diff mbox series

[1/5] io: Add support for MSG_PEEK for socket channel

Message ID 20221213213850.1481858-2-peterx@redhat.com
State New
Headers show
Series migration: Fix disorder of channel creations | expand

Commit Message

Peter Xu Dec. 13, 2022, 9:38 p.m. UTC
From: "manish.mishra" <manish.mishra@nutanix.com>

MSG_PEEK reads from the peek of channel, The data is treated as
unread and the next read shall still return this data. This
support is currently added only for socket class. Extra parameter
'flags' is added to io_readv calls to pass extra read flags like
MSG_PEEK.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.co
Suggested-by: Daniel P. Berrangé <berrange@redhat.com
Signed-off-by: manish.mishra <manish.mishra@nutanix.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 chardev/char-socket.c               |  4 ++--
 include/io/channel.h                |  6 ++++++
 io/channel-buffer.c                 |  1 +
 io/channel-command.c                |  1 +
 io/channel-file.c                   |  1 +
 io/channel-null.c                   |  1 +
 io/channel-socket.c                 | 17 ++++++++++++++++-
 io/channel-tls.c                    |  1 +
 io/channel-websock.c                |  1 +
 io/channel.c                        | 16 ++++++++++++----
 migration/channel-block.c           |  1 +
 migration/rdma.c                    |  1 +
 scsi/qemu-pr-helper.c               |  2 +-
 tests/qtest/tpm-emu.c               |  2 +-
 tests/unit/test-io-channel-socket.c |  1 +
 util/vhost-user-server.c            |  2 +-
 16 files changed, 48 insertions(+), 10 deletions(-)

Comments

Daniel P. Berrangé Dec. 14, 2022, 9:14 a.m. UTC | #1
On Tue, Dec 13, 2022 at 04:38:46PM -0500, Peter Xu wrote:
> From: "manish.mishra" <manish.mishra@nutanix.com>
> 
> MSG_PEEK reads from the peek of channel, The data is treated as
> unread and the next read shall still return this data. This
> support is currently added only for socket class. Extra parameter
> 'flags' is added to io_readv calls to pass extra read flags like
> MSG_PEEK.
> 
> Reviewed-by: Daniel P. Berrang?? <berrange@redhat.co
> Suggested-by: Daniel P. Berrang?? <berrange@redhat.com

The last letter of my name has been mangled - whatever tools used
to pull in manish's patches seem to not be UTF-8 clean.

Also the email addr isn't terminated, but that was pre-existing
in manish's previous posting.

With regards,
Daniel
Peter Xu Dec. 14, 2022, 9:30 p.m. UTC | #2
On Wed, Dec 14, 2022 at 09:14:09AM +0000, Daniel P. Berrangé wrote:
> On Tue, Dec 13, 2022 at 04:38:46PM -0500, Peter Xu wrote:
> > From: "manish.mishra" <manish.mishra@nutanix.com>
> > 
> > MSG_PEEK reads from the peek of channel, The data is treated as
> > unread and the next read shall still return this data. This
> > support is currently added only for socket class. Extra parameter
> > 'flags' is added to io_readv calls to pass extra read flags like
> > MSG_PEEK.
> > 
> > Reviewed-by: Daniel P. Berrang?? <berrange@redhat.co
> > Suggested-by: Daniel P. Berrang?? <berrange@redhat.com
> 
> The last letter of my name has been mangled - whatever tools used
> to pull in manish's patches seem to not be UTF-8 clean.
> 
> Also the email addr isn't terminated, but that was pre-existing
> in manish's previous posting.

I'll fix at least the latter in my next post, sorry.

For the 1st one - I am still looking at what went wrong.

Here from the web interfaces it all looks good (besides the wrong
ending..), e.g. on lore or patchew:

https://lore.kernel.org/all/20221213213850.1481858-2-peterx@redhat.com/
https://patchew.org/QEMU/20221213213850.1481858-1-peterx@redhat.com/20221213213850.1481858-2-peterx@redhat.com/

It also looks good with e.g. Gmail webclient.

