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Re: [PATCH v2 1/2] x86/dom0: fix restoring %cr3 and the mapcache override on PV build error


  • To: Roger Pau Monne <roger.pau@xxxxxxxxxx>
  • From: Jan Beulich <jbeulich@xxxxxxxx>
  • Date: Wed, 31 Jul 2024 08:32:03 +0200
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  • Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxxx
  • Delivery-date: Wed, 31 Jul 2024 06:32:15 +0000
  • List-id: Xen developer discussion <xen-devel.lists.xenproject.org>

On 30.07.2024 17:28, Roger Pau Monne wrote:
> One of the error paths in the PV dom0 builder section that runs on the guest
> page-tables wasn't restoring the Xen value of %cr3, neither removing the
> mapcache override.

s/neither/nor/ ?

> --- a/xen/arch/x86/pv/dom0_build.c
> +++ b/xen/arch/x86/pv/dom0_build.c
> @@ -825,6 +825,8 @@ int __init dom0_construct_pv(struct domain *d,
>      rc = elf_load_binary(&elf);
>      if ( rc < 0 )
>      {
> +        mapcache_override_current(NULL);
> +        switch_cr3_cr4(current->arch.cr3, read_cr4());
>          printk("Failed to load the kernel binary\n");
>          goto out;
>      }

Just below here we have

    bootstrap_map(NULL);

This too is wanted in the error case aiui. Happy to move it up immediately
ahead of the if() while committing, so long as you agree. Then:
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>

Jan



 


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