MSG_PEEK peeks at the 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: Peter Xu <peterx@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Suggested-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: manish.mishra <manish.mishra@nutanix.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 +
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 +-
15 files changed, 47 insertions(+), 10 deletions(-)
diff --git a/chardev/char-socket.c b/chardev/char-socket.c
index 29ffe5075e..c2265436ac 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 f1b7e05f81..5b41d02b2b 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/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);
--
2.22.3"manish.mishra" <manish.mishra@nutanix.com> wrote:
> MSG_PEEK peeks at the 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: Peter Xu <peterx@redhat.com>
> Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
> Suggested-by: Daniel P. Berrange <berrange@redhat.com>
> Signed-off-by: manish.mishra <manish.mishra@nutanix.com>
This change breaks RDMA migration.
FAILED: libcommon.fa.p/migration_rdma.c.o
cc -m64 -mcx16 -Ilibcommon.fa.p -I/usr/include/pixman-1 -I/usr/include/libpng16 -I/usr/include/spice-server -I/usr/include/spice-1 -I/usr/include/cacard -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/sysprof-4 -I/usr/include/nss3 -I/usr/include/nspr4 -I/usr/include/PCSC -I/usr/include/p11-kit-1 -I/usr/include/libusb-1.0 -I/usr/include/SDL2 -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/gio-unix-2.0 -I/usr/include/slirp -fdiagnostics-color=auto -Wall -Winvalid-pch -Werror -std=gnu11 -O2 -g -isystem /mnt/code/qemu/full/linux-headers -isystem linux-headers -iquote . -iquote /mnt/code/qemu/full -iquote /mnt/code/qemu/full/include -iquote /mnt/code/qemu/full/tcg/i386 -pthread -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -fno-strict-aliasing -fno-common -fwrapv -Wundef -Wwrite-strings -Wmissing-prototypes -Wstrict-prototypes -Wredundant-decls -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wmissing-format-attribute -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIE -D_REENTRANT -Wno-undef -DSTRUCT_IOVEC_DEFINED -MD -MQ libcommon.fa.p/migration_rdma.c.o -MF libcommon.fa.p/migration_rdma.c.o.d -o libcommon.fa.p/migration_rdma.c.o -c ../../../../mnt/code/qemu/full/migration/rdma.c
../../../../mnt/code/qemu/full/migration/rdma.c: In function ‘qio_channel_rdma_class_init’:
../../../../mnt/code/qemu/full/migration/rdma.c:4020:25: error: assignment to ‘ssize_t (*)(QIOChannel *, const struct iovec *, size_t, int **, size_t *, int, Error **)’ {aka ‘long int (*)(QIOChannel *, const struct iovec *, long unsigned int, int **, long unsigned int *, int, Error **)’} from incompatible pointer type ‘ssize_t (*)(QIOChannel *, const struct iovec *, size_t, int **, size_t *, Error **)’ {aka ‘long int (*)(QIOChannel *, const struct iovec *, long unsigned int, int **, long unsigned int *, Error **)’} [-Werror=incompatible-pointer-types]
4020 | ioc_klass->io_readv = qio_channel_rdma_readv;
| ^
cc1: all warnings being treated as errors
And I don't really know how to fix it, because the problem is that rdma
don't use qio_channel_readv_full() at all.
Sorry, I have to drop the series until a fix is found.
Later, Juan.
On Thu, Feb 02, 2023 at 01:22:12PM +0100, Juan Quintela wrote:
> "manish.mishra" <manish.mishra@nutanix.com> wrote:
> > MSG_PEEK peeks at the 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: Peter Xu <peterx@redhat.com>
> > Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
> > Suggested-by: Daniel P. Berrange <berrange@redhat.com>
> > Signed-off-by: manish.mishra <manish.mishra@nutanix.com>
>
>
> This change breaks RDMA migration.
