From: Borislav Petkov <bp@alien8.de>
To: "Koralahalli Channabasappa, Smita" <skoralah@amd.com>
Cc: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>,
x86@kernel.org, linux-edac@vger.kernel.org,
linux-kernel@vger.kernel.org, Tony Luck <tony.luck@intel.com>,
"H . Peter Anvin" <hpa@zytor.com>,
yazen.ghannam@amd.com
Subject: Re: [PATCH v2 2/5] x86/mce/inject: Warn the user on a not set valid bit in MCA_STATUS
Date: Tue, 26 Oct 2021 19:15:24 +0200 [thread overview]
Message-ID: <YXg3rIump+CAtgs6@zn.tnic> (raw)
In-Reply-To: <00f4a0ab-f241-6674-f37f-623f3d9a8337@amd.com>
On Tue, Oct 26, 2021 at 11:58:58AM -0500, Koralahalli Channabasappa, Smita wrote:
> Like how it was done here?
> https://lkml.kernel.org/r/20210915232739.6367-3-Smita.KoralahalliChannabasappa@amd.com
Whoops, sorry about that.
So let's analyze this properly - there are two cases:
1. warn if VAL=0: what does that bring us? The person doing the injection
will simply have to set the valid bit and repeat the injection.
I guess "maybe the user wants to inject with Val not set" doesn't make a
whole lot of sense because nothing will happen - error will get ignored.
So we can do all the warning we want - it will be useless and in some
cases the user might not even see it.
So it sounds to me like setting the valid bit directly makes a lot more
sense.
2. Automatically set VAL=1 to correct any VAL=0 injections.
Yes, we force the VAL bit to 1 and that is not what the user injected
but the user injecting with VAL=0 will get ignored, i.e., it will be
pointless.
So we "help" here and set the valid bit.
Anything else I'm missing?
Sorry again for being back'n'forth on this.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2021-10-26 17:15 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-19 23:36 [PATCH v2 0/5] x86/mce: Handle error injection failures in mce-inject module Smita Koralahalli
2021-10-19 23:36 ` [PATCH v2 1/5] x86/mce/inject: Check if a bank is unpopulated before error injection Smita Koralahalli
2021-10-25 13:56 ` Borislav Petkov
2021-10-25 17:09 ` Koralahalli Channabasappa, Smita
2021-10-19 23:36 ` [PATCH v2 2/5] x86/mce/inject: Warn the user on a not set valid bit in MCA_STATUS Smita Koralahalli
2021-10-20 15:06 ` Luck, Tony
2021-10-26 10:02 ` Borislav Petkov
2021-10-26 16:58 ` Koralahalli Channabasappa, Smita
2021-10-26 17:15 ` Borislav Petkov [this message]
2021-10-26 18:53 ` Koralahalli Channabasappa, Smita
2021-10-26 20:25 ` Borislav Petkov
2021-10-19 23:36 ` [PATCH v2 3/5] x86/mce: Use mca_msr_reg() in prepare_msrs() Smita Koralahalli
2021-10-27 11:41 ` Borislav Petkov
2021-10-27 20:19 ` Koralahalli Channabasappa, Smita
2021-10-28 8:53 ` Borislav Petkov
2021-11-01 18:51 ` Koralahalli Channabasappa, Smita
2021-10-19 23:36 ` [PATCH v2 4/5] x86/mce/inject: Check for writes ignored in status registers Smita Koralahalli
2021-10-19 23:36 ` [PATCH v2 5/5] x86/mce/mce-inject: Return error code to userspace from mce-inject module Smita Koralahalli
2021-10-20 15:18 ` Luck, Tony
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