[PATCH v7 0/5] support subsets of virtual memory extension

[PATCH v7 0/5] support subsets of virtual memory extension

[Weiwei Li]

This patchset implements virtual memory related RISC-V extensions: Svnapot version 1.0, Svinval vesion 1.0, Svpbmt version 1.0. 

Specification:
https://github.com/riscv/virtual-memory/tree/main/specs

The port is available here:
https://github.com/plctlab/plct-qemu/tree/plct-virtmem-upstream-v7

To test this implementation, specify cpu argument with 'svinval=true,svnapot=true,svpbmt=true'.

This implementation can pass the riscv-tests for rv64ssvnapot.

v7:
* delete definition of PTE_PPN_MASK for TARGET_RISCV32
* make riscv_cpu_sxl works for user mode
* add commit msg for patch 2

v6:
* select ppn mask base on sxl

v5:
* merge patch https://lore.kernel.org/qemu-devel/1569456861-8502-1-git-send-email-guoren@kernel.org/
* relax pte attribute check

v4:
* fix encodings for hinval_vvma and hinval_gvma
* partition inner PTE check into several steps
* improve commit messages to describe changes

v3:
* drop "x-" in exposed properties

v2:
* add extension check for svnapot and svpbmt

Guo Ren (1):
  target/riscv: Ignore reserved bits in PTE for RV64

Weiwei Li (4):
  target/riscv: add PTE_A/PTE_D/PTE_U bits check for inner PTE
  target/riscv: add support for svnapot extension
  target/riscv: add support for svinval extension
  target/riscv: add support for svpbmt extension

 target/riscv/cpu.c                          |  4 ++
 target/riscv/cpu.h                          | 16 +++++
 target/riscv/cpu_bits.h                     |  6 ++
 target/riscv/cpu_helper.c                   | 34 +++++++++-
 target/riscv/insn32.decode                  |  7 ++
 target/riscv/insn_trans/trans_svinval.c.inc | 75 +++++++++++++++++++++
 target/riscv/translate.c                    |  1 +
 7 files changed, 140 insertions(+), 3 deletions(-)
 create mode 100644 target/riscv/insn_trans/trans_svinval.c.inc

-- 
2.17.1

[PATCH v7 1/5] target/riscv: Ignore reserved bits in PTE for RV64

[Weiwei Li]

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>
Reviewed-by: Liu Zhiwei <zhiwei_liu@c-sky.com>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/cpu.h        | 15 +++++++++++++++
 target/riscv/cpu_bits.h   |  3 +++
 target/riscv/cpu_helper.c | 14 +++++++++++++-
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 55635d68d5..336fe8e3d5 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -341,6 +341,8 @@ struct RISCVCPU {
         bool ext_counters;
         bool ext_ifencei;
         bool ext_icsr;
+        bool ext_svnapot;
+        bool ext_svpbmt;
         bool ext_zfh;
         bool ext_zfhmin;
         bool ext_zve32f;
@@ -495,6 +497,19 @@ static inline int riscv_cpu_xlen(CPURISCVState *env)
     return 16 << env->xl;
 }
 
+#ifdef TARGET_RISCV32
+#define riscv_cpu_sxl(env)  ((void)(env), MXL_RV32)
+#else
+static inline RISCVMXL riscv_cpu_sxl(CPURISCVState *env)
+{
+#ifdef CONFIG_USER_ONLY
+    return env->misa_mxl;
+#else
+    return get_field(env->mstatus, MSTATUS64_SXL);
+#endif
+}
+#endif
+
 /*
  * Encode LMUL to lmul as follows:
  *     LMUL    vlmul    lmul
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 7c87433645..6ea3944423 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -493,6 +493,9 @@ typedef enum {
 /* Page table PPN shift amount */
 #define PTE_PPN_SHIFT       10
 
+/* Page table PPN mask */
+#define PTE_PPN_MASK        0x3FFFFFFFFFFC00ULL
+
 /* Leaf page shift amount */
 #define PGSHIFT             12
 
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 327a2c4f1d..5a1c0e239e 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -622,7 +622,19 @@ restart:
             return TRANSLATE_FAIL;
         }
 
-        hwaddr ppn = pte >> PTE_PPN_SHIFT;
+        hwaddr ppn;
+        RISCVCPU *cpu = env_archcpu(env);
+
+        if (riscv_cpu_sxl(env) == MXL_RV32) {
+            ppn = pte >> PTE_PPN_SHIFT;
+        } else if (cpu->cfg.ext_svpbmt || cpu->cfg.ext_svnapot) {
+            ppn = (pte & (target_ulong)PTE_PPN_MASK) >> PTE_PPN_SHIFT;
+        } else {
+            ppn = pte >> PTE_PPN_SHIFT;
+            if ((pte & ~(target_ulong)PTE_PPN_MASK) >> PTE_PPN_SHIFT) {
+                return TRANSLATE_FAIL;
+            }
+        }
 
         if (!(pte & PTE_V)) {
             /* Invalid PTE */
-- 
2.17.1

[PATCH v7 2/5] target/riscv: add PTE_A/PTE_D/PTE_U bits check for inner PTE

[Weiwei Li]

For non-leaf PTEs, the D, A, and U bits are reserved for future standard use.

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>
---
 target/riscv/cpu_helper.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 5a1c0e239e..b820166dc5 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -641,6 +641,9 @@ restart:
             return TRANSLATE_FAIL;
         } else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
             /* Inner PTE, continue walking */
+            if (pte & (PTE_D | PTE_A | PTE_U)) {
+                return TRANSLATE_FAIL;
+            }
             base = ppn << PGSHIFT;
         } else if ((pte & (PTE_R | PTE_W | PTE_X)) == PTE_W) {
             /* Reserved leaf PTE flags: PTE_W */
-- 
2.17.1

[PATCH v7 3/5] target/riscv: add support for svnapot extension

[Weiwei Li]

- add PTE_N bit
- add PTE_N bit check for inner PTE
- update address translation to support 64KiB continuous region (napot_bits = 4)

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>
---
 target/riscv/cpu.c        |  2 ++
 target/riscv/cpu_bits.h   |  1 +
 target/riscv/cpu_helper.c | 17 ++++++++++++++---
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 1cb0436187..8752fa1544 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -729,6 +729,8 @@ static Property riscv_cpu_properties[] = {
     DEFINE_PROP_UINT16("vlen", RISCVCPU, cfg.vlen, 128),
     DEFINE_PROP_UINT16("elen", RISCVCPU, cfg.elen, 64),
 
+    DEFINE_PROP_BOOL("svnapot", RISCVCPU, cfg.ext_svnapot, false),
+
     DEFINE_PROP_BOOL("zba", RISCVCPU, cfg.ext_zba, true),
     DEFINE_PROP_BOOL("zbb", RISCVCPU, cfg.ext_zbb, true),
     DEFINE_PROP_BOOL("zbc", RISCVCPU, cfg.ext_zbc, true),
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 6ea3944423..f6ff1c5012 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -489,6 +489,7 @@ typedef enum {
 #define PTE_A               0x040 /* Accessed */
 #define PTE_D               0x080 /* Dirty */
 #define PTE_SOFT            0x300 /* Reserved for Software */
+#define PTE_N               0x8000000000000000 /* NAPOT translation */
 
 /* Page table PPN shift amount */
 #define PTE_PPN_SHIFT       10
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index b820166dc5..6262d157e2 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -641,7 +641,7 @@ restart:
             return TRANSLATE_FAIL;
         } else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
             /* Inner PTE, continue walking */
-            if (pte & (PTE_D | PTE_A | PTE_U)) {
+            if (pte & (target_ulong)(PTE_D | PTE_A | PTE_U | PTE_N)) {
                 return TRANSLATE_FAIL;
             }
             base = ppn << PGSHIFT;
@@ -717,8 +717,19 @@ restart:
             /* for superpage mappings, make a fake leaf PTE for the TLB's
                benefit. */
             target_ulong vpn = addr >> PGSHIFT;
-            *physical = ((ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT) |
-                        (addr & ~TARGET_PAGE_MASK);
+
+            int napot_bits = 0;
+            if (cpu->cfg.ext_svnapot && (pte & (target_ulong)PTE_N)) {
+                napot_bits = ctzl(ppn) + 1;
+                if ((i != (levels - 1)) || (napot_bits != 4)) {
+                    return TRANSLATE_FAIL;
+                }
+            }
+
+            *physical = (((ppn & ~(((target_ulong)1 << napot_bits) - 1)) |
+                          (vpn & (((target_ulong)1 << napot_bits) - 1)) |
+                          (vpn & (((target_ulong)1 << ptshift) - 1))
+                        ) << PGSHIFT) | (addr & ~TARGET_PAGE_MASK);
 
