Re: [PATCH 08/12] x86/boot: convert domain construction to use boot info

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 02/11/2024 5:25 pm, Daniel P. Smith wrote:
> @@ -1301,16 +1302,25 @@ static void __hwdom_init pvh_setup_mmcfg(struct 
> domain *d)
>      }
>  }
>  
> -int __init dom0_construct_pvh(struct domain *d, const module_t *image,
> -                              unsigned long image_headroom,
> -                              module_t *initrd,
> -                              const char *cmdline)
> +int __init dom0_construct_pvh(struct boot_info *bi, struct domain *d)
>  {
>      paddr_t entry, start_info;
> +    struct boot_module *image;
> +    struct boot_module *initrd = NULL;
>      int rc;
>  
>      printk(XENLOG_INFO "*** Building a PVH Dom%d ***\n", d->domain_id);
>  
> +    rc = first_boot_module_index(bi, BOOTMOD_KERNEL);
> +    if ( unlikely(rc < 0 || rc > bi->nr_modules) )
> +        panic("Missing kernel boot module for %pd construction\n", d);

Just noticed while experimenting.  The upper bound (for the error case)
should be >= because nothing good can come of being handed the Xen module.

> +
> +    image = &bi->mods[rc];
> +
> +    rc = first_boot_module_index(bi, BOOTMOD_RAMDISK);
> +    if ( rc > 0 || rc < bi->nr_modules )
> +        initrd = &bi->mods[rc];

This range check is tautologically true.  You want && instead of ||.

Same elsewhere, although this goes away when the variable is unsigned
(and we remove assumptions about the dom0 kernel's index).

~Andrew