On 11/6/24 18:00, Andrew Cooper wrote:
On 02/11/2024 5:25 pm, Daniel P. Smith wrote:diff --git a/xen/arch/x86/include/asm/bootinfo.h b/xen/arch/x86/include/asm/bootinfo.h index b1549d8c8f93..e337baa905f0 100644 --- a/xen/arch/x86/include/asm/bootinfo.h +++ b/xen/arch/x86/include/asm/bootinfo.h @@ -30,6 +30,28 @@ struct boot_module {enum bootmod_type type; + /*+ * A boot module may need decompressing by Xen. Headroom is an estimate of + * the additional space required to decompress the module. + * + * Headroom is accounted for at the start of the module. Decompressing is + * done in-place with input=start, output=start-headroom, expecting the + * pointers to become equal (give or take some rounding) when decompression + * is complete. + * + * Memory layout at boot: + * + * start ----+ + * v + * |<-----headroom------>|<------size------->| + * +-------------------+ + * | Compressed Module | + * +---------------------+-------------------+ + * | Decompressed Module | + * +-----------------------------------------+ + */ + unsigned long headroom; + /* * Module State Flags: * relocated: indicates module has been relocated in memory.By the end of the series, this ends very poorly laid out. It works a whole lot better when putting the bitfields between type and headroom.
Ack.
Otherwise, Reviewed-by: Andrew Cooper <andrew.coop...@citrix.com>
Thanks. v/r, dps