             /* set permissions on the TLB entry */
             if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
-- 
2.17.1

[PATCH v7 4/5] target/riscv: add support for svinval extension

[Weiwei Li]

- sinval.vma, hinval.vvma and hinval.gvma do the same as sfence.vma, hfence.vvma and hfence.gvma except extension check
- do nothing other than extension check for sfence.w.inval and sfence.inval.ir

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>
---
 target/riscv/cpu.c                          |  1 +
 target/riscv/cpu.h                          |  1 +
 target/riscv/insn32.decode                  |  7 ++
 target/riscv/insn_trans/trans_svinval.c.inc | 75 +++++++++++++++++++++
 target/riscv/translate.c                    |  1 +
 5 files changed, 85 insertions(+)
 create mode 100644 target/riscv/insn_trans/trans_svinval.c.inc

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 8752fa1544..4efdc16780 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -729,6 +729,7 @@ static Property riscv_cpu_properties[] = {
     DEFINE_PROP_UINT16("vlen", RISCVCPU, cfg.vlen, 128),
     DEFINE_PROP_UINT16("elen", RISCVCPU, cfg.elen, 64),
 
+    DEFINE_PROP_BOOL("svinval", RISCVCPU, cfg.ext_svinval, false),
     DEFINE_PROP_BOOL("svnapot", RISCVCPU, cfg.ext_svnapot, false),
 
     DEFINE_PROP_BOOL("zba", RISCVCPU, cfg.ext_zba, true),
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 336fe8e3d5..eca7f6266d 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -341,6 +341,7 @@ struct RISCVCPU {
         bool ext_counters;
         bool ext_ifencei;
         bool ext_icsr;
+        bool ext_svinval;
         bool ext_svnapot;
         bool ext_svpbmt;
         bool ext_zfh;
diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode
index 5bbedc254c..1d3ff1efe1 100644
--- a/target/riscv/insn32.decode
+++ b/target/riscv/insn32.decode
@@ -809,3 +809,10 @@ fcvt_l_h   1100010  00010 ..... ... ..... 1010011 @r2_rm
 fcvt_lu_h  1100010  00011 ..... ... ..... 1010011 @r2_rm
 fcvt_h_l   1101010  00010 ..... ... ..... 1010011 @r2_rm
 fcvt_h_lu  1101010  00011 ..... ... ..... 1010011 @r2_rm
+
+# *** Svinval Standard Extension ***
+sinval_vma        0001011 ..... ..... 000 00000 1110011 @sfence_vma
+sfence_w_inval    0001100 00000 00000 000 00000 1110011
+sfence_inval_ir   0001100 00001 00000 000 00000 1110011
+hinval_vvma       0010011 ..... ..... 000 00000 1110011 @hfence_vvma
+hinval_gvma       0110011 ..... ..... 000 00000 1110011 @hfence_gvma
diff --git a/target/riscv/insn_trans/trans_svinval.c.inc b/target/riscv/insn_trans/trans_svinval.c.inc
new file mode 100644
index 0000000000..1dde665661
--- /dev/null
+++ b/target/riscv/insn_trans/trans_svinval.c.inc
@@ -0,0 +1,75 @@
+/*
+ * RISC-V translation routines for the Svinval Standard Instruction Set.
+ *
+ * Copyright (c) 2020-2021 PLCT lab
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define REQUIRE_SVINVAL(ctx) do {                    \
+    if (!RISCV_CPU(ctx->cs)->cfg.ext_svinval) {      \
+        return false;                                \
+    }                                                \
+} while (0)
+
+static bool trans_sinval_vma(DisasContext *ctx, arg_sinval_vma *a)
+{
+    REQUIRE_SVINVAL(ctx);
+    /* Do the same as sfence.vma currently */
+    REQUIRE_EXT(ctx, RVS);
+#ifndef CONFIG_USER_ONLY
+    gen_helper_tlb_flush(cpu_env);
+    return true;
+#endif
+    return false;
+}
+
+static bool trans_sfence_w_inval(DisasContext *ctx, arg_sfence_w_inval *a)
+{
+    REQUIRE_SVINVAL(ctx);
+    REQUIRE_EXT(ctx, RVS);
+    /* Do nothing currently */
+    return true;
+}
+
+static bool trans_sfence_inval_ir(DisasContext *ctx, arg_sfence_inval_ir *a)
+{
+    REQUIRE_SVINVAL(ctx);
+    REQUIRE_EXT(ctx, RVS);
+    /* Do nothing currently */
+    return true;
+}
+
+static bool trans_hinval_vvma(DisasContext *ctx, arg_hinval_vvma *a)
+{
+    REQUIRE_SVINVAL(ctx);
+    /* Do the same as hfence.vvma currently */
+    REQUIRE_EXT(ctx, RVH);
+#ifndef CONFIG_USER_ONLY
+    gen_helper_hyp_tlb_flush(cpu_env);
+    return true;
+#endif
+    return false;
+}
+
+static bool trans_hinval_gvma(DisasContext *ctx, arg_hinval_gvma *a)
+{
+    REQUIRE_SVINVAL(ctx);
+    /* Do the same as hfence.gvma currently */
+    REQUIRE_EXT(ctx, RVH);
+#ifndef CONFIG_USER_ONLY
+    gen_helper_hyp_gvma_tlb_flush(cpu_env);
+    return true;
+#endif
+    return false;
+}
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index f0bbe80875..cbf3b43348 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -855,6 +855,7 @@ static uint32_t opcode_at(DisasContextBase *dcbase, target_ulong pc)
 #include "insn_trans/trans_rvb.c.inc"
 #include "insn_trans/trans_rvzfh.c.inc"
 #include "insn_trans/trans_privileged.c.inc"
+#include "insn_trans/trans_svinval.c.inc"
 
