From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: Re: [PATCH 14/22] x86/fpu: Eager switch PKRU state
Date: Thu, 21 Mar 2019 18:10:05 +0100
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Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
        Andy Lutomirski <luto@kernel.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        kvm@vger.kernel.org, "Jason A. Donenfeld" <Jason@zx2c4.com>,
        Rik van Riel <riel@surriel.com>,
        Dave Hansen <dave.hansen@linux.intel.com>
To: Dave Hansen <dave.hansen@intel.com>
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On 2019-03-12 17:06:18 [-0700], Dave Hansen wrote:
> Thanks for doing this.  I'll see if I can dig into the test case and
> figure out why it's not doing what I expected.  It might be that the CPU
> _could_ go back to the init state but chooses not to, or that something
> else is taking us out of the init state before we reach the kernel code
> in question.

I'm going to drop that WARN_ON() check. The reason is that we are fully
preemptible during fpstate_init() and a context switch during memset()
and fpstate_init_xstate() triggers this warning.

Sebastian