On Tue, Nov 4, 2025 at 6:03 AM Jan Kiszka <[email protected]> wrote:
> From: Jan Kiszka <[email protected]> > > Alignment rules apply the the individual partitions (user, boot, later > on also RPMB) and depend both on the size of the image and the type of > the device. Up to and including 2GB, the power-of-2 rule applies to the > user data area. For larger images, multiples of 512 sectors must be used > for eMMC and multiples of 512K for SD-cards. Fix the check accordingly > and also detect if the image is too small to even hold the boot > partitions. > > Signed-off-by: Jan Kiszka <[email protected]> > --- > CC: Warner Losh <[email protected]> > CC: Cédric Le Goater <[email protected]> > CC: Joel Stanley <[email protected]> > CC: Alistair Francis <[email protected]> > CC: Alexander Bulekov <[email protected]> > --- > hw/sd/sd.c | 69 +++++++++++++++++++++++++++++++++++++----------------- > 1 file changed, 48 insertions(+), 21 deletions(-) > Reviewed-by: Warner Losh <[email protected]> Thanks for chasing down all the weird special cases to come up with this. It's a big improvement for modern cards. Warner > diff --git a/hw/sd/sd.c b/hw/sd/sd.c > index d7a496d77c..76e915e190 100644 > --- a/hw/sd/sd.c > +++ b/hw/sd/sd.c > @@ -2759,9 +2759,32 @@ static void sd_instance_finalize(Object *obj) > timer_free(sd->ocr_power_timer); > } > > +static void sd_blk_size_error(SDState *sd, int64_t blk_size, > + int64_t blk_size_aligned, const char *rule, > + Error **errp) > +{ > + const char *dev_type = sd_is_emmc(sd) ? "eMMC" : "SD card"; > + char *blk_size_str; > + > + blk_size_str = size_to_str(blk_size); > + error_setg(errp, "Invalid %s size: %s", dev_type, blk_size_str); > + g_free(blk_size_str); > + > + blk_size_str = size_to_str(blk_size_aligned); > + error_append_hint(errp, > + "%s size has to be %s, e.g. %s.\n" > + "You can resize disk images with" > + " 'qemu-img resize <imagefile> <new-size>'\n" > + "(note that this will lose data if you make the" > + " image smaller than it currently is).\n", > + dev_type, rule, blk_size_str); > + g_free(blk_size_str); > +} > + > static void sd_realize(DeviceState *dev, Error **errp) > { > SDState *sd = SDMMC_COMMON(dev); > + int64_t blk_size = -ENOMEDIUM; > int ret; > > switch (sd->spec_version) { > @@ -2774,32 +2797,36 @@ static void sd_realize(DeviceState *dev, Error > **errp) > } > > if (sd->blk) { > - int64_t blk_size; > - > if (!blk_supports_write_perm(sd->blk)) { > error_setg(errp, "Cannot use read-only drive as SD card"); > return; > } > > blk_size = blk_getlength(sd->blk); > - if (blk_size > 0 && !is_power_of_2(blk_size)) { > - int64_t blk_size_aligned = pow2ceil(blk_size); > - char *blk_size_str; > - > - blk_size_str = size_to_str(blk_size); > - error_setg(errp, "Invalid SD card size: %s", blk_size_str); > - g_free(blk_size_str); > - > - blk_size_str = size_to_str(blk_size_aligned); > - error_append_hint(errp, > - "SD card size has to be a power of 2, e.g. > %s.\n" > - "You can resize disk images with" > - " 'qemu-img resize <imagefile> > <new-size>'\n" > - "(note that this will lose data if you make > the" > - " image smaller than it currently is).\n", > - blk_size_str); > - g_free(blk_size_str); > - > + } > + if (blk_size >= 0) { > + blk_size -= sd->boot_part_size * 2; > + if (blk_size > SDSC_MAX_CAPACITY) { > + if (sd_is_emmc(sd) && > + !QEMU_IS_ALIGNED(blk_size, 1 << HWBLOCK_SHIFT)) { > + int64_t blk_size_aligned = > + ((blk_size >> HWBLOCK_SHIFT) + 1) << HWBLOCK_SHIFT; > + sd_blk_size_error(sd, blk_size, blk_size_aligned, > + "multiples of 512", errp); > + return; > + } else if (!sd_is_emmc(sd) && > + !QEMU_IS_ALIGNED(blk_size, 512 * KiB)) { > + int64_t blk_size_aligned = ((blk_size >> 19) + 1) << 19; > + sd_blk_size_error(sd, blk_size, blk_size_aligned, > + "multiples of 512K", errp); > + return; > + } > + } else if (blk_size > 0 && !is_power_of_2(blk_size)) { > + sd_blk_size_error(sd, blk_size, pow2ceil(blk_size), "a power > of 2", > + errp); > + return; > + } else if (blk_size < 0) { > + error_setg(errp, "eMMC image smaller than boot partitions"); > return; > } > > @@ -2810,7 +2837,7 @@ static void sd_realize(DeviceState *dev, Error > **errp) > } > blk_set_dev_ops(sd->blk, &sd_block_ops, sd); > } > - if (sd->boot_part_size % (128 * KiB) || > + if (!QEMU_IS_ALIGNED(sd->boot_part_size, 128 * KiB) || > sd->boot_part_size > 255 * 128 * KiB) { > g_autofree char *size_str = size_to_str(sd->boot_part_size); > > -- > 2.51.0 > >