>
> FAILED: libcommon.fa.p/migration_rdma.c.o
> cc -m64 -mcx16 -Ilibcommon.fa.p -I/usr/include/pixman-1 -I/usr/include/libpng16 -I/usr/include/spice-server -I/usr/include/spice-1 -I/usr/include/cacard -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/sysprof-4 -I/usr/include/nss3 -I/usr/include/nspr4 -I/usr/include/PCSC -I/usr/include/p11-kit-1 -I/usr/include/libusb-1.0 -I/usr/include/SDL2 -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/gio-unix-2.0 -I/usr/include/slirp -fdiagnostics-color=auto -Wall -Winvalid-pch -Werror -std=gnu11 -O2 -g -isystem /mnt/code/qemu/full/linux-headers -isystem linux-headers -iquote . -iquote /mnt/code/qemu/full -iquote /mnt/code/qemu/full/include -iquote /mnt/code/qemu/full/tcg/i386 -pthread -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -fno-strict-aliasing -fno-common -fwrapv -Wundef -Wwrite-strings -Wmissing-prototypes -Wstrict-prototypes -Wredundant-decls -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wmissing-format-attribute -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIE -D_REENTRANT -Wno-undef -DSTRUCT_IOVEC_DEFINED -MD -MQ libcommon.fa.p/migration_rdma.c.o -MF libcommon.fa.p/migration_rdma.c.o.d -o libcommon.fa.p/migration_rdma.c.o -c ../../../../mnt/code/qemu/full/migration/rdma.c
> ../../../../mnt/code/qemu/full/migration/rdma.c: In function ‘qio_channel_rdma_class_init’:
> ../../../../mnt/code/qemu/full/migration/rdma.c:4020:25: error: assignment to ‘ssize_t (*)(QIOChannel *, const struct iovec *, size_t, int **, size_t *, int, Error **)’ {aka ‘long int (*)(QIOChannel *, const struct iovec *, long unsigned int, int **, long unsigned int *, int, Error **)’} from incompatible pointer type ‘ssize_t (*)(QIOChannel *, const struct iovec *, size_t, int **, size_t *, Error **)’ {aka ‘long int (*)(QIOChannel *, const struct iovec *, long unsigned int, int **, long unsigned int *, Error **)’} [-Werror=incompatible-pointer-types]
> 4020 | ioc_klass->io_readv = qio_channel_rdma_readv;
> | ^
> cc1: all warnings being treated as errors
>
> And I don't really know how to fix it, because the problem is that rdma
> don't use qio_channel_readv_full() at all.
Likely qio_channel_rdma_readv just adds the 'int flags' param added.
It doesn't need to actually do anything with the flags as they are
checked before
With regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o- https://fstop138.berrange.com :|
|: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
Daniel P. Berrangé <berrange@redhat.com> wrote:
> On Thu, Feb 02, 2023 at 01:22:12PM +0100, Juan Quintela wrote:
>> "manish.mishra" <manish.mishra@nutanix.com> wrote:
>> > MSG_PEEK peeks at the 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: Peter Xu <peterx@redhat.com>
>> > Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
>> > Suggested-by: Daniel P. Berrange <berrange@redhat.com>
>> > Signed-off-by: manish.mishra <manish.mishra@nutanix.com>
>>
>>
>> This change breaks RDMA migration.
