Re: [PATCH 2/4] qemu-options.hx: Update the reduced-phys-bits documentation

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Tom Lendacky (thomas.lendacky@amd.com) wrote:
> A guest only ever experiences, at most, 1 bit of reduced physical
> addressing. Update the documentation to reflect this as well as change
> the example value on the reduced-phys-bits option.
> 
> Fixes: a9b4942f48 ("target/i386: add Secure Encrypted Virtualization (SEV) object")
> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  qemu-options.hx | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 913c71e38f..3396085cf0 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -5391,7 +5391,7 @@ SRST
>          physical address space. The ``reduced-phys-bits`` is used to
>          provide the number of bits we loose in physical address space.
>          Similar to C-bit, the value is Host family dependent. On EPYC,
> -        the value should be 5.
> +        a guest will lose a maximum of 1 bit, so the value should be 1.
>  
>          The ``sev-device`` provides the device file to use for
>          communicating with the SEV firmware running inside AMD Secure
> @@ -5426,7 +5426,7 @@ SRST
>  
>               # |qemu_system_x86| \\
>                   ...... \\
> -                 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=5 \\
> +                 -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1 \\
>                   -machine ...,memory-encryption=sev0 \\
>                   .....
>  
> -- 
> 2.37.3
> 
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK