Re: [PATCH v2 25/58] kvm/tdx: Don't complain when converting vMMIO region to shared

[Daniel P . Berrangé]

On Fri, Aug 18, 2023 at 05:50:08AM -0400, Xiaoyao Li wrote:
> From: Isaku Yamahata <isaku.yamahata@intel.com>
> 
> Because vMMIO region needs to be shared region, guest TD may explicitly
> convert such region from private to shared.  Don't complain such
> conversion.
> 
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
> ---
>  accel/kvm/kvm-all.c | 20 ++++++++++++++++++--
>  1 file changed, 18 insertions(+), 2 deletions(-)
> 
> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
> index fceec7f2a83f..9d0aa8c97feb 100644
> --- a/accel/kvm/kvm-all.c
> +++ b/accel/kvm/kvm-all.c
> @@ -3094,8 +3094,24 @@ static int kvm_convert_memory(hwaddr start, hwaddr 
> size, bool to_private)
>           */
>          ram_block_convert_range(rb, offset, size, to_private);
>      } else {
> -        warn_report("Convert non guest-memfd backed memory region 
> (0x%"HWADDR_PRIx" ,+ 0x%"HWADDR_PRIx") to %s",
> -                    start, size, to_private ? "private" : "shared");
> +        MemoryRegion *mr = section.mr;
> +
> +        /*
> +         * Because vMMIO region must be shared, guest TD may convert vMMIO
> +         * region to shared explicitly.  Don't complain such case.  See
> +         * memory_region_type() for checking if the region is MMIO region.
> +         */
> +        if (to_private ||
> +            memory_region_is_ram(mr) ||
> +            memory_region_is_ram_device(mr) ||
> +            memory_region_is_rom(mr) ||
> +            memory_region_is_romd(mr)) {

Should we also have  !is_tdx_vm() as the first clause to check, as IIUC
you only need the special logic for TDX VMs.

> +            warn_report("Convert non guest-memfd backed memory region 
> (0x%"HWADDR_PRIx" ,+ 0x%"HWADDR_PRIx") of %s to %s",
> +                        start, size, mr->name, to_private ? "private" : 
> "shared");
> +         } else {
> +                 ret = 0;
> +         }

Inconsistent indentation here due to use of tabs

> +
>      }
>  
>      memory_region_unref(section.mr);
> -- 
> 2.34.1
> 

With regards,
Daniel
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