
>> error occurs because of a buffer size of URB that cannot be divided
>> by the bulk max packet size. The error situation is as follows.
>>
>> When USB Storage driver requests 31.5 KB data and has SG list which
>> has 3584 bytes buffer followed by 7 4096 bytes buffer for some
>> reason. USB Storage driver splits this SG list into several URBs
>> because VHCI doesn't support SG and sends them separately. So the
>> first URB buffer size is 3584 bytes. When receiving data from device,
>> USB 3.0 device sends data packet of 1024 bytes size because the max
>> packet size of BULK pipe is 1024 bytes. So device sends 4096 bytes.
>> But the first URB buffer has only 3584 bytes buffer size. So host
>> controller terminates the transfer even though there is more data to
>> receive. So, vhci needs to support SG transfer to prevent this error.
>>
>> In this patch, vhci supports SG regardless of whether the server's
>> host controller supports SG or not, because stub driver splits SG
>> list into several URBs if the server's host controller doesn't
>> support SG.
>>
>> To support SG, vhci_map_urb_for_dma() sets URB_DMA_MAP_SG flag in
>> urb->transfer_flags if URB has SG list and this flag will tell stub
>> driver to use SG list.
>>
>> vhci sends each SG list entry to stub driver. Then, stub driver sees
>> the total length of the buffer and allocates SG table and pages
>> according to the total buffer length calling sgl_alloc(). After stub
>> driver receives completed URB, it again sends each SG list entry to
>> vhci.
>>
>> If the server's host controller doesn't support SG, stub driver
>> breaks a single SG request into several URBs and submits them to
>> the server's host controller. When all the split URBs are completed,
>> stub driver reassembles the URBs into a single return command and
>> sends it to vhci.
>>
>> Moreover, in the situation where vhci supports SG, but stub driver
>> does not, or vice versa, usbip works normally. Because there is no
>> protocol modification, there is no problem in communication between
>> server and client even if the one has a kernel without SG support.
>>
>> In the case of vhci supports SG and stub driver doesn't, because
>> vhci sends only the total length of the buffer to stub driver as
>> it did before the patch applied, stub driver only needs to allocate
>> the required length of buffers using only kmalloc() regardless of
>> whether vhci supports SG or not. But stub driver has to allocate
>> buffer with kmalloc() as much as the total length of SG buffer which
>> is quite huge when vhci sends SG request, so it has overhead in
>> buffer allocation in this situation.
>>
>> If stub driver needs to send data buffer to vhci because of IN pipe,
>> stub driver also sends only total length of buffer as metadata and
>> then sends real data as vhci does. Then vhci receive data from stub
>> driver and store it to the corresponding buffer of SG list entry.
>>
>> And for the case of stub driver supports SG and vhci doesn't, since
>> the USB storage driver checks that vhci doesn't support SG and sends
>> the request to stub driver by splitting the SG list into multiple
>> URBs, stub driver allocates a buffer for each URB with kmalloc() as
>> it did before this patch.
>>
>> * Test environment
>>
>> Test uses two difference machines and two different kernel version
>> to make mismatch situation between the client and the server where
>> vhci supports SG, but stub driver does not, or vice versa. All tests
>> are conducted in both full SG support that both vhci and stub support
>> SG and half SG support that is the mismatch situation.
>>
>>   - Test kernel version
>>      - 5.2-rc6 with SG support
>>      - 5.1.20-200.fc29.x86_64 without SG support
>>
>> * SG support test
>>
>>   - Test devices
>>      - Super-speed storage device - SanDisk Ultra USB 3.0
>>      - High-speed storage device - SMI corporation USB 2.0 flash drive
>>
>>   - Test description
>>
>> Test read and write operation of mass storage device that uses the
>> BULK transfer. In test, the client reads and writes files whose size
>> is over 1G and it works normally.
>>
>> * Regression test
>>
>>   - Test devices
>>      - Super-speed device - Logitech Brio webcam
>>      - High-speed device - Logitech C920 HD Pro webcam
>>      - Full-speed device - Logitech bluetooth mouse
>>                          - Britz BR-Orion speaker
>>      - Low-speed device - Logitech wired mouse
>>
>>   - Test description
>>
>> Moving and click test for mouse. To test the webcam, use gnome-cheese.
>> To test the speaker, play music and video on the client. All works
>> normally.
>>
>> * VUDC compatibility test
>>
>> VUDC also works well with this patch. Tests are done with two USB
>> gadget created by CONFIGFS USB gadget. Both use the BULK pipe.
>>
>>          1. Serial gadget
>>          2. Mass storage gadget
>>
>>   - Serial gadget test
>>
>> Serial gadget on the host sends and receives data using cat command
>> on the /dev/ttyGS<N>. The client uses minicom to communicate with
>> the serial gadget.
>>
>>   - Mass storage gadget test
>>
>> After connecting the gadget with vhci, use "dd" to test read and
>> write operation on the client side.
>>
>> Read  - dd if=/dev/sd<N> iflag=direct of=/dev/null bs=1G count=1
>> Write - dd if=<my file path> iflag=direct of=/dev/sd<N> bs=1G count=1
>>
> 
> Thanks for including the detailed test description.
