No need to loop if < 8 bytes are written, since that will happen only
for pipes and is harmless. eventfd writes of 8 bytes will always succeed
or fail with EAGAIN.
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
qemu-kvm.c | 34 ++++++++++++----------------------
1 files changed, 12 insertions(+), 22 deletions(-)
diff --git a/qemu-kvm.c b/qemu-kvm.c
index a305907..669a784 100644
--- a/qemu-kvm.c
+++ b/qemu-kvm.c
@@ -1991,32 +1991,22 @@ int kvm_init_ap(void)
void qemu_kvm_notify_work(void)
{
- uint64_t value = 1;
- char buffer[8];
- size_t offset = 0;
+ /* Write 8 bytes to be compatible with eventfd. */
+ static uint64_t val = 1;
+ ssize_t ret;
if (io_thread_fd == -1)
return;
- memcpy(buffer, &value, sizeof(value));
-
- while (offset < 8) {
- ssize_t len;
-
- len = write(io_thread_fd, buffer + offset, 8 - offset);
- if (len == -1 && errno == EINTR)
- continue;
-
- /* In case we have a pipe, there is not reason to insist writing
- * 8 bytes
- */
- if (len == -1 && errno == EAGAIN)
- break;
-
- if (len <= 0)
- break;
-
- offset += len;
+ do {
+ ret = write(io_thread_fd, &val, sizeof(val));
+ } while (ret < 0 && errno == EINTR);
+
+ /* EAGAIN is fine in case we have a pipe. */
+ if (ret < 0 && errno != EAGAIN) {
+ fprintf(stderr, "qemu_kvm_notify_work: write() filed: %s\n",
+ strerror(errno));
+ exit (1);
}
}
--
1.6.6
--
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