Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Mon, 8 Feb 2021 13:33:59 +0100
From:   Borislav Petkov <bp@suse.de>
To:     "Chang S. Bae" <chang.seok.bae@intel.com>
Cc:     luto@kernel.org, tglx@linutronix.de, mingo@kernel.org,
        x86@kernel.org, len.brown@intel.com, dave.hansen@intel.com,
        jing2.liu@intel.com, ravi.v.shankar@intel.com,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH v3 10/21] x86/fpu/xstate: Update xstate save function to
 support dynamic xstate
Message-ID: <20210208123359.GG17908@zn.tnic>
References: <20201223155717.19556-1-chang.seok.bae@intel.com>
 <20201223155717.19556-11-chang.seok.bae@intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <20201223155717.19556-11-chang.seok.bae@intel.com>
Precedence: bulk

On Wed, Dec 23, 2020 at 07:57:06AM -0800, Chang S. Bae wrote:
> copy_xregs_to_kernel() used to save all user states in a kernel buffer.
> When the dynamic user state is enabled, it becomes conditional which state
> to be saved.
> 
> fpu->state_mask can indicate which state components are reserved to be
> saved in XSAVE buffer. Use it as XSAVE's instruction mask to select states.
> 
> KVM used to save all xstate via copy_xregs_to_kernel(). Update KVM to set a
> valid fpu->state_mask, which will be necessary to correctly handle dynamic
> state buffers.

All this commit message should say is something along the lines of
"extend copy_xregs_to_kernel() to receive a mask argument of which
states to save, in preparation of dynamic states handling."

> No functional change until the kernel supports dynamic user states.

Same comment as before.

-- 
Regards/Gruss,
    Boris.

SUSE Software Solutions Germany GmbH, GF: Felix Imendörffer, HRB 36809, AG Nürnberg