In the early days of io_uring it was possible for io_uring_setup(2) to
fail due to exhausting RLIMIT_MEMLOCK. QEMU's solution was to fall back
to epoll(7) or ppoll(2) when io_uring could not be used in an
AioContext.
Nowadays io_uring memory is accounted differently so io_uring_setup(2)
won't fail. Treat failure as a fatal error. Keep it simple: io_uring is
available if and only if CONFIG_LINUX_IO_URING is defined.
Upcoming features that rely on io_uring won't need to handle the case
where a subset of AioContexts lacks io_uring. This will simplify the
aio_add_sqe() API introduced in the next commit.
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
---
util/fdmon-io_uring.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/util/fdmon-io_uring.c b/util/fdmon-io_uring.c
index 2092d08d24..18b33a0370 100644
--- a/util/fdmon-io_uring.c
+++ b/util/fdmon-io_uring.c
@@ -45,6 +45,7 @@
#include "qemu/osdep.h"
#include <poll.h>
+#include "qemu/error-report.h"
#include "qemu/rcu_queue.h"
#include "aio-posix.h"
@@ -369,7 +370,8 @@ bool fdmon_io_uring_setup(AioContext *ctx)
ret = io_uring_queue_init(FDMON_IO_URING_ENTRIES, &ctx->fdmon_io_uring, 0);
if (ret != 0) {
- return false;
+ error_report("failed to initialize io_uring: %s", strerror(-ret));
+ exit(EXIT_FAILURE);
}
QSLIST_INIT(&ctx->submit_list);
--
2.49.0