>>
>> FAILED: libcommon.fa.p/migration_rdma.c.o
>> cc -m64 -mcx16 -Ilibcommon.fa.p -I/usr/include/pixman-1 -I/usr/include/libpng16 -I/usr/include/spice-server -I/usr/include/spice-1 -I/usr/include/cacard -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/sysprof-4 -I/usr/include/nss3 -I/usr/include/nspr4 -I/usr/include/PCSC -I/usr/include/p11-kit-1 -I/usr/include/libusb-1.0 -I/usr/include/SDL2 -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/gio-unix-2.0 -I/usr/include/slirp -fdiagnostics-color=auto -Wall -Winvalid-pch -Werror -std=gnu11 -O2 -g -isystem /mnt/code/qemu/full/linux-headers -isystem linux-headers -iquote . -iquote /mnt/code/qemu/full -iquote /mnt/code/qemu/full/include -iquote /mnt/code/qemu/full/tcg/i386 -pthread -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -fno-strict-aliasing -fno-common -fwrapv -Wundef -Wwrite-strings -Wmissing-prototypes -Wstrict-prototypes -Wredundant-decls -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wmissing-format-attribute -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIE -D_REENTRANT -Wno-undef -DSTRUCT_IOVEC_DEFINED -MD -MQ libcommon.fa.p/migration_rdma.c.o -MF libcommon.fa.p/migration_rdma.c.o.d -o libcommon.fa.p/migration_rdma.c.o -c ../../../../mnt/code/qemu/full/migration/rdma.c
>> ../../../../mnt/code/qemu/full/migration/rdma.c: In function ‘qio_channel_rdma_class_init’:
>> ../../../../mnt/code/qemu/full/migration/rdma.c:4020:25: error: assignment to ‘ssize_t (*)(QIOChannel *, const struct iovec *, size_t, int **, size_t *, int, Error **)’ {aka ‘long int (*)(QIOChannel *, const struct iovec *, long unsigned int, int **, long unsigned int *, int, Error **)’} from incompatible pointer type ‘ssize_t (*)(QIOChannel *, const struct iovec *, size_t, int **, size_t *, Error **)’ {aka ‘long int (*)(QIOChannel *, const struct iovec *, long unsigned int, int **, long unsigned int *, Error **)’} [-Werror=incompatible-pointer-types]
>> 4020 | ioc_klass->io_readv = qio_channel_rdma_readv;
>> | ^
>> cc1: all warnings being treated as errors
>>
>> And I don't really know how to fix it, because the problem is that rdma
>> don't use qio_channel_readv_full() at all.
>
> Likely qio_channel_rdma_readv just adds the 'int flags' param added.
> It doesn't need to actually do anything with the flags as they are
> checked before
I can do that. That would fix the compilation issue.
But will rdma work? Because it fakes a qio channel, so what is going to
implement the MSG_PEEK functionality for it? It don't end calling
recv() at all.
Later, Juan.
On Thu, Feb 02, 2023 at 01:51:28PM +0100, Juan Quintela wrote:
> Daniel P. Berrangé <berrange@redhat.com> wrote:
> > On Thu, Feb 02, 2023 at 01:22:12PM +0100, Juan Quintela wrote:
> >> "manish.mishra" <manish.mishra@nutanix.com> wrote:
> >> > MSG_PEEK peeks at the 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: Peter Xu <peterx@redhat.com>
> >> > Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
> >> > Suggested-by: Daniel P. Berrange <berrange@redhat.com>
> >> > Signed-off-by: manish.mishra <manish.mishra@nutanix.com>
> >>
> >>
> >> This change breaks RDMA migration.
> >>
> >> FAILED: libcommon.fa.p/migration_rdma.c.o