> 
>> Signed-off-by: Suwan Kim <suwan.kim027@gmail.com>
>> ---
>> v4 - v5
>> - Add the test description about SG support test and regression test
>>    for other USB devices which have various speed.
>> - Fix list_del() error in stub_device_cleanup_urbs()
>>    - when stub_device_cleanup_urbs() calls stub_pirv_pop() to get a
>>    stub_priv, stub_priv_pop() uses list_del_init() instead of
>>    list_del(). After getting the stub_priv, stub_device_cleanup_urbs()
>>    calls stub_free_priv_and_urb() and it checks if list of the
>>    stub_priv is empty. Because stub_priv_pop() calls list_del_init(),
>>    stub_free_priv_and_urb() doesn't call list_del()
>>
>> v3 - v4
>> - Rewrite the description about the vhci bug with USB 3.0 storage
>>    device.
>> - Add the description about the test with VUDC.
>> - Fix the error message in stub_recv_cmd_unlink().
>>
>> v2 - v3
>> - Rewrite the commit log to make it more clear.
>> - Add the description about the mismatch situation in commit log.
>> - Run chechpatch.pl and fix errors with coding style and typos.
>> - Fix the error path of usbip_recv_xbuff() to stop receiving data
>>    after TCP error occurs.
>> - Consolidate the duplicated error path in usbip_recv_xbuff() and
>>    vhci_send_cmd_submit().
>> - Undo the unnecessary changes
>>    * Undo the deletion of empty line in stub_send_ret_submit()
>>    * Move memset() lines in stub_send_ret_submit() to the original
>>      position.
>>
>> v1 - v2
>> - Add the logic that splits single SG request into several URBs in
>>    stub driver if server’s HC doesn’t support SG.
>> ---
>>   drivers/usb/usbip/stub.h         |   7 +-
>>   drivers/usb/usbip/stub_main.c    |  57 ++++++---
>>   drivers/usb/usbip/stub_rx.c      | 204 ++++++++++++++++++++++---------
>>   drivers/usb/usbip/stub_tx.c      |  99 +++++++++++----
>>   drivers/usb/usbip/usbip_common.c |  59 ++++++---
>>   drivers/usb/usbip/vhci_hcd.c     |  15 ++-
>>   drivers/usb/usbip/vhci_tx.c      |  63 ++++++++--
>>   7 files changed, 377 insertions(+), 127 deletions(-)
>>
>> diff --git a/drivers/usb/usbip/stub.h b/drivers/usb/usbip/stub.h
>> index 35618ceb2791..d11270560c24 100644
>> --- a/drivers/usb/usbip/stub.h
>> +++ b/drivers/usb/usbip/stub.h
>> @@ -52,7 +52,11 @@ struct stub_priv {
>>       unsigned long seqnum;
>>       struct list_head list;
>>       struct stub_device *sdev;
>> -    struct urb *urb;
>> +    struct urb **urbs;
>> +    struct scatterlist *sgl;
>> +    int num_urbs;
>> +    int completed_urbs;
>> +    int urb_status;
>>       int unlinking;
>>   };
>> @@ -86,6 +90,7 @@ extern struct usb_device_driver stub_driver;
>>   struct bus_id_priv *get_busid_priv(const char *busid);
>>   void put_busid_priv(struct bus_id_priv *bid);
>>   int del_match_busid(char *busid);
>> +void stub_free_priv_and_urb(struct stub_priv *priv);
>>   void stub_device_cleanup_urbs(struct stub_device *sdev);
>>   /* stub_rx.c */
>> diff --git a/drivers/usb/usbip/stub_main.c 
>> b/drivers/usb/usbip/stub_main.c
>> index 2e4bfccd4bfc..c1c0bbc9f8b1 100644
>> --- a/drivers/usb/usbip/stub_main.c
>> +++ b/drivers/usb/usbip/stub_main.c
>> @@ -6,6 +6,7 @@
>>   #include <linux/string.h>
>>   #include <linux/module.h>
>>   #include <linux/device.h>
>> +#include <linux/scatterlist.h>
>>   #include "usbip_common.h"
>>   #include "stub.h"
>> @@ -281,13 +282,49 @@ static struct stub_priv 
>> *stub_priv_pop_from_listhead(struct list_head *listhead)
>>       struct stub_priv *priv, *tmp;
>>       list_for_each_entry_safe(priv, tmp, listhead, list) {
>> -        list_del(&priv->list);
>> +        list_del_init(&priv->list);
>>           return priv;
>>       }
>>       return NULL;
>>   }
>> +void stub_free_priv_and_urb(struct stub_priv *priv)
>> +{
>> +    struct urb *urb;
>> +    int i;
>> +
>> +    for (i = 0; i < priv->num_urbs; i++) {
>> +        urb = priv->urbs[i];
>> +
>> +        if (!urb)
>> +            return;
>> +
>> +        kfree(urb->setup_packet);
>> +        urb->setup_packet = NULL;
>> +
>> +
>> +        if (urb->transfer_buffer && !priv->sgl) {
>> +            kfree(urb->transfer_buffer);
