[PATCH v3 0/7] target/riscv: Expose RV32 cpu to RV64 QEMU

[PATCH v3 0/7] target/riscv: Expose RV32 cpu to RV64 QEMU

[LIU Zhiwei]

This patch set aims to expose 32-bit RISC-V cpu to RV64 QEMU. Thus
qemu-system-riscv64 can directly boot a RV32 Linux.

This patch set has been tested with 6.9.0 Linux Image.
And add an avocado test in tests/avocado.

v3:
  Rebase to the master branch

v2:
  Remove the line that was inadvertently left in PATCH v1 4/6.
  Add an avocado test.

v1:
  https://mail.gnu.org/archive/html/qemu-riscv/2024-06/msg00501.html

TANG Tiancheng (7):
  target/riscv: Add fw_dynamic_info32 for booting RV32 OpenSBI
  target/riscv: Adjust PMP size for no-MMU RV64 QEMU running RV32
  target/riscv: Correct SXL return value for RV32 in RV64 QEMU
  target/riscv: Detect sxl to set bit width for RV32 in RV64
  target/riscv: Correct mcause/scause bit width for RV32 in RV64 QEMU
  target/riscv: Enable RV32 CPU support in RV64 QEMU
  tests/avocado: Add an avocado test for riscv64

 configs/targets/riscv64-softmmu.mak |  2 +-
 hw/riscv/boot.c                     | 35 +++++++++++++++++----------
 hw/riscv/sifive_u.c                 |  3 ++-
 include/hw/riscv/boot.h             |  4 +++-
 include/hw/riscv/boot_opensbi.h     | 29 ++++++++++++++++++++++
 target/riscv/cpu.c                  | 17 +++++++++----
 target/riscv/cpu.h                  |  5 +++-
 target/riscv/cpu_helper.c           | 25 +++++++++++++------
 target/riscv/pmp.c                  |  2 +-
 tests/avocado/boot_linux_console.py | 37 +++++++++++++++++++++++++++++
 10 files changed, 131 insertions(+), 28 deletions(-)

-- 
2.25.1

[PATCH v3 1/7] target/riscv: Add fw_dynamic_info32 for booting RV32 OpenSBI

[LIU Zhiwei]

From: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>

RV32 OpenSBI need a fw_dynamic_info parameter with 32-bit fields instead
of target_ulong.

In RV64 QEMU, target_ulong is 64. So it is not right for booting RV32 OpenSBI.
We create a fw_dynmaic_info32 struct for this purpose.

Signed-off-by: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
Reviewed-by: Liu Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
 hw/riscv/boot.c                 | 35 ++++++++++++++++++++++-----------
 hw/riscv/sifive_u.c             |  3 ++-
 include/hw/riscv/boot.h         |  4 +++-
 include/hw/riscv/boot_opensbi.h | 29 +++++++++++++++++++++++++++
 4 files changed, 57 insertions(+), 14 deletions(-)

diff --git a/hw/riscv/boot.c b/hw/riscv/boot.c
index 47281ca853..1a2c1ff9e0 100644
--- a/hw/riscv/boot.c
+++ b/hw/riscv/boot.c
@@ -342,27 +342,33 @@ void riscv_load_fdt(hwaddr fdt_addr, void *fdt)
                         rom_ptr_for_as(&address_space_memory, fdt_addr, fdtsize));
 }
 
-void riscv_rom_copy_firmware_info(MachineState *machine, hwaddr rom_base,
-                                  hwaddr rom_size, uint32_t reset_vec_size,
+void riscv_rom_copy_firmware_info(MachineState *machine,
+                                  RISCVHartArrayState *harts,
+                                  hwaddr rom_base, hwaddr rom_size,
+                                  uint32_t reset_vec_size,
                                   uint64_t kernel_entry)
 {
+    struct fw_dynamic_info32 dinfo32;
     struct fw_dynamic_info dinfo;
     size_t dinfo_len;
 
-    if (sizeof(dinfo.magic) == 4) {
-        dinfo.magic = cpu_to_le32(FW_DYNAMIC_INFO_MAGIC_VALUE);
-        dinfo.version = cpu_to_le32(FW_DYNAMIC_INFO_VERSION);
-        dinfo.next_mode = cpu_to_le32(FW_DYNAMIC_INFO_NEXT_MODE_S);
-        dinfo.next_addr = cpu_to_le32(kernel_entry);
+    if (riscv_is_32bit(harts)) {
+        dinfo32.magic = cpu_to_le32(FW_DYNAMIC_INFO_MAGIC_VALUE);
+        dinfo32.version = cpu_to_le32(FW_DYNAMIC_INFO_VERSION);
+        dinfo32.next_mode = cpu_to_le32(FW_DYNAMIC_INFO_NEXT_MODE_S);
+        dinfo32.next_addr = cpu_to_le32(kernel_entry);
+        dinfo32.options = 0;
+        dinfo32.boot_hart = 0;
+        dinfo_len = sizeof(dinfo32);
     } else {
         dinfo.magic = cpu_to_le64(FW_DYNAMIC_INFO_MAGIC_VALUE);
         dinfo.version = cpu_to_le64(FW_DYNAMIC_INFO_VERSION);
         dinfo.next_mode = cpu_to_le64(FW_DYNAMIC_INFO_NEXT_MODE_S);
         dinfo.next_addr = cpu_to_le64(kernel_entry);
+        dinfo.options = 0;
+        dinfo.boot_hart = 0;
+        dinfo_len = sizeof(dinfo);
     }
-    dinfo.options = 0;
-    dinfo.boot_hart = 0;
-    dinfo_len = sizeof(dinfo);
 