 /* Include the auto-generated decoder for 16 bit insn */
 #include "decode-insn16.c.inc"
-- 
2.17.1

[PATCH v7 5/5] target/riscv: add support for svpbmt extension

[Weiwei Li]

- 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>
---
 target/riscv/cpu.c        | 1 +
 target/riscv/cpu_bits.h   | 2 ++
 target/riscv/cpu_helper.c | 4 +++-
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 4efdc16780..44c8229d3a 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -731,6 +731,7 @@ 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_bits.h b/target/riscv/cpu_bits.h
index f6ff1c5012..d3e4245964 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -489,7 +489,9 @@ typedef enum {
 #define PTE_A               0x040 /* Accessed */
 #define PTE_D               0x080 /* Dirty */
 #define PTE_SOFT            0x300 /* Reserved for Software */
+#define PTE_PBMT            0x6000000000000000 /* Page-based memory types */
 #define PTE_N               0x8000000000000000 /* 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_helper.c b/target/riscv/cpu_helper.c
index 6262d157e2..8398e4cbb6 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -639,9 +639,11 @@ restart:
         if (!(pte & PTE_V)) {
             /* Invalid PTE */
             return TRANSLATE_FAIL;
+        } else if (!cpu->cfg.ext_svpbmt && (pte & (target_ulong)PTE_PBMT)) {
+            return TRANSLATE_FAIL;
         } else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
             /* Inner PTE, continue walking */
-            if (pte & (target_ulong)(PTE_D | PTE_A | PTE_U | PTE_N)) {
+            if (pte & (target_ulong)(PTE_D | PTE_A | PTE_U | PTE_ATTR)) {
                 return TRANSLATE_FAIL;
             }
             base = ppn << PGSHIFT;
-- 
2.17.1

Re: [PATCH v7 1/5] target/riscv: Ignore reserved bits in PTE for RV64

[Alistair Francis]

