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* [PATCH 0/3] util: Add cpuinfo support for riscv
@ 2024-06-27 18:03 Richard Henderson
  2024-06-27 18:03 ` [PATCH 1/3] util/cpuinfo-riscv: Support host/cpuinfo.h " Richard Henderson
                   ` (3 more replies)
  0 siblings, 4 replies; 17+ messages in thread
From: Richard Henderson @ 2024-06-27 18:03 UTC (permalink / raw)
  To: qemu-devel; +Cc: brad, Alistair.Francis, palmer, qemu-riscv

Do cpu feature detection in util, like other hosts.
Support the OpenBSD ucontext_t.
Support the Linux __riscv_hwprobe syscall.

r~

Richard Henderson (3):
  util/cpuinfo-riscv: Support host/cpuinfo.h for riscv
  util/cpuinfo-riscv: Support OpenBSD signal frame
  util/cpuinfo-riscv: Use linux __riscv_hwprobe syscall

 meson.build                       |   6 ++
 host/include/riscv/host/cpuinfo.h |  23 ++++++
 tcg/riscv/tcg-target.h            |  46 ++++++------
 util/cpuinfo-riscv.c              | 118 ++++++++++++++++++++++++++++++
 tcg/riscv/tcg-target.c.inc        |  84 ++-------------------
 util/meson.build                  |   2 +
 6 files changed, 178 insertions(+), 101 deletions(-)
 create mode 100644 host/include/riscv/host/cpuinfo.h
 create mode 100644 util/cpuinfo-riscv.c

-- 
2.34.1



^ permalink raw reply	[flat|nested] 17+ messages in thread

* [PATCH 1/3] util/cpuinfo-riscv: Support host/cpuinfo.h for riscv
  2024-06-27 18:03 [PATCH 0/3] util: Add cpuinfo support for riscv Richard Henderson
@ 2024-06-27 18:03 ` Richard Henderson
  2024-07-02 19:55   ` Philippe Mathieu-Daudé
                     ` (3 more replies)
  2024-06-27 18:03 ` [PATCH 2/3] util/cpuinfo-riscv: Support OpenBSD signal frame Richard Henderson
                   ` (2 subsequent siblings)
  3 siblings, 4 replies; 17+ messages in thread
From: Richard Henderson @ 2024-06-27 18:03 UTC (permalink / raw)
  To: qemu-devel; +Cc: brad, Alistair.Francis, palmer, qemu-riscv

Move detection code out of tcg, similar to other hosts.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 host/include/riscv/host/cpuinfo.h | 23 +++++++++
 tcg/riscv/tcg-target.h            | 46 ++++++++---------
 util/cpuinfo-riscv.c              | 85 +++++++++++++++++++++++++++++++
 tcg/riscv/tcg-target.c.inc        | 84 +++---------------------------
 util/meson.build                  |  2 +
 5 files changed, 139 insertions(+), 101 deletions(-)
 create mode 100644 host/include/riscv/host/cpuinfo.h
 create mode 100644 util/cpuinfo-riscv.c

diff --git a/host/include/riscv/host/cpuinfo.h b/host/include/riscv/host/cpuinfo.h
new file mode 100644
index 0000000000..2b00660e36
--- /dev/null
+++ b/host/include/riscv/host/cpuinfo.h
@@ -0,0 +1,23 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ * Host specific cpu identification for RISC-V.
+ */
+
+#ifndef HOST_CPUINFO_H
+#define HOST_CPUINFO_H
+
+#define CPUINFO_ALWAYS          (1u << 0)  /* so cpuinfo is nonzero */
+#define CPUINFO_ZBA             (1u << 1)
+#define CPUINFO_ZBB             (1u << 2)
+#define CPUINFO_ZICOND          (1u << 3)
+
+/* Initialized with a constructor. */
+extern unsigned cpuinfo;
+
+/*
+ * We cannot rely on constructor ordering, so other constructors must
+ * use the function interface rather than the variable above.
+ */
+unsigned cpuinfo_init(void);
+
+#endif /* HOST_CPUINFO_H */
diff --git a/tcg/riscv/tcg-target.h b/tcg/riscv/tcg-target.h
index 2c1b680b93..1a347eaf6e 100644
--- a/tcg/riscv/tcg-target.h
+++ b/tcg/riscv/tcg-target.h
@@ -25,6 +25,8 @@
 #ifndef RISCV_TCG_TARGET_H
 #define RISCV_TCG_TARGET_H
 
+#include "host/cpuinfo.h"
+
 #define TCG_TARGET_INSN_UNIT_SIZE 4
 #define TCG_TARGET_NB_REGS 32
 #define MAX_CODE_GEN_BUFFER_SIZE  ((size_t)-1)
@@ -80,18 +82,12 @@ typedef enum {
 #define TCG_TARGET_CALL_ARG_I128        TCG_CALL_ARG_NORMAL
 #define TCG_TARGET_CALL_RET_I128        TCG_CALL_RET_NORMAL
 