Then I digged into the email headers and I found that comparing to Manish's
original message, the patches I posted has one more line of "Content-type":

  Content-Type: text/plain; charset="utf-8"
  Content-type: text/plain
  https://patchew.org/QEMU/20221213213850.1481858-2-peterx@redhat.com/mbox

While Manish's patch only has one line:

  Content-Type: text/plain; charset="utf-8"
  https://patchew.org/QEMU/20221123172735.25181-2-manish.mishra@nutanix.com/mbox

I found that it also happens in my local mail archive, so with my local
mail client it doesn't show correctly either (mutt here).  After I manually
removed that extra Content-type line in the archive it went right even
locally on mutt.

So it seems the 2nd "Content-type: text/plain" overwrote the first one and
it may not correctly apply utf-8 in the email client depending on what the
email client uses as default.  Said that, I'm pretty sure my muttrc has:

 set charset = "UTF-8"
 set send_charset = "UTF-8"

So neither do I know why that mutt config didn't apply to these patches,
nor do I (yet..) have an idea where that extra line comes from.. :-(
Daniel P. Berrangé Dec. 15, 2022, 9:40 a.m. UTC | #3
On Wed, Dec 14, 2022 at 04:30:48PM -0500, Peter Xu wrote:
> On Wed, Dec 14, 2022 at 09:14:09AM +0000, Daniel P. Berrangé wrote:
> > On Tue, Dec 13, 2022 at 04:38:46PM -0500, Peter Xu wrote:
> > > From: "manish.mishra" <manish.mishra@nutanix.com>
> > > 
> > > MSG_PEEK reads from the peek of channel, The data is treated as
> > > unread and the next read shall still return this data. This
> > > support is currently added only for socket class. Extra parameter
> > > 'flags' is added to io_readv calls to pass extra read flags like
> > > MSG_PEEK.
> > > 
> > > Reviewed-by: Daniel P. Berrang?? <berrange@redhat.co
> > > Suggested-by: Daniel P. Berrang?? <berrange@redhat.com
> > 
> > The last letter of my name has been mangled - whatever tools used
> > to pull in manish's patches seem to not be UTF-8 clean.
> > 
> > Also the email addr isn't terminated, but that was pre-existing
> > in manish's previous posting.
> 
> I'll fix at least the latter in my next post, sorry.
> 
> For the 1st one - I am still looking at what went wrong.
> 
> Here from the web interfaces it all looks good (besides the wrong
> ending..), e.g. on lore or patchew:
> 
> https://lore.kernel.org/all/20221213213850.1481858-2-peterx@redhat.com/
> https://patchew.org/QEMU/20221213213850.1481858-1-peterx@redhat.com/20221213213850.1481858-2-peterx@redhat.com/
> 
> It also looks good with e.g. Gmail webclient.
> 
> Then I digged into the email headers and I found that comparing to Manish's
> original message, the patches I posted has one more line of "Content-type":
> 
>   Content-Type: text/plain; charset="utf-8"
>   Content-type: text/plain
>   https://patchew.org/QEMU/20221213213850.1481858-2-peterx@redhat.com/mbox
> 
> While Manish's patch only has one line:
> 
>   Content-Type: text/plain; charset="utf-8"
>   https://patchew.org/QEMU/20221123172735.25181-2-manish.mishra@nutanix.com/mbox

Don't trust what is shown by patchew, as that's been through many
hops.

The copy I receieved came directly to me via CC, so didn't hit mailman,
nor patchew, and that *only* has  "Content-type: text/plain".  So the
extra Content-type line with utf8 must have been added either by
mailman or patchew.

So it probably looks like a config problem in the tool you use to send
the patches originally.

