target/riscv: Update the local interrupt mask

The RISC-V spec describes bits 0-15 as standard fixed interrupts. The
AIA spec on the other hand describes bits 0-12 as standard fixed
interrupts. This conflict causes issues for us as we don't dynamically
determine if AIA is enabled when setting the *delegable_ints consts.

This means currently we incorrectly treat the LCOFIP bit as delegable,
even if AIA is disabled, which is incorrect (see the issues mentioned
below).

The AIA spec indicates that implementations can determine which bits of
13-63 in mvien are writable, so let's just make it bits 15-63 to match
the main spec.

Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/3133
Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/3134
Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/3135
Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/3138
Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/3140
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Daniel Henrique Barboza <daniel.barboza@oss.qualcomm.com>
Message-ID: <20260513051841.1671987-1-alistair.francis@wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 7ba4f0383c475be9f6e2097a17f5089fbb9e2e56..b470d37050bbe6062a5b8b43314f1683e213b87e 100644 (file)
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -1781,13 +1781,13 @@ static RISCVException write_stimecmph(CPURISCVState *env, int csrno,
 #define VSTOPI_NUM_SRCS 5
 
 /*
- * All core local interrupts except the fixed ones 0:12. This macro is for
+ * All core local interrupts except the fixed ones 0:15. 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)
+#define LOCAL_INTERRUPTS   (~0xFFFFULL)
 
 static const uint64_t delegable_ints =
     S_MODE_INTERRUPTS | VS_MODE_INTERRUPTS | MIP_LCOFIP;