Sender: Paolo Bonzini <paolo.bonzini@gmail.com>
Message-ID: <f49f9358-a903-3ee1-46f8-1662911390ef@redhat.com>
Date:   Tue, 14 Dec 2021 11:21:51 +0100
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Subject: Re: [patch 4/6] x86/fpu: Add guest support to xfd_enable_feature()
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To:     "Tian, Kevin" <kevin.tian@intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        LKML <linux-kernel@vger.kernel.org>
Cc:     Jing Liu <jing2.liu@linux.intel.com>,
        "Zhong, Yang" <yang.zhong@intel.com>,
        "x86@kernel.org" <x86@kernel.org>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "Christopherson,, Sean" <seanjc@google.com>,
        "Nakajima, Jun" <jun.nakajima@intel.com>
References: <20211214022825.563892248@linutronix.de>
 <20211214024947.991506193@linutronix.de>
 <BN9PR11MB5276D76F3F0729865FCE02938C759@BN9PR11MB5276.namprd11.prod.outlook.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
In-Reply-To: <BN9PR11MB5276D76F3F0729865FCE02938C759@BN9PR11MB5276.namprd11.prod.outlook.com>
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On 12/14/21 07:05, Tian, Kevin wrote:
>> +	if (guest_fpu) {
>> +		newfps->is_guest = true;
>> +		newfps->is_confidential = curfps->is_confidential;
>> +		newfps->in_use = curfps->in_use;
>> +		guest_fpu->xfeatures |= xfeatures;
>> +	}
>> +
> As you explained guest fpstate is not current active in the restoring
> path, thus it's not correct to always inherit attributes from the
> active one.

Indeed, guest_fpu->fpstate should be used instead of curfps.

Paolo