On Fri, Jan 28, 2022 at 7:11 PM 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>
> Reviewed-by: Liu Zhiwei <zhiwei_liu@c-sky.com>
> Cc: Bin Meng <bmeng.cn@gmail.com>
> Cc: Alistair Francis <alistair.francis@wdc.com>
> ---
>  target/riscv/cpu.h        | 15 +++++++++++++++
>  target/riscv/cpu_bits.h   |  3 +++
>  target/riscv/cpu_helper.c | 14 +++++++++++++-
>  3 files changed, 31 insertions(+), 1 deletion(-)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 55635d68d5..336fe8e3d5 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -341,6 +341,8 @@ struct RISCVCPU {
>          bool ext_counters;
>          bool ext_ifencei;
>          bool ext_icsr;
> +        bool ext_svnapot;
> +        bool ext_svpbmt;
>          bool ext_zfh;
>          bool ext_zfhmin;
>          bool ext_zve32f;

Hello, thanks for the patches.

This looks good, but you might need to rebase it as there are patches
on list that move this into a different struct.

> @@ -495,6 +497,19 @@ static inline int riscv_cpu_xlen(CPURISCVState *env)
>      return 16 << env->xl;
>  }
>
> +#ifdef TARGET_RISCV32
> +#define riscv_cpu_sxl(env)  ((void)(env), MXL_RV32)
> +#else
> +static inline RISCVMXL riscv_cpu_sxl(CPURISCVState *env)
> +{
> +#ifdef CONFIG_USER_ONLY
> +    return env->misa_mxl;
> +#else
> +    return get_field(env->mstatus, MSTATUS64_SXL);
> +#endif
> +}
> +#endif
> +
>  /*
>   * Encode LMUL to lmul as follows:
>   *     LMUL    vlmul    lmul
> diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
> index 7c87433645..6ea3944423 100644
> --- a/target/riscv/cpu_bits.h
> +++ b/target/riscv/cpu_bits.h
> @@ -493,6 +493,9 @@ typedef enum {
>  /* Page table PPN shift amount */
>  #define PTE_PPN_SHIFT       10
>
> +/* Page table PPN mask */
> +#define PTE_PPN_MASK        0x3FFFFFFFFFFC00ULL
> +
>  /* Leaf page shift amount */
>  #define PGSHIFT             12
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 327a2c4f1d..5a1c0e239e 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -622,7 +622,19 @@ restart:
>              return TRANSLATE_FAIL;
>          }
>
> -        hwaddr ppn = pte >> PTE_PPN_SHIFT;
> +        hwaddr ppn;
> +        RISCVCPU *cpu = env_archcpu(env);

I know there is existing code in this function that does this, but
please don't initiate variables mid function. Can you move this to the
top of the function?

Otherwise:

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> +
> +        if (riscv_cpu_sxl(env) == MXL_RV32) {
> +            ppn = pte >> PTE_PPN_SHIFT;
> +        } else if (cpu->cfg.ext_svpbmt || cpu->cfg.ext_svnapot) {
> +            ppn = (pte & (target_ulong)PTE_PPN_MASK) >> PTE_PPN_SHIFT;
> +        } else {
> +            ppn = pte >> PTE_PPN_SHIFT;
> +            if ((pte & ~(target_ulong)PTE_PPN_MASK) >> PTE_PPN_SHIFT) {
> +                return TRANSLATE_FAIL;
> +            }
> +        }
>
>          if (!(pte & PTE_V)) {
>              /* Invalid PTE */
> --
> 2.17.1
>
>

Re: [PATCH v7 2/5] target/riscv: add PTE_A/PTE_D/PTE_U bits check for inner PTE

[Alistair Francis]

On Fri, Jan 28, 2022 at 7:06 PM Weiwei Li <liweiwei@iscas.ac.cn> wrote:
>
> For non-leaf PTEs, the D, A, and U bits are reserved for future standard use.
>
> 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>

Alistair

> ---
>  target/riscv/cpu_helper.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 5a1c0e239e..b820166dc5 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -641,6 +641,9 @@ restart:
>              return TRANSLATE_FAIL;
>          } else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
>              /* Inner PTE, continue walking */
> +            if (pte & (PTE_D | PTE_A | PTE_U)) {
> +                return TRANSLATE_FAIL;
> +            }
>              base = ppn << PGSHIFT;
>          } else if ((pte & (PTE_R | PTE_W | PTE_X)) == PTE_W) {
>              /* Reserved leaf PTE flags: PTE_W */
> --
> 2.17.1
>
>

