riscv: KVM: Add vector lazy save/restore support

This patch adds vector context save/restore for guest VCPUs. To reduce the
impact on KVM performance, the implementation imitates the FP context
switch mechanism to lazily store and restore the vector context only when
the kernel enters/exits the in-kernel run loop and not during the KVM
world switch.

Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Acked-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20230605110724.21391-20-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Vincent Chen 2023-06-05 11:07:16 +00:00 • committed by Palmer Dabbelt
commit 0f4b825797
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