     /**
      * copy the dynamic firmware info. This information is specific to
@@ -374,7 +380,10 @@ void riscv_rom_copy_firmware_info(MachineState *machine, hwaddr rom_base,
         exit(1);
     }
 
-    rom_add_blob_fixed_as("mrom.finfo", &dinfo, dinfo_len,
+    rom_add_blob_fixed_as("mrom.finfo",
+                           riscv_is_32bit(harts) ?
+                           (void *)&dinfo32 : (void *)&dinfo,
+                           dinfo_len,
                            rom_base + reset_vec_size,
                            &address_space_memory);
 }
@@ -430,7 +439,9 @@ void riscv_setup_rom_reset_vec(MachineState *machine, RISCVHartArrayState *harts
     }
     rom_add_blob_fixed_as("mrom.reset", reset_vec, sizeof(reset_vec),
                           rom_base, &address_space_memory);
-    riscv_rom_copy_firmware_info(machine, rom_base, rom_size, sizeof(reset_vec),
+    riscv_rom_copy_firmware_info(machine, harts,
+                                 rom_base, rom_size,
+                                 sizeof(reset_vec),
                                  kernel_entry);
 }
 
diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
index af5f923f54..5010c3eadb 100644
--- a/hw/riscv/sifive_u.c
+++ b/hw/riscv/sifive_u.c
@@ -646,7 +646,8 @@ static void sifive_u_machine_init(MachineState *machine)
     rom_add_blob_fixed_as("mrom.reset", reset_vec, sizeof(reset_vec),
                           memmap[SIFIVE_U_DEV_MROM].base, &address_space_memory);
 
-    riscv_rom_copy_firmware_info(machine, memmap[SIFIVE_U_DEV_MROM].base,
+    riscv_rom_copy_firmware_info(machine, &s->soc.u_cpus,
+                                 memmap[SIFIVE_U_DEV_MROM].base,
                                  memmap[SIFIVE_U_DEV_MROM].size,
                                  sizeof(reset_vec), kernel_entry);
 
diff --git a/include/hw/riscv/boot.h b/include/hw/riscv/boot.h
index a2e4ae9cb0..806256d23f 100644
--- a/include/hw/riscv/boot.h
+++ b/include/hw/riscv/boot.h
@@ -56,7 +56,9 @@ void riscv_setup_rom_reset_vec(MachineState *machine, RISCVHartArrayState *harts
                                hwaddr rom_base, hwaddr rom_size,
                                uint64_t kernel_entry,
                                uint64_t fdt_load_addr);
-void riscv_rom_copy_firmware_info(MachineState *machine, hwaddr rom_base,
+void riscv_rom_copy_firmware_info(MachineState *machine,
+                                  RISCVHartArrayState *harts,
+                                  hwaddr rom_base,
                                   hwaddr rom_size,
                                   uint32_t reset_vec_size,
                                   uint64_t kernel_entry);
diff --git a/include/hw/riscv/boot_opensbi.h b/include/hw/riscv/boot_opensbi.h
index 1b749663dc..18664a174b 100644
--- a/include/hw/riscv/boot_opensbi.h
+++ b/include/hw/riscv/boot_opensbi.h
@@ -58,4 +58,33 @@ struct fw_dynamic_info {
     target_long boot_hart;
 };
 
+/** Representation dynamic info passed by previous booting stage */
+struct fw_dynamic_info32 {
+    /** Info magic */
+    int32_t magic;
+    /** Info version */
+    int32_t version;
+    /** Next booting stage address */
+    int32_t next_addr;
+    /** Next booting stage mode */
+    int32_t next_mode;
+    /** Options for OpenSBI library */
+    int32_t options;
+    /**
+     * Preferred boot HART id
+     *
+     * It is possible that the previous booting stage uses same link
+     * address as the FW_DYNAMIC firmware. In this case, the relocation
+     * lottery mechanism can potentially overwrite the previous booting
+     * stage while other HARTs are still running in the previous booting
+     * stage leading to boot-time crash. To avoid this boot-time crash,
+     * the previous booting stage can specify last HART that will jump
+     * to the FW_DYNAMIC firmware as the preferred boot HART.
+     *
+     * To avoid specifying a preferred boot HART, the previous booting
+     * stage can set it to -1UL which will force the FW_DYNAMIC firmware
+     * to use the relocation lottery mechanism.
+     */
+    int32_t boot_hart;
+};
 #endif
-- 
2.25.1

