[RFC,2/2] vhost: support vhost-user request only handled by external backend
Checks
Commit Message
External backends may have specific requests to handle, and so
we don't want the vhost-user lib to handle these requests as
errors.
This patch also catch the case where a request is neither handled
by the external backend nor by the vhost library.
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
lib/librte_vhost/vhost_user.c | 28 +++++++++++++++-------------
1 file changed, 15 insertions(+), 13 deletions(-)
Comments
On 27.02.2019 13:02, Maxime Coquelin wrote:
> External backends may have specific requests to handle, and so
> we don't want the vhost-user lib to handle these requests as
> errors.
>
> This patch also catch the case where a request is neither handled
> by the external backend nor by the vhost library.
>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
> lib/librte_vhost/vhost_user.c | 28 +++++++++++++++-------------
> 1 file changed, 15 insertions(+), 13 deletions(-)
>
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index 36c0c676d..bae5ef1cc 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -1924,27 +1924,29 @@ vhost_user_msg_handler(int vid, int fd)
> }
>
> ret = read_vhost_message(fd, &msg);
> - if (ret <= 0 || msg.request.master >= VHOST_USER_MAX) {
> + if (ret <= 0) {
> if (ret < 0)
> RTE_LOG(ERR, VHOST_CONFIG,
> "vhost read message failed\n");
> - else if (ret == 0)
> + else
> RTE_LOG(INFO, VHOST_CONFIG,
> "vhost peer closed\n");
> - else
> - RTE_LOG(ERR, VHOST_CONFIG,
> - "vhost read incorrect message\n");
>
> return -1;
> }
>
> ret = 0;
> - if (msg.request.master != VHOST_USER_IOTLB_MSG)
> - RTE_LOG(INFO, VHOST_CONFIG, "read message %s\n",
> - vhost_message_str[msg.request.master]);
> - else
> - RTE_LOG(DEBUG, VHOST_CONFIG, "read message %s\n",
> - vhost_message_str[msg.request.master]);
> + request = msg.request.master;
> + if (request < VHOST_USER_MAX && vhost_message_str[req]) {
> + if (request != VHOST_USER_IOTLB_MSG)
> + RTE_LOG(INFO, VHOST_CONFIG, "read message %s\n",
> + vhost_message_str[request]);
> + else if (
> + RTE_LOG(DEBUG, VHOST_CONFIG, "read message %s\n",
> + vhost_message_str[request]);
There is no need for the 'if' without the body.
> + } else {
> + RTE_LOG(INFO, VHOST_CONFIG, "External request %d\n", request);
External requests could be annoying. Maybe we'll need to move them under DBG ?
I'm not sure.
> + }
>
> ret = vhost_user_check_and_alloc_queue_pair(dev, &msg);
> if (ret < 0) {
> @@ -1960,7 +1962,7 @@ vhost_user_msg_handler(int vid, int fd)
> * inactive, so it is safe. Otherwise taking the access_lock
> * would cause a dead lock.
> */
> - switch (msg.request.master) {
> + switch (request) {
> case VHOST_USER_SET_FEATURES:
> case VHOST_USER_SET_PROTOCOL_FEATURES:
> case VHOST_USER_SET_OWNER:
> @@ -1985,6 +1987,7 @@ vhost_user_msg_handler(int vid, int fd)
>
> }
>
> + ret = RTE_VHOST_MSG_RESULT_ERR;
This will break the 'vhost_crypto', because it has no 'pre_msg_handler'
and master will skip to 'post_msg_handler', but it will not be called
because current status is ERR.
Maybe it's easier to introduce RTE_VHOST_MSG_RESULT_NOT_HANDLED and convert
it to ERR before the reply ?
This will require changing the pre_msg_handlers to return
RTE_VHOST_MSG_RESULT_NOT_HANDLED if message wasn't recognized.
And we'll possibly be able to drop the 'skip_master' in this case.