With regards,
Daniel
Peter Xu Dec. 15, 2022, 5:35 p.m. UTC | #4
On Thu, Dec 15, 2022 at 09:40:41AM +0000, Daniel P. Berrangé wrote:
> On Wed, Dec 14, 2022 at 04:30:48PM -0500, Peter Xu wrote:
> > On Wed, Dec 14, 2022 at 09:14:09AM +0000, Daniel P. Berrangé wrote:
> > > On Tue, Dec 13, 2022 at 04:38:46PM -0500, Peter Xu wrote:
> > > > From: "manish.mishra" <manish.mishra@nutanix.com>
> > > > 
> > > > MSG_PEEK reads from the peek of channel, The data is treated as
> > > > unread and the next read shall still return this data. This
> > > > support is currently added only for socket class. Extra parameter
> > > > 'flags' is added to io_readv calls to pass extra read flags like
> > > > MSG_PEEK.
> > > > 
> > > > Reviewed-by: Daniel P. Berrang?? <berrange@redhat.co
> > > > Suggested-by: Daniel P. Berrang?? <berrange@redhat.com
> > > 
> > > The last letter of my name has been mangled - whatever tools used
> > > to pull in manish's patches seem to not be UTF-8 clean.
> > > 
> > > Also the email addr isn't terminated, but that was pre-existing
> > > in manish's previous posting.
> > 
> > I'll fix at least the latter in my next post, sorry.
> > 
> > For the 1st one - I am still looking at what went wrong.
> > 
> > Here from the web interfaces it all looks good (besides the wrong
> > ending..), e.g. on lore or patchew:
> > 
> > https://lore.kernel.org/all/20221213213850.1481858-2-peterx@redhat.com/
> > https://patchew.org/QEMU/20221213213850.1481858-1-peterx@redhat.com/20221213213850.1481858-2-peterx@redhat.com/
> > 
> > It also looks good with e.g. Gmail webclient.
> > 
> > Then I digged into the email headers and I found that comparing to Manish's
> > original message, the patches I posted has one more line of "Content-type":
> > 
> >   Content-Type: text/plain; charset="utf-8"
> >   Content-type: text/plain
> >   https://patchew.org/QEMU/20221213213850.1481858-2-peterx@redhat.com/mbox
> > 
> > While Manish's patch only has one line:
> > 
> >   Content-Type: text/plain; charset="utf-8"
> >   https://patchew.org/QEMU/20221123172735.25181-2-manish.mishra@nutanix.com/mbox
> 
> Don't trust what is shown by patchew, as that's been through many
> hops.
> 
> The copy I receieved came directly to me via CC, so didn't hit mailman,
> nor patchew, and that *only* has  "Content-type: text/plain".  So the
> extra Content-type line with utf8 must have been added either by
> mailman or patchew.
> 
> So it probably looks like a config problem in the tool you use to send
> the patches originally.

Ouch... for misterious reasons I had one line in .gitconfig:

177 [format]
178         headers = "Content-type: text/plain"

And that'll also affect git-publish too...  I have it dropped now.

Thanks,
manish.mishra Dec. 16, 2022, 10:40 a.m. UTC | #5
On 15/12/22 11:05 pm, Peter Xu wrote:
> On Thu, Dec 15, 2022 at 09:40:41AM +0000, Daniel P. Berrangé wrote:
>> On Wed, Dec 14, 2022 at 04:30:48PM -0500, Peter Xu wrote:
>>> On Wed, Dec 14, 2022 at 09:14:09AM +0000, Daniel P. Berrangé wrote:
>>>> On Tue, Dec 13, 2022 at 04:38:46PM -0500, Peter Xu wrote:
>>>>> From: "manish.mishra" <manish.mishra@nutanix.com>
>>>>>
>>>>> MSG_PEEK reads from the peek of channel, The data is treated as
>>>>> unread and the next read shall still return this data. This
>>>>> support is currently added only for socket class. Extra parameter
>>>>> 'flags' is added to io_readv calls to pass extra read flags like
>>>>> MSG_PEEK.
>>>>>
>>>>> Reviewed-by: Daniel P. Berrang?? <berrange@redhat.co
>>>>> Suggested-by: Daniel P. Berrang?? <berrange@redhat.com
>>>> The last letter of my name has been mangled - whatever tools used
>>>> to pull in manish's patches seem to not be UTF-8 clean.
>>>>
>>>> Also the email addr isn't terminated, but that was pre-existing
>>>> in manish's previous posting.


