linux-kernel - Re: [PATCH 1/5] x86/mce/inject: Check if a bank is unpopulated before error simulation

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Message-ID: <YWiZpm/HzKybyOt2@zn.tnic>
Date:   Thu, 14 Oct 2021 22:57:10 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     "Koralahalli Channabasappa, Smita" <skoralah@....com>
Cc:     Smita Koralahalli <Smita.KoralahalliChannabasappa@....com>,
        x86@...nel.org, linux-edac@...r.kernel.org,
        linux-kernel@...r.kernel.org, Tony Luck <tony.luck@...el.com>,
        "H . Peter Anvin" <hpa@...or.com>, yazen.ghannam@....com
Subject: Re: [PATCH 1/5] x86/mce/inject: Check if a bank is unpopulated
 before error simulation

On Thu, Oct 14, 2021 at 03:26:13PM -0500, Koralahalli Channabasappa, Smita wrote:
> My concern was, we need to determine whether the bank is unpopulated or
> populated before trying to inject the errors on a hw injection, for which
> we need to read the IPID MSR of that bank.

Ah, that. Look at the smca_banks[] array in .../mce/amd.c and how
smca_configure() prepares all banks in there. You could use that array
to query which SMCA bank on which CPU is initialized, before injecting
into it.

> should be retained inside inj_bank_set() ?

And yes, I guess you'll have to do it there because then you know which
bank and which CPU the hw injection is supposed to happen on.

> And inj_ipid_set() should just set m->ipid = val on a SW_INJ as you mentioned
> above?

Yap.

Thx.

-- 
Regards/Gruss,
    Boris.

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