[PATCH v3 2/7] target/riscv: Adjust PMP size for no-MMU RV64 QEMU running RV32

[LIU Zhiwei]

From: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>

Ensure pmp_size is correctly determined using mxl for RV32
in RV64 QEMU.

Signed-off-by: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
Reviewed-by: Liu Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/pmp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c
index 9eea397e72..f65aa3dba7 100644
--- a/target/riscv/pmp.c
+++ b/target/riscv/pmp.c
@@ -326,7 +326,7 @@ bool pmp_hart_has_privs(CPURISCVState *env, hwaddr addr,
              */
             pmp_size = -(addr | TARGET_PAGE_MASK);
         } else {
-            pmp_size = sizeof(target_ulong);
+            pmp_size = 2UL << riscv_cpu_mxl(env);
         }
     } else {
         pmp_size = size;
-- 
2.25.1

[PATCH v3 3/7] target/riscv: Correct SXL return value for RV32 in RV64 QEMU

[LIU Zhiwei]

From: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>

Ensure that riscv_cpu_sxl returns MXL_RV32 when runningRV32 in an
RV64 QEMU.

Signed-off-by: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
Fixes: 05e6ca5e156 ("target/riscv: Ignore reserved bits in PTE for RV64")
Reviewed-by: Liu Zhiwei <zhiwei_liu@linux.alibaba.com>
---
 target/riscv/cpu.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 87742047ce..49de81be7e 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -693,8 +693,11 @@ static inline RISCVMXL riscv_cpu_sxl(CPURISCVState *env)
 #ifdef CONFIG_USER_ONLY
     return env->misa_mxl;
 #else
-    return get_field(env->mstatus, MSTATUS64_SXL);
+    if (env->misa_mxl != MXL_RV32) {
+        return get_field(env->mstatus, MSTATUS64_SXL);
+    }
 #endif
+    return MXL_RV32;
 }
 #endif
 
-- 
2.25.1

[PATCH v3 4/7] target/riscv: Detect sxl to set bit width for RV32 in RV64

[LIU Zhiwei]

From: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>

Ensure correct bit width based on sxl when running RV32 on RV64 QEMU.
This is required as MMU address translations run in S-mode.

Signed-off-by: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
Reviewed-by: Liu Zhiwei <zhiwei_liu@linux.alibaba.com>
---
 target/riscv/cpu_helper.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 6709622dd3..fa3b845c85 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -887,12 +887,14 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
 
     CPUState *cs = env_cpu(env);
     int va_bits = PGSHIFT + levels * ptidxbits + widened;
+    int sxlen = 16UL << riscv_cpu_sxl(env);
+    int sxlen_bytes = sxlen / 8;
 
     if (first_stage == true) {
         target_ulong mask, masked_msbs;
 
-        if (TARGET_LONG_BITS > (va_bits - 1)) {
-            mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
+        if (sxlen > (va_bits - 1)) {
+            mask = (1L << (sxlen - (va_bits - 1))) - 1;
         } else {
             mask = 0;
         }
@@ -961,7 +963,7 @@ restart:
 
         int pmp_prot;
         int pmp_ret = get_physical_address_pmp(env, &pmp_prot, pte_addr,
-                                               sizeof(target_ulong),
+                                               sxlen_bytes,
                                                MMU_DATA_LOAD, PRV_S);
         if (pmp_ret != TRANSLATE_SUCCESS) {
             return TRANSLATE_PMP_FAIL;
@@ -1113,7 +1115,7 @@ restart:
          *   it is no longer valid and we must re-walk the page table.
          */
         MemoryRegion *mr;
-        hwaddr l = sizeof(target_ulong), addr1;
+        hwaddr l = sxlen_bytes, addr1;
         mr = address_space_translate(cs->as, pte_addr, &addr1, &l,
                                      false, MEMTXATTRS_UNSPECIFIED);
         if (memory_region_is_ram(mr)) {
@@ -1125,7 +1127,12 @@ restart:
              */
             *pte_pa = pte = updated_pte;
 #else
-            target_ulong old_pte = qatomic_cmpxchg(pte_pa, pte, updated_pte);
+            target_ulong old_pte;
+            if (riscv_cpu_sxl(env) == MXL_RV32) {
+                old_pte = qatomic_cmpxchg((uint32_t *)pte_pa, pte, updated_pte);
+            } else {
+                old_pte = qatomic_cmpxchg(pte_pa, pte, updated_pte);
+            }
             if (old_pte != pte) {
                 goto restart;
             }
-- 
2.25.1

[PATCH v3 5/7] target/riscv: Correct mcause/scause bit width for RV32 in RV64 QEMU

[LIU Zhiwei]

From: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>

Ensure mcause high bit is correctly set by using 32-bit width for RV32
mode and 64-bit width for RV64 mode.

