linux-kernel - Re: [PATCH] EDAC/mce_amd: Do not load edac_mce

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Date:   Thu, 8 Jul 2021 16:41:06 -0400
From:   Yazen Ghannam <yazen.ghannam@....com>
To:     Smita Koralahalli <Smita.KoralahalliChannabasappa@....com>
Cc:     x86@...nel.org, linux-edac@...r.kernel.org,
        linux-kernel@...r.kernel.org, Robert Richter <rric@...nel.org>,
        Tony Luck <tony.luck@...el.com>,
        James Morse <james.morse@....com>
Subject: Re: [PATCH] EDAC/mce_amd: Do not load edac_mce_amd module on guests

On Mon, Jun 28, 2021 at 12:27:40PM -0500, Smita Koralahalli wrote:
> Hypervisors may not expose SMCA feature to the guest.
> 
> Check for X86_FEATURE_HYPERVISOR on entry in mce_amd_init() and return
> -ENODEV if set.
> 
> Suggested-by: Borislav Petkov <bp@...e.de>
> Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@....com>
> ---
>  drivers/edac/mce_amd.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/edac/mce_amd.c b/drivers/edac/mce_amd.c
> index 5dd905a3f30c..1a1629166aa3 100644
> --- a/drivers/edac/mce_amd.c
> +++ b/drivers/edac/mce_amd.c
> @@ -1176,6 +1176,9 @@ static int __init mce_amd_init(void)
>  	    c->x86_vendor != X86_VENDOR_HYGON)
>  		return -ENODEV;
>  
> +	if (cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
> +		return -ENODEV;
> +
>  	if (boot_cpu_has(X86_FEATURE_SMCA)) {
>  		xec_mask = 0x3f;
>  		goto out;
> --

Looks good to me.

Reviewed-by: Yazen Ghannam <yazen.ghannam@....com>

Thanks,
Yazen