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From: Borislav Petkov <bp@alien8.de>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Richard Hughes <hughsient@gmail.com>,
	Daniel Gutson <daniel@eclypsium.com>,
	Dave Hansen <dave.hansen@intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Peter Zijlstra <peterz@infradead.org>,
	"David S. Miller" <davem@davemloft.net>,
	Rob Herring <robh@kernel.org>, Tony Luck <tony.luck@intel.com>,
	Rahul Tanwar <rahul.tanwar@linux.intel.com>,
	Xiaoyao Li <xiaoyao.li@intel.com>,
	Sean Christopherson <sean.j.christopherson@intel.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] Ability to read the MKTME status from userspace
Date: Fri, 19 Jun 2020 18:17:52 +0200	[thread overview]
Message-ID: <20200619161752.GG32683@zn.tnic> (raw)
In-Reply-To: <0DD7FAE4-3976-4835-8090-80B84B737F3E@amacapital.net>

On Fri, Jun 19, 2020 at 08:48:47AM -0700, Andy Lutomirski wrote:
> Boris, it wouldn’t be totally crazy for cpuinfo to learn to
> distinguish between “your platform has this feature but Linux
> isn’t using it” and “your platform doesn’t have this feature
> in the first place”. And I suppose there’s this extra silly state
> “your platform has this feature, but your firmware didn’t enable
> it”. This would be a big job.

Well, I believe all the kernel can do is supply bits of information -
just like MSRs - and depending on the settings of those bits, userspace
can decide what the situation is. For example:

bit 0 - CPUID support
bit 1 - BIOS enabled
bit 2 - quirk applied
bit 3 - microcode fixes present
...

and so on.

It needs a proper definition though and userspace to say, yes, we want
that and that is useful for us.

Where it ends up is then beside the point - /proc/cpuinfo,
/sys/devices/system/cpu, whatever...

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

  reply	other threads:[~2020-06-19 16:18 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-18 21:02 [PATCH] Ability to read the MKTME status from userspace Daniel Gutson
2020-06-18 21:08 ` Dave Hansen
     [not found]   ` <CAFmMkTHNxSN_uWtm63TdkGxj44NXQQKEOmATXhjA=4DSCS92kQ@mail.gmail.com>
2020-06-18 22:01     ` Borislav Petkov
     [not found]       ` <CAFmMkTGMAu-huTnP1aeMb_W4NddbTD_b2jhbDVKBDrkwgB97wg@mail.gmail.com>
2020-06-19  7:40         ` Borislav Petkov
     [not found]           ` <CAFmMkTGV0ZR6C=EBGQAiz1vw1vrUXSLTnH5ZbBUvfhPLg_tF6g@mail.gmail.com>
2020-06-19 13:22             ` Borislav Petkov
2020-06-19 13:31               ` Richard Hughes
2020-06-19 13:44                 ` Borislav Petkov
2020-06-19 13:50                   ` Richard Hughes
2020-06-19 15:48                     ` Andy Lutomirski
2020-06-19 16:17                       ` Borislav Petkov [this message]
2020-06-19 16:28                         ` Andy Lutomirski
2020-06-19 16:31                         ` Richard Hughes
2020-06-19 16:10                     ` Borislav Petkov
2020-06-19 16:33                       ` Richard Hughes
2020-06-19 16:40                         ` Greg Kroah-Hartman
2020-06-19 16:47                           ` Richard Hughes
2020-06-19 19:41                             ` Andy Lutomirski
2020-06-19 19:58                               ` Richard Hughes
2020-06-19 20:20                                 ` Andy Lutomirski
2020-06-19 20:24                                   ` Dave Hansen
2020-06-22  9:34                                     ` Boris Petkov
2020-06-18 23:52     ` Dave Hansen
2020-06-19  7:41       ` Borislav Petkov
2020-06-19 13:25       ` Richard Hughes
2020-06-19 13:33         ` Dave Hansen
2020-06-19 13:37           ` Richard Hughes
2020-06-19 13:58             ` Dave Hansen
2020-06-19 14:09               ` Richard Hughes
2020-06-19 14:23                 ` Dave Hansen
2020-06-19 14:36                   ` Richard Hughes
2020-06-19 14:48                     ` Dave Hansen
2020-06-19 15:02                       ` Richard Hughes
2020-06-19 15:36                         ` Dave Hansen
2020-06-19  7:20 ` Greg Kroah-Hartman
     [not found]   ` <CAFmMkTF7QBJQdKxhsPiUPifsxykyCVv=NYandpB0z8EccAxMXw@mail.gmail.com>
2020-06-19 14:02     ` Greg Kroah-Hartman

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