On Mon, Oct 28, 2024 at 11:45:25AM +0100, Paolo Bonzini wrote: > On 10/28/24 11:02, Tao Su wrote: > > On Mon, Oct 28, 2024 at 09:45:39AM +0100, Paolo Bonzini wrote: > > > On 10/28/24 03:45, Tao Su wrote: > > > > Since the highest supported vector length for a processor implies that > > > > all lesser vector lengths are also supported, add the dependencies of > > > > the supported vector lengths. If all vector lengths aren't supported, > > > > clear AVX10 enable bit as well. > > > > > > > > Note that the order of AVX10 related dependencies should be kept as: > > > > CPUID_24_0_EBX_AVX10_128 -> CPUID_24_0_EBX_AVX10_256, > > > > CPUID_24_0_EBX_AVX10_256 -> CPUID_24_0_EBX_AVX10_512, > > > > CPUID_24_0_EBX_AVX10_VL_MASK -> CPUID_7_1_EDX_AVX10, > > > > > > I think you need to add a set of dependencies so that avx10 cannot be set, > > > unless all the older AVX features that it's composed of are available. > > > From > > > the manual these are > > > > > > AVX512F, AVX512CD, AVX512VW, AVX512DQ, AVX512_VBMI, AVX512_IFMA, > > > AVX512_VNNI, AVX512_BF16, AVX512_VPOPCNTDQ, AVX512_VBMI2, VAES, GFNI, > > > VPCLMULQDQ, AVX512_BITALG, AVX512_FP16. > > > > Thanks for such a quick review!! > > > > AVX10.1 spec said: > > Intel AVX-512 will continue to be supported on P-core-only processors for > > the foreseeable future to support legacy applications. However, new vector > > ISA features will only be added to the Intel AVX10 ISA moving forward. > > While Intel AVX10/512 includes all Intel AVX-512 instructions, it > > important to note that applications compiled to Intel AVX-512 with vector > > length limited to 256 bits are not guaranteed to be compatible on an Intel > > AVX10/256 processor. > > > > I.e. AVX10/256 processors will support old AVX-512 instructions > > (limited to 256 bits and enumerated by AVX10) but not set AVX-512 related > > CPUIDs. So, I think we can't add these dependencies… > > Of course you're right about AVX10 in general, you still need to add the > dependency but only for CPUID_24_0_EBX_AVX10_512. >
I agree, will add in v2, thanks!
