diff mbox series

[10/10] block: check availablity for preadv/pwritev on mac

Message ID 20201012232939.48481-11-j@getutm.app (mailing list archive)
State New, archived
Headers show
Series iOS and Apple Silicon host support | expand

Commit Message

Joelle van Dyne Oct. 12, 2020, 11:29 p.m. UTC 
From: osy <osy86@users.noreply.github.com>

macOS 11/iOS 14 added preadv/pwritev APIs. Due to weak linking, configure
will succeed with CONFIG_PREADV even when targeting a lower OS version. We
therefore need to check at run time if we can actually use these APIs.

Signed-off-by: Joelle van Dyne <j@getutm.app>
---
 block/file-posix.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)
diff mbox series

Patch

diff --git a/block/file-posix.c b/block/file-posix.c
index cdc73b5f1d..d7482036a3 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1393,12 +1393,24 @@  static bool preadv_present = true;
 static ssize_t
 qemu_preadv(int fd, const struct iovec *iov, int nr_iov, off_t offset)
 {
+#ifdef CONFIG_DARWIN /* preadv introduced in macOS 11 */
+    if (!__builtin_available(macOS 11, iOS 14, watchOS 7, tvOS 14, *)) {
+        preadv_present = false;
+        return -ENOSYS;
+    } else
+#endif
     return preadv(fd, iov, nr_iov, offset);
 }
 
 static ssize_t
 qemu_pwritev(int fd, const struct iovec *iov, int nr_iov, off_t offset)
 {
+#ifdef CONFIG_DARWIN /* pwritev introduced in macOS 11 */
+    if (!__builtin_available(macOS 11, iOS 14, watchOS 7, tvOS 14, *)) {
+        preadv_present = false;
+        return -ENOSYS;
+    } else
+#endif
     return pwritev(fd, iov, nr_iov, offset);
 }