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h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=WYbNs0ctWfr3ZA0tJCGViTN9Egeb6OHEEy0IvZRRgh1NVevajMoInuHD1PTq4tjkt Xrk7gmKoLuMAKkDne0uAvwE98sc5z4AHU37JSkHMvLkZFOJi47oEzOd4GLIdet4Ea0 WjOgBKM4rPuQb47p3hzR7k7iSoel7URRnI/tMAL9YPfC3cFb2HoDhNFMkILL48Yc6X Pn5NE4Hw1opAu2luag6UXk9CMaKrnTPSFqzudduZSc2aOszSvvDBah7xUuPPHXVTp1 xIOnZZB/JRTffQs8doDJWeMaqgzHXYO63FG5IgB6Lk2fl1O/r2IPMNLojTeCgPe2a5 fVJ4yZn76HVng== Message-ID: <853c6f7c-b4ea-4c25-8816-856bb56895bc@zytor.com> Date: Sun, 27 Apr 2025 23:31:05 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 3/7] x86/fpu/xstate: Differentiate default features for host and guest FPUs To: Sean Christopherson , Rick P Edgecombe Cc: Chao Gao , "kvm@vger.kernel.org" , "ebiggers@google.com" , Dave Hansen , "dave.hansen@linux.intel.com" , Stanislav Spassov , "levymitchell0@gmail.com" , "samuel.holland@sifive.com" , Xin3 Li , "linux-kernel@vger.kernel.org" , Weijiang Yang , "mingo@redhat.com" , "pbonzini@redhat.com" , "tglx@linutronix.de" , "john.allen@amd.com" , "mlevitsk@redhat.com" , Chang Seok Bae , "vigbalas@amd.com" , "peterz@infradead.org" , "hpa@zytor.com" , "bp@alien8.de" , "aruna.ramakrishna@oracle.com" , "x86@kernel.org" References: <20250410072605.2358393-1-chao.gao@intel.com> <20250410072605.2358393-4-chao.gao@intel.com> <4a4b1f18d585c7799e5262453e4cfa2cf47c3175.camel@intel.com> Content-Language: en-US From: Xin Li Autocrypt: addr=xin@zytor.com; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 4/25/2025 4:48 PM, Sean Christopherson wrote: > CET_S probably shouldn't be in XSAVE ABI, because that would technically leak > kernel state to userspace for the non-KVM use case. I assume the kernel has > bigger problems if CET_S is somehow tied to a userspace task. +1000