Yes sorry, noticed it now, should i send another patch to update it. Also in our internal testing we noticed multifd_init was skipped for 1 case, so if this patch series is not yet submitted should i send another version of it early morning monday?

Thanks

Manish Mishra

>>> I'll fix at least the latter in my next post, sorry.
>>>
>>> For the 1st one - I am still looking at what went wrong.
>>>
>>> Here from the web interfaces it all looks good (besides the wrong
>>> ending..), e.g. on lore or patchew:
>>>
>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__lore.kernel.org_all_20221213213850.1481858-2D2-2Dpeterx-40redhat.com_&d=DwIDaQ&c=s883GpUCOChKOHiocYtGcg&r=c4KON2DiMd-szjwjggQcuUvTsPWblztAL0gVzaHnNmc&m=UYXwYmi1YA2mdAgHNDIkmgh-Xbem8hmqgCedCRNaj-32GKMVK8X30wH3nnXE9VF9&s=_9G0TGvGLvwCdB7vumPEboQqcrX5RoaxZ_4aZTnMDzY&e=
>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__patchew.org_QEMU_20221213213850.1481858-2D1-2Dpeterx-40redhat.com_20221213213850.1481858-2D2-2Dpeterx-40redhat.com_&d=DwIDaQ&c=s883GpUCOChKOHiocYtGcg&r=c4KON2DiMd-szjwjggQcuUvTsPWblztAL0gVzaHnNmc&m=UYXwYmi1YA2mdAgHNDIkmgh-Xbem8hmqgCedCRNaj-32GKMVK8X30wH3nnXE9VF9&s=Nv0ek8VsMHEDFdQ--vwCOrwxT_u1KqbV9014SQzI1kQ&e=
>>>
>>> It also looks good with e.g. Gmail webclient.
>>>
>>> Then I digged into the email headers and I found that comparing to Manish's
>>> original message, the patches I posted has one more line of "Content-type":
>>>
>>>    Content-Type: text/plain; charset="utf-8"
>>>    Content-type: text/plain
>>>    https://urldefense.proofpoint.com/v2/url?u=https-3A__patchew.org_QEMU_20221213213850.1481858-2D2-2Dpeterx-40redhat.com_mbox&d=DwIDaQ&c=s883GpUCOChKOHiocYtGcg&r=c4KON2DiMd-szjwjggQcuUvTsPWblztAL0gVzaHnNmc&m=UYXwYmi1YA2mdAgHNDIkmgh-Xbem8hmqgCedCRNaj-32GKMVK8X30wH3nnXE9VF9&s=wD5Y-ZvvyUOVKpYHJkM7M8znJ3BjjpkbRIE1NVlMloI&e=
>>>
>>> While Manish's patch only has one line:
>>>
>>>    Content-Type: text/plain; charset="utf-8"
>>>    https://urldefense.proofpoint.com/v2/url?u=https-3A__patchew.org_QEMU_20221123172735.25181-2D2-2Dmanish.mishra-40nutanix.com_mbox&d=DwIDaQ&c=s883GpUCOChKOHiocYtGcg&r=c4KON2DiMd-szjwjggQcuUvTsPWblztAL0gVzaHnNmc&m=UYXwYmi1YA2mdAgHNDIkmgh-Xbem8hmqgCedCRNaj-32GKMVK8X30wH3nnXE9VF9&s=eQ3eyB3GvzUzyHdjTlWTt14dw4x0PL2xSbmXWPfN104&e=
>> Don't trust what is shown by patchew, as that's been through many
>> hops.
>>
>> The copy I receieved came directly to me via CC, so didn't hit mailman,
>> nor patchew, and that *only* has  "Content-type: text/plain".  So the
>> extra Content-type line with utf8 must have been added either by
>> mailman or patchew.
>>
>> So it probably looks like a config problem in the tool you use to send
>> the patches originally.
> Ouch... for misterious reasons I had one line in .gitconfig:
>
> 177 [format]
> 178         headers = "Content-type: text/plain"
>
> And that'll also affect git-publish too...  I have it dropped now.
>
> Thanks,
>
Peter Xu Dec. 16, 2022, 2:30 p.m. UTC | #6
On Fri, Dec 16, 2022 at 04:10:22PM +0530, manish.mishra wrote:
> Yes sorry, noticed it now, should i send another patch to update it. Also
> in our internal testing we noticed multifd_init was skipped for 1 case,
> so if this patch series is not yet submitted should i send another
> version of it early morning monday?

