On Tue, Jan 18, 2022 at 6:47 AM Weiwei Li <liweiwei@iscas.ac.cn> wrote:
From: Guo Ren <ren_guo@c-sky.com>
Highest bits of PTE has been used for svpbmt, ref: [1], [2], so we
need to ignore them. They cannot be a part of ppn.
1: The RISC-V Instruction Set Manual, Volume II: Privileged Architecture
4.4 Sv39: Page-Based 39-bit Virtual-Memory System
4.5 Sv48: Page-Based 48-bit Virtual-Memory System
2: https://github.com/riscv/virtual-memory/blob/main/specs/663-Svpbmt-diff.pdf
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Liu Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
target/riscv/cpu_bits.h | 7 +++++++
target/riscv/cpu_helper.c | 2 +-
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 5a6d49aa64..282cd8eecd 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -490,6 +490,13 @@ typedef enum {
/* Page table PPN shift amount */
#define PTE_PPN_SHIFT 10
+/* Page table PPN mask */
+#if defined(TARGET_RISCV32)
+#define PTE_PPN_MASK 0xffffffffUL
+#elif defined(TARGET_RISCV64)
+#define PTE_PPN_MASK 0x3fffffffffffffULL
+#endif
+
Going forward we should avoid using target specific "#if"
so that we can use the same qemu-system-riscv64 for both
RV32 and RV64.
/* Leaf page shift amount */
#define PGSHIFT 12
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 434a83e66a..26608ddf1c 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -619,7 +619,7 @@ restart:
return TRANSLATE_FAIL;
}
- hwaddr ppn = pte >> PTE_PPN_SHIFT;
+ hwaddr ppn = (pte & PTE_PPN_MASK) >> PTE_PPN_SHIFT;
Rather than using "#if", please use "xlen" comparison to extract
PPN correctly from PTE.