> if (dev->extern_ops.pre_msg_handle) {
> ret = (*dev->extern_ops.pre_msg_handle)(dev->vid,
> (void *)&msg, &skip_master);
> @@ -1997,7 +2000,6 @@ vhost_user_msg_handler(int vid, int fd)
> goto skip_to_post_handle;
> }
>
> - request = msg.request.master;
> if (request > VHOST_USER_NONE && request < VHOST_USER_MAX) {
> if (!vhost_message_handlers[request])
> goto skip_to_post_handle;
>
On 2/27/19 2:15 PM, Ilya Maximets wrote:
> On 27.02.2019 13:02, Maxime Coquelin wrote:
>> External backends may have specific requests to handle, and so
>> we don't want the vhost-user lib to handle these requests as
>> errors.
>>
>> This patch also catch the case where a request is neither handled
>> by the external backend nor by the vhost library.
>>
>> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>> ---
>> lib/librte_vhost/vhost_user.c | 28 +++++++++++++++-------------
>> 1 file changed, 15 insertions(+), 13 deletions(-)
>>
>> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
>> index 36c0c676d..bae5ef1cc 100644
>> --- a/lib/librte_vhost/vhost_user.c
>> +++ b/lib/librte_vhost/vhost_user.c
>> @@ -1924,27 +1924,29 @@ vhost_user_msg_handler(int vid, int fd)
>> }
>>
>> ret = read_vhost_message(fd, &msg);
>> - if (ret <= 0 || msg.request.master >= VHOST_USER_MAX) {
>> + if (ret <= 0) {
>> if (ret < 0)
>> RTE_LOG(ERR, VHOST_CONFIG,
>> "vhost read message failed\n");
>> - else if (ret == 0)
>> + else
>> RTE_LOG(INFO, VHOST_CONFIG,
>> "vhost peer closed\n");
>> - else
>> - RTE_LOG(ERR, VHOST_CONFIG,
>> - "vhost read incorrect message\n");
>>
>> return -1;
>> }
>>
>> ret = 0;
>> - if (msg.request.master != VHOST_USER_IOTLB_MSG)
>> - RTE_LOG(INFO, VHOST_CONFIG, "read message %s\n",
>> - vhost_message_str[msg.request.master]);
>> - else
>> - RTE_LOG(DEBUG, VHOST_CONFIG, "read message %s\n",
>> - vhost_message_str[msg.request.master]);
>> + request = msg.request.master;
>> + if (request < VHOST_USER_MAX && vhost_message_str[req]) {
>> + if (request != VHOST_USER_IOTLB_MSG)
>> + RTE_LOG(INFO, VHOST_CONFIG, "read message %s\n",
>> + vhost_message_str[request]);
>> + else if (
>> + RTE_LOG(DEBUG, VHOST_CONFIG, "read message %s\n",
>> + vhost_message_str[request]);
>
> There is no need for the 'if' without the body.
Oops, indeed. I was pretty sure I did compile test it, but looking at
the history I didn't.
>> + } else {
>> + RTE_LOG(INFO, VHOST_CONFIG, "External request %d\n", request);
>
> External requests could be annoying. Maybe we'll need to move them under DBG ?
> I'm not sure.
Fair point. I'll change to DBG.
>> + }
>>
>> ret = vhost_user_check_and_alloc_queue_pair(dev, &msg);
>> if (ret < 0) {
>> @@ -1960,7 +1962,7 @@ vhost_user_msg_handler(int vid, int fd)
>> * inactive, so it is safe. Otherwise taking the access_lock
>> * would cause a dead lock.
>> */
>> - switch (msg.request.master) {
>> + switch (request) {
>> case VHOST_USER_SET_FEATURES:
>> case VHOST_USER_SET_PROTOCOL_FEATURES:
>> case VHOST_USER_SET_OWNER:
>> @@ -1985,6 +1987,7 @@ vhost_user_msg_handler(int vid, int fd)
>>
>> }
>>
>> + ret = RTE_VHOST_MSG_RESULT_ERR;
>
> This will break the 'vhost_crypto', because it has no 'pre_msg_handler'
> and master will skip to 'post_msg_handler', but it will not be called
> because current status is ERR.