I think yes.

Thanks,
diff mbox series

Patch

diff --git a/chardev/char-socket.c b/chardev/char-socket.c
index 879564aa8a..5afce9a464 100644
--- a/chardev/char-socket.c
+++ b/chardev/char-socket.c
@@ -283,11 +283,11 @@  static ssize_t tcp_chr_recv(Chardev *chr, char *buf, size_t len)
     if (qio_channel_has_feature(s->ioc, QIO_CHANNEL_FEATURE_FD_PASS)) {
         ret = qio_channel_readv_full(s->ioc, &iov, 1,
                                      &msgfds, &msgfds_num,
-                                     NULL);
+                                     0, NULL);
     } else {
         ret = qio_channel_readv_full(s->ioc, &iov, 1,
                                      NULL, NULL,
-                                     NULL);
+                                     0, NULL);
     }
 
     if (msgfds_num) {
diff --git a/include/io/channel.h b/include/io/channel.h
index c680ee7480..716235d496 100644
--- a/include/io/channel.h
+++ b/include/io/channel.h
@@ -34,6 +34,8 @@  OBJECT_DECLARE_TYPE(QIOChannel, QIOChannelClass,
 
 #define QIO_CHANNEL_WRITE_FLAG_ZERO_COPY 0x1
 
+#define QIO_CHANNEL_READ_FLAG_MSG_PEEK 0x1
+
 typedef enum QIOChannelFeature QIOChannelFeature;
 
 enum QIOChannelFeature {
@@ -41,6 +43,7 @@  enum QIOChannelFeature {
     QIO_CHANNEL_FEATURE_SHUTDOWN,
     QIO_CHANNEL_FEATURE_LISTEN,
     QIO_CHANNEL_FEATURE_WRITE_ZERO_COPY,
+    QIO_CHANNEL_FEATURE_READ_MSG_PEEK,
 };
 
 
@@ -114,6 +117,7 @@  struct QIOChannelClass {
                         size_t niov,
                         int **fds,
                         size_t *nfds,
+                        int flags,
                         Error **errp);
     int (*io_close)(QIOChannel *ioc,
                     Error **errp);
@@ -188,6 +192,7 @@  void qio_channel_set_name(QIOChannel *ioc,
  * @niov: the length of the @iov array
  * @fds: pointer to an array that will received file handles
  * @nfds: pointer filled with number of elements in @fds on return
+ * @flags: read flags (QIO_CHANNEL_READ_FLAG_*)
  * @errp: pointer to a NULL-initialized error object
  *
  * Read data from the IO channel, storing it in the
@@ -224,6 +229,7 @@  ssize_t qio_channel_readv_full(QIOChannel *ioc,
                                size_t niov,
                                int **fds,
                                size_t *nfds,
+                               int flags,
                                Error **errp);
 
