Merge tag 'block-pull-request' of https://gitlab.com/stefanha/qemu into staging
Pull request
Bug fixes for 7.0.
# gpg: Signature made Thu 17 Mar 2022 16:42:22 GMT
# gpg: using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35 775A 9CA4 ABB3 81AB 73C8
* tag 'block-pull-request' of https://gitlab.com/stefanha/qemu:
aio-posix: fix spurious ->poll_ready() callbacks in main loop
aio-posix: fix build failure io_uring 2.2
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/util/aio-posix.c b/util/aio-posix.c
index 7b9f629..be0182a 100644
--- a/util/aio-posix.c
+++ b/util/aio-posix.c
@@ -23,15 +23,6 @@
#include "trace.h"
#include "aio-posix.h"
-/*
- * G_IO_IN and G_IO_OUT are not appropriate revents values for polling, since
- * the handler may not need to access the file descriptor. For example, the
- * handler doesn't need to read from an EventNotifier if it polled a memory
- * location and a read syscall would be slow. Define our own unique revents
- * value to indicate that polling determined this AioHandler is ready.
- */
-#define REVENTS_POLL_READY 0
-
/* Stop userspace polling on a handler if it isn't active for some time */
#define POLL_IDLE_INTERVAL_NS (7 * NANOSECONDS_PER_SECOND)
@@ -49,6 +40,14 @@
QLIST_INSERT_HEAD(ready_list, node, node_ready);
}
+static void aio_add_poll_ready_handler(AioHandlerList *ready_list,
+ AioHandler *node)
+{
+ QLIST_SAFE_REMOVE(node, node_ready); /* remove from nested parent's list */
+ node->poll_ready = true;
+ QLIST_INSERT_HEAD(ready_list, node, node_ready);
+}
+
static AioHandler *find_aio_handler(AioContext *ctx, int fd)
{
AioHandler *node;
@@ -76,6 +75,7 @@
}
node->pfd.revents = 0;
+ node->poll_ready = false;
/* If the fd monitor has already marked it deleted, leave it alone */
if (QLIST_IS_INSERTED(node, node_deleted)) {
@@ -247,7 +247,7 @@
/* Poll one last time in case ->io_poll_end() raced with the event */
if (!started && node->io_poll(node->opaque)) {
- aio_add_ready_handler(ready_list, node, REVENTS_POLL_READY);
+ aio_add_poll_ready_handler(ready_list, node);
progress = true;
}
}
@@ -282,6 +282,7 @@
QLIST_FOREACH_RCU(node, &ctx->aio_handlers, node) {
int revents;
+ /* TODO should this check poll ready? */
revents = node->pfd.revents & node->pfd.events;
if (revents & (G_IO_IN | G_IO_HUP | G_IO_ERR) && node->io_read &&
aio_node_check(ctx, node->is_external)) {
@@ -323,11 +324,15 @@
static bool aio_dispatch_handler(AioContext *ctx, AioHandler *node)
{
bool progress = false;
+ bool poll_ready;
int revents;
revents = node->pfd.revents & node->pfd.events;
node->pfd.revents = 0;
+ poll_ready = node->poll_ready;
+ node->poll_ready = false;
+
/*
* Start polling AioHandlers when they become ready because activity is
* likely to continue. Note that starvation is theoretically possible when
@@ -344,7 +349,7 @@
QLIST_INSERT_HEAD(&ctx->poll_aio_handlers, node, node_poll);
}
if (!QLIST_IS_INSERTED(node, node_deleted) &&
- revents == 0 &&
+ poll_ready && revents == 0 &&
aio_node_check(ctx, node->is_external) &&
node->io_poll_ready) {
node->io_poll_ready(node->opaque);
@@ -432,7 +437,7 @@
QLIST_FOREACH_SAFE(node, &ctx->poll_aio_handlers, node_poll, tmp) {
if (aio_node_check(ctx, node->is_external) &&
node->io_poll(node->opaque)) {
- aio_add_ready_handler(ready_list, node, REVENTS_POLL_READY);
+ aio_add_poll_ready_handler(ready_list, node);
node->poll_idle_timeout = now + POLL_IDLE_INTERVAL_NS;
@@ -491,8 +496,7 @@
* this causes progress.
*/
if (node->io_poll(node->opaque)) {
- aio_add_ready_handler(ready_list, node,
- REVENTS_POLL_READY);
+ aio_add_poll_ready_handler(ready_list, node);
progress = true;
}
}
diff --git a/util/aio-posix.h b/util/aio-posix.h
index 7f2c37a..80b927c 100644
--- a/util/aio-posix.h
+++ b/util/aio-posix.h
@@ -37,6 +37,7 @@
unsigned flags; /* see fdmon-io_uring.c */
#endif
int64_t poll_idle_timeout; /* when to stop userspace polling */
+ bool poll_ready; /* has polling detected an event? */
bool is_external;
};
diff --git a/util/fdmon-io_uring.c b/util/fdmon-io_uring.c
index 1461dfa..ab43052 100644
--- a/util/fdmon-io_uring.c
+++ b/util/fdmon-io_uring.c
@@ -179,7 +179,11 @@
{
struct io_uring_sqe *sqe = get_sqe(ctx);
+#ifdef LIBURING_HAVE_DATA64
+ io_uring_prep_poll_remove(sqe, (__u64)(uintptr_t)node);
+#else
io_uring_prep_poll_remove(sqe, node);
+#endif
}
/* Add a timeout that self-cancels when another cqe becomes ready */