Signed-off-by: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
Reviewed-by: Liu Zhiwei <zhiwei_liu@linux.alibaba.com>
---
 target/riscv/cpu_helper.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index fa3b845c85..a79a03c7e0 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -1673,6 +1673,8 @@ void riscv_cpu_do_interrupt(CPUState *cs)
     target_ulong tinst = 0;
     target_ulong htval = 0;
     target_ulong mtval2 = 0;
+    int sxlen = 0;
+    int mxlen = 0;
 
     if (!async) {
         /* set tval to badaddr for traps with address information */
@@ -1799,7 +1801,8 @@ void riscv_cpu_do_interrupt(CPUState *cs)
         s = set_field(s, MSTATUS_SPP, env->priv);
         s = set_field(s, MSTATUS_SIE, 0);
         env->mstatus = s;
-        env->scause = cause | ((target_ulong)async << (TARGET_LONG_BITS - 1));
+        sxlen = 16UL << riscv_cpu_sxl(env);
+        env->scause = cause | ((target_ulong)async << (sxlen - 1));
         env->sepc = env->pc;
         env->stval = tval;
         env->htval = htval;
@@ -1830,7 +1833,8 @@ void riscv_cpu_do_interrupt(CPUState *cs)
         s = set_field(s, MSTATUS_MPP, env->priv);
         s = set_field(s, MSTATUS_MIE, 0);
         env->mstatus = s;
-        env->mcause = cause | ~(((target_ulong)-1) >> async);
+        mxlen = 16UL << riscv_cpu_mxl(env);
+        env->mcause = cause | ((target_ulong)async << (mxlen - 1));
         env->mepc = env->pc;
         env->mtval = tval;
         env->mtval2 = mtval2;
-- 
2.25.1

[PATCH v3 6/7] target/riscv: Enable RV32 CPU support in RV64 QEMU

[LIU Zhiwei]

From: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>

Add gdb XML files and adjust CPU initialization to allow running RV32 CPUs
in RV64 QEMU.

Signed-off-by: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
Reviewed-by: Liu Zhiwei <zhiwei_liu@linux.alibaba.com>
---
 configs/targets/riscv64-softmmu.mak |  2 +-
 target/riscv/cpu.c                  | 17 +++++++++++++----
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/configs/targets/riscv64-softmmu.mak b/configs/targets/riscv64-softmmu.mak
index 917980e63e..6c5de72e03 100644
--- a/configs/targets/riscv64-softmmu.mak
+++ b/configs/targets/riscv64-softmmu.mak
@@ -2,6 +2,6 @@ TARGET_ARCH=riscv64
 TARGET_BASE_ARCH=riscv
 TARGET_SUPPORTS_MTTCG=y
 TARGET_KVM_HAVE_GUEST_DEBUG=y
-TARGET_XML_FILES= gdb-xml/riscv-64bit-cpu.xml gdb-xml/riscv-32bit-fpu.xml gdb-xml/riscv-64bit-fpu.xml gdb-xml/riscv-64bit-virtual.xml
+TARGET_XML_FILES= gdb-xml/riscv-64bit-cpu.xml gdb-xml/riscv-32bit-fpu.xml gdb-xml/riscv-64bit-fpu.xml gdb-xml/riscv-64bit-virtual.xml gdb-xml/riscv-32bit-cpu.xml gdb-xml/riscv-32bit-virtual.xml
 # needed by boot.c
 TARGET_NEED_FDT=y
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index a2640cf259..fdd0f10aa5 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -630,8 +630,10 @@ static void rv64e_bare_cpu_init(Object *obj)
     riscv_cpu_set_misa_ext(env, RVE);
 }
 
