From: Yu-cheng Yu <yu-cheng.yu@intel.com>
To: Dave Hansen <dave.hansen@linux.intel.com>
Cc: fenghua.yu@intel.com, dvlasenk@redhat.com, peterz@infradead.org,
oleg@redhat.com, mingo@kernel.org, linux-kernel@vger.kernel.org,
brgerst@gmail.com, luto@kernel.org, bp@alien8.de,
jpoimboe@redhat.com, haokexin@gmail.com, hpa@zytor.com,
quentin.casasnovas@oracle.com, tglx@linutronix.de,
torvalds@linux-foundation.org, riel@redhat.com,
linux-tip-commits@vger.kernel.org
Subject: Re: [tip:x86/urgent] x86/fpu: Set the xcomp_bv when we fake up a XSAVES area
Date: Mon, 23 Jan 2017 13:16:40 -0800 [thread overview]
Message-ID: <20170123211640.GA3976@test-lenovo> (raw)
In-Reply-To: <90b0fbee-273b-31c2-6fe9-228f00c0a205@linux.intel.com>
On Mon, Jan 23, 2017 at 01:10:20PM -0800, Dave Hansen wrote:
> The code is:
>
> > void fpstate_init(union fpregs_state *state)
> > {
> > if (!static_cpu_has(X86_FEATURE_FPU)) {
> > fpstate_init_soft(&state->soft);
> > return;
> > }
> >
> > memset(state, 0, fpu_kernel_xstate_size);
> >
> > /*
> > * XRSTORS requires that this bit is set in xcomp_bv, or
> > * it will #GP. Make sure it is replaced after the memset().
> > */
> > if (static_cpu_has(X86_FEATURE_XSAVES))
> > state->xsave.header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT;
>
> That seems to set it unconditionally. What am I missing?
The fix I am proposing is...
state->xsave.header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT |
xfeatures_mask;
next prev parent reply other threads:[~2017-01-23 21:20 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-22 8:50 [PATCH] x86/fpu: set the xcomp_bv when we fake up a XSAVES area Kevin Hao
2017-01-23 8:28 ` [tip:x86/urgent] x86/fpu: Set " tip-bot for Kevin Hao
2017-01-23 15:36 ` Dave Hansen
2017-01-23 16:55 ` Yu-cheng Yu
2017-01-23 17:23 ` Dave Hansen
2017-01-23 20:57 ` Yu-cheng Yu
2017-01-23 21:10 ` Dave Hansen
2017-01-23 21:16 ` Yu-cheng Yu [this message]
2017-01-23 21:28 ` Dave Hansen
2017-01-24 0:14 ` Kevin Hao
2017-01-24 0:53 ` Dave Hansen
2017-01-24 1:50 ` Kevin Hao
2017-01-24 2:01 ` Dave Hansen
2017-01-24 2:09 ` Kevin Hao
2017-01-24 2:38 ` Dave Hansen
2017-01-24 5:18 ` Kevin Hao
2017-01-24 8:08 ` Ingo Molnar
2017-01-23 9:43 ` tip-bot for Kevin Hao
2017-02-14 16:47 ` Dave Hansen
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