-#if defined(__riscv_arch_test) && defined(__riscv_zbb)
-# define have_zbb true
-#else
-extern bool have_zbb;
-#endif
-
 /* optional instructions */
 #define TCG_TARGET_HAS_negsetcond_i32   1
 #define TCG_TARGET_HAS_div_i32          1
 #define TCG_TARGET_HAS_rem_i32          1
 #define TCG_TARGET_HAS_div2_i32         0
-#define TCG_TARGET_HAS_rot_i32          have_zbb
+#define TCG_TARGET_HAS_rot_i32          (cpuinfo & CPUINFO_ZBB)
 #define TCG_TARGET_HAS_deposit_i32      0
 #define TCG_TARGET_HAS_extract_i32      0
 #define TCG_TARGET_HAS_sextract_i32     0
@@ -106,17 +102,17 @@ extern bool have_zbb;
 #define TCG_TARGET_HAS_ext16s_i32       1
 #define TCG_TARGET_HAS_ext8u_i32        1
 #define TCG_TARGET_HAS_ext16u_i32       1
-#define TCG_TARGET_HAS_bswap16_i32      have_zbb
-#define TCG_TARGET_HAS_bswap32_i32      have_zbb
+#define TCG_TARGET_HAS_bswap16_i32      (cpuinfo & CPUINFO_ZBB)
+#define TCG_TARGET_HAS_bswap32_i32      (cpuinfo & CPUINFO_ZBB)
 #define TCG_TARGET_HAS_not_i32          1
-#define TCG_TARGET_HAS_andc_i32         have_zbb
-#define TCG_TARGET_HAS_orc_i32          have_zbb
-#define TCG_TARGET_HAS_eqv_i32          have_zbb
+#define TCG_TARGET_HAS_andc_i32         (cpuinfo & CPUINFO_ZBB)
+#define TCG_TARGET_HAS_orc_i32          (cpuinfo & CPUINFO_ZBB)
+#define TCG_TARGET_HAS_eqv_i32          (cpuinfo & CPUINFO_ZBB)
 #define TCG_TARGET_HAS_nand_i32         0
 #define TCG_TARGET_HAS_nor_i32          0
-#define TCG_TARGET_HAS_clz_i32          have_zbb
-#define TCG_TARGET_HAS_ctz_i32          have_zbb
-#define TCG_TARGET_HAS_ctpop_i32        have_zbb
+#define TCG_TARGET_HAS_clz_i32          (cpuinfo & CPUINFO_ZBB)
+#define TCG_TARGET_HAS_ctz_i32          (cpuinfo & CPUINFO_ZBB)
+#define TCG_TARGET_HAS_ctpop_i32        (cpuinfo & CPUINFO_ZBB)
 #define TCG_TARGET_HAS_brcond2          1
 #define TCG_TARGET_HAS_setcond2         1
 #define TCG_TARGET_HAS_qemu_st8_i32     0
@@ -125,7 +121,7 @@ extern bool have_zbb;
 #define TCG_TARGET_HAS_div_i64          1
 #define TCG_TARGET_HAS_rem_i64          1
 #define TCG_TARGET_HAS_div2_i64         0
-#define TCG_TARGET_HAS_rot_i64          have_zbb
+#define TCG_TARGET_HAS_rot_i64          (cpuinfo & CPUINFO_ZBB)
 #define TCG_TARGET_HAS_deposit_i64      0
 #define TCG_TARGET_HAS_extract_i64      0
 #define TCG_TARGET_HAS_sextract_i64     0
@@ -137,18 +133,18 @@ extern bool have_zbb;
 #define TCG_TARGET_HAS_ext8u_i64        1
 #define TCG_TARGET_HAS_ext16u_i64       1
 #define TCG_TARGET_HAS_ext32u_i64       1
-#define TCG_TARGET_HAS_bswap16_i64      have_zbb
-#define TCG_TARGET_HAS_bswap32_i64      have_zbb
-#define TCG_TARGET_HAS_bswap64_i64      have_zbb
+#define TCG_TARGET_HAS_bswap16_i64      (cpuinfo & CPUINFO_ZBB)
+#define TCG_TARGET_HAS_bswap32_i64      (cpuinfo & CPUINFO_ZBB)
+#define TCG_TARGET_HAS_bswap64_i64      (cpuinfo & CPUINFO_ZBB)
 #define TCG_TARGET_HAS_not_i64          1
-#define TCG_TARGET_HAS_andc_i64         have_zbb
-#define TCG_TARGET_HAS_orc_i64          have_zbb
-#define TCG_TARGET_HAS_eqv_i64          have_zbb
+#define TCG_TARGET_HAS_andc_i64         (cpuinfo & CPUINFO_ZBB)
+#define TCG_TARGET_HAS_orc_i64          (cpuinfo & CPUINFO_ZBB)
+#define TCG_TARGET_HAS_eqv_i64          (cpuinfo & CPUINFO_ZBB)
 #define TCG_TARGET_HAS_nand_i64         0
 #define TCG_TARGET_HAS_nor_i64          0
-#define TCG_TARGET_HAS_clz_i64          have_zbb
-#define TCG_TARGET_HAS_ctz_i64          have_zbb
-#define TCG_TARGET_HAS_ctpop_i64        have_zbb
+#define TCG_TARGET_HAS_clz_i64          (cpuinfo & CPUINFO_ZBB)
+#define TCG_TARGET_HAS_ctz_i64          (cpuinfo & CPUINFO_ZBB)
+#define TCG_TARGET_HAS_ctpop_i64        (cpuinfo & CPUINFO_ZBB)
 #define TCG_TARGET_HAS_add2_i64         1
 #define TCG_TARGET_HAS_sub2_i64         1
 #define TCG_TARGET_HAS_mulu2_i64        0
diff --git a/util/cpuinfo-riscv.c b/util/cpuinfo-riscv.c
new file mode 100644
index 0000000000..6b97100620
--- /dev/null
+++ b/util/cpuinfo-riscv.c
@@ -0,0 +1,85 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ * Host specific cpu identification for RISC-V.
+ */
+
+#include "qemu/osdep.h"
+#include "host/cpuinfo.h"
+
+unsigned cpuinfo;
+static volatile sig_atomic_t got_sigill;
+
+static void sigill_handler(int signo, siginfo_t *si, void *data)
+{
+    /* Skip the faulty instruction */
+    ucontext_t *uc = (ucontext_t *)data;
+    uc->uc_mcontext.__gregs[REG_PC] += 4;
+
+    got_sigill = 1;
+}
+
+/* Called both as constructor and (possibly) via other constructors. */
+unsigned __attribute__((constructor)) cpuinfo_init(void)
+{
+    unsigned left = CPUINFO_ZBA | CPUINFO_ZBB | CPUINFO_ZICOND;
+    unsigned info = cpuinfo;
+
+    if (info) {
+        return info;
+    }
+
+    /* Test for compile-time settings. */
+#if defined(__riscv_arch_test) && defined(__riscv_zba)
+    info |= CPUINFO_ZBA;
+#endif
+#if defined(__riscv_arch_test) && defined(__riscv_zbb)
+    info |= CPUINFO_ZBB;
+#endif
+#if defined(__riscv_arch_test) && defined(__riscv_zicond)
+    info |= CPUINFO_ZICOND;
+#endif
+    left &= ~info;
+
+    if (left) {
+        struct sigaction sa_old, sa_new;
+
+        memset(&sa_new, 0, sizeof(sa_new));
+        sa_new.sa_flags = SA_SIGINFO;
+        sa_new.sa_sigaction = sigill_handler;
+        sigaction(SIGILL, &sa_new, &sa_old);
+
+        if (left & CPUINFO_ZBA) {
+            /* Probe for Zba: add.uw zero,zero,zero. */
+            got_sigill = 0;
+            asm volatile(".insn r 0x3b, 0, 0x04, zero, zero, zero"
+                         : : : "memory");
+            info |= !got_sigill * CPUINFO_ZBA;
+            left &= ~CPUINFO_ZBA;
+        }
+
+        if (left & CPUINFO_ZBB) {
+            /* Probe for Zba: andn zero,zero,zero. */
+            got_sigill = 0;
+            asm volatile(".insn r 0x33, 7, 0x20, zero, zero, zero"
+                         : : : "memory");
+            info |= !got_sigill * CPUINFO_ZBB;
+            left &= ~CPUINFO_ZBB;
+        }
+
+        if (left & CPUINFO_ZICOND) {
+            /* Probe for Zicond: czero.eqz zero,zero,zero. */
+            got_sigill = 0;
+            asm volatile(".insn r 0x33, 5, 0x07, zero, zero, zero"
+                         : : : "memory");
+            info |= !got_sigill * CPUINFO_ZICOND;
+            left &= ~CPUINFO_ZICOND;
+        }
+
+        sigaction(SIGILL, &sa_old, NULL);
+        assert(left == 0);
+    }
+
+    info |= CPUINFO_ALWAYS;
+    cpuinfo = info;
+    return info;
+}
diff --git a/tcg/riscv/tcg-target.c.inc b/tcg/riscv/tcg-target.c.inc
index 639363039b..d334857226 100644
--- a/tcg/riscv/tcg-target.c.inc
+++ b/tcg/riscv/tcg-target.c.inc
@@ -113,20 +113,6 @@ static const int tcg_target_call_iarg_regs[] = {
     TCG_REG_A7,
 };
 
