target/riscv: Move Guest irqs out of the core local irqs range.

Qemu maps IRQs 0:15 for core interrupts and 16 onward for
guest interrupts which are later translated to hgiep in
`riscv_cpu_set_irq()` function.

With virtual IRQ support added, software now can fully
use the whole local interrupt range without any actual
hardware attached.

This change moves the guest interrupt range after the
core local interrupt range to avoid clash.

Fixes: 1697837ed9 ("target/riscv: Add M-mode virtual interrupt and IRQ filtering support.")
Fixes: 40336d5b1d ("target/riscv: Add HS-mode virtual interrupt and IRQ filtering support.")

Signed-off-by: Rajnesh Kanwal <rkanwal@rivosinc.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20240520125157.311503-3-rkanwal@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/cpu_bits.h

@@ -695,7 +695,8 @@ typedef enum RISCVException {
 #define IRQ_M_EXT                          11
 #define IRQ_S_GEXT                         12
 #define IRQ_PMU_OVF                        13
-#define IRQ_LOCAL_MAX                      16
+#define IRQ_LOCAL_MAX                      64
+/* -1 is due to bit zero of hgeip and hgeie being ROZ. */
 #define IRQ_LOCAL_GUEST_MAX                (TARGET_LONG_BITS - 1)
 
 /* mip masks */

target/riscv/csr.c

@@ -1145,7 +1145,14 @@ static RISCVException write_stimecmph(CPURISCVState *env, int csrno,
 
 #define VSTOPI_NUM_SRCS 5
 
-#define LOCAL_INTERRUPTS (~0x1FFF)
+/*
+ * All core local interrupts except the fixed ones 0:12. This macro is for
+ * virtual interrupts logic so please don't change this to avoid messing up
+ * the whole support, For reference see AIA spec: `5.3 Interrupt filtering and
+ * virtual interrupts for supervisor level` and `6.3.2 Virtual interrupts for
+ * VS level`.
+ */
+#define LOCAL_INTERRUPTS   (~0x1FFFULL)
 
 static const uint64_t delegable_ints =
     S_MODE_INTERRUPTS | VS_MODE_INTERRUPTS | MIP_LCOFIP;