-#else /* !TARGET_RISCV64 */
+#endif /* !TARGET_RISCV64 */
 
+#if defined(TARGET_RISCV32) || \
+    (defined(TARGET_RISCV64) && !defined(CONFIG_USER_ONLY))
 static void rv32_base_cpu_init(Object *obj)
 {
     RISCVCPU *cpu = RISCV_CPU(obj);
@@ -2944,6 +2946,13 @@ static const TypeInfo riscv_cpu_type_infos[] = {
 #if defined(TARGET_RISCV32)
     DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_ANY,       MXL_RV32,  riscv_any_cpu_init),
     DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_MAX,       MXL_RV32,  riscv_max_cpu_init),
+#elif defined(TARGET_RISCV64)
+    DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_ANY,       MXL_RV64,  riscv_any_cpu_init),
+    DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_MAX,       MXL_RV64,  riscv_max_cpu_init),
+#endif
+
+#if defined(TARGET_RISCV32) || \
+    (defined(TARGET_RISCV64) && !defined(CONFIG_USER_ONLY))
     DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_BASE32,    MXL_RV32,  rv32_base_cpu_init),
     DEFINE_VENDOR_CPU(TYPE_RISCV_CPU_IBEX,       MXL_RV32,  rv32_ibex_cpu_init),
     DEFINE_VENDOR_CPU(TYPE_RISCV_CPU_SIFIVE_E31, MXL_RV32,  rv32_sifive_e_cpu_init),
@@ -2951,9 +2960,9 @@ static const TypeInfo riscv_cpu_type_infos[] = {
     DEFINE_VENDOR_CPU(TYPE_RISCV_CPU_SIFIVE_U34, MXL_RV32,  rv32_sifive_u_cpu_init),
     DEFINE_BARE_CPU(TYPE_RISCV_CPU_RV32I,        MXL_RV32,  rv32i_bare_cpu_init),
     DEFINE_BARE_CPU(TYPE_RISCV_CPU_RV32E,        MXL_RV32,  rv32e_bare_cpu_init),
-#elif defined(TARGET_RISCV64)
-    DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_ANY,       MXL_RV64,  riscv_any_cpu_init),
-    DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_MAX,       MXL_RV64,  riscv_max_cpu_init),
+#endif
+
+#if defined(TARGET_RISCV64)
     DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_BASE64,    MXL_RV64,  rv64_base_cpu_init),
     DEFINE_VENDOR_CPU(TYPE_RISCV_CPU_SIFIVE_E51, MXL_RV64,  rv64_sifive_e_cpu_init),
     DEFINE_VENDOR_CPU(TYPE_RISCV_CPU_SIFIVE_U54, MXL_RV64,  rv64_sifive_u_cpu_init),
-- 
2.25.1

[PATCH v3 7/7] tests/avocado: Add an avocado test for riscv64

[LIU Zhiwei]

From: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>

To regularly test booting Linux with rv32 on QEMU RV64,
we have added a test to boot_linux_console.py to retrieve
cpuinfo and verify if it shows 'rv32' when using RV64 to
boot rv32 CPUs.

Signed-off-by: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
Reviewed-by: Liu Zhiwei <zhiwei_liu@linux.alibaba.com>
---
 tests/avocado/boot_linux_console.py | 37 +++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/tests/avocado/boot_linux_console.py b/tests/avocado/boot_linux_console.py
index c35fc5e9ba..193b03d970 100644
--- a/tests/avocado/boot_linux_console.py
+++ b/tests/avocado/boot_linux_console.py
@@ -12,6 +12,7 @@
 import lzma
 import gzip
 import shutil
+import time
 
 from avocado import skip
 from avocado import skipUnless
@@ -1545,3 +1546,39 @@ def test_xtensa_lx60(self):
         """
         tar_hash = '49e88d9933742f0164b60839886c9739cb7a0d34'
         self.do_test_advcal_2018('02', tar_hash, 'santas-sleigh-ride.elf')
+
+    def test_riscv64_virt_rv32i(self):
+        """
+        :avocado: tags=arch:riscv64
+        :avocado: tags=machine:virt
+        :avocado: tags=cpu:rv32
+        """
+        kernel_url = ('https://github.com/romanheros/rv32-linux/raw'
+                      '/master/Image32.xz')
+        kernel_hash = 'a7ced5c38722481e0821b7cd70719cf53e46c13b'
+        kernel_path_xz = self.fetch_asset(kernel_url, asset_hash=kernel_hash)
+
+        kernel_path =  os.path.join(self.workdir, 'kernel.riscv32')
+        archive.lzma_uncompress(kernel_path_xz, kernel_path)
+
+        rootfs_url = ('https://github.com/romanheros/rv32-linux/raw'
+                      '/master/rootfs.ext2.xz')
+        rootfs_hash = 'dc25ab9d4b233e8e0bcf7eb220d56fd2008fe263'
+        rootfs_path_xz = self.fetch_asset(rootfs_url, asset_hash=rootfs_hash)
+
+        rootfs_path =  os.path.join(self.workdir, 'rootfs.riscv32')
+        archive.lzma_uncompress(rootfs_path_xz, rootfs_path)
+
+        self.vm.set_console()
+        kernel_command_line = 'root=/dev/vda ro console=ttyS0'
+        self.vm.add_args('-kernel', kernel_path,
+                         '-append', kernel_command_line,
+                         '-drive', f'file={rootfs_path},format=raw,id=hd0',
+                         '-device', 'virtio-blk-device,drive=hd0',)
+        self.vm.launch()
+
+        console_pattern = 'Welcome to Buildroot'
+        self.wait_for_console_pattern(console_pattern)
+        exec_command(self, 'root')
+        time.sleep(0.1)
+        exec_command_and_wait_for_pattern(self, 'cat /proc/cpuinfo', 'rv32i')
-- 
2.25.1

