target/riscv/kvm: consider irqchip_split() in aia_create()

target/riscv/kvm: consider irqchip_split() in aia_create()

Before adding support to kernel-irqchip=split when using KVM AIA we need
to change how we create the in-kernel AIA device.

In the use case we have so far, i.e. in-kernel irqchip without split
mode, both the s-mode APLIC and IMSIC controllers are provided by the
irqchip. In irqchip_split() mode we'll emulate the s-mode APLIC
controller, which will send MSIs to the in-kernel IMSIC controller. To
do that we need to change kvm_riscv_aia_create() to not create the
in-kernel s-mode APLIC controller.

In the kernel source arch/riscv/kvm/aia_aplic.c, function
kvm_riscv_aia_aplic_init(), we verify that the APLIC controller won't be
instantiated by KVM if we do not set 'nr_sources', which is set via
KVM_DEV_RISCV_AIA_CONFIG_SRCS. For QEMU this means that we should not
set 'aia_irq_num' during kvm_riscv_aia_create() in irqchip_split() mode.

In this same condition, skip KVM_DEV_RISCV_AIA_ADDR_APLIC as well since
it is used to set the base address for the in-kernel APLIC controller.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20241119191706.718860-5-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>