> >> cc -m64 -mcx16 -Ilibcommon.fa.p -I/usr/include/pixman-1 -I/usr/include/libpng16 -I/usr/include/spice-server -I/usr/include/spice-1 -I/usr/include/cacard -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/sysprof-4 -I/usr/include/nss3 -I/usr/include/nspr4 -I/usr/include/PCSC -I/usr/include/p11-kit-1 -I/usr/include/libusb-1.0 -I/usr/include/SDL2 -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/gio-unix-2.0 -I/usr/include/slirp -fdiagnostics-color=auto -Wall -Winvalid-pch -Werror -std=gnu11 -O2 -g -isystem /mnt/code/qemu/full/linux-headers -isystem linux-headers -iquote . -iquote /mnt/code/qemu/full -iquote /mnt/code/qemu/full/include -iquote /mnt/code/qemu/full/tcg/i386 -pthread -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -fno-strict-aliasing -fno-common -fwrapv -Wundef -Wwrite-strings -Wmissing-prototypes -Wstrict-prototypes -Wredundant-decls -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wmissing-format-attribute -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIE -D_REENTRANT -Wno-undef -DSTRUCT_IOVEC_DEFINED -MD -MQ libcommon.fa.p/migration_rdma.c.o -MF libcommon.fa.p/migration_rdma.c.o.d -o libcommon.fa.p/migration_rdma.c.o -c ../../../../mnt/code/qemu/full/migration/rdma.c
> >> ../../../../mnt/code/qemu/full/migration/rdma.c: In function ‘qio_channel_rdma_class_init’:
> >> ../../../../mnt/code/qemu/full/migration/rdma.c:4020:25: error: assignment to ‘ssize_t (*)(QIOChannel *, const struct iovec *, size_t, int **, size_t *, int, Error **)’ {aka ‘long int (*)(QIOChannel *, const struct iovec *, long unsigned int, int **, long unsigned int *, int, Error **)’} from incompatible pointer type ‘ssize_t (*)(QIOChannel *, const struct iovec *, size_t, int **, size_t *, Error **)’ {aka ‘long int (*)(QIOChannel *, const struct iovec *, long unsigned int, int **, long unsigned int *, Error **)’} [-Werror=incompatible-pointer-types]
> >> 4020 | ioc_klass->io_readv = qio_channel_rdma_readv;
> >> | ^
> >> cc1: all warnings being treated as errors
> >>
> >> And I don't really know how to fix it, because the problem is that rdma
> >> don't use qio_channel_readv_full() at all.
> >
> > Likely qio_channel_rdma_readv just adds the 'int flags' param added.
> > It doesn't need to actually do anything with the flags as they are
> > checked before
>
> I can do that. That would fix the compilation issue.
>
> But will rdma work? Because it fakes a qio channel, so what is going to
> implement the MSG_PEEK functionality for it? It don't end calling
> recv() at all.
It is no problem - the qio_channel_readv method changes in this patch
add:
+ 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;
+ }
so it is impossible for qio_channel_rdma_readv to be invoked with
flags having MSG_PEEK set, thus RDMA can ignore the whole concept.
With regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o- https://fstop138.berrange.com :|
|: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
Daniel P. Berrangé <berrange@redhat.com> wrote:
> On Thu, Feb 02, 2023 at 01:51:28PM +0100, Juan Quintela wrote:
>> Daniel P. Berrangé <berrange@redhat.com> wrote:
>> > On Thu, Feb 02, 2023 at 01:22:12PM +0100, Juan Quintela wrote:
>> >> "manish.mishra" <manish.mishra@nutanix.com> wrote:
>> >> > MSG_PEEK peeks at the 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: Peter Xu <peterx@redhat.com>
>> >> > Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
>> >> > Suggested-by: Daniel P. Berrange <berrange@redhat.com>
>> >> > Signed-off-by: manish.mishra <manish.mishra@nutanix.com>
>> >>
>> >>
>> >> This change breaks RDMA migration.
>> >>
>> >> FAILED: libcommon.fa.p/migration_rdma.c.o
