From 06f1521795207359a395996c253c306f4ab7586e Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Tue, 19 Mar 2019 17:35:50 +0100 Subject: pflash: Require backend size to match device, improve errors MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Markus Armbruster Message-Id: <20190319163551.32499-2-armbru@redhat.com> Reviewed-by: Laszlo Ersek Reviewed-by: Alex Bennée Reviewed-by: Philippe Mathieu-Daudé --- include/hw/block/block.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'include/hw/block') diff --git a/include/hw/block/block.h b/include/hw/block/block.h index e9f9e2223f..d06f25aa0f 100644 --- a/include/hw/block/block.h +++ b/include/hw/block/block.h @@ -11,7 +11,7 @@ #ifndef HW_BLOCK_H #define HW_BLOCK_H -#include "qemu-common.h" +#include "exec/hwaddr.h" #include "qapi/qapi-types-block-core.h" /* Configuration */ @@ -70,6 +70,11 @@ static inline unsigned int get_physical_block_exp(BlockConf *conf) DEFINE_PROP_BLOCKDEV_ON_ERROR("werror", _state, _conf.werror, \ BLOCKDEV_ON_ERROR_AUTO) +/* Backend access helpers */ + +bool blk_check_size_and_read_all(BlockBackend *blk, void *buf, hwaddr size, + Error **errp); + /* Configuration helpers */ bool blkconf_geometry(BlockConf *conf, int *trans, -- cgit v1.2.3