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Message-ID: <d8c3888c-4266-d781-5d0a-381a57a9c35c@intel.com>
Date:   Thu, 14 Sep 2023 09:22:23 -0700
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Subject: Re: [PATCH v6 05/25] x86/fpu/xstate: Remove kernel dynamic xfeatures
 from kernel default_features
Content-Language: en-US
To:     Yang Weijiang <weijiang.yang@intel.com>, seanjc@google.com,
        pbonzini@redhat.com, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     peterz@infradead.org, chao.gao@intel.com,
        rick.p.edgecombe@intel.com, john.allen@amd.com
References: <20230914063325.85503-1-weijiang.yang@intel.com>
 <20230914063325.85503-6-weijiang.yang@intel.com>
From:   Dave Hansen <dave.hansen@intel.com>
In-Reply-To: <20230914063325.85503-6-weijiang.yang@intel.com>
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On 9/13/23 23:33, Yang Weijiang wrote:
> --- a/arch/x86/kernel/fpu/xstate.c
> +++ b/arch/x86/kernel/fpu/xstate.c
> @@ -845,6 +845,7 @@ void __init fpu__init_system_xstate(unsigned int legacy_size)
>  	/* Clean out dynamic features from default */
>  	fpu_kernel_cfg.default_features = fpu_kernel_cfg.max_features;
>  	fpu_kernel_cfg.default_features &= ~XFEATURE_MASK_USER_DYNAMIC;
> +	fpu_kernel_cfg.default_features &= ~fpu_kernel_dynamic_xfeatures;

I'd much rather that this be a closer analog to XFEATURE_MASK_USER_DYNAMIC.

Please define a XFEATURE_MASK_KERNEL_DYNAMIC value and use it here.
Don't use a dynamically generated one.