Re: [PATCH 3/4] x86/hvm: Remove cross-vendor checks from MSR handlers.

["Teddy Astie" <teddy.astie@xxxxxxxxxx>]

Le 22/01/2026 à 17:51, Alejandro Vallejo a écrit :
> Not a functional change now that cross-vendor guests are not launchable.
>
> Signed-off-by: Alejandro Vallejo <alejandro.garciavallejo@xxxxxxx>
> ---
>   xen/arch/x86/msr.c | 6 ++----
>   1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/xen/arch/x86/msr.c b/xen/arch/x86/msr.c
> index ad75a2e108..c9cc4f0692 100644
> --- a/xen/arch/x86/msr.c
> +++ b/xen/arch/x86/msr.c
> @@ -169,9 +169,9 @@ int guest_rdmsr(struct vcpu *v, uint32_t msr, uint64_t 
> *val)
>           break;
>
>       case MSR_IA32_PLATFORM_ID:
> -        if ( !(cp->x86_vendor & X86_VENDOR_INTEL) ||
> -             !(boot_cpu_data.x86_vendor & X86_VENDOR_INTEL) )
> +        if ( cp->x86_vendor != X86_VENDOR_INTEL )
>               goto gp_fault;
> +
>           rdmsrl(MSR_IA32_PLATFORM_ID, *val);
>           break;
>
> @@ -190,8 +190,6 @@ int guest_rdmsr(struct vcpu *v, uint32_t msr, uint64_t 
> *val)
>            * the guest.
>            */
>           if ( !(cp->x86_vendor & (X86_VENDOR_INTEL | X86_VENDOR_AMD)) ||
> -             !(boot_cpu_data.x86_vendor &
> -               (X86_VENDOR_INTEL | X86_VENDOR_AMD)) ||
>                rdmsr_safe(MSR_AMD_PATCHLEVEL, val) )
>               goto gp_fault;
>           break;

Reviewed-by: Teddy Astie <teddy.astie@xxxxxxxxxx>


--
Teddy Astie | Vates XCP-ng Developer

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