[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH RFC 1/6] io: only allow return path for socket typed
From: |
Peter Xu |
Subject: |
[Qemu-devel] [PATCH RFC 1/6] io: only allow return path for socket typed |
Date: |
Fri, 19 May 2017 14:43:27 +0800 |
We don't really have a return path for the other types yet. Let's check
this when .get_return_path() is called.
For this, we introduce a new feature bit, and set it up only for socket
typed IO channels.
This will help detect earlier failure for postcopy, e.g., logically
speaking postcopy cannot work with "exec:". Before this patch, when we
try to migrate with "migrate -d exec:cat>out", we'll hang the system.
With this patch, we'll get:
(qemu) migrate -d exec:cat>out
Unable to open return-path for postcopy
CC: Daniel P. Berrange <address@hidden>
Signed-off-by: Peter Xu <address@hidden>
---
include/io/channel.h | 1 +
io/channel-socket.c | 1 +
migration/qemu-file-channel.c | 9 +++++++++
3 files changed, 11 insertions(+)
diff --git a/include/io/channel.h b/include/io/channel.h
index db9bb02..7876534 100644
--- a/include/io/channel.h
+++ b/include/io/channel.h
@@ -45,6 +45,7 @@ enum QIOChannelFeature {
QIO_CHANNEL_FEATURE_FD_PASS,
QIO_CHANNEL_FEATURE_SHUTDOWN,
QIO_CHANNEL_FEATURE_LISTEN,
+ QIO_CHANNEL_FEATURE_RETURN_PATH,
};
diff --git a/io/channel-socket.c b/io/channel-socket.c
index 53386b7..ee81b2d 100644
--- a/io/channel-socket.c
+++ b/io/channel-socket.c
@@ -56,6 +56,7 @@ qio_channel_socket_new(void)
ioc = QIO_CHANNEL(sioc);
qio_channel_set_feature(ioc, QIO_CHANNEL_FEATURE_SHUTDOWN);
+ qio_channel_set_feature(ioc, QIO_CHANNEL_FEATURE_RETURN_PATH);
#ifdef WIN32
ioc->event = CreateEvent(NULL, FALSE, FALSE, NULL);
diff --git a/migration/qemu-file-channel.c b/migration/qemu-file-channel.c
index 45c13f1..3bd7940 100644
--- a/migration/qemu-file-channel.c
+++ b/migration/qemu-file-channel.c
@@ -23,6 +23,7 @@
*/
#include "qemu/osdep.h"
+#include "qom/object.h"
#include "migration/qemu-file.h"
#include "io/channel-socket.h"
#include "qemu/iov.h"
@@ -139,6 +140,10 @@ static QEMUFile *channel_get_input_return_path(void
*opaque)
{
QIOChannel *ioc = QIO_CHANNEL(opaque);
+ if (!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_RETURN_PATH)) {
+ return NULL;
+ }
+
return qemu_fopen_channel_output(ioc);
}
@@ -146,6 +151,10 @@ static QEMUFile *channel_get_output_return_path(void
*opaque)
{
QIOChannel *ioc = QIO_CHANNEL(opaque);
+ if (!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_RETURN_PATH)) {
+ return NULL;
+ }
+
return qemu_fopen_channel_input(ioc);
}
--
2.7.4