-#ifndef have_zbb
-bool have_zbb;
-#endif
-#if defined(__riscv_arch_test) && defined(__riscv_zba)
-# define have_zba true
-#else
-static bool have_zba;
-#endif
-#if defined(__riscv_arch_test) && defined(__riscv_zicond)
-# define have_zicond true
-#else
-static bool have_zicond;
-#endif
-
 static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot)
 {
     tcg_debug_assert(kind == TCG_CALL_RET_NORMAL);
@@ -594,7 +580,7 @@ static void tcg_out_ext8u(TCGContext *s, TCGReg ret, TCGReg arg)
 
 static void tcg_out_ext16u(TCGContext *s, TCGReg ret, TCGReg arg)
 {
-    if (have_zbb) {
+    if (cpuinfo & CPUINFO_ZBB) {
         tcg_out_opc_reg(s, OPC_ZEXT_H, ret, arg, TCG_REG_ZERO);
     } else {
         tcg_out_opc_imm(s, OPC_SLLIW, ret, arg, 16);
@@ -604,7 +590,7 @@ static void tcg_out_ext16u(TCGContext *s, TCGReg ret, TCGReg arg)
 
 static void tcg_out_ext32u(TCGContext *s, TCGReg ret, TCGReg arg)
 {
-    if (have_zba) {
+    if (cpuinfo & CPUINFO_ZBA) {
         tcg_out_opc_reg(s, OPC_ADD_UW, ret, arg, TCG_REG_ZERO);
     } else {
         tcg_out_opc_imm(s, OPC_SLLI, ret, arg, 32);
@@ -614,7 +600,7 @@ static void tcg_out_ext32u(TCGContext *s, TCGReg ret, TCGReg arg)
 
 static void tcg_out_ext8s(TCGContext *s, TCGType type, TCGReg ret, TCGReg arg)
 {
-    if (have_zbb) {
+    if (cpuinfo & CPUINFO_ZBB) {
         tcg_out_opc_imm(s, OPC_SEXT_B, ret, arg, 0);
     } else {
         tcg_out_opc_imm(s, OPC_SLLIW, ret, arg, 24);
@@ -624,7 +610,7 @@ static void tcg_out_ext8s(TCGContext *s, TCGType type, TCGReg ret, TCGReg arg)
 
 static void tcg_out_ext16s(TCGContext *s, TCGType type, TCGReg ret, TCGReg arg)
 {
-    if (have_zbb) {
+    if (cpuinfo & CPUINFO_ZBB) {
         tcg_out_opc_imm(s, OPC_SEXT_H, ret, arg, 0);
     } else {
         tcg_out_opc_imm(s, OPC_SLLIW, ret, arg, 16);
@@ -1080,7 +1066,7 @@ static void tcg_out_movcond(TCGContext *s, TCGCond cond, TCGReg ret,
     int tmpflags;
     TCGReg t;
 
-    if (!have_zicond && (!c_cmp2 || cmp2 == 0)) {
+    if (!(cpuinfo & CPUINFO_ZICOND) && (!c_cmp2 || cmp2 == 0)) {
         tcg_out_movcond_br2(s, cond, ret, cmp1, cmp2,
                             val1, c_val1, val2, c_val2);
         return;
@@ -1089,7 +1075,7 @@ static void tcg_out_movcond(TCGContext *s, TCGCond cond, TCGReg ret,
     tmpflags = tcg_out_setcond_int(s, cond, TCG_REG_TMP0, cmp1, cmp2, c_cmp2);
     t = tmpflags & ~SETCOND_FLAGS;
 
-    if (have_zicond) {
+    if (cpuinfo & CPUINFO_ZICOND) {
         if (tmpflags & SETCOND_INV) {
             tcg_out_movcond_zicond(s, ret, t, val2, c_val2, val1, c_val1);
         } else {
@@ -1304,7 +1290,7 @@ static TCGLabelQemuLdst *prepare_host_addr(TCGContext *s, TCGReg *pbase,
         /* TLB Hit - translate address using addend.  */
         if (addr_type != TCG_TYPE_I32) {
             tcg_out_opc_reg(s, OPC_ADD, TCG_REG_TMP0, addr_reg, TCG_REG_TMP2);
-        } else if (have_zba) {
+        } else if (cpuinfo & CPUINFO_ZBA) {
             tcg_out_opc_reg(s, OPC_ADD_UW, TCG_REG_TMP0,
                             addr_reg, TCG_REG_TMP2);
         } else {
@@ -1335,7 +1321,7 @@ static TCGLabelQemuLdst *prepare_host_addr(TCGContext *s, TCGReg *pbase,
             if (addr_type != TCG_TYPE_I32) {
                 tcg_out_opc_reg(s, OPC_ADD, base, addr_reg,
                                 TCG_GUEST_BASE_REG);
-            } else if (have_zba) {
+            } else if (cpuinfo & CPUINFO_ZBA) {
                 tcg_out_opc_reg(s, OPC_ADD_UW, base, addr_reg,
                                 TCG_GUEST_BASE_REG);
             } else {
@@ -2110,62 +2096,8 @@ static void tcg_out_tb_start(TCGContext *s)
     /* nothing to do */
 }
 
