CONFIG_ARM64_SVE is not available for the default architecture x86.
Result is shown for architecture arm64

ARM Scalable Vector Extension support

configname: CONFIG_ARM64_SVE

Linux Kernel Configuration
└─> Kernel Features
└─> ARM Scalable Vector Extension support

The Scalable Vector Extension (SVE) is an extension to the AArch64
execution state which complements and extends the SIMD functionality
of the base architecture to support much larger vectors and to enable
additional vectorisation opportunities.

To enable use of this extension on CPUs that implement it, say Y.

On CPUs that support the SVE2 extensions, this option will enable
those too.

Note that for architectural reasons, firmware _must_ implement SVE
support when running on SVE capable hardware. The required support
is present in:

* version 1.5 and later of the ARM Trusted Firmware
* the AArch64 boot wrapper since commit 5e1261e08abf
("bootwrapper: SVE: Enable SVE for EL2 and below").

For other firmware implementations, consult the firmware documentation
or vendor.

If you need the kernel to boot on SVE-capable hardware with broken
firmware, you may need to say N here until you get your firmware
fixed. Otherwise, you may experience firmware panics or lockups when
booting the kernel. If unsure and you are not observing these
symptoms, you should assume that it is safe to say Y.

CPUs that support SVE are architecturally required to support the
Virtualization Host Extensions (VHE), so the kernel makes no
provision for supporting SVE alongside KVM without VHE enabled.
Thus, you will need to enable CONFIG_ARM64_VHE if you want to support
KVM in the same kernel image.