>> >> cc -m64 -mcx16 -Ilibcommon.fa.p -I/usr/include/pixman-1 -I/usr/include/libpng16 -I/usr/include/spice-server -I/usr/include/spice-1 -I/usr/include/cacard -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/sysprof-4 -I/usr/include/nss3 -I/usr/include/nspr4 -I/usr/include/PCSC -I/usr/include/p11-kit-1 -I/usr/include/libusb-1.0 -I/usr/include/SDL2 -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/gio-unix-2.0 -I/usr/include/slirp -fdiagnostics-color=auto -Wall -Winvalid-pch -Werror -std=gnu11 -O2 -g -isystem /mnt/code/qemu/full/linux-headers -isystem linux-headers -iquote . -iquote /mnt/code/qemu/full -iquote /mnt/code/qemu/full/include -iquote /mnt/code/qemu/full/tcg/i386 -pthread -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -fno-strict-aliasing -fno-common -fwrapv -Wundef -Wwrite-strings -Wmissing-prototypes -Wstrict-prototypes -Wredundant-decls -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wmissing-format-attribute -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIE -D_REENTRANT -Wno-undef -DSTRUCT_IOVEC_DEFINED -MD -MQ libcommon.fa.p/migration_rdma.c.o -MF libcommon.fa.p/migration_rdma.c.o.d -o libcommon.fa.p/migration_rdma.c.o -c ../../../../mnt/code/qemu/full/migration/rdma.c
>> >> ../../../../mnt/code/qemu/full/migration/rdma.c: In function ‘qio_channel_rdma_class_init’:
>> >> ../../../../mnt/code/qemu/full/migration/rdma.c:4020:25: error: assignment to ‘ssize_t (*)(QIOChannel *, const struct iovec *, size_t, int **, size_t *, int, Error **)’ {aka ‘long int (*)(QIOChannel *, const struct iovec *, long unsigned int, int **, long unsigned int *, int, Error **)’} from incompatible pointer type ‘ssize_t (*)(QIOChannel *, const struct iovec *, size_t, int **, size_t *, Error **)’ {aka ‘long int (*)(QIOChannel *, const struct iovec *, long unsigned int, int **, long unsigned int *, Error **)’} [-Werror=incompatible-pointer-types]
>> >> 4020 | ioc_klass->io_readv = qio_channel_rdma_readv;
>> >> | ^
>> >> cc1: all warnings being treated as errors
>> >>
>> >> And I don't really know how to fix it, because the problem is that rdma
>> >> don't use qio_channel_readv_full() at all.
>> >
>> > Likely qio_channel_rdma_readv just adds the 'int flags' param added.
>> > It doesn't need to actually do anything with the flags as they are
>> > checked before
>>
>> I can do that. That would fix the compilation issue.
>>
>> But will rdma work? Because it fakes a qio channel, so what is going to
>> implement the MSG_PEEK functionality for it? It don't end calling
>> recv() at all.
>
> It is no problem - the qio_channel_readv method changes in this patch
> add:
>
> + 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;
> + }
>
>
> so it is impossible for qio_channel_rdma_readv to be invoked with
> flags having MSG_PEEK set, thus RDMA can ignore the whole concept.
And as we require MSG_PEEK to do migration, we have lost RDMA migration
in the process.
The following patch on the series use this functionality to read the
beggining of the streams in the channels.
Later, Juan.
On Thu, Feb 02, 2023 at 02:39:05PM +0100, Juan Quintela wrote:
> Daniel P. Berrangé <berrange@redhat.com> wrote:
> > On Thu, Feb 02, 2023 at 01:51:28PM +0100, Juan Quintela wrote:
> >> Daniel P. Berrangé <berrange@redhat.com> wrote:
> >> > On Thu, Feb 02, 2023 at 01:22:12PM +0100, Juan Quintela wrote:
> >> >> "manish.mishra" <manish.mishra@nutanix.com> wrote:
> >> >> > MSG_PEEK peeks at the 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: Peter Xu <peterx@redhat.com>
> >> >> > Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
> >> >> > Suggested-by: Daniel P. Berrange <berrange@redhat.com>
> >> >> > Signed-off-by: manish.mishra <manish.mishra@nutanix.com>
> >> >>
> >> >>
> >> >> This change breaks RDMA migration.
