[Discussion] Proposal to future v4 build

[leleobhz]

Hello!

This PR brings an idea to future: When qemu-static binaries supports v4 stacks, this Dockerfile-v4 maybe able to build x86_64_v4 version at any CPU (Including Github hosts itself).

QEMU does already support v3 but v4/avx512 support wasn't considered important at time to be supported on Qemu TCG. Maybe report an issue on qemu issues helps to this support comes in, but without qemu-x86_64-static, CachyOS v4 builds will be only able to be built on proper v4 hardware.

That said, what are CachyOS mantainers thoughts about my suggestion at Dockerfile-v4?

[ptr1337]

If it works, it seems good to me :) will run some tests.

[leleobhz]

If it works, it seems good to me :) will run some tests.

Today it will not work as qemu does not support avx512 on TCG.

❯ qemu-x86_64-static --cpu Skylake-Server-v5 /usr/bin/uname -a
qemu-x86_64-static: warning: TCG doesn't support requested feature: CPUID.07H:EBX.avx512f [bit 16]
qemu-x86_64-static: warning: TCG doesn't support requested feature: CPUID.07H:EBX.avx512dq [bit 17]
qemu-x86_64-static: warning: TCG doesn't support requested feature: CPUID.07H:EBX.avx512cd [bit 28]
qemu-x86_64-static: warning: TCG doesn't support requested feature: CPUID.07H:EBX.avx512bw [bit 30]
qemu-x86_64-static: warning: TCG doesn't support requested feature: CPUID.07H:EBX.avx512vl [bit 31]
qemu-x86_64-static: warning: TCG doesn't support requested feature: CPUID.0DH:EAX.xsavec [bit 1]
qemu-x86_64-static: warning: TCG doesn't support requested feature: CPUID.0DH:EAX.xsaves [bit 3]
qemu: uncaught target signal 4 (Illegal instruction) - core dumped

My proposal is: a machine without avx512 will not be able to build the image the way it was today. The chance we have to build like this are or qemu-static or an vm inside vm.

This is the reason I'm opening this as Draft and trying to map a way to ask Qemu for this support.