>> +            urb->transfer_buffer = NULL;
>> +        }
>> +
>> +        if (urb->num_sgs) {
>> +            sgl_free(urb->sg);
>> +            urb->sg = NULL;
>> +            urb->num_sgs = 0;
>> +        }
>> +
>> +        usb_free_urb(urb);
>> +    }
>> +    if (!list_empty(&priv->list))
>> +        list_del(&priv->list);
>> +    if (priv->sgl)
>> +        sgl_free(priv->sgl);
>> +    kfree(priv->urbs);
>> +    kmem_cache_free(stub_priv_cache, priv);
>> +}
>> +
>>   static struct stub_priv *stub_priv_pop(struct stub_device *sdev)
>>   {
>>       unsigned long flags;
>> @@ -314,25 +351,15 @@ static struct stub_priv *stub_priv_pop(struct 
>> stub_device *sdev)
>>   void stub_device_cleanup_urbs(struct stub_device *sdev)
>>   {
>>       struct stub_priv *priv;
>> -    struct urb *urb;
>> +    int i;
>>       dev_dbg(&sdev->udev->dev, "Stub device cleaning up urbs\n");
>>       while ((priv = stub_priv_pop(sdev))) {
>> -        urb = priv->urb;
>> -        dev_dbg(&sdev->udev->dev, "free urb seqnum %lu\n",
>> -            priv->seqnum);
>> -        usb_kill_urb(urb);
>> -
>> -        kmem_cache_free(stub_priv_cache, priv);
>> +        for (i = 0; i < priv->num_urbs; i++)
>> +            usb_kill_urb(priv->urbs[i]);
>> -        kfree(urb->transfer_buffer);
>> -        urb->transfer_buffer = NULL;
>> -
>> -        kfree(urb->setup_packet);
>> -        urb->setup_packet = NULL;
>> -
>> -        usb_free_urb(urb);
>> +        stub_free_priv_and_urb(priv);
>>       }
>>   }
>> diff --git a/drivers/usb/usbip/stub_rx.c b/drivers/usb/usbip/stub_rx.c
>> index b0a855acafa3..66edfeea68fe 100644
>> --- a/drivers/usb/usbip/stub_rx.c
>> +++ b/drivers/usb/usbip/stub_rx.c
>> @@ -7,6 +7,7 @@
>>   #include <linux/kthread.h>
>>   #include <linux/usb.h>
>>   #include <linux/usb/hcd.h>
>> +#include <linux/scatterlist.h>
>>   #include "usbip_common.h"
>>   #include "stub.h"
>> @@ -201,7 +202,7 @@ static void tweak_special_requests(struct urb *urb)
>>   static int stub_recv_cmd_unlink(struct stub_device *sdev,
>>                   struct usbip_header *pdu)
>>   {
>> -    int ret;
>> +    int ret, i;
>>       unsigned long flags;
>>       struct stub_priv *priv;
>> @@ -246,12 +247,14 @@ static int stub_recv_cmd_unlink(struct 
>> stub_device *sdev,
>>            * so a driver in a client host will know the failure
>>            * of the unlink request ?
>>            */
>> -        ret = usb_unlink_urb(priv->urb);
>> -        if (ret != -EINPROGRESS)
>> -            dev_err(&priv->urb->dev->dev,
>> -                "failed to unlink a urb # %lu, ret %d\n",
>> -                priv->seqnum, ret);
>> -
>> +        for (i = priv->completed_urbs; i < priv->num_urbs; i++) {
>> +            ret = usb_unlink_urb(priv->urbs[i]);
>> +            if (ret != -EINPROGRESS)
>> +                dev_err(&priv->urbs[i]->dev->dev,
>> +                    "failed to unlink %d/%d urb of seqnum %lu, ret 
>> %d\n",
>> +                    i + 1, priv->num_urbs,
>> +                    priv->seqnum, ret);
>> +        }
>>           return 0;
>>       }
>> @@ -433,14 +436,36 @@ static void masking_bogus_flags(struct urb *urb)
>>       urb->transfer_flags &= allowed;
>>   }
>> +static int stub_recv_xbuff(struct usbip_device *ud, struct stub_priv 
>> *priv)
>> +{
>> +    int ret;
>> +    int i;
>> +
>> +    for (i = 0; i < priv->num_urbs; i++) {
>> +        ret = usbip_recv_xbuff(ud, priv->urbs[i]);
>> +        if (ret < 0)
>> +            break;
>> +    }
>> +
>> +    return ret;
>> +}
>> +
>>   static void stub_recv_cmd_submit(struct stub_device *sdev,
>>                    struct usbip_header *pdu)
>>   {
>> -    int ret;
>>       struct stub_priv *priv;
>>       struct usbip_device *ud = &sdev->ud;
>>       struct usb_device *udev = sdev->udev;
>> +    struct scatterlist *sgl = NULL, *sg;
>> +    void *buffer = NULL;
>> +    unsigned long long buf_len;
>> +    int nents;
>> +    int num_urbs = 1;
>>       int pipe = get_pipe(sdev, pdu);
>> +    int use_sg = pdu->u.cmd_submit.transfer_flags & URB_DMA_MAP_SG;
>> +    int support_sg = 1;