Re: [PATCH v3 2/7] target/riscv: Adjust PMP size for no-MMU RV64 QEMU running RV32

[Richard Henderson]

On 7/3/24 07:49, LIU Zhiwei wrote:
> -            pmp_size = sizeof(target_ulong);
> +            pmp_size = 2UL << riscv_cpu_mxl(env);

UL is almost always incorrect in qemu, as 'long' has no specifically useful meaning.

In this case you can drop it completely.


r~

Re: [PATCH v3 5/7] target/riscv: Correct mcause/scause bit width for RV32 in RV64 QEMU

[Richard Henderson]

On 7/3/24 07:49, LIU Zhiwei wrote:
> +        sxlen = 16UL << riscv_cpu_sxl(env);

As before, drop UL.


r~

Re: [PATCH v3 3/7] target/riscv: Correct SXL return value for RV32 in RV64 QEMU

[Alistair Francis]

On Thu, Jul 4, 2024 at 12:53 AM LIU Zhiwei <zhiwei_liu@linux.alibaba.com> wrote:
>
> From: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
>
> Ensure that riscv_cpu_sxl returns MXL_RV32 when runningRV32 in an
> RV64 QEMU.
>
> Signed-off-by: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
> Fixes: 05e6ca5e156 ("target/riscv: Ignore reserved bits in PTE for RV64")
> Reviewed-by: Liu Zhiwei <zhiwei_liu@linux.alibaba.com>

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

Alistair

> ---
>  target/riscv/cpu.h | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 87742047ce..49de81be7e 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -693,8 +693,11 @@ static inline RISCVMXL riscv_cpu_sxl(CPURISCVState *env)
>  #ifdef CONFIG_USER_ONLY
>      return env->misa_mxl;
>  #else
> -    return get_field(env->mstatus, MSTATUS64_SXL);
> +    if (env->misa_mxl != MXL_RV32) {
> +        return get_field(env->mstatus, MSTATUS64_SXL);
> +    }
>  #endif
> +    return MXL_RV32;
>  }
>  #endif
>
> --
> 2.25.1
>
>

Re: [PATCH v3 4/7] target/riscv: Detect sxl to set bit width for RV32 in RV64

[Alistair Francis]

On Thu, Jul 4, 2024 at 12:54 AM LIU Zhiwei <zhiwei_liu@linux.alibaba.com> wrote:
>
> From: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
>
> Ensure correct bit width based on sxl when running RV32 on RV64 QEMU.
> This is required as MMU address translations run in S-mode.
>
> Signed-off-by: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
> Reviewed-by: Liu Zhiwei <zhiwei_liu@linux.alibaba.com>
> ---
>  target/riscv/cpu_helper.c | 17 ++++++++++++-----
>  1 file changed, 12 insertions(+), 5 deletions(-)
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 6709622dd3..fa3b845c85 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -887,12 +887,14 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
>
>      CPUState *cs = env_cpu(env);
>      int va_bits = PGSHIFT + levels * ptidxbits + widened;
> +    int sxlen = 16UL << riscv_cpu_sxl(env);

A leftover UL here

Otherwise:

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

Alistair

> +    int sxlen_bytes = sxlen / 8;
>
>      if (first_stage == true) {
>          target_ulong mask, masked_msbs;
>
> -        if (TARGET_LONG_BITS > (va_bits - 1)) {
> -            mask = (1L << (TARGET_LONG_BITS - (va_bits - 1))) - 1;
> +        if (sxlen > (va_bits - 1)) {
> +            mask = (1L << (sxlen - (va_bits - 1))) - 1;
>          } else {
>              mask = 0;
>          }
> @@ -961,7 +963,7 @@ restart:
>
>          int pmp_prot;
>          int pmp_ret = get_physical_address_pmp(env, &pmp_prot, pte_addr,
> -                                               sizeof(target_ulong),
> +                                               sxlen_bytes,
>                                                 MMU_DATA_LOAD, PRV_S);
>          if (pmp_ret != TRANSLATE_SUCCESS) {
>              return TRANSLATE_PMP_FAIL;
> @@ -1113,7 +1115,7 @@ restart:
>           *   it is no longer valid and we must re-walk the page table.
>           */
>          MemoryRegion *mr;
> -        hwaddr l = sizeof(target_ulong), addr1;
> +        hwaddr l = sxlen_bytes, addr1;
>          mr = address_space_translate(cs->as, pte_addr, &addr1, &l,
>                                       false, MEMTXATTRS_UNSPECIFIED);
>          if (memory_region_is_ram(mr)) {
> @@ -1125,7 +1127,12 @@ restart:
>               */
>              *pte_pa = pte = updated_pte;
>  #else
> -            target_ulong old_pte = qatomic_cmpxchg(pte_pa, pte, updated_pte);
> +            target_ulong old_pte;
> +            if (riscv_cpu_sxl(env) == MXL_RV32) {
> +                old_pte = qatomic_cmpxchg((uint32_t *)pte_pa, pte, updated_pte);
> +            } else {
> +                old_pte = qatomic_cmpxchg(pte_pa, pte, updated_pte);
> +            }
>              if (old_pte != pte) {
>                  goto restart;
>              }
> --
> 2.25.1
>
>