Thanks for catching it.
> Maybe it's easier to introduce RTE_VHOST_MSG_RESULT_NOT_HANDLED and convert
> it to ERR before the reply ?
> This will require changing the pre_msg_handlers to return
> RTE_VHOST_MSG_RESULT_NOT_HANDLED if message wasn't recognized.
> And we'll possibly be able to drop the 'skip_master' in this case.
Ok, that means breaking the API, but it is still experimental so not a
blocker.
I like the idea because it would also make it possible to add some debug
prints.
I'll post new iteration this morning.
Thanks,
Maxime
>> if (dev->extern_ops.pre_msg_handle) {
>> ret = (*dev->extern_ops.pre_msg_handle)(dev->vid,
>> (void *)&msg, &skip_master);
>> @@ -1997,7 +2000,6 @@ vhost_user_msg_handler(int vid, int fd)
>> goto skip_to_post_handle;
>> }
>>
>> - request = msg.request.master;
>> if (request > VHOST_USER_NONE && request < VHOST_USER_MAX) {
>> if (!vhost_message_handlers[request])
>> goto skip_to_post_handle;
>>
@@ -1924,27 +1924,29 @@ vhost_user_msg_handler(int vid, int fd)
}
ret = read_vhost_message(fd, &msg);
- if (ret <= 0 || msg.request.master >= VHOST_USER_MAX) {
+ if (ret <= 0) {
if (ret < 0)
RTE_LOG(ERR, VHOST_CONFIG,
"vhost read message failed\n");
- else if (ret == 0)
+ else
RTE_LOG(INFO, VHOST_CONFIG,
"vhost peer closed\n");
- else
- RTE_LOG(ERR, VHOST_CONFIG,
- "vhost read incorrect message\n");
return -1;
}
ret = 0;
- if (msg.request.master != VHOST_USER_IOTLB_MSG)
- RTE_LOG(INFO, VHOST_CONFIG, "read message %s\n",
- vhost_message_str[msg.request.master]);
- else
- RTE_LOG(DEBUG, VHOST_CONFIG, "read message %s\n",
- vhost_message_str[msg.request.master]);
+ request = msg.request.master;
+ if (request < VHOST_USER_MAX && vhost_message_str[req]) {
+ if (request != VHOST_USER_IOTLB_MSG)
+ RTE_LOG(INFO, VHOST_CONFIG, "read message %s\n",
+ vhost_message_str[request]);
+ else if (
+ RTE_LOG(DEBUG, VHOST_CONFIG, "read message %s\n",
+ vhost_message_str[request]);
+ } else {
+ RTE_LOG(INFO, VHOST_CONFIG, "External request %d\n", request);
+ }
ret = vhost_user_check_and_alloc_queue_pair(dev, &msg);
if (ret < 0) {
@@ -1960,7 +1962,7 @@ vhost_user_msg_handler(int vid, int fd)
* inactive, so it is safe. Otherwise taking the access_lock
* would cause a dead lock.
*/
- switch (msg.request.master) {
+ switch (request) {
case VHOST_USER_SET_FEATURES:
case VHOST_USER_SET_PROTOCOL_FEATURES:
case VHOST_USER_SET_OWNER:
@@ -1985,6 +1987,7 @@ vhost_user_msg_handler(int vid, int fd)
}
+ ret = RTE_VHOST_MSG_RESULT_ERR;
if (dev->extern_ops.pre_msg_handle) {
ret = (*dev->extern_ops.pre_msg_handle)(dev->vid,
(void *)&msg, &skip_master);
@@ -1997,7 +2000,6 @@ vhost_user_msg_handler(int vid, int fd)
goto skip_to_post_handle;
}
- request = msg.request.master;
if (request > VHOST_USER_NONE && request < VHOST_USER_MAX) {
if (!vhost_message_handlers[request])
goto skip_to_post_handle;