Re: [PATCH v7 3/5] target/riscv: add support for svnapot extension

[Alistair Francis]

On Fri, Jan 28, 2022 at 6:57 PM Weiwei Li <liweiwei@iscas.ac.cn> wrote:
>
> - add PTE_N bit
> - add PTE_N bit check for inner PTE
> - update address translation to support 64KiB continuous region (napot_bits = 4)
>
> 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>
> ---
>  target/riscv/cpu.c        |  2 ++
>  target/riscv/cpu_bits.h   |  1 +
>  target/riscv/cpu_helper.c | 17 ++++++++++++++---
>  3 files changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 1cb0436187..8752fa1544 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -729,6 +729,8 @@ static Property riscv_cpu_properties[] = {
>      DEFINE_PROP_UINT16("vlen", RISCVCPU, cfg.vlen, 128),
>      DEFINE_PROP_UINT16("elen", RISCVCPU, cfg.elen, 64),
>
> +    DEFINE_PROP_BOOL("svnapot", RISCVCPU, cfg.ext_svnapot, false),
> +
>      DEFINE_PROP_BOOL("zba", RISCVCPU, cfg.ext_zba, true),
>      DEFINE_PROP_BOOL("zbb", RISCVCPU, cfg.ext_zbb, true),
>      DEFINE_PROP_BOOL("zbc", RISCVCPU, cfg.ext_zbc, true),
> diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
> index 6ea3944423..f6ff1c5012 100644
> --- a/target/riscv/cpu_bits.h
> +++ b/target/riscv/cpu_bits.h
> @@ -489,6 +489,7 @@ typedef enum {
>  #define PTE_A               0x040 /* Accessed */
>  #define PTE_D               0x080 /* Dirty */
>  #define PTE_SOFT            0x300 /* Reserved for Software */
> +#define PTE_N               0x8000000000000000 /* NAPOT translation */

This should be 0x8000000000000000ULL to avoid casting

>
>  /* Page table PPN shift amount */
>  #define PTE_PPN_SHIFT       10
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index b820166dc5..6262d157e2 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -641,7 +641,7 @@ restart:
>              return TRANSLATE_FAIL;
>          } else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
>              /* Inner PTE, continue walking */
> -            if (pte & (PTE_D | PTE_A | PTE_U)) {
> +            if (pte & (target_ulong)(PTE_D | PTE_A | PTE_U | PTE_N)) {
>                  return TRANSLATE_FAIL;
>              }
>              base = ppn << PGSHIFT;
> @@ -717,8 +717,19 @@ restart:
>              /* for superpage mappings, make a fake leaf PTE for the TLB's
>                 benefit. */
>              target_ulong vpn = addr >> PGSHIFT;
> -            *physical = ((ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT) |
> -                        (addr & ~TARGET_PAGE_MASK);
> +
> +            int napot_bits = 0;
> +            if (cpu->cfg.ext_svnapot && (pte & (target_ulong)PTE_N)) {
> +                napot_bits = ctzl(ppn) + 1;
> +                if ((i != (levels - 1)) || (napot_bits != 4)) {
> +                    return TRANSLATE_FAIL;
> +                }
> +            }
> +
> +            *physical = (((ppn & ~(((target_ulong)1 << napot_bits) - 1)) |

It might be clearer to create the mask as a variable, there are a lot
of brackets here :)

Alistair

> +                          (vpn & (((target_ulong)1 << napot_bits) - 1)) |
> +                          (vpn & (((target_ulong)1 << ptshift) - 1))
> +                        ) << PGSHIFT) | (addr & ~TARGET_PAGE_MASK);
>
>              /* set permissions on the TLB entry */
>              if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
> --
> 2.17.1
>
>

Re: [PATCH v7 1/5] target/riscv: Ignore reserved bits in PTE for RV64

[Weiwei Li]

