On Tue, 15 Nov 2022 at 14:51, Cédric Le Goater <c...@kaod.org> wrote: > > 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.
Can we use blk_check_size_and_read_all() here rather than a manual "check size, and then pread" ? That will take care of the error message for you and make this device behave the same way as other flash devices which use block backends. thanks -- PMM