-static volatile sig_atomic_t got_sigill;
-
-static void sigill_handler(int signo, siginfo_t *si, void *data)
-{
-    /* Skip the faulty instruction */
-    ucontext_t *uc = (ucontext_t *)data;
-    uc->uc_mcontext.__gregs[REG_PC] += 4;
-
-    got_sigill = 1;
-}
-
-static void tcg_target_detect_isa(void)
-{
-#if !defined(have_zba) || !defined(have_zbb) || !defined(have_zicond)
-    /*
-     * TODO: It is expected that this will be determinable via
-     * linux riscv_hwprobe syscall, not yet merged.
-     * In the meantime, test via sigill.
-     */
-
-    struct sigaction sa_old, sa_new;
-
-    memset(&sa_new, 0, sizeof(sa_new));
-    sa_new.sa_flags = SA_SIGINFO;
-    sa_new.sa_sigaction = sigill_handler;
-    sigaction(SIGILL, &sa_new, &sa_old);
-
-#ifndef have_zba
-    /* Probe for Zba: add.uw zero,zero,zero. */
-    got_sigill = 0;
-    asm volatile(".insn r 0x3b, 0, 0x04, zero, zero, zero" : : : "memory");
-    have_zba = !got_sigill;
-#endif
-
-#ifndef have_zbb
-    /* Probe for Zba: andn zero,zero,zero. */
-    got_sigill = 0;
-    asm volatile(".insn r 0x33, 7, 0x20, zero, zero, zero" : : : "memory");
-    have_zbb = !got_sigill;
-#endif
-
-#ifndef have_zicond
-    /* Probe for Zicond: czero.eqz zero,zero,zero. */
-    got_sigill = 0;
-    asm volatile(".insn r 0x33, 5, 0x07, zero, zero, zero" : : : "memory");
-    have_zicond = !got_sigill;
-#endif
-
-    sigaction(SIGILL, &sa_old, NULL);
-#endif
-}
-
 static void tcg_target_init(TCGContext *s)
 {
-    tcg_target_detect_isa();
-
     tcg_target_available_regs[TCG_TYPE_I32] = 0xffffffff;
     tcg_target_available_regs[TCG_TYPE_I64] = 0xffffffff;
 
diff --git a/util/meson.build b/util/meson.build
index 72b505df11..5d8bef9891 100644
--- a/util/meson.build
+++ b/util/meson.build
@@ -127,4 +127,6 @@ elif cpu == 'loongarch64'
   util_ss.add(files('cpuinfo-loongarch.c'))
 elif cpu in ['ppc', 'ppc64']
   util_ss.add(files('cpuinfo-ppc.c'))
+elif cpu in ['riscv32', 'riscv64']
+  util_ss.add(files('cpuinfo-riscv.c'))
 endif
-- 
2.34.1



^ permalink raw reply related	[flat|nested] 17+ messages in thread

* [PATCH 2/3] util/cpuinfo-riscv: Support OpenBSD signal frame
  2024-06-27 18:03 [PATCH 0/3] util: Add cpuinfo support for riscv Richard Henderson
  2024-06-27 18:03 ` [PATCH 1/3] util/cpuinfo-riscv: Support host/cpuinfo.h " Richard Henderson
@ 2024-06-27 18:03 ` Richard Henderson
  2024-07-02 19:58   ` Philippe Mathieu-Daudé
                     ` (2 more replies)
  2024-06-27 18:03 ` [PATCH 3/3] util/cpuinfo-riscv: Use linux __riscv_hwprobe syscall Richard Henderson
  2024-07-02 16:26 ` [PATCH 0/3] util: Add cpuinfo support for riscv Richard Henderson
  3 siblings, 3 replies; 17+ messages in thread
From: Richard Henderson @ 2024-06-27 18:03 UTC (permalink / raw)
  To: qemu-devel; +Cc: brad, Alistair.Francis, palmer, qemu-riscv

Reported-by: Brad Smith <brad@comstyle.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 util/cpuinfo-riscv.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/util/cpuinfo-riscv.c b/util/cpuinfo-riscv.c
index 6b97100620..abf799794f 100644
--- a/util/cpuinfo-riscv.c
+++ b/util/cpuinfo-riscv.c
@@ -13,7 +13,14 @@ static void sigill_handler(int signo, siginfo_t *si, void *data)
 {
     /* Skip the faulty instruction */
     ucontext_t *uc = (ucontext_t *)data;
+
+#ifdef __linux__
     uc->uc_mcontext.__gregs[REG_PC] += 4;
+#elif defined(__OpenBSD__)
+    uc->sc_sepc += 4;
+#else
+# error Unsupported OS
+#endif
 
     got_sigill = 1;
 }
-- 
2.34.1



^ permalink raw reply related	[flat|nested] 17+ messages in thread

* [PATCH 3/3] util/cpuinfo-riscv: Use linux __riscv_hwprobe syscall
  2024-06-27 18:03 [PATCH 0/3] util: Add cpuinfo support for riscv Richard Henderson
  2024-06-27 18:03 ` [PATCH 1/3] util/cpuinfo-riscv: Support host/cpuinfo.h " Richard Henderson
  2024-06-27 18:03 ` [PATCH 2/3] util/cpuinfo-riscv: Support OpenBSD signal frame Richard Henderson
@ 2024-06-27 18:03 ` Richard Henderson
  2024-07-02 22:15   ` Daniel Henrique Barboza
  2024-07-02 23:58   ` Alistair Francis
  2024-07-02 16:26 ` [PATCH 0/3] util: Add cpuinfo support for riscv Richard Henderson
  3 siblings, 2 replies; 17+ messages in thread
From: Richard Henderson @ 2024-06-27 18:03 UTC (permalink / raw)
  To: qemu-devel; +Cc: brad, Alistair.Francis, palmer, qemu-riscv

With recent linux kernels, there is a syscall to probe for various
ISA extensions.  These bits were phased in over several kernel
releases, so we still require checks for symbol availability.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 meson.build          |  6 ++++++
 util/cpuinfo-riscv.c | 26 ++++++++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/meson.build b/meson.build
index 97e00d6f59..58afd0125d 100644
--- a/meson.build
+++ b/meson.build
@@ -2837,6 +2837,12 @@ have_cpuid_h = cc.links('''
   }''')
 config_host_data.set('CONFIG_CPUID_H', have_cpuid_h)
 
+# Don't bother to advertise asm/hwprobe.h for old versions that do
+# not contain RISCV_HWPROBE_EXT_ZBA.
+config_host_data.set('CONFIG_ASM_HWPROBE_H',
+                     cc.has_header_symbol('asm/hwprobe.h',
+                                          'RISCV_HWPROBE_EXT_ZBA'))
+
 config_host_data.set('CONFIG_AVX2_OPT', get_option('avx2') \
   .require(have_cpuid_h, error_message: 'cpuid.h not available, cannot enable AVX2') \
   .require(cc.links('''
diff --git a/util/cpuinfo-riscv.c b/util/cpuinfo-riscv.c
index abf799794f..cf59ce83a3 100644
--- a/util/cpuinfo-riscv.c
+++ b/util/cpuinfo-riscv.c
@@ -6,6 +6,11 @@
 #include "qemu/osdep.h"
 #include "host/cpuinfo.h"
 
+#ifdef CONFIG_ASM_HWPROBE_H
+#include <asm/hwprobe.h>
+#include <sys/syscall.h>
+#endif
+
 unsigned cpuinfo;
 static volatile sig_atomic_t got_sigill;
 
@@ -47,6 +52,27 @@ unsigned __attribute__((constructor)) cpuinfo_init(void)
 #endif
     left &= ~info;
 
