For reasons related to code-generation quality, the offset of CPUTLBDescFast and IcountDecr from CPUArchState needs to fit within 11 bits of displacement (arm[32|64] and riscv addressing modes).
This commit introduces a new constant to store the maximum allowed negative offset, so it can be statically asserted to hold later on. Signed-off-by: Anton Johansson <a...@rev.ng> --- include/hw/core/cpu.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h index c226d7263c..0377f74d48 100644 --- a/include/hw/core/cpu.h +++ b/include/hw/core/cpu.h @@ -259,6 +259,17 @@ struct qemu_work_item; #define CPU_UNSET_NUMA_NODE_ID -1 +/* + * For reasons related to code-generation quality the fast path + * CPUTLBDescFast array and IcountDecr fields need to be located within a + * small negative offset of CPUArchState. This requirement comes from + * host-specific addressing modes of arm[32|64] and riscv which uses 12- + * and 11 bits of displacement respectively. + */ +#define CPU_MIN_DISPLACEMENT_BITS 11 +#define CPU_MAX_NEGATIVE_ENV_OFFSET \ + (-(1 << CPU_MIN_DISPLACEMENT_BITS)) + /** * CPUState: * @cpu_index: CPU index (informative). -- 2.41.0