 
diff --git a/io/channel-buffer.c b/io/channel-buffer.c
index bf52011be2..8096180f85 100644
--- a/io/channel-buffer.c
+++ b/io/channel-buffer.c
@@ -54,6 +54,7 @@  static ssize_t qio_channel_buffer_readv(QIOChannel *ioc,
                                         size_t niov,
                                         int **fds,
                                         size_t *nfds,
+                                        int flags,
                                         Error **errp)
 {
     QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
diff --git a/io/channel-command.c b/io/channel-command.c
index 74516252ba..e7edd091af 100644
--- a/io/channel-command.c
+++ b/io/channel-command.c
@@ -203,6 +203,7 @@  static ssize_t qio_channel_command_readv(QIOChannel *ioc,
                                          size_t niov,
                                          int **fds,
                                          size_t *nfds,
+                                         int flags,
                                          Error **errp)
 {
     QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
diff --git a/io/channel-file.c b/io/channel-file.c
index b67687c2aa..d76663e6ae 100644
--- a/io/channel-file.c
+++ b/io/channel-file.c
@@ -86,6 +86,7 @@  static ssize_t qio_channel_file_readv(QIOChannel *ioc,
                                       size_t niov,
                                       int **fds,
                                       size_t *nfds,
+                                      int flags,
                                       Error **errp)
 {
     QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
diff --git a/io/channel-null.c b/io/channel-null.c
index 75e3781507..4fafdb770d 100644
--- a/io/channel-null.c
+++ b/io/channel-null.c
@@ -60,6 +60,7 @@  qio_channel_null_readv(QIOChannel *ioc,
                        size_t niov,
                        int **fds G_GNUC_UNUSED,
                        size_t *nfds G_GNUC_UNUSED,
+                       int flags,
                        Error **errp)
 {
     QIOChannelNull *nioc = QIO_CHANNEL_NULL(ioc);
diff --git a/io/channel-socket.c b/io/channel-socket.c
index b76dca9cc1..dfb8cb6c40 100644
--- a/io/channel-socket.c
+++ b/io/channel-socket.c
@@ -173,6 +173,8 @@  int qio_channel_socket_connect_sync(QIOChannelSocket *ioc,
     }
 #endif
 
+    qio_channel_set_feature(QIO_CHANNEL(ioc), QIO_CHANNEL_FEATURE_READ_MSG_PEEK);
+
     return 0;
 }
 
@@ -406,6 +408,8 @@  qio_channel_socket_accept(QIOChannelSocket *ioc,
     }
 #endif /* WIN32 */
 
+    qio_channel_set_feature(QIO_CHANNEL(cioc), QIO_CHANNEL_FEATURE_READ_MSG_PEEK);
+
     trace_qio_channel_socket_accept_complete(ioc, cioc, cioc->fd);
     return cioc;
 
@@ -496,6 +500,7 @@  static ssize_t qio_channel_socket_readv(QIOChannel *ioc,
                                         size_t niov,
                                         int **fds,
                                         size_t *nfds,
+                                        int flags,
                                         Error **errp)
 {
     QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
@@ -517,6 +522,10 @@  static ssize_t qio_channel_socket_readv(QIOChannel *ioc,
 
     }
 
+    if (flags & QIO_CHANNEL_READ_FLAG_MSG_PEEK) {
+        sflags |= MSG_PEEK;
+    }
+
  retry:
     ret = recvmsg(sioc->fd, &msg, sflags);
     if (ret < 0) {
@@ -624,11 +633,17 @@  static ssize_t qio_channel_socket_readv(QIOChannel *ioc,
                                         size_t niov,
                                         int **fds,
                                         size_t *nfds,
+                                        int flags,
                                         Error **errp)
 {
     QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
     ssize_t done = 0;
     ssize_t i;
+    int sflags = 0;
+
+    if (flags & QIO_CHANNEL_READ_FLAG_MSG_PEEK) {
+        sflags |= MSG_PEEK;
+    }
 
