RISC-V: KVM: Document RISC-V specific parts of KVM API
Document RISC-V specific parts of the KVM API, such as:
- The interrupt numbers passed to the KVM_INTERRUPT ioctl.
- The states supported by the KVM_{GET,SET}_MP_STATE ioctls.
- The registers supported by the KVM_{GET,SET}_ONE_REG interface
and the encoding of those register ids.
- The exit reason KVM_EXIT_RISCV_SBI for SBI calls forwarded to
userspace tool.
CC: Jonathan Corbet <corbet@lwn.net>
CC: linux-doc@vger.kernel.org
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>