[PULL 39/40] target/riscv: add support for svpbmt extension

[Alistair Francis]

From: Weiwei Li <liweiwei@iscas.ac.cn>

- add PTE_PBMT bits: It uses two PTE bits, but otherwise has no effect on QEMU, 
since QEMU is sequentially consistent and doesn't model PMAs currently
- add PTE_PBMT bit check for inner PTE

Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220204022658.18097-6-liweiwei@iscas.ac.cn>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu_bits.h   | 2 ++
 target/riscv/cpu.c        | 1 +
 target/riscv/cpu_helper.c | 4 +++-
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 37ed4da72c..0fe01d7da5 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -561,7 +561,9 @@ typedef enum {
 #define PTE_A               0x040 /* Accessed */
 #define PTE_D               0x080 /* Dirty */
 #define PTE_SOFT            0x300 /* Reserved for Software */
+#define PTE_PBMT            0x6000000000000000ULL /* Page-based memory types */
 #define PTE_N               0x8000000000000000ULL /* NAPOT translation */
+#define PTE_ATTR            (PTE_N | PTE_PBMT) /* All attributes bits */
 
 /* Page table PPN shift amount */
 #define PTE_PPN_SHIFT       10
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index e5676b40d1..b0a40b83e7 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -776,6 +776,7 @@ static Property riscv_cpu_properties[] = {
 
     DEFINE_PROP_BOOL("svinval", RISCVCPU, cfg.ext_svinval, false),
     DEFINE_PROP_BOOL("svnapot", RISCVCPU, cfg.ext_svnapot, false),
+    DEFINE_PROP_BOOL("svpbmt", RISCVCPU, cfg.ext_svpbmt, false),
 
     DEFINE_PROP_BOOL("zba", RISCVCPU, cfg.ext_zba, true),
     DEFINE_PROP_BOOL("zbb", RISCVCPU, cfg.ext_zbb, true),
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 437c9488a6..746335bfd6 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -937,9 +937,11 @@ restart:
         if (!(pte & PTE_V)) {
             /* Invalid PTE */
             return TRANSLATE_FAIL;
+        } else if (!cpu->cfg.ext_svpbmt && (pte & PTE_PBMT)) {
+            return TRANSLATE_FAIL;
         } else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
             /* Inner PTE, continue walking */
-            if (pte & (PTE_D | PTE_A | PTE_U | PTE_N)) {
+            if (pte & (PTE_D | PTE_A | PTE_U | PTE_ATTR)) {
                 return TRANSLATE_FAIL;
             }
             base = ppn << PGSHIFT;
-- 
2.34.1