Re: [PATCH 01/12] x86/boot: introduce boot module types

["Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx>]

On 11/6/24 09:05, Andrew Cooper wrote:
> On 02/11/2024 5:25 pm, Daniel P. Smith wrote:
> > This commit introduces module types for the types of boot modules that may be
> > passed to Xen. These include xen, kernel, ramdisk, microcode, and xsm policy.
> > This reduces the need for hard coded order assumptions and global variables to
> > be used by consumers of boot modules, such as domain construction.
> >
> > Signed-off-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>
> Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, albeit it with
> one extra suggestion.
Sure.

> > ---
> > Changes since v7:
> > - merged the addition of microcode and xsm boot mod types
> >
> > Changes since v5:
> > - added guard around initrd type assignment
> > - removed a missed rebase artifact
> > ---
> >   xen/arch/x86/cpu/microcode/core.c   |  1 +
> >   xen/arch/x86/include/asm/bootinfo.h | 12 ++++++++++++
> >   xen/arch/x86/setup.c                |  4 ++++
> >   xen/xsm/xsm_policy.c                |  1 +
> >   4 files changed, 18 insertions(+)
> >
> > diff --git a/xen/arch/x86/cpu/microcode/core.c 
> > b/xen/arch/x86/cpu/microcode/core.c
> > index 1fa6cbf3d364..f46464241557 100644
> > --- a/xen/arch/x86/cpu/microcode/core.c
> > +++ b/xen/arch/x86/cpu/microcode/core.c
> @@ -831,6 +831,10 @@ static int __init early_microcode_load(struct
> boot_info *bi)
>                   continue;
>               }
>   
> +            /*
> +             * Do not alter this boot module's type.  We're most likely
> +             * peeking at dom0's initrd.
> +             */
>               data = cd.data;
>               size = cd.size;
>               goto found;
>
>
> To make it absolutely crystal clear that ...
Absolutely, as it might not be clear to a future editor of the code.

> > @@ -845,6 +845,7 @@ static int __init early_microcode_load(struct boot_info *bi)
> >               printk(XENLOG_WARNING "Microcode: Chosen module %d already 
> > used\n", idx);
> >               return -ENODEV;
> >           }
> > +        bi->mods[idx].type = BOOTMOD_MICROCODE;
> ... this is deliberately not done on the scan path.
v/r,
dps