在 2022/2/1 上午11:31, Alistair Francis 写道:
> On Fri, Jan 28, 2022 at 7:11 PM 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>
>> Reviewed-by: Liu Zhiwei <zhiwei_liu@c-sky.com>
>> Cc: Bin Meng <bmeng.cn@gmail.com>
>> Cc: Alistair Francis <alistair.francis@wdc.com>
>> ---
>>   target/riscv/cpu.h        | 15 +++++++++++++++
>>   target/riscv/cpu_bits.h   |  3 +++
>>   target/riscv/cpu_helper.c | 14 +++++++++++++-
>>   3 files changed, 31 insertions(+), 1 deletion(-)
>>
>> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
>> index 55635d68d5..336fe8e3d5 100644
>> --- a/target/riscv/cpu.h
>> +++ b/target/riscv/cpu.h
>> @@ -341,6 +341,8 @@ struct RISCVCPU {
>>           bool ext_counters;
>>           bool ext_ifencei;
>>           bool ext_icsr;
>> +        bool ext_svnapot;
>> +        bool ext_svpbmt;
>>           bool ext_zfh;
>>           bool ext_zfhmin;
>>           bool ext_zve32f;
> Hello, thanks for the patches.
>
> This looks good, but you might need to rebase it as there are patches
> on list that move this into a different struct.

Thanks for your review.

I'll rebase it.

>
>> @@ -495,6 +497,19 @@ static inline int riscv_cpu_xlen(CPURISCVState *env)
>>       return 16 << env->xl;
>>   }
>>
>> +#ifdef TARGET_RISCV32
>> +#define riscv_cpu_sxl(env)  ((void)(env), MXL_RV32)
>> +#else
>> +static inline RISCVMXL riscv_cpu_sxl(CPURISCVState *env)
>> +{
>> +#ifdef CONFIG_USER_ONLY
>> +    return env->misa_mxl;
>> +#else
>> +    return get_field(env->mstatus, MSTATUS64_SXL);
>> +#endif
>> +}
>> +#endif
>> +
>>   /*
>>    * Encode LMUL to lmul as follows:
>>    *     LMUL    vlmul    lmul
>> diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
>> index 7c87433645..6ea3944423 100644
>> --- a/target/riscv/cpu_bits.h
>> +++ b/target/riscv/cpu_bits.h
>> @@ -493,6 +493,9 @@ typedef enum {
>>   /* Page table PPN shift amount */
>>   #define PTE_PPN_SHIFT       10
>>
>> +/* Page table PPN mask */
>> +#define PTE_PPN_MASK        0x3FFFFFFFFFFC00ULL
>> +
>>   /* Leaf page shift amount */
>>   #define PGSHIFT             12
>>
>> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
>> index 327a2c4f1d..5a1c0e239e 100644
>> --- a/target/riscv/cpu_helper.c
>> +++ b/target/riscv/cpu_helper.c
>> @@ -622,7 +622,19 @@ restart:
>>               return TRANSLATE_FAIL;
>>           }
>>
>> -        hwaddr ppn = pte >> PTE_PPN_SHIFT;
>> +        hwaddr ppn;
>> +        RISCVCPU *cpu = env_archcpu(env);
> I know there is existing code in this function that does this, but
> please don't initiate variables mid function. Can you move this to the
> top of the function?
OK.
>
> Otherwise:
>
> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
>
> Alistair
>
>> +
>> +        if (riscv_cpu_sxl(env) == MXL_RV32) {
>> +            ppn = pte >> PTE_PPN_SHIFT;
>> +        } else if (cpu->cfg.ext_svpbmt || cpu->cfg.ext_svnapot) {
>> +            ppn = (pte & (target_ulong)PTE_PPN_MASK) >> PTE_PPN_SHIFT;
>> +        } else {
>> +            ppn = pte >> PTE_PPN_SHIFT;
>> +            if ((pte & ~(target_ulong)PTE_PPN_MASK) >> PTE_PPN_SHIFT) {
>> +                return TRANSLATE_FAIL;
>> +            }
>> +        }
>>
>>           if (!(pte & PTE_V)) {
>>               /* Invalid PTE */
>> --
>> 2.17.1
>>
>>

Re: [PATCH v7 3/5] target/riscv: add support for svnapot extension

[Weiwei Li]