>> +    int np = 0;
>> +    int ret, i;
>>       if (pipe == -1)
>>           return;
>> @@ -449,76 +474,139 @@ static void stub_recv_cmd_submit(struct 
>> stub_device *sdev,
>>       if (!priv)
>>           return;
>> -    /* setup a urb */
>> -    if (usb_pipeisoc(pipe))
>> -        priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets,
>> -                      GFP_KERNEL);
>> -    else
>> -        priv->urb = usb_alloc_urb(0, GFP_KERNEL);
>> +    buf_len = (unsigned long 
>> long)pdu->u.cmd_submit.transfer_buffer_length;
>> -    if (!priv->urb) {
>> -        usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
>> -        return;
>> +    /* allocate urb transfer buffer, if needed */
>> +    if (buf_len) {
>> +        if (use_sg) {
>> +            sgl = sgl_alloc(buf_len, GFP_KERNEL, &nents);
>> +            if (!sgl)
>> +                goto err_malloc;
>> +        } else {
>> +            buffer = kzalloc(buf_len, GFP_KERNEL);
>> +            if (!buffer)
>> +                goto err_malloc;
>> +        }
>>       }
>> -    /* allocate urb transfer buffer, if needed */
>> -    if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
>> -        priv->urb->transfer_buffer =
>> -            kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
>> -                GFP_KERNEL);
>> -        if (!priv->urb->transfer_buffer) {
>> +    /* Check if the server's HCD supports SG */
>> +    if (use_sg && !udev->bus->sg_tablesize) {
>> +        /*
>> +         * If the server's HCD doesn't support SG, break a single SG
>> +         * request into several URBs and map each SG list entry to
>> +         * corresponding URB buffer. The previously allocated SG
>> +         * list is stored in priv->sgl (If the server's HCD support SG,
>> +         * SG list is stored only in urb->sg) and it is used as an
>> +         * indicator that the server split single SG request into
>> +         * several URBs. Later, priv->sgl is used by stub_complete() and
>> +         * stub_send_ret_submit() to reassemble the divied URBs.
>> +         */
>> +        support_sg = 0;
>> +        num_urbs = nents;
>> +        priv->completed_urbs = 0;
>> +        pdu->u.cmd_submit.transfer_flags &= ~URB_DMA_MAP_SG;
>> +    }
>> +
>> +    /* allocate urb array */
>> +    priv->num_urbs = num_urbs;
>> +    priv->urbs = kmalloc_array(num_urbs, sizeof(*priv->urbs), 
>> GFP_KERNEL);
>> +    if (!priv->urbs)
>> +        goto err_urbs;
>> +
>> +    /* setup a urb */
>> +    if (support_sg) {
>> +        if (usb_pipeisoc(pipe))
>> +            np = pdu->u.cmd_submit.number_of_packets;
>> +
>> +        priv->urbs[0] = usb_alloc_urb(np, GFP_KERNEL);
>> +        if (!priv->urbs[0])
>> +            goto err_urb;
>> +
>> +        if (buf_len) {
>> +            if (use_sg) {
>> +                priv->urbs[0]->sg = sgl;
>> +                priv->urbs[0]->num_sgs = nents;
>> +                priv->urbs[0]->transfer_buffer = NULL;
>> +            } else {
>> +                priv->urbs[0]->transfer_buffer = buffer;
>> +            }
>> +        }
>> +
>> +        /* copy urb setup packet */
>> +        priv->urbs[0]->setup_packet = kmemdup(&pdu->u.cmd_submit.setup,
>> +                    8, GFP_KERNEL);
>> +        if (!priv->urbs[0]->setup_packet) {
>>               usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
>>               return;
>>           }
>> -    }
>> -    /* copy urb setup packet */
>> -    priv->urb->setup_packet = kmemdup(&pdu->u.cmd_submit.setup, 8,
>> -                      GFP_KERNEL);
>> -    if (!priv->urb->setup_packet) {
>> -        dev_err(&udev->dev, "allocate setup_packet\n");
>> -        usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
>> -        return;
>> +        usbip_pack_pdu(pdu, priv->urbs[0], USBIP_CMD_SUBMIT, 0);
>> +    } else {
>> +        for_each_sg(sgl, sg, nents, i) {
>> +            priv->urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
>> +            /* The URBs which is previously allocated will be freed
>> +             * in stub_device_cleanup_urbs() if error occurs.