Re: [PATCH v3 6/7] target/riscv: Enable RV32 CPU support in RV64 QEMU

[Alistair Francis]

On Thu, Jul 4, 2024 at 12:55 AM LIU Zhiwei <zhiwei_liu@linux.alibaba.com> wrote:
>
> From: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
>
> Add gdb XML files and adjust CPU initialization to allow running RV32 CPUs
> in RV64 QEMU.
>
> Signed-off-by: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
> Reviewed-by: Liu Zhiwei <zhiwei_liu@linux.alibaba.com>

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

Alistair

> ---
>  configs/targets/riscv64-softmmu.mak |  2 +-
>  target/riscv/cpu.c                  | 17 +++++++++++++----
>  2 files changed, 14 insertions(+), 5 deletions(-)
>
> diff --git a/configs/targets/riscv64-softmmu.mak b/configs/targets/riscv64-softmmu.mak
> index 917980e63e..6c5de72e03 100644
> --- a/configs/targets/riscv64-softmmu.mak
> +++ b/configs/targets/riscv64-softmmu.mak
> @@ -2,6 +2,6 @@ TARGET_ARCH=riscv64
>  TARGET_BASE_ARCH=riscv
>  TARGET_SUPPORTS_MTTCG=y
>  TARGET_KVM_HAVE_GUEST_DEBUG=y
> -TARGET_XML_FILES= gdb-xml/riscv-64bit-cpu.xml gdb-xml/riscv-32bit-fpu.xml gdb-xml/riscv-64bit-fpu.xml gdb-xml/riscv-64bit-virtual.xml
> +TARGET_XML_FILES= gdb-xml/riscv-64bit-cpu.xml gdb-xml/riscv-32bit-fpu.xml gdb-xml/riscv-64bit-fpu.xml gdb-xml/riscv-64bit-virtual.xml gdb-xml/riscv-32bit-cpu.xml gdb-xml/riscv-32bit-virtual.xml
>  # needed by boot.c
>  TARGET_NEED_FDT=y
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index a2640cf259..fdd0f10aa5 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -630,8 +630,10 @@ static void rv64e_bare_cpu_init(Object *obj)
>      riscv_cpu_set_misa_ext(env, RVE);
>  }
>
> -#else /* !TARGET_RISCV64 */
> +#endif /* !TARGET_RISCV64 */
>
> +#if defined(TARGET_RISCV32) || \
> +    (defined(TARGET_RISCV64) && !defined(CONFIG_USER_ONLY))
>  static void rv32_base_cpu_init(Object *obj)
>  {
>      RISCVCPU *cpu = RISCV_CPU(obj);
> @@ -2944,6 +2946,13 @@ static const TypeInfo riscv_cpu_type_infos[] = {
>  #if defined(TARGET_RISCV32)
>      DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_ANY,       MXL_RV32,  riscv_any_cpu_init),
>      DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_MAX,       MXL_RV32,  riscv_max_cpu_init),
> +#elif defined(TARGET_RISCV64)
> +    DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_ANY,       MXL_RV64,  riscv_any_cpu_init),
> +    DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_MAX,       MXL_RV64,  riscv_max_cpu_init),
> +#endif
> +
> +#if defined(TARGET_RISCV32) || \
> +    (defined(TARGET_RISCV64) && !defined(CONFIG_USER_ONLY))
>      DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_BASE32,    MXL_RV32,  rv32_base_cpu_init),
>      DEFINE_VENDOR_CPU(TYPE_RISCV_CPU_IBEX,       MXL_RV32,  rv32_ibex_cpu_init),
>      DEFINE_VENDOR_CPU(TYPE_RISCV_CPU_SIFIVE_E31, MXL_RV32,  rv32_sifive_e_cpu_init),
> @@ -2951,9 +2960,9 @@ static const TypeInfo riscv_cpu_type_infos[] = {
>      DEFINE_VENDOR_CPU(TYPE_RISCV_CPU_SIFIVE_U34, MXL_RV32,  rv32_sifive_u_cpu_init),
>      DEFINE_BARE_CPU(TYPE_RISCV_CPU_RV32I,        MXL_RV32,  rv32i_bare_cpu_init),
>      DEFINE_BARE_CPU(TYPE_RISCV_CPU_RV32E,        MXL_RV32,  rv32e_bare_cpu_init),
> -#elif defined(TARGET_RISCV64)
> -    DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_ANY,       MXL_RV64,  riscv_any_cpu_init),
> -    DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_MAX,       MXL_RV64,  riscv_max_cpu_init),
> +#endif
> +
> +#if defined(TARGET_RISCV64)
>      DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_BASE64,    MXL_RV64,  rv64_base_cpu_init),
>      DEFINE_VENDOR_CPU(TYPE_RISCV_CPU_SIFIVE_E51, MXL_RV64,  rv64_sifive_e_cpu_init),
>      DEFINE_VENDOR_CPU(TYPE_RISCV_CPU_SIFIVE_U54, MXL_RV64,  rv64_sifive_u_cpu_init),
> --
> 2.25.1
>
>