+#ifdef CONFIG_ASM_HWPROBE_H
+    if (left) {
+        /*
+         * TODO: glibc 2.40 will introduce <sys/hwprobe.h>, which
+         * provides __riscv_hwprobe and __riscv_hwprobe_one,
+         * which is a slightly cleaner interface.
+         */
+        struct riscv_hwprobe pair = { .key = RISCV_HWPROBE_KEY_IMA_EXT_0 };
+        if (syscall(__NR_riscv_hwprobe, &pair, 1, 0, NULL, 0) == 0
+            && pair.key >= 0) {
+            info |= pair.value & RISCV_HWPROBE_EXT_ZBA ? CPUINFO_ZBA : 0;
+            info |= pair.value & RISCV_HWPROBE_EXT_ZBB ? CPUINFO_ZBB : 0;
+            left &= ~(CPUINFO_ZBA | CPUINFO_ZBB);
+#ifdef RISCV_HWPROBE_EXT_ZICOND
+            info |= pair.value & RISCV_HWPROBE_EXT_ZICOND ? CPUINFO_ZICOND : 0;
+            left &= ~CPUINFO_ZICOND;
+#endif
+        }
+    }
+#endif /* CONFIG_ASM_HWPROBE_H */
+
     if (left) {
         struct sigaction sa_old, sa_new;
 
-- 
2.34.1



^ permalink raw reply related	[flat|nested] 17+ messages in thread

* Re: [PATCH 0/3] util: Add cpuinfo support for riscv
  2024-06-27 18:03 [PATCH 0/3] util: Add cpuinfo support for riscv Richard Henderson
                   ` (2 preceding siblings ...)
  2024-06-27 18:03 ` [PATCH 3/3] util/cpuinfo-riscv: Use linux __riscv_hwprobe syscall Richard Henderson
@ 2024-07-02 16:26 ` Richard Henderson
  3 siblings, 0 replies; 17+ messages in thread
From: Richard Henderson @ 2024-07-02 16:26 UTC (permalink / raw)
  To: qemu-devel
  Cc: brad, Alistair.Francis, palmer, qemu-riscv,
	Daniel Henrique Barboza, Bin Meng

Ping, particularly from the riscv folk.
I'm keen to get on Brad's *BSD patches in my next PR.

r~

On 6/27/24 11:03, Richard Henderson wrote:
> Do cpu feature detection in util, like other hosts.
> Support the OpenBSD ucontext_t.
> Support the Linux __riscv_hwprobe syscall.
> 
> r~
> 
> Richard Henderson (3):
>    util/cpuinfo-riscv: Support host/cpuinfo.h for riscv
>    util/cpuinfo-riscv: Support OpenBSD signal frame
>    util/cpuinfo-riscv: Use linux __riscv_hwprobe syscall
> 
>   meson.build                       |   6 ++
>   host/include/riscv/host/cpuinfo.h |  23 ++++++
>   tcg/riscv/tcg-target.h            |  46 ++++++------
>   util/cpuinfo-riscv.c              | 118 ++++++++++++++++++++++++++++++
>   tcg/riscv/tcg-target.c.inc        |  84 ++-------------------
>   util/meson.build                  |   2 +
>   6 files changed, 178 insertions(+), 101 deletions(-)
>   create mode 100644 host/include/riscv/host/cpuinfo.h
>   create mode 100644 util/cpuinfo-riscv.c
> 



^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH 1/3] util/cpuinfo-riscv: Support host/cpuinfo.h for riscv
  2024-06-27 18:03 ` [PATCH 1/3] util/cpuinfo-riscv: Support host/cpuinfo.h " Richard Henderson
@ 2024-07-02 19:55   ` Philippe Mathieu-Daudé
  2024-07-02 23:04     ` Richard Henderson
  2024-07-02 22:17   ` Daniel Henrique Barboza
                     ` (2 subsequent siblings)
  3 siblings, 1 reply; 17+ messages in thread
From: Philippe Mathieu-Daudé @ 2024-07-02 19:55 UTC (permalink / raw)
  To: Richard Henderson, qemu-devel; +Cc: brad, Alistair.Francis, palmer, qemu-riscv

On 27/6/24 20:03, Richard Henderson wrote:
> Move detection code out of tcg, similar to other hosts.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   host/include/riscv/host/cpuinfo.h | 23 +++++++++
>   tcg/riscv/tcg-target.h            | 46 ++++++++---------
>   util/cpuinfo-riscv.c              | 85 +++++++++++++++++++++++++++++++
>   tcg/riscv/tcg-target.c.inc        | 84 +++---------------------------
>   util/meson.build                  |  2 +
>   5 files changed, 139 insertions(+), 101 deletions(-)
>   create mode 100644 host/include/riscv/host/cpuinfo.h
>   create mode 100644 util/cpuinfo-riscv.c


> +/* Called both as constructor and (possibly) via other constructors. */
> +unsigned __attribute__((constructor)) cpuinfo_init(void)
> +{
> +    unsigned left = CPUINFO_ZBA | CPUINFO_ZBB | CPUINFO_ZICOND;
> +    unsigned info = cpuinfo;
> +
> +    if (info) {
> +        return info;
> +    }
> +
> +    /* Test for compile-time settings. */
> +#if defined(__riscv_arch_test) && defined(__riscv_zba)
> +    info |= CPUINFO_ZBA;
> +#endif
> +#if defined(__riscv_arch_test) && defined(__riscv_zbb)
> +    info |= CPUINFO_ZBB;
> +#endif
> +#if defined(__riscv_arch_test) && defined(__riscv_zicond)
> +    info |= CPUINFO_ZICOND;
> +#endif
> +    left &= ~info;
> +
> +    if (left) {
> +        struct sigaction sa_old, sa_new;
> +
> +        memset(&sa_new, 0, sizeof(sa_new));
> +        sa_new.sa_flags = SA_SIGINFO;
> +        sa_new.sa_sigaction = sigill_handler;
> +        sigaction(SIGILL, &sa_new, &sa_old);
> +
> +        if (left & CPUINFO_ZBA) {
> +            /* Probe for Zba: add.uw zero,zero,zero. */
> +            got_sigill = 0;
> +            asm volatile(".insn r 0x3b, 0, 0x04, zero, zero, zero"
> +                         : : : "memory");
> +            info |= !got_sigill * CPUINFO_ZBA;

A bit too optimized to my taste, 'if (sigill) info|=ZBA' would be 
simpler to follow. Otherwise,

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

> +            left &= ~CPUINFO_ZBA;
> +        }



^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH 2/3] util/cpuinfo-riscv: Support OpenBSD signal frame
  2024-06-27 18:03 ` [PATCH 2/3] util/cpuinfo-riscv: Support OpenBSD signal frame Richard Henderson
@ 2024-07-02 19:58   ` Philippe Mathieu-Daudé
  2024-07-02 22:16   ` Daniel Henrique Barboza
  2024-07-02 23:56   ` Alistair Francis
  2 siblings, 0 replies; 17+ messages in thread
From: Philippe Mathieu-Daudé @ 2024-07-02 19:58 UTC (permalink / raw)
  To: Richard Henderson, qemu-devel; +Cc: brad, Alistair.Francis, palmer, qemu-riscv