>> +             */
>> +            if (!priv->urbs[i])
>> +                goto err_urb;
>> +
>> +            usbip_pack_pdu(pdu, priv->urbs[i], USBIP_CMD_SUBMIT, 0);
>> +            priv->urbs[i]->transfer_buffer = sg_virt(sg);
>> +            priv->urbs[i]->transfer_buffer_length = sg->length;
>> +        }
>> +        priv->sgl = sgl;
>>       }
>> -    /* set other members from the base header of pdu */
>> -    priv->urb->context                = (void *) priv;
>> -    priv->urb->dev                    = udev;
>> -    priv->urb->pipe                   = pipe;
>> -    priv->urb->complete               = stub_complete;
>> +    for (i = 0; i < num_urbs; i++) {
>> +        /* set other members from the base header of pdu */
>> +        priv->urbs[i]->context = (void *) priv;
>> +        priv->urbs[i]->dev = udev;
>> +        priv->urbs[i]->pipe = pipe;
>> +        priv->urbs[i]->complete = stub_complete;
>> -    usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);
>> +        /* no need to submit an intercepted request, but harmless? */
>> +        tweak_special_requests(priv->urbs[i]);
>> +        masking_bogus_flags(priv->urbs[i]);
>> +    }
>> -    if (usbip_recv_xbuff(ud, priv->urb) < 0)
>> +    if (stub_recv_xbuff(ud, priv) < 0)
>>           return;
>> -    if (usbip_recv_iso(ud, priv->urb) < 0)
>> +    if (usbip_recv_iso(ud, priv->urbs[0]) < 0)
>>           return;
>> -    /* no need to submit an intercepted request, but harmless? */
>> -    tweak_special_requests(priv->urb);
>> -
>> -    masking_bogus_flags(priv->urb);
>>       /* urb is now ready to submit */
>> -    ret = usb_submit_urb(priv->urb, GFP_KERNEL);
>> -
>> -    if (ret == 0)
>> -        usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
>> -                  pdu->base.seqnum);
>> -    else {
>> -        dev_err(&udev->dev, "submit_urb error, %d\n", ret);
>> -        usbip_dump_header(pdu);
>> -        usbip_dump_urb(priv->urb);
>> -
>> -        /*
>> -         * Pessimistic.
>> -         * This connection will be discarded.
>> -         */
>> -        usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
>> +    for (i = 0; i < priv->num_urbs; i++) {
>> +        ret = usb_submit_urb(priv->urbs[i], GFP_KERNEL);
>> +
>> +        if (ret == 0)
>> +            usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
>> +                    pdu->base.seqnum);
>> +        else {
>> +            dev_err(&udev->dev, "submit_urb error, %d\n", ret);
>> +            usbip_dump_header(pdu);
>> +            usbip_dump_urb(priv->urbs[i]);
>> +
>> +            /*
>> +             * Pessimistic.
>> +             * This connection will be discarded.
>> +             */
>> +            usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
>> +            break;
>> +        }
>>       }
>>       usbip_dbg_stub_rx("Leave\n");
>> +    return;
>> +
>> +err_urb:
>> +    kfree(priv->urbs);
>> +err_urbs:
>> +    kfree(buffer);
>> +    sgl_free(sgl);
>> +err_malloc:
>> +    usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
>>   }
>>   /* recv a pdu */
>> diff --git a/drivers/usb/usbip/stub_tx.c b/drivers/usb/usbip/stub_tx.c
>> index f0ec41a50cbc..36010a82b359 100644
>> --- a/drivers/usb/usbip/stub_tx.c
>> +++ b/drivers/usb/usbip/stub_tx.c
>> @@ -5,25 +5,11 @@
>>   #include <linux/kthread.h>
>>   #include <linux/socket.h>
>> +#include <linux/scatterlist.h>
>>   #include "usbip_common.h"
>>   #include "stub.h"
>> -static void stub_free_priv_and_urb(struct stub_priv *priv)
>> -{
>> -    struct urb *urb = priv->urb;
>> -
>> -    kfree(urb->setup_packet);
>> -    urb->setup_packet = NULL;
>> -
>> -    kfree(urb->transfer_buffer);
>> -    urb->transfer_buffer = NULL;
>> -
>> -    list_del(&priv->list);
>> -    kmem_cache_free(stub_priv_cache, priv);
>> -    usb_free_urb(urb);
>> -}
>> -
>>   /* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
>>   void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
>>                    __u32 status)
>> @@ -85,6 +71,22 @@ void stub_complete(struct urb *urb)
>>           break;
>>       }
>> +    /*
>> +     * If the server breaks single SG request into the several URBs, the
>> +     * URBs must be reassembled before sending completed URB to the 
>> vhci.
>> +     * Don't wake up the tx thread until all the URBs are completed.