Re: [PATCH v3 7/7] tests/avocado: Add an avocado test for riscv64

[Alistair Francis]

On Thu, Jul 4, 2024 at 12:55 AM LIU Zhiwei <zhiwei_liu@linux.alibaba.com> wrote:
>
> From: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
>
> To regularly test booting Linux with rv32 on QEMU RV64,
> we have added a test to boot_linux_console.py to retrieve
> cpuinfo and verify if it shows 'rv32' when using RV64 to
> boot rv32 CPUs.
>
> Signed-off-by: TANG Tiancheng <tangtiancheng.ttc@alibaba-inc.com>
> Reviewed-by: Liu Zhiwei <zhiwei_liu@linux.alibaba.com>

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

Alistair

> ---
>  tests/avocado/boot_linux_console.py | 37 +++++++++++++++++++++++++++++
>  1 file changed, 37 insertions(+)
>
> diff --git a/tests/avocado/boot_linux_console.py b/tests/avocado/boot_linux_console.py
> index c35fc5e9ba..193b03d970 100644
> --- a/tests/avocado/boot_linux_console.py
> +++ b/tests/avocado/boot_linux_console.py
> @@ -12,6 +12,7 @@
>  import lzma
>  import gzip
>  import shutil
> +import time
>
>  from avocado import skip
>  from avocado import skipUnless
> @@ -1545,3 +1546,39 @@ def test_xtensa_lx60(self):
>          """
>          tar_hash = '49e88d9933742f0164b60839886c9739cb7a0d34'
>          self.do_test_advcal_2018('02', tar_hash, 'santas-sleigh-ride.elf')
> +
> +    def test_riscv64_virt_rv32i(self):
> +        """
> +        :avocado: tags=arch:riscv64
> +        :avocado: tags=machine:virt
> +        :avocado: tags=cpu:rv32
> +        """
> +        kernel_url = ('https://github.com/romanheros/rv32-linux/raw'
> +                      '/master/Image32.xz')
> +        kernel_hash = 'a7ced5c38722481e0821b7cd70719cf53e46c13b'
> +        kernel_path_xz = self.fetch_asset(kernel_url, asset_hash=kernel_hash)
> +
> +        kernel_path =  os.path.join(self.workdir, 'kernel.riscv32')
> +        archive.lzma_uncompress(kernel_path_xz, kernel_path)
> +
> +        rootfs_url = ('https://github.com/romanheros/rv32-linux/raw'
> +                      '/master/rootfs.ext2.xz')
> +        rootfs_hash = 'dc25ab9d4b233e8e0bcf7eb220d56fd2008fe263'
> +        rootfs_path_xz = self.fetch_asset(rootfs_url, asset_hash=rootfs_hash)
> +
> +        rootfs_path =  os.path.join(self.workdir, 'rootfs.riscv32')
> +        archive.lzma_uncompress(rootfs_path_xz, rootfs_path)
> +
> +        self.vm.set_console()
> +        kernel_command_line = 'root=/dev/vda ro console=ttyS0'
> +        self.vm.add_args('-kernel', kernel_path,
> +                         '-append', kernel_command_line,
> +                         '-drive', f'file={rootfs_path},format=raw,id=hd0',
> +                         '-device', 'virtio-blk-device,drive=hd0',)
> +        self.vm.launch()
> +
> +        console_pattern = 'Welcome to Buildroot'
> +        self.wait_for_console_pattern(console_pattern)
> +        exec_command(self, 'root')
> +        time.sleep(0.1)
> +        exec_command_and_wait_for_pattern(self, 'cat /proc/cpuinfo', 'rv32i')
> --
> 2.25.1
>
>