On 27/6/24 20:03, Richard Henderson wrote:
> Reported-by: Brad Smith <brad@comstyle.com>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   util/cpuinfo-riscv.c | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/util/cpuinfo-riscv.c b/util/cpuinfo-riscv.c
> index 6b97100620..abf799794f 100644
> --- a/util/cpuinfo-riscv.c
> +++ b/util/cpuinfo-riscv.c
> @@ -13,7 +13,14 @@ static void sigill_handler(int signo, siginfo_t *si, void *data)
>   {
>       /* Skip the faulty instruction */
>       ucontext_t *uc = (ucontext_t *)data;
> +
> +#ifdef __linux__
>       uc->uc_mcontext.__gregs[REG_PC] += 4;
> +#elif defined(__OpenBSD__)
> +    uc->sc_sepc += 4;

To the best of my non-existent OpenBSD knowledge reviewing corresponding
https://github.com/openbsd/src/blob/master/sys/arch/riscv64/riscv64/sig_machdep.c,
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

> +#else
> +# error Unsupported OS
> +#endif
>   
>       got_sigill = 1;
>   }



^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH 3/3] util/cpuinfo-riscv: Use linux __riscv_hwprobe syscall
  2024-06-27 18:03 ` [PATCH 3/3] util/cpuinfo-riscv: Use linux __riscv_hwprobe syscall Richard Henderson
@ 2024-07-02 22:15   ` Daniel Henrique Barboza
  2024-07-02 23:08     ` Richard Henderson
  2024-07-02 23:58   ` Alistair Francis
  1 sibling, 1 reply; 17+ messages in thread
From: Daniel Henrique Barboza @ 2024-07-02 22:15 UTC (permalink / raw)
  To: Richard Henderson, qemu-devel; +Cc: brad, Alistair.Francis, palmer, qemu-riscv



On 6/27/24 3:03 PM, Richard Henderson wrote:
> With recent linux kernels, there is a syscall to probe for various
> ISA extensions.  These bits were phased in over several kernel
> releases, so we still require checks for symbol availability.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   meson.build          |  6 ++++++
>   util/cpuinfo-riscv.c | 26 ++++++++++++++++++++++++++
>   2 files changed, 32 insertions(+)
> 
> diff --git a/meson.build b/meson.build
> index 97e00d6f59..58afd0125d 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -2837,6 +2837,12 @@ have_cpuid_h = cc.links('''
>     }''')
>   config_host_data.set('CONFIG_CPUID_H', have_cpuid_h)
>   
> +# Don't bother to advertise asm/hwprobe.h for old versions that do
> +# not contain RISCV_HWPROBE_EXT_ZBA.
> +config_host_data.set('CONFIG_ASM_HWPROBE_H',
> +                     cc.has_header_symbol('asm/hwprobe.h',
> +                                          'RISCV_HWPROBE_EXT_ZBA'))
> +

FWIW I looked around Linux and I think we can snapshot hwprobe support by
checking for RISCV_HWPROBE_KEY_IMA_EXT_0 (Linux commit 162e4df137c) if we
ever need hwprobe for exts earlier than ZBA (C and V).

Checking for ZBA is fine for this patch though.


Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>


>   config_host_data.set('CONFIG_AVX2_OPT', get_option('avx2') \
>     .require(have_cpuid_h, error_message: 'cpuid.h not available, cannot enable AVX2') \
>     .require(cc.links('''
> diff --git a/util/cpuinfo-riscv.c b/util/cpuinfo-riscv.c
> index abf799794f..cf59ce83a3 100644
> --- a/util/cpuinfo-riscv.c
> +++ b/util/cpuinfo-riscv.c
> @@ -6,6 +6,11 @@
>   #include "qemu/osdep.h"
>   #include "host/cpuinfo.h"
>   
> +#ifdef CONFIG_ASM_HWPROBE_H
> +#include <asm/hwprobe.h>
> +#include <sys/syscall.h>
> +#endif
> +
>   unsigned cpuinfo;
>   static volatile sig_atomic_t got_sigill;
>   
> @@ -47,6 +52,27 @@ unsigned __attribute__((constructor)) cpuinfo_init(void)
>   #endif
>       left &= ~info;
>   
> +#ifdef CONFIG_ASM_HWPROBE_H
> +    if (left) {
> +        /*
> +         * TODO: glibc 2.40 will introduce <sys/hwprobe.h>, which
> +         * provides __riscv_hwprobe and __riscv_hwprobe_one,
> +         * which is a slightly cleaner interface.
> +         */
> +        struct riscv_hwprobe pair = { .key = RISCV_HWPROBE_KEY_IMA_EXT_0 };
> +        if (syscall(__NR_riscv_hwprobe, &pair, 1, 0, NULL, 0) == 0
> +            && pair.key >= 0) {
> +            info |= pair.value & RISCV_HWPROBE_EXT_ZBA ? CPUINFO_ZBA : 0;
> +            info |= pair.value & RISCV_HWPROBE_EXT_ZBB ? CPUINFO_ZBB : 0;
> +            left &= ~(CPUINFO_ZBA | CPUINFO_ZBB);
> +#ifdef RISCV_HWPROBE_EXT_ZICOND
> +            info |= pair.value & RISCV_HWPROBE_EXT_ZICOND ? CPUINFO_ZICOND : 0;
> +            left &= ~CPUINFO_ZICOND;
> +#endif
> +        }
> +    }
> +#endif /* CONFIG_ASM_HWPROBE_H */
> +
>       if (left) {
>           struct sigaction sa_old, sa_new;
>   


^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH 2/3] util/cpuinfo-riscv: Support OpenBSD signal frame
  2024-06-27 18:03 ` [PATCH 2/3] util/cpuinfo-riscv: Support OpenBSD signal frame Richard Henderson
  2024-07-02 19:58   ` Philippe Mathieu-Daudé
@ 2024-07-02 22:16   ` Daniel Henrique Barboza
  2024-07-02 23:56   ` Alistair Francis
  2 siblings, 0 replies; 17+ messages in thread
From: Daniel Henrique Barboza @ 2024-07-02 22:16 UTC (permalink / raw)
  To: Richard Henderson, qemu-devel; +Cc: brad, Alistair.Francis, palmer, qemu-riscv



On 6/27/24 3:03 PM, Richard Henderson wrote:
> Reported-by: Brad Smith <brad@comstyle.com>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---