>> +     */
>> +    if (priv->sgl) {
>> +        priv->completed_urbs++;
>> +
>> +        /* Only save the first error status */
>> +        if (urb->status && !priv->urb_status)
>> +            priv->urb_status = urb->status;
>> +
>> +        if (priv->completed_urbs < priv->num_urbs)
>> +            return;
>> +    }
>> +
>>       /* link a urb to the queue of tx. */
>>       spin_lock_irqsave(&sdev->priv_lock, flags);
>>       if (sdev->ud.tcp_socket == NULL) {
>> @@ -156,18 +158,22 @@ static int stub_send_ret_submit(struct 
>> stub_device *sdev)
>>       size_t total_size = 0;
>>       while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
>> -        int ret;
>> -        struct urb *urb = priv->urb;
>> +        struct urb *urb = priv->urbs[0];
>>           struct usbip_header pdu_header;
>>           struct usbip_iso_packet_descriptor *iso_buffer = NULL;
>>           struct kvec *iov = NULL;
>> +        struct scatterlist *sg;
>> +        u32 actual_length = 0;
>>           int iovnum = 0;
>> +        int ret;
>> +        int i;
>>           txsize = 0;
>>           memset(&pdu_header, 0, sizeof(pdu_header));
>>           memset(&msg, 0, sizeof(msg));
>> -        if (urb->actual_length > 0 && !urb->transfer_buffer) {
>> +        if (urb->actual_length > 0 && !urb->transfer_buffer &&
>> +           !urb->num_sgs) {
>>               dev_err(&sdev->udev->dev,
>>                   "urb: actual_length %d transfer_buffer null\n",
>>                   urb->actual_length);
>> @@ -176,6 +182,11 @@ static int stub_send_ret_submit(struct 
>> stub_device *sdev)
>>           if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
>>               iovnum = 2 + urb->number_of_packets;
>> +        else if (usb_pipein(urb->pipe) && urb->actual_length > 0 &&
>> +            urb->num_sgs)
>> +            iovnum = 1 + urb->num_sgs;
>> +        else if (usb_pipein(urb->pipe) && priv->sgl)
>> +            iovnum = 1 + priv->num_urbs;
>>           else
>>               iovnum = 2;
>> @@ -192,6 +203,15 @@ static int stub_send_ret_submit(struct 
>> stub_device *sdev)
>>           setup_ret_submit_pdu(&pdu_header, urb);
>>           usbip_dbg_stub_tx("setup txdata seqnum: %d\n",
>>                     pdu_header.base.seqnum);
>> +
>> +        if (priv->sgl) {
>> +            for (i = 0; i < priv->num_urbs; i++)
>> +                actual_length += priv->urbs[i]->actual_length;
>> +
>> +            pdu_header.u.ret_submit.status = priv->urb_status;
>> +            pdu_header.u.ret_submit.actual_length = actual_length;
>> +        }
>> +
>>           usbip_header_correct_endian(&pdu_header, 1);
>>           iov[iovnum].iov_base = &pdu_header;
>> @@ -200,12 +220,47 @@ static int stub_send_ret_submit(struct 
>> stub_device *sdev)
>>           txsize += sizeof(pdu_header);
>>           /* 2. setup transfer buffer */
>> -        if (usb_pipein(urb->pipe) &&
>> +        if (usb_pipein(urb->pipe) && priv->sgl) {
>> +            /* If the server split a single SG request into several
>> +             * URBs because the server's HCD doesn't support SG,
>> +             * reassemble the split URB buffers into a single
>> +             * return command.
>> +             */
>> +            for (i = 0; i < priv->num_urbs; i++) {
>> +                iov[iovnum].iov_base =
>> +                    priv->urbs[i]->transfer_buffer;
>> +                iov[iovnum].iov_len =
>> +                    priv->urbs[i]->actual_length;
>> +                iovnum++;
>> +            }
>> +            txsize += actual_length;
>> +        } else if (usb_pipein(urb->pipe) &&
>>               usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
>>               urb->actual_length > 0) {
>> -            iov[iovnum].iov_base = urb->transfer_buffer;
>> -            iov[iovnum].iov_len  = urb->actual_length;
>> -            iovnum++;
>> +            if (urb->num_sgs) {
>> +                unsigned int copy = urb->actual_length;
>> +                int size;
>> +
>> +                for_each_sg(urb->sg, sg, urb->num_sgs, i) {
>> +                    if (copy == 0)
>> +                        break;
>> +
>> +                    if (copy < sg->length)
>> +                        size = copy;
>> +                    else
>> +                        size = sg->length;
>> +
>> +                    iov[iovnum].iov_base = sg_virt(sg);
>> +                    iov[iovnum].iov_len = size;
>> +
>> +                    iovnum++;
>> +                    copy -= size;
>> +                }
>> +            } else {
>> +                iov[iovnum].iov_base = urb->transfer_buffer;
>> +                iov[iovnum].iov_len  = urb->actual_length;
>> +                iovnum++;
>> +            }
>>               txsize += urb->actual_length;
>>           } else if (usb_pipein(urb->pipe) &&
>>                  usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