     for (i = 0; i < niov; i++) {
         ssize_t ret;
@@ -636,7 +651,7 @@  static ssize_t qio_channel_socket_readv(QIOChannel *ioc,
         ret = recv(sioc->fd,
                    iov[i].iov_base,
                    iov[i].iov_len,
-                   0);
+                   sflags);
         if (ret < 0) {
             if (errno == EAGAIN) {
                 if (done) {
diff --git a/io/channel-tls.c b/io/channel-tls.c
index 4ce890a538..c730cb8ec5 100644
--- a/io/channel-tls.c
+++ b/io/channel-tls.c
@@ -260,6 +260,7 @@  static ssize_t qio_channel_tls_readv(QIOChannel *ioc,
                                      size_t niov,
                                      int **fds,
                                      size_t *nfds,
+                                     int flags,
                                      Error **errp)
 {
     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
diff --git a/io/channel-websock.c b/io/channel-websock.c
index fb4932ade7..a12acc27cf 100644
--- a/io/channel-websock.c
+++ b/io/channel-websock.c
@@ -1081,6 +1081,7 @@  static ssize_t qio_channel_websock_readv(QIOChannel *ioc,
                                          size_t niov,
                                          int **fds,
                                          size_t *nfds,
+                                         int flags,
                                          Error **errp)
 {
     QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(ioc);
diff --git a/io/channel.c b/io/channel.c
index 0640941ac5..a8c7f11649 100644
--- a/io/channel.c
+++ b/io/channel.c
@@ -52,6 +52,7 @@  ssize_t qio_channel_readv_full(QIOChannel *ioc,
                                size_t niov,
                                int **fds,
                                size_t *nfds,
+                               int flags,
                                Error **errp)
 {
     QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc);
@@ -63,7 +64,14 @@  ssize_t qio_channel_readv_full(QIOChannel *ioc,
         return -1;
     }
 
-    return klass->io_readv(ioc, iov, niov, fds, nfds, errp);
+    if ((flags & QIO_CHANNEL_READ_FLAG_MSG_PEEK) &&
+        !qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_READ_MSG_PEEK)) {
+        error_setg_errno(errp, EINVAL,
+                         "Channel does not support peek read");
+        return -1;
+    }
+
+    return klass->io_readv(ioc, iov, niov, fds, nfds, flags, errp);
 }
 
 
@@ -146,7 +154,7 @@  int qio_channel_readv_full_all_eof(QIOChannel *ioc,
     while ((nlocal_iov > 0) || local_fds) {
         ssize_t len;
         len = qio_channel_readv_full(ioc, local_iov, nlocal_iov, local_fds,
-                                     local_nfds, errp);
+                                     local_nfds, 0, errp);
         if (len == QIO_CHANNEL_ERR_BLOCK) {
             if (qemu_in_coroutine()) {
                 qio_channel_yield(ioc, G_IO_IN);
@@ -284,7 +292,7 @@  ssize_t qio_channel_readv(QIOChannel *ioc,
                           size_t niov,
                           Error **errp)
 {
-    return qio_channel_readv_full(ioc, iov, niov, NULL, NULL, errp);
+    return qio_channel_readv_full(ioc, iov, niov, NULL, NULL, 0, errp);
 }
 
 
@@ -303,7 +311,7 @@  ssize_t qio_channel_read(QIOChannel *ioc,
                          Error **errp)
 {
     struct iovec iov = { .iov_base = buf, .iov_len = buflen };
-    return qio_channel_readv_full(ioc, &iov, 1, NULL, NULL, errp);
+    return qio_channel_readv_full(ioc, &iov, 1, NULL, NULL, 0, errp);
 }
 