> >> >>
> >> >> FAILED: libcommon.fa.p/migration_rdma.c.o
> >> >> cc -m64 -mcx16 -Ilibcommon.fa.p -I/usr/include/pixman-1 -I/usr/include/libpng16 -I/usr/include/spice-server -I/usr/include/spice-1 -I/usr/include/cacard -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/sysprof-4 -I/usr/include/nss3 -I/usr/include/nspr4 -I/usr/include/PCSC -I/usr/include/p11-kit-1 -I/usr/include/libusb-1.0 -I/usr/include/SDL2 -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/gio-unix-2.0 -I/usr/include/slirp -fdiagnostics-color=auto -Wall -Winvalid-pch -Werror -std=gnu11 -O2 -g -isystem /mnt/code/qemu/full/linux-headers -isystem linux-headers -iquote . -iquote /mnt/code/qemu/full -iquote /mnt/code/qemu/full/include -iquote /mnt/code/qemu/full/tcg/i386 -pthread -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -fno-strict-aliasing -fno-common -fwrapv -Wundef -Wwrite-strings -Wmissing-prototypes -Wstrict-prototypes -Wredundant-decls -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wmissing-format-attribute -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIE -D_REENTRANT -Wno-undef -DSTRUCT_IOVEC_DEFINED -MD -MQ libcommon.fa.p/migration_rdma.c.o -MF libcommon.fa.p/migration_rdma.c.o.d -o libcommon.fa.p/migration_rdma.c.o -c ../../../../mnt/code/qemu/full/migration/rdma.c
> >> >> ../../../../mnt/code/qemu/full/migration/rdma.c: In function ‘qio_channel_rdma_class_init’:
> >> >> ../../../../mnt/code/qemu/full/migration/rdma.c:4020:25: error: assignment to ‘ssize_t (*)(QIOChannel *, const struct iovec *, size_t, int **, size_t *, int, Error **)’ {aka ‘long int (*)(QIOChannel *, const struct iovec *, long unsigned int, int **, long unsigned int *, int, Error **)’} from incompatible pointer type ‘ssize_t (*)(QIOChannel *, const struct iovec *, size_t, int **, size_t *, Error **)’ {aka ‘long int (*)(QIOChannel *, const struct iovec *, long unsigned int, int **, long unsigned int *, Error **)’} [-Werror=incompatible-pointer-types]
> >> >> 4020 | ioc_klass->io_readv = qio_channel_rdma_readv;
> >> >> | ^
> >> >> cc1: all warnings being treated as errors
> >> >>
> >> >> And I don't really know how to fix it, because the problem is that rdma
> >> >> don't use qio_channel_readv_full() at all.
> >> >
> >> > Likely qio_channel_rdma_readv just adds the 'int flags' param added.
> >> > It doesn't need to actually do anything with the flags as they are
> >> > checked before
> >>
> >> I can do that. That would fix the compilation issue.
> >>
> >> But will rdma work? Because it fakes a qio channel, so what is going to
> >> implement the MSG_PEEK functionality for it? It don't end calling
> >> recv() at all.
> >
> > It is no problem - the qio_channel_readv method changes in this patch
> > add:
> >
> > + 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;
> > + }
> >
> >
> > so it is impossible for qio_channel_rdma_readv to be invoked with
> > flags having MSG_PEEK set, thus RDMA can ignore the whole concept.
>
> And as we require MSG_PEEK to do migration, we have lost RDMA migration
> in the process.
>
> The following patch on the series use this functionality to read the
> beggining of the streams in the channels.
It guards that usage of MSG_PEEK with
if (... && qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_READ_MSG_PEEK)) {
With regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o- https://fstop138.berrange.com :|
|: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
Daniel P. Berrangé <berrange@redhat.com> wrote:
> On Thu, Feb 02, 2023 at 02:39:05PM +0100, Juan Quintela wrote:
>> Daniel P. Berrangé <berrange@redhat.com> wrote:
>> > On Thu, Feb 02, 2023 at 01:51:28PM +0100, Juan Quintela wrote:
>> >> Daniel P. Berrangé <berrange@redhat.com> wrote:
>> >> > On Thu, Feb 02, 2023 at 01:22:12PM +0100, Juan Quintela wrote:
>> >> >> "manish.mishra" <manish.mishra@nutanix.com> wrote:
>> >> >> > MSG_PEEK peeks at the 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: Peter Xu <peterx@redhat.com>
>> >> >> > Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
>> >> >> > Suggested-by: Daniel P. Berrange <berrange@redhat.com>
>> >> >> > Signed-off-by: manish.mishra <manish.mishra@nutanix.com>
>> >> >>
>> >> >>
>> >> >> This change breaks RDMA migration.
