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Fri, 28 Feb 2025 03:10:50 +0000 Message-ID: <9381647d-de62-4c72-9b1c-930cbd9231d6@intel.com> Date: Thu, 27 Feb 2025 19:10:48 -0800 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH RFC v1 02/11] x86/fpu/xstate: Introduce xstate order table and accessor macro To: Ingo Molnar , Andrew Cooper CC: , , , , , , References: <94083f1c-dab1-4b57-bd45-a4d4f8ac262e@citrix.com> Content-Language: en-US From: "Chang S. 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Obviously only >> AVX-aware host and guest kernels would enable AVX. > > Erm, s/AVX/APX ... Just thought of another aspect of this: I'm curious about how core dumps should handle this. Initially, an xfeature mask was added to the software-reserved area [1] to indicate which xfeatures were present in the layout. More recently, a new note [2] was introduced to expose CPUID-reported size and offset information, helping tools like GDB. From an offline interpretation standpoint, I think these bits will become ambiguous without further extensions. [1] commit 5b3efd500854 ("x86, ptrace: regset extensions to support xstate") [2] commit ba386777a30b ("x86/elf: Add a new FPU buffer layout info to x86 core files") Thanks, Chang