From: Andi Kleen <ak@linux.intel.com>
To: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Andi Kleen <andi@firstfloor.org>,
x86@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v8 4/5] x86/xsave: Make XSAVE check the base CPUID features before enabling
Date: Mon, 1 Jul 2019 09:39:24 -0700 [thread overview]
Message-ID: <20190701163924.GB31027@tassilo.jf.intel.com> (raw)
In-Reply-To: <a36a8cc2-3d9e-dc70-bbe4-bfc5edef395a@oracle.com>
>
> The commit for this patch in mainline
> (ccb18db2ab9d923df07e7495123fe5fb02329713) causes the kernel to hang on
> boot when passing the "nofxsr" option:
Thanks.
Hmm, I'm not sure nofxsr ever worked on 64bit. Certainly SSE cannot be
saved/restored in any other way during the context switch.
So even if you pass it successfully I doubt user space will really work
for very long. 64bit binaries require SSE.
AFAIK it is only useful on systems without SSE, presumably
running 32bit kernels.
Should check that case.
My recommended solution would be to just get rid of the option.
Presumably it's just some old chicken bit.
-Anfi
next prev parent reply other threads:[~2019-07-01 16:39 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-05 21:52 Support generic disabling of all XSAVE features Andi Kleen
2017-10-05 21:52 ` [PATCH v8 1/5] x86/xsave: Move xsave initialization to after parsing early parameters Andi Kleen
2017-10-05 21:52 ` [PATCH v8 2/5] x86/cpuid: Add generic table for cpuid dependencies Andi Kleen
2017-10-05 22:41 ` Thomas Gleixner
2017-10-05 23:08 ` Andi Kleen
2017-10-05 23:34 ` Andi Kleen
2017-10-05 21:52 ` [PATCH v8 3/5] x86/cpuid: Make clearcpuid an early param Andi Kleen
2017-10-05 21:52 ` [PATCH v8 4/5] x86/xsave: Make XSAVE check the base CPUID features before enabling Andi Kleen
2017-11-11 23:15 ` [v8, " Guenter Roeck
2017-11-12 6:41 ` Andi Kleen
2017-11-14 1:28 ` Andi Kleen
2017-11-14 1:49 ` Guenter Roeck
2017-11-16 19:03 ` Andi Kleen
2017-11-16 22:13 ` Guenter Roeck
2017-11-14 2:33 ` Guenter Roeck
2019-06-29 15:22 ` [PATCH v8 " Vegard Nossum
2019-07-01 12:17 ` Sebastian Andrzej Siewior
2019-07-01 16:41 ` Andi Kleen
2019-07-01 16:39 ` Andi Kleen [this message]
2017-10-05 21:52 ` [PATCH v8 5/5] x86/xsave: Remove the explicit clearing of XSAVE dependend features Andi Kleen
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