>> >> >>
>> >> >> FAILED: libcommon.fa.p/migration_rdma.c.o
>> >> >> cc -m64 -mcx16 -Ilibcommon.fa.p -I/usr/include/pixman-1 -I/usr/include/libpng16 -I/usr/include/spice-server -I/usr/include/spice-1 -I/usr/include/cacard -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/sysprof-4 -I/usr/include/nss3 -I/usr/include/nspr4 -I/usr/include/PCSC -I/usr/include/p11-kit-1 -I/usr/include/libusb-1.0 -I/usr/include/SDL2 -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/gio-unix-2.0 -I/usr/include/slirp -fdiagnostics-color=auto -Wall -Winvalid-pch -Werror -std=gnu11 -O2 -g -isystem /mnt/code/qemu/full/linux-headers -isystem linux-headers -iquote . -iquote /mnt/code/qemu/full -iquote /mnt/code/qemu/full/include -iquote /mnt/code/qemu/full/tcg/i386 -pthread -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -fno-strict-aliasing -fno-common -fwrapv -Wundef -Wwrite-strings -Wmissing-prototypes -Wstrict-prototypes -Wredundant-decls -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wmissing-format-attribute -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIE -D_REENTRANT -Wno-undef -DSTRUCT_IOVEC_DEFINED -MD -MQ libcommon.fa.p/migration_rdma.c.o -MF libcommon.fa.p/migration_rdma.c.o.d -o libcommon.fa.p/migration_rdma.c.o -c ../../../../mnt/code/qemu/full/migration/rdma.c
>> >> >> ../../../../mnt/code/qemu/full/migration/rdma.c: In function ‘qio_channel_rdma_class_init’:
>> >> >> ../../../../mnt/code/qemu/full/migration/rdma.c:4020:25: error: assignment to ‘ssize_t (*)(QIOChannel *, const struct iovec *, size_t, int **, size_t *, int, Error **)’ {aka ‘long int (*)(QIOChannel *, const struct iovec *, long unsigned int, int **, long unsigned int *, int, Error **)’} from incompatible pointer type ‘ssize_t (*)(QIOChannel *, const struct iovec *, size_t, int **, size_t *, Error **)’ {aka ‘long int (*)(QIOChannel *, const struct iovec *, long unsigned int, int **, long unsigned int *, Error **)’} [-Werror=incompatible-pointer-types]
>> >> >> 4020 | ioc_klass->io_readv = qio_channel_rdma_readv;
>> >> >> | ^
>> >> >> cc1: all warnings being treated as errors
>> >> >>
>> >> >> And I don't really know how to fix it, because the problem is that rdma
>> >> >> don't use qio_channel_readv_full() at all.
>> >> >
>> >> > Likely qio_channel_rdma_readv just adds the 'int flags' param added.
>> >> > It doesn't need to actually do anything with the flags as they are
>> >> > checked before
>> >>
>> >> I can do that. That would fix the compilation issue.
>> >>
>> >> But will rdma work? Because it fakes a qio channel, so what is going to
>> >> implement the MSG_PEEK functionality for it? It don't end calling
>> >> recv() at all.
>> >
>> > It is no problem - the qio_channel_readv method changes in this patch
>> > add:
>> >
>> > + 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;
>> > + }
>> >
>> >
>> > so it is impossible for qio_channel_rdma_readv to be invoked with
>> > flags having MSG_PEEK set, thus RDMA can ignore the whole concept.
>>
>> And as we require MSG_PEEK to do migration, we have lost RDMA migration
>> in the process.
>>
>> The following patch on the series use this functionality to read the
>> beggining of the streams in the channels.
>
> It guards that usage of MSG_PEEK with
>
> if (... && qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_READ_MSG_PEEK)) {
You win.
They are back.
Thanks very much for the explanation.
"manish.mishra" <manish.mishra@nutanix.com> wrote: > MSG_PEEK peeks at the 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: Peter Xu <peterx@redhat.com> > Reviewed-by: Daniel P. Berrange <berrange@redhat.com> > Suggested-by: Daniel P. Berrange <berrange@redhat.com> > Signed-off-by: manish.mishra <manish.mishra@nutanix.com> Reviewed-by: Juan Quintela <quintela@redhat.com> queued.
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