On Tue, Jul 09, 2024 at 05:38:54PM -0300, Fabiano Rosas wrote:
Philippe Mathieu-Daudé <philmd@linaro.org> writes:
"General command" (GEN_CMD, CMD56) is described as:
GEN_CMD is the same as the single block read or write commands (CMD24 or CMD17). The difference is that [...] the data block is not a memory payload data but has a vendor specific format and meaning.
Thus this block must not be stored overwriting data block on underlying storage drive. Keep it in a dedicated 'vendor_data[]' array.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Tested-by: Cédric Le Goater <clg@redhat.com> --- RFC: Is it safe to reuse VMSTATE_UNUSED_V() (which happens to be the same size)?
Hi, sorry it took some time to get to this, I had just left for vacation when you first posted.
And I totally overlooked there's the email.. until you replied. Welcome back.
I think it's ok:
{ "field": "unused", "version_id": 1, "field_exists": false, "size": 512 },
vs.
{ "field": "vendor_data", "version_id": 0, "field_exists": false, "num": 512, "size": 1 },
The unused field was introduced in 2016 so there's no chance of migrating a QEMU that old to/from 9.1.
What happens if an old qemu 9.0 sends rubbish here to a new QEMU, while the new QEMU would consider it meaningful data? -- Peter Xu