On 11/15/22 15:34, Peter Maydell wrote:
On Tue, 15 Nov 2022 at 14:22, Cédric Le Goater <c...@kaod.org> wrote:
Currently, when a block backend is attached to a m25p80 device and the
associated file size does not match the flash model, QEMU complains
with the error message "failed to read the initial flash content".
This is confusing for the user.
The commit message says we get an unhelpful error if the
file size "does not match"...
Improve the reported error with a new message regarding the file size.
Signed-off-by: Cédric Le Goater <c...@kaod.org>
---
hw/block/m25p80.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/hw/block/m25p80.c b/hw/block/m25p80.c
index 02adc87527..e0515e2a1e 100644
--- a/hw/block/m25p80.c
+++ b/hw/block/m25p80.c
@@ -1606,6 +1606,14 @@ static void m25p80_realize(SSIPeripheral *ss, Error
**errp)
if (s->blk) {
uint64_t perm = BLK_PERM_CONSISTENT_READ |
(blk_supports_write_perm(s->blk) ? BLK_PERM_WRITE :
0);
+
+ if (blk_getlength(s->blk) < s->size) {
...but the code change is only checking for "too small".
What happens if the user provides a backing file that is too large ?
That's ok because the blk_pread() call following, which loads in RAM
the initial data, won't fail.
It might be better to enforce a strict check on the size to avoid
further confusion ? and change the error message to be clear.
+ error_setg(errp,
+ "backend file is too small for flash device %s (%d MB)",
+ object_class_get_name(OBJECT_CLASS(mc)), s->size >> 20);
This potentially reports to the user a size which isn't the
right one for them to use to set the size of the backing file,
if that required size isn't an exact number of MB.
True. We have a few devices which size is below 1MB. Using a KB unit
should be fine.
Thanks,
C.
+ return;
+ }
+
ret = blk_set_perm(s->blk, perm, BLK_PERM_ALL, errp);
if (ret < 0) {
return;
--
2.38.1
thanks
-- PMM
