On 02.09.2024 10:46, Alejandro Vallejo wrote: > On Wed Aug 21, 2024 at 5:07 PM BST, Jan Beulich wrote: >> On 21.08.2024 17:34, Matthew Barnes wrote: >>> Upon running `xen-cpuid -v` on a host machine with Sapphire Rapids >>> within Dom0, there exist unrecognised features. >>> >>> This patch adds these features as macros to the CPU featureset, >>> disabled by default. >>> >>> Signed-off-by: Matthew Barnes <[email protected]> >> >> I don't strictly mind the patch in this shape, but ... >> >>> @@ -276,10 +283,13 @@ XEN_CPUFEATURE(TSX_FORCE_ABORT, 9*32+13) /* >>> MSR_TSX_FORCE_ABORT.RTM_ABORT */ >>> XEN_CPUFEATURE(SERIALIZE, 9*32+14) /*A SERIALIZE insn */ >>> XEN_CPUFEATURE(HYBRID, 9*32+15) /* Heterogeneous platform */ >>> XEN_CPUFEATURE(TSXLDTRK, 9*32+16) /*a TSX load tracking >>> suspend/resume insns */ >>> +XEN_CPUFEATURE(PCONFIG, 9*32+18) /* PCONFIG insn */ >>> XEN_CPUFEATURE(ARCH_LBR, 9*32+19) /* Architectural Last Branch >>> Record */ >>> XEN_CPUFEATURE(CET_IBT, 9*32+20) /* CET - Indirect Branch Tracking >>> */ >>> +XEN_CPUFEATURE(AMX_BF16, 9*32+22) /* Tile computational operations >>> on bfloat16 numbers */ >>> XEN_CPUFEATURE(AVX512_FP16, 9*32+23) /*A AVX512 FP16 instructions */ >>> XEN_CPUFEATURE(AMX_TILE, 9*32+24) /* AMX Tile architecture */ >>> +XEN_CPUFEATURE(AMX_INT8, 9*32+25) /* Tile computational operations >>> on 8-bit integers */ >>> XEN_CPUFEATURE(IBRSB, 9*32+26) /*A IBRS and IBPB support (used by >>> Intel) */ >>> XEN_CPUFEATURE(STIBP, 9*32+27) /*A STIBP */ >>> XEN_CPUFEATURE(L1D_FLUSH, 9*32+28) /*S MSR_FLUSH_CMD and L1D flush. */ >> >> ... having had a respective (more complete) patch pending for years I really >> wonder if it shouldn't be that one to be taken. While it would need >> adjustment >> to go ahead of other stuff (as posted in v3), I don't think it has any true >> dependency on earlier patches in the AMX series. IOW I could re-post v4 >> standalone, and then we'd have a more complete view on AMX as well as proper >> dependencies in place. >> >> Thoughts? >> >> Jan > > Oh! I had no idea you already posted patches to enable AMX. Is this the one? > > https://lore.kernel.org/xen-devel/[email protected]/
Yes. And specifically patch 9 there for the purposes here, suitably re-based of course and extended to cover AMX-FP16 and AMX-COMPLEX. Jan
