Markus Armbruster 06f1521795 pflash: Require backend size to match device, improve errors ... We reject undersized backends with a rather enigmatic "failed to read the initial flash content" error. For instance: $ qemu-system-ppc64 -S -display none -M sam460ex -drive if=pflash,format=raw,file=eins.img qemu-system-ppc64: Initialization of device cfi.pflash02 failed: failed to read the initial flash content We happily accept oversized images, ignoring their tail. Throwing away parts of firmware that way is pretty much certain to end in an even more enigmatic failure to boot. Require the backend's size to match the device's size exactly. Report mismatch like this: qemu-system-ppc64: Initialization of device cfi.pflash01 failed: device requires 1048576 bytes, block backend provides 512 bytes Improve the error for actual read failures to "can't read block backend". To avoid duplicating even more code between the two pflash device models, do all that in new helper blk_check_size_and_read_all(). The error reporting can still be confusing. For instance: qemu-system-ppc64 -S -display none -M taihu -drive if=pflash,format=raw,file=eins.img -drive if=pflash,unit=1,format=raw,file=zwei.img qemu-system-ppc64: Initialization of device cfi.pflash02 failed: device requires 2097152 bytes, block backend provides 512 bytes Leaves the user guessing which of the two -drive is wrong. Mention the issue in a TODO comment. Suggested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20190319163551.32499-2-armbru@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>		2019-03-26 08:16:24 +01:00
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block.h	pflash: Require backend size to match device, improve errors	2019-03-26 08:16:24 +01:00
fdc.h	Include less of the generated modular QAPI headers	2018-03-02 13:45:50 -06:00
flash.h	pflash_cfi01: Add pflash_cfi01_get_blk() helper	2019-03-11 22:53:44 +01:00