>> diff --git a/drivers/usb/usbip/usbip_common.c 
>> b/drivers/usb/usbip/usbip_common.c
>> index 45da3e01c7b0..6532d68e8808 100644
>> --- a/drivers/usb/usbip/usbip_common.c
>> +++ b/drivers/usb/usbip/usbip_common.c
>> @@ -680,8 +680,12 @@ EXPORT_SYMBOL_GPL(usbip_pad_iso);
>>   /* some members of urb must be substituted before. */
>>   int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb)
>>   {
>> -    int ret;
>> +    struct scatterlist *sg;
>> +    int ret = 0;
>> +    int recv;
>>       int size;
>> +    int copy;
>> +    int i;
>>       if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC) {
>>           /* the direction of urb must be OUT. */
>> @@ -701,29 +705,48 @@ int usbip_recv_xbuff(struct usbip_device *ud, 
>> struct urb *urb)
>>       if (!(size > 0))
>>           return 0;
>> -    if (size > urb->transfer_buffer_length) {
>> +    if (size > urb->transfer_buffer_length)
>>           /* should not happen, probably malicious packet */
>> -        if (ud->side == USBIP_STUB) {
>> -            usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
>> -            return 0;
>> -        } else {
>> -            usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
>> -            return -EPIPE;
>> -        }
>> -    }
>> +        goto error;
>> -    ret = usbip_recv(ud->tcp_socket, urb->transfer_buffer, size);
>> -    if (ret != size) {
>> -        dev_err(&urb->dev->dev, "recv xbuf, %d\n", ret);
>> -        if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC) {
>> -            usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
>> -        } else {
>> -            usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
>> -            return -EPIPE;
>> +    if (urb->num_sgs) {
>> +        copy = size;
>> +        for_each_sg(urb->sg, sg, urb->num_sgs, i) {
>> +            int recv_size;
>> +
>> +            if (copy < sg->length)
>> +                recv_size = copy;
>> +            else
>> +                recv_size = sg->length;
>> +
>> +            recv = usbip_recv(ud->tcp_socket, sg_virt(sg),
>> +                        recv_size);
>> +
>> +            if (recv != recv_size)
>> +                goto error;
>> +
>> +            copy -= recv;
>> +            ret += recv;
>>           }
>> +
>> +        if (ret != size)
>> +            goto error;
>> +    } else {
>> +        ret = usbip_recv(ud->tcp_socket, urb->transfer_buffer, size);
>> +        if (ret != size)
>> +            goto error;
>>       }
>>       return ret;
>> +
>> +error:
>> +    dev_err(&urb->dev->dev, "recv xbuf, %d\n", ret);
>> +    if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
>> +        usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
>> +    else
>> +        usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
>> +
>> +    return -EPIPE;
>>   }
>>   EXPORT_SYMBOL_GPL(usbip_recv_xbuff);
>> diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c
>> index ea82b932a2f9..e64ab50cbe2b 100644
>> --- a/drivers/usb/usbip/vhci_hcd.c
>> +++ b/drivers/usb/usbip/vhci_hcd.c
>> @@ -697,7 +697,8 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, 
>> struct urb *urb, gfp_t mem_flag
>>       }
>>       vdev = &vhci_hcd->vdev[portnum-1];
>> -    if (!urb->transfer_buffer && urb->transfer_buffer_length) {
>> +    if (!urb->transfer_buffer && !urb->num_sgs &&
>> +         urb->transfer_buffer_length) {
>>           dev_dbg(dev, "Null URB transfer buffer\n");
>>           return -EINVAL;
>>       }
>> @@ -1143,6 +1144,15 @@ static int vhci_setup(struct usb_hcd *hcd)
>>           hcd->speed = HCD_USB3;
>>           hcd->self.root_hub->speed = USB_SPEED_SUPER;
>>       }
>> +
>> +    /*
>> +     * Support SG.
>> +     * sg_tablesize is an arbitrary value to alleviate memory pressure
>> +     * on the host.
>> +     */
>> +    hcd->self.sg_tablesize = 32;
>> +    hcd->self.no_sg_constraint = 1;
>> +
>>       return 0;
>>   }
>> @@ -1296,6 +1306,9 @@ static int vhci_map_urb_for_dma(struct usb_hcd 
>> *hcd, struct urb *urb,
>>           return -EINVAL;
>>       }
>> +    if (urb->num_sgs)
>> +        urb->transfer_flags |= URB_DMA_MAP_SG;
>> +
>>       return 0;
>>   }
>> diff --git a/drivers/usb/usbip/vhci_tx.c b/drivers/usb/usbip/vhci_tx.c
>> index 2fa26d0578d7..865eb1276b6c 100644
>> --- a/drivers/usb/usbip/vhci_tx.c
>> +++ b/drivers/usb/usbip/vhci_tx.c
>> @@ -5,6 +5,7 @@
>>   #include <linux/kthread.h>
>>   #include <linux/slab.h>
>> +#include <linux/scatterlist.h>
>>   #include "usbip_common.h"
>>   #include "vhci.h"
>> @@ -50,19 +51,23 @@ static struct vhci_priv 
>> *dequeue_from_priv_tx(struct vhci_device *vdev)
>>   static int vhci_send_cmd_submit(struct vhci_device *vdev)
>>   {
>> +    struct usbip_iso_packet_descriptor *iso_buffer = NULL;
>>       struct vhci_priv *priv = NULL;
>> +    struct scatterlist *sg;
>>       struct msghdr msg;
>> -    struct kvec iov[3];
>> +    struct kvec *iov;