 
diff --git a/migration/channel-block.c b/migration/channel-block.c
index f4ab53acdb..b7374363c3 100644
--- a/migration/channel-block.c
+++ b/migration/channel-block.c
@@ -53,6 +53,7 @@  qio_channel_block_readv(QIOChannel *ioc,
                         size_t niov,
                         int **fds,
                         size_t *nfds,
+                        int flags,
                         Error **errp)
 {
     QIOChannelBlock *bioc = QIO_CHANNEL_BLOCK(ioc);
diff --git a/migration/rdma.c b/migration/rdma.c
index 94a55dd95b..d8b4632094 100644
--- a/migration/rdma.c
+++ b/migration/rdma.c
@@ -2854,6 +2854,7 @@  static ssize_t qio_channel_rdma_readv(QIOChannel *ioc,
                                       size_t niov,
                                       int **fds,
                                       size_t *nfds,
+                                      int flags,
                                       Error **errp)
 {
     QIOChannelRDMA *rioc = QIO_CHANNEL_RDMA(ioc);
diff --git a/scsi/qemu-pr-helper.c b/scsi/qemu-pr-helper.c
index 196b78c00d..199227a556 100644
--- a/scsi/qemu-pr-helper.c
+++ b/scsi/qemu-pr-helper.c
@@ -614,7 +614,7 @@  static int coroutine_fn prh_read(PRHelperClient *client, void *buf, int sz,
         iov.iov_base = buf;
         iov.iov_len = sz;
         n_read = qio_channel_readv_full(QIO_CHANNEL(client->ioc), &iov, 1,
-                                        &fds, &nfds, errp);
+                                        &fds, &nfds, 0, errp);
 
         if (n_read == QIO_CHANNEL_ERR_BLOCK) {
             qio_channel_yield(QIO_CHANNEL(client->ioc), G_IO_IN);
diff --git a/tests/qtest/tpm-emu.c b/tests/qtest/tpm-emu.c
index 2994d1cf42..3cf1acaf7d 100644
--- a/tests/qtest/tpm-emu.c
+++ b/tests/qtest/tpm-emu.c
@@ -106,7 +106,7 @@  void *tpm_emu_ctrl_thread(void *data)
         int *pfd = NULL;
         size_t nfd = 0;
 
-        qio_channel_readv_full(ioc, &iov, 1, &pfd, &nfd, &error_abort);
+        qio_channel_readv_full(ioc, &iov, 1, &pfd, &nfd, 0, &error_abort);
         cmd = be32_to_cpu(cmd);
         g_assert_cmpint(cmd, ==, CMD_SET_DATAFD);
         g_assert_cmpint(nfd, ==, 1);
diff --git a/tests/unit/test-io-channel-socket.c b/tests/unit/test-io-channel-socket.c
index b36a5d972a..b964bb202d 100644
--- a/tests/unit/test-io-channel-socket.c
+++ b/tests/unit/test-io-channel-socket.c
@@ -460,6 +460,7 @@  static void test_io_channel_unix_fd_pass(void)
                            G_N_ELEMENTS(iorecv),
                            &fdrecv,
                            &nfdrecv,
+                           0,
                            &error_abort);
 
     g_assert(nfdrecv == G_N_ELEMENTS(fdsend));
diff --git a/util/vhost-user-server.c b/util/vhost-user-server.c
index 232984ace6..145eb17c08 100644
--- a/util/vhost-user-server.c
+++ b/util/vhost-user-server.c
@@ -116,7 +116,7 @@  vu_message_read(VuDev *vu_dev, int conn_fd, VhostUserMsg *vmsg)
          * qio_channel_readv_full may have short reads, keeping calling it
          * until getting VHOST_USER_HDR_SIZE or 0 bytes in total
          */
-        rc = qio_channel_readv_full(ioc, &iov, 1, &fds, &nfds, &local_err);
+        rc = qio_channel_readv_full(ioc, &iov, 1, &fds, &nfds, 0, &local_err);
         if (rc < 0) {
             if (rc == QIO_CHANNEL_ERR_BLOCK) {
                 assert(local_err == NULL);