hw/intc/riscv_aplic.c fix non-KVM --enable-debug build

Commit 6df0b37 breaks a --enable-debug build in a non-KVM
environment with the following error:

/usr/bin/ld: libqemu-riscv64-softmmu.fa.p/hw_intc_riscv_aplic.c.o: in function `riscv_kvm_aplic_request':
./qemu/build/../hw/intc/riscv_aplic.c:486: undefined reference to `kvm_set_irq'
collect2: error: ld returned 1 exit status

This happens because the debug build will poke into the
'if (is_kvm_aia(aplic->msimode))' block and fail to find a reference to
the KVM only function riscv_kvm_aplic_request().

There are multiple solutions to fix this. We'll go with the same
solution from the previous patch, i.e. add a kvm_enabled() conditional
to filter out the block. But there's a catch: riscv_kvm_aplic_request()
is a local function that would end up being used if the compiler crops
the block, and this won't work. Quoting Richard Henderson's explanation
in [1]:

"(...) the compiler won't eliminate entire unused functions with -O0"

We'll solve it by moving riscv_kvm_aplic_request() to kvm.c and add its
declaration in kvm_riscv.h, where all other KVM specific public
functions are already declared. Other archs handles KVM specific code in
this manner and we expect to do the same from now on.

[1] https://lore.kernel.org/qemu-riscv/d2f1ad02-eb03-138f-9d08-db676deeed05@linaro.org/

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20230830133503.711138-3-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

hw/intc/riscv_aplic.c

@@ -32,6 +32,7 @@
 #include "target/riscv/cpu.h"
 #include "sysemu/sysemu.h"
 #include "sysemu/kvm.h"
+#include "kvm_riscv.h"
 #include "migration/vmstate.h"
 
 #define APLIC_MAX_IDC                  (1UL << 14)
@@ -481,11 +482,6 @@ static uint32_t riscv_aplic_idc_claimi(RISCVAPLICState *aplic, uint32_t idc)
     return topi;
 }
 
-static void riscv_kvm_aplic_request(void *opaque, int irq, int level)
-{
-    kvm_set_irq(kvm_state, irq, !!level);
-}
-
 static void riscv_aplic_request(void *opaque, int irq, int level)
 {
     bool update = false;
@@ -840,7 +836,7 @@ static void riscv_aplic_realize(DeviceState *dev, Error **errp)
      * have IRQ lines delegated by their parent APLIC.
      */
     if (!aplic->parent) {
-        if (is_kvm_aia(aplic->msimode)) {
+        if (kvm_enabled() && is_kvm_aia(aplic->msimode)) {
             qdev_init_gpio_in(dev, riscv_kvm_aplic_request, aplic->num_irqs);
         } else {
             qdev_init_gpio_in(dev, riscv_aplic_request, aplic->num_irqs);

target/riscv/kvm.c

@@ -46,6 +46,11 @@
 #include "sysemu/runstate.h"
 #include "hw/riscv/numa.h"
 
+void riscv_kvm_aplic_request(void *opaque, int irq, int level)
+{
+    kvm_set_irq(kvm_state, irq, !!level);
+}
+
 static uint64_t kvm_riscv_reg_id(CPURISCVState *env, uint64_t type,
                                  uint64_t idx)
 {

target/riscv/kvm_riscv.h

@@ -26,5 +26,6 @@ void kvm_riscv_aia_create(MachineState *machine, uint64_t group_shift,
                           uint64_t aia_irq_num, uint64_t aia_msi_num,
                           uint64_t aplic_base, uint64_t imsic_base,
                           uint64_t guest_num);
+void riscv_kvm_aplic_request(void *opaque, int irq, int level);
 
 #endif