在 2022/2/1 下午2:22, Alistair Francis 写道:
> On Fri, Jan 28, 2022 at 6:57 PM Weiwei Li <liweiwei@iscas.ac.cn> wrote:
>> - add PTE_N bit
>> - add PTE_N bit check for inner PTE
>> - update address translation to support 64KiB continuous region (napot_bits = 4)
>>
>> 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>
>> ---
>>   target/riscv/cpu.c        |  2 ++
>>   target/riscv/cpu_bits.h   |  1 +
>>   target/riscv/cpu_helper.c | 17 ++++++++++++++---
>>   3 files changed, 17 insertions(+), 3 deletions(-)
>>
>> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
>> index 1cb0436187..8752fa1544 100644
>> --- a/target/riscv/cpu.c
>> +++ b/target/riscv/cpu.c
>> @@ -729,6 +729,8 @@ static Property riscv_cpu_properties[] = {
>>       DEFINE_PROP_UINT16("vlen", RISCVCPU, cfg.vlen, 128),
>>       DEFINE_PROP_UINT16("elen", RISCVCPU, cfg.elen, 64),
>>
>> +    DEFINE_PROP_BOOL("svnapot", RISCVCPU, cfg.ext_svnapot, false),
>> +
>>       DEFINE_PROP_BOOL("zba", RISCVCPU, cfg.ext_zba, true),
>>       DEFINE_PROP_BOOL("zbb", RISCVCPU, cfg.ext_zbb, true),
>>       DEFINE_PROP_BOOL("zbc", RISCVCPU, cfg.ext_zbc, true),
>> diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
>> index 6ea3944423..f6ff1c5012 100644
>> --- a/target/riscv/cpu_bits.h
>> +++ b/target/riscv/cpu_bits.h
>> @@ -489,6 +489,7 @@ typedef enum {
>>   #define PTE_A               0x040 /* Accessed */
>>   #define PTE_D               0x080 /* Dirty */
>>   #define PTE_SOFT            0x300 /* Reserved for Software */
>> +#define PTE_N               0x8000000000000000 /* NAPOT translation */
> This should be 0x8000000000000000ULL to avoid casting
OK. I'll fix it.
>
>>   /* Page table PPN shift amount */
>>   #define PTE_PPN_SHIFT       10
>> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
>> index b820166dc5..6262d157e2 100644
>> --- a/target/riscv/cpu_helper.c
>> +++ b/target/riscv/cpu_helper.c
>> @@ -641,7 +641,7 @@ restart:
>>               return TRANSLATE_FAIL;
>>           } else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
>>               /* Inner PTE, continue walking */
>> -            if (pte & (PTE_D | PTE_A | PTE_U)) {
>> +            if (pte & (target_ulong)(PTE_D | PTE_A | PTE_U | PTE_N)) {
>>                   return TRANSLATE_FAIL;
>>               }
>>               base = ppn << PGSHIFT;
>> @@ -717,8 +717,19 @@ restart:
>>               /* for superpage mappings, make a fake leaf PTE for the TLB's
>>                  benefit. */
>>               target_ulong vpn = addr >> PGSHIFT;
>> -            *physical = ((ppn | (vpn & ((1L << ptshift) - 1))) << PGSHIFT) |
>> -                        (addr & ~TARGET_PAGE_MASK);
>> +
>> +            int napot_bits = 0;
>> +            if (cpu->cfg.ext_svnapot && (pte & (target_ulong)PTE_N)) {
>> +                napot_bits = ctzl(ppn) + 1;
>> +                if ((i != (levels - 1)) || (napot_bits != 4)) {
>> +                    return TRANSLATE_FAIL;
>> +                }
>> +            }
>> +
>> +            *physical = (((ppn & ~(((target_ulong)1 << napot_bits) - 1)) |
> It might be clearer to create the mask as a variable, there are a lot
> of brackets here :)
OK.
>
> Alistair
>
>> +                          (vpn & (((target_ulong)1 << napot_bits) - 1)) |
>> +                          (vpn & (((target_ulong)1 << ptshift) - 1))
>> +                        ) << PGSHIFT) | (addr & ~TARGET_PAGE_MASK);
>>
>>               /* set permissions on the TLB entry */
>>               if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
>> --
>> 2.17.1
>>
>>