>>       size_t txsize;
>>       size_t total_size = 0;
>> +    int iovnum;
>> +    int err = -ENOMEM;
>> +    int i;
>>       while ((priv = dequeue_from_priv_tx(vdev)) != NULL) {
>>           int ret;
>>           struct urb *urb = priv->urb;
>>           struct usbip_header pdu_header;
>> -        struct usbip_iso_packet_descriptor *iso_buffer = NULL;
>>           txsize = 0;
>>           memset(&pdu_header, 0, sizeof(pdu_header));
>> @@ -72,18 +77,42 @@ static int vhci_send_cmd_submit(struct vhci_device 
>> *vdev)
>>           usbip_dbg_vhci_tx("setup txdata urb seqnum %lu\n",
>>                     priv->seqnum);
>> +        if (urb->num_sgs && usb_pipeout(urb->pipe))
>> +            iovnum = 2 + urb->num_sgs;
>> +        else
>> +            iovnum = 3;
>> +
>> +        iov = kcalloc(iovnum, sizeof(*iov), GFP_KERNEL);
>> +        if (!iov) {
>> +            usbip_event_add(&vdev->ud, SDEV_EVENT_ERROR_MALLOC);
>> +            return -ENOMEM;
>> +        }
>> +
>>           /* 1. setup usbip_header */
>>           setup_cmd_submit_pdu(&pdu_header, urb);
>>           usbip_header_correct_endian(&pdu_header, 1);
>> +        iovnum = 0;
>> -        iov[0].iov_base = &pdu_header;
>> -        iov[0].iov_len  = sizeof(pdu_header);
>> +        iov[iovnum].iov_base = &pdu_header;
>> +        iov[iovnum].iov_len  = sizeof(pdu_header);
>>           txsize += sizeof(pdu_header);
>> +        iovnum++;
>>           /* 2. setup transfer buffer */
>>           if (!usb_pipein(urb->pipe) && urb->transfer_buffer_length > 
>> 0) {
>> -            iov[1].iov_base = urb->transfer_buffer;
>> -            iov[1].iov_len  = urb->transfer_buffer_length;
>> +            if (urb->num_sgs &&
>> +                      !usb_endpoint_xfer_isoc(&urb->ep->desc)) {
>> +                for_each_sg(urb->sg, sg, urb->num_sgs, i) {
>> +                    iov[iovnum].iov_base = sg_virt(sg);
>> +                    iov[iovnum].iov_len = sg->length;
>> +                    iovnum++;
>> +                }
>> +            } else {
>> +                iov[iovnum].iov_base = urb->transfer_buffer;
>> +                iov[iovnum].iov_len  =
>> +                        urb->transfer_buffer_length;
>> +                iovnum++;
>> +            }
>>               txsize += urb->transfer_buffer_length;
>>           }
>> @@ -95,23 +124,26 @@ static int vhci_send_cmd_submit(struct 
>> vhci_device *vdev)
>>               if (!iso_buffer) {
>>                   usbip_event_add(&vdev->ud,
>>                           SDEV_EVENT_ERROR_MALLOC);
>> -                return -1;
>> +                goto err_iso_buffer;
>>               }
>> -            iov[2].iov_base = iso_buffer;
>> -            iov[2].iov_len  = len;
>> +            iov[iovnum].iov_base = iso_buffer;
>> +            iov[iovnum].iov_len  = len;
>> +            iovnum++;
>>               txsize += len;
>>           }
>> -        ret = kernel_sendmsg(vdev->ud.tcp_socket, &msg, iov, 3, txsize);
>> +        ret = kernel_sendmsg(vdev->ud.tcp_socket, &msg, iov, iovnum,
>> +                     txsize);
>>           if (ret != txsize) {
>>               pr_err("sendmsg failed!, ret=%d for %zd\n", ret,
>>                      txsize);
>> -            kfree(iso_buffer);
>>               usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_TCP);
>> -            return -1;
>> +            err = -EPIPE;
>> +            goto err_tx;
>>           }
>> +        kfree(iov);
>>           kfree(iso_buffer);
>>           usbip_dbg_vhci_tx("send txdata\n");
>> @@ -119,6 +151,13 @@ static int vhci_send_cmd_submit(struct 
>> vhci_device *vdev)
>>       }
>>       return total_size;
>> +
>> +err_tx:
>> +    kfree(iso_buffer);
>> +err_iso_buffer:
>> +    kfree(iov);
>> +
>> +    return err;
>>   }
>>   static struct vhci_unlink *dequeue_from_unlink_tx(struct vhci_device 
>> *vdev)
>>
> 
> Thanks for doing this work.
> 
> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
> 

Greg!

Please pick this up as well. This is good from usbip
perspective.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>

thanks,
-- Shuah


  reply index

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-08 15:54 [PATCH v5 0/2] usbip: Implement SG support Suwan Kim
2019-08-08 15:54 ` [PATCH v5 1/2] usbip: Skip DMA mapping and unmapping for urb at vhci Suwan Kim
2019-08-08 16:18   ` shuah
2019-08-13 18:34     ` shuah
2019-08-22 16:40   ` Greg KH
2019-08-22 22:19     ` Suwan Kim
2019-08-08 15:54 ` [PATCH v5 2/2] usbip: Implement SG support to vhci-hcd and stub driver Suwan Kim
2019-08-08 16:21   ` shuah
2019-08-13 18:36     ` shuah [this message]
2019-08-22  1:52     ` Suwan Kim
2019-08-14 13:19 ` [PATCH v5 0/2] usbip: Implement SG support Christoph Hellwig
2019-08-15 13:23   ` Greg KH
2019-08-15 14:10     ` shuah
2019-08-15 15:25       ` Suwan Kim

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