Acked-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>

>   util/cpuinfo-riscv.c | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/util/cpuinfo-riscv.c b/util/cpuinfo-riscv.c
> index 6b97100620..abf799794f 100644
> --- a/util/cpuinfo-riscv.c
> +++ b/util/cpuinfo-riscv.c
> @@ -13,7 +13,14 @@ static void sigill_handler(int signo, siginfo_t *si, void *data)
>   {
>       /* Skip the faulty instruction */
>       ucontext_t *uc = (ucontext_t *)data;
> +
> +#ifdef __linux__
>       uc->uc_mcontext.__gregs[REG_PC] += 4;
> +#elif defined(__OpenBSD__)
> +    uc->sc_sepc += 4;
> +#else
> +# error Unsupported OS
> +#endif
>   
>       got_sigill = 1;
>   }


^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH 1/3] util/cpuinfo-riscv: Support host/cpuinfo.h for riscv
  2024-06-27 18:03 ` [PATCH 1/3] util/cpuinfo-riscv: Support host/cpuinfo.h " Richard Henderson
  2024-07-02 19:55   ` Philippe Mathieu-Daudé
@ 2024-07-02 22:17   ` Daniel Henrique Barboza
  2024-07-02 23:56   ` Alistair Francis
  2024-07-03  8:46   ` LIU Zhiwei
  3 siblings, 0 replies; 17+ messages in thread
From: Daniel Henrique Barboza @ 2024-07-02 22:17 UTC (permalink / raw)
  To: Richard Henderson, qemu-devel; +Cc: brad, Alistair.Francis, palmer, qemu-riscv



On 6/27/24 3:03 PM, Richard Henderson wrote:
> Move detection code out of tcg, similar to other hosts.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---

Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>

>   host/include/riscv/host/cpuinfo.h | 23 +++++++++
>   tcg/riscv/tcg-target.h            | 46 ++++++++---------
>   util/cpuinfo-riscv.c              | 85 +++++++++++++++++++++++++++++++
>   tcg/riscv/tcg-target.c.inc        | 84 +++---------------------------
>   util/meson.build                  |  2 +
>   5 files changed, 139 insertions(+), 101 deletions(-)
>   create mode 100644 host/include/riscv/host/cpuinfo.h
>   create mode 100644 util/cpuinfo-riscv.c
> 
> diff --git a/host/include/riscv/host/cpuinfo.h b/host/include/riscv/host/cpuinfo.h
> new file mode 100644
> index 0000000000..2b00660e36
> --- /dev/null
> +++ b/host/include/riscv/host/cpuinfo.h
> @@ -0,0 +1,23 @@
> +/*
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + * Host specific cpu identification for RISC-V.
> + */
> +
> +#ifndef HOST_CPUINFO_H
> +#define HOST_CPUINFO_H
> +
> +#define CPUINFO_ALWAYS          (1u << 0)  /* so cpuinfo is nonzero */
> +#define CPUINFO_ZBA             (1u << 1)
> +#define CPUINFO_ZBB             (1u << 2)
> +#define CPUINFO_ZICOND          (1u << 3)
> +
> +/* Initialized with a constructor. */
> +extern unsigned cpuinfo;
> +
> +/*
> + * We cannot rely on constructor ordering, so other constructors must
> + * use the function interface rather than the variable above.
> + */
> +unsigned cpuinfo_init(void);
> +
> +#endif /* HOST_CPUINFO_H */
> diff --git a/tcg/riscv/tcg-target.h b/tcg/riscv/tcg-target.h
> index 2c1b680b93..1a347eaf6e 100644
> --- a/tcg/riscv/tcg-target.h
> +++ b/tcg/riscv/tcg-target.h
> @@ -25,6 +25,8 @@
>   #ifndef RISCV_TCG_TARGET_H
>   #define RISCV_TCG_TARGET_H
>   
> +#include "host/cpuinfo.h"
> +
>   #define TCG_TARGET_INSN_UNIT_SIZE 4
>   #define TCG_TARGET_NB_REGS 32
>   #define MAX_CODE_GEN_BUFFER_SIZE  ((size_t)-1)
> @@ -80,18 +82,12 @@ typedef enum {
>   #define TCG_TARGET_CALL_ARG_I128        TCG_CALL_ARG_NORMAL
>   #define TCG_TARGET_CALL_RET_I128        TCG_CALL_RET_NORMAL
>   
> -#if defined(__riscv_arch_test) && defined(__riscv_zbb)
> -# define have_zbb true
> -#else
> -extern bool have_zbb;
> -#endif
> -
>   /* optional instructions */
>   #define TCG_TARGET_HAS_negsetcond_i32   1
>   #define TCG_TARGET_HAS_div_i32          1
>   #define TCG_TARGET_HAS_rem_i32          1
>   #define TCG_TARGET_HAS_div2_i32         0
> -#define TCG_TARGET_HAS_rot_i32          have_zbb
> +#define TCG_TARGET_HAS_rot_i32          (cpuinfo & CPUINFO_ZBB)
>   #define TCG_TARGET_HAS_deposit_i32      0
>   #define TCG_TARGET_HAS_extract_i32      0
>   #define TCG_TARGET_HAS_sextract_i32     0
> @@ -106,17 +102,17 @@ extern bool have_zbb;
>   #define TCG_TARGET_HAS_ext16s_i32       1
>   #define TCG_TARGET_HAS_ext8u_i32        1
>   #define TCG_TARGET_HAS_ext16u_i32       1
> -#define TCG_TARGET_HAS_bswap16_i32      have_zbb
> -#define TCG_TARGET_HAS_bswap32_i32      have_zbb
> +#define TCG_TARGET_HAS_bswap16_i32      (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_bswap32_i32      (cpuinfo & CPUINFO_ZBB)
>   #define TCG_TARGET_HAS_not_i32          1
> -#define TCG_TARGET_HAS_andc_i32         have_zbb
> -#define TCG_TARGET_HAS_orc_i32          have_zbb
> -#define TCG_TARGET_HAS_eqv_i32          have_zbb
> +#define TCG_TARGET_HAS_andc_i32         (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_orc_i32          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_eqv_i32          (cpuinfo & CPUINFO_ZBB)
>   #define TCG_TARGET_HAS_nand_i32         0
>   #define TCG_TARGET_HAS_nor_i32          0
> -#define TCG_TARGET_HAS_clz_i32          have_zbb
> -#define TCG_TARGET_HAS_ctz_i32          have_zbb
> -#define TCG_TARGET_HAS_ctpop_i32        have_zbb
> +#define TCG_TARGET_HAS_clz_i32          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_ctz_i32          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_ctpop_i32        (cpuinfo & CPUINFO_ZBB)
>   #define TCG_TARGET_HAS_brcond2          1
>   #define TCG_TARGET_HAS_setcond2         1
>   #define TCG_TARGET_HAS_qemu_st8_i32     0
> @@ -125,7 +121,7 @@ extern bool have_zbb;
>   #define TCG_TARGET_HAS_div_i64          1
>   #define TCG_TARGET_HAS_rem_i64          1
>   #define TCG_TARGET_HAS_div2_i64         0
> -#define TCG_TARGET_HAS_rot_i64          have_zbb
> +#define TCG_TARGET_HAS_rot_i64          (cpuinfo & CPUINFO_ZBB)
>   #define TCG_TARGET_HAS_deposit_i64      0
>   #define TCG_TARGET_HAS_extract_i64      0
>   #define TCG_TARGET_HAS_sextract_i64     0
> @@ -137,18 +133,18 @@ extern bool have_zbb;
>   #define TCG_TARGET_HAS_ext8u_i64        1
>   #define TCG_TARGET_HAS_ext16u_i64       1
>   #define TCG_TARGET_HAS_ext32u_i64       1
> -#define TCG_TARGET_HAS_bswap16_i64      have_zbb
> -#define TCG_TARGET_HAS_bswap32_i64      have_zbb
> -#define TCG_TARGET_HAS_bswap64_i64      have_zbb
> +#define TCG_TARGET_HAS_bswap16_i64      (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_bswap32_i64      (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_bswap64_i64      (cpuinfo & CPUINFO_ZBB)
>   #define TCG_TARGET_HAS_not_i64          1
> -#define TCG_TARGET_HAS_andc_i64         have_zbb
> -#define TCG_TARGET_HAS_orc_i64          have_zbb
> -#define TCG_TARGET_HAS_eqv_i64          have_zbb
> +#define TCG_TARGET_HAS_andc_i64         (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_orc_i64          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_eqv_i64          (cpuinfo & CPUINFO_ZBB)
>   #define TCG_TARGET_HAS_nand_i64         0
>   #define TCG_TARGET_HAS_nor_i64          0
> -#define TCG_TARGET_HAS_clz_i64          have_zbb
> -#define TCG_TARGET_HAS_ctz_i64          have_zbb
> -#define TCG_TARGET_HAS_ctpop_i64        have_zbb
> +#define TCG_TARGET_HAS_clz_i64          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_ctz_i64          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_ctpop_i64        (cpuinfo & CPUINFO_ZBB)
>   #define TCG_TARGET_HAS_add2_i64         1
>   #define TCG_TARGET_HAS_sub2_i64         1
>   #define TCG_TARGET_HAS_mulu2_i64        0
> diff --git a/util/cpuinfo-riscv.c b/util/cpuinfo-riscv.c
> new file mode 100644
> index 0000000000..6b97100620
> --- /dev/null
> +++ b/util/cpuinfo-riscv.c
> @@ -0,0 +1,85 @@
> +/*
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + * Host specific cpu identification for RISC-V.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "host/cpuinfo.h"
> +
> +unsigned cpuinfo;
> +static volatile sig_atomic_t got_sigill;
> +
> +static void sigill_handler(int signo, siginfo_t *si, void *data)
> +{
> +    /* Skip the faulty instruction */
> +    ucontext_t *uc = (ucontext_t *)data;
> +    uc->uc_mcontext.__gregs[REG_PC] += 4;
> +
> +    got_sigill = 1;
> +}
> +
> +/* Called both as constructor and (possibly) via other constructors. */
> +unsigned __attribute__((constructor)) cpuinfo_init(void)
> +{
> +    unsigned left = CPUINFO_ZBA | CPUINFO_ZBB | CPUINFO_ZICOND;
> +    unsigned info = cpuinfo;
> +
> +    if (info) {
> +        return info;
> +    }
> +
> +    /* Test for compile-time settings. */
> +#if defined(__riscv_arch_test) && defined(__riscv_zba)
> +    info |= CPUINFO_ZBA;
> +#endif
> +#if defined(__riscv_arch_test) && defined(__riscv_zbb)
> +    info |= CPUINFO_ZBB;
> +#endif
> +#if defined(__riscv_arch_test) && defined(__riscv_zicond)
> +    info |= CPUINFO_ZICOND;
> +#endif
> +    left &= ~info;
> +
> +    if (left) {
> +        struct sigaction sa_old, sa_new;
> +
> +        memset(&sa_new, 0, sizeof(sa_new));
> +        sa_new.sa_flags = SA_SIGINFO;
> +        sa_new.sa_sigaction = sigill_handler;
> +        sigaction(SIGILL, &sa_new, &sa_old);
> +
> +        if (left & CPUINFO_ZBA) {
> +            /* Probe for Zba: add.uw zero,zero,zero. */
> +            got_sigill = 0;
> +            asm volatile(".insn r 0x3b, 0, 0x04, zero, zero, zero"
> +                         : : : "memory");
> +            info |= !got_sigill * CPUINFO_ZBA;
> +            left &= ~CPUINFO_ZBA;
> +        }
> +
> +        if (left & CPUINFO_ZBB) {
> +            /* Probe for Zba: andn zero,zero,zero. */
> +            got_sigill = 0;
> +            asm volatile(".insn r 0x33, 7, 0x20, zero, zero, zero"
> +                         : : : "memory");
> +            info |= !got_sigill * CPUINFO_ZBB;
> +            left &= ~CPUINFO_ZBB;
> +        }
> +
> +        if (left & CPUINFO_ZICOND) {
> +            /* Probe for Zicond: czero.eqz zero,zero,zero. */
> +            got_sigill = 0;
> +            asm volatile(".insn r 0x33, 5, 0x07, zero, zero, zero"
> +                         : : : "memory");
> +            info |= !got_sigill * CPUINFO_ZICOND;
> +            left &= ~CPUINFO_ZICOND;
> +        }
> +
> +        sigaction(SIGILL, &sa_old, NULL);
> +        assert(left == 0);
> +    }
> +
> +    info |= CPUINFO_ALWAYS;
> +    cpuinfo = info;
> +    return info;
> +}
> diff --git a/tcg/riscv/tcg-target.c.inc b/tcg/riscv/tcg-target.c.inc
> index 639363039b..d334857226 100644
> --- a/tcg/riscv/tcg-target.c.inc
> +++ b/tcg/riscv/tcg-target.c.inc
> @@ -113,20 +113,6 @@ static const int tcg_target_call_iarg_regs[] = {
>       TCG_REG_A7,
>   };
>   
> -#ifndef have_zbb
> -bool have_zbb;
> -#endif
> -#if defined(__riscv_arch_test) && defined(__riscv_zba)
> -# define have_zba true
> -#else
> -static bool have_zba;
> -#endif
> -#if defined(__riscv_arch_test) && defined(__riscv_zicond)
> -# define have_zicond true
> -#else
> -static bool have_zicond;
> -#endif
> -
>   static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot)
>   {
>       tcg_debug_assert(kind == TCG_CALL_RET_NORMAL);
> @@ -594,7 +580,7 @@ static void tcg_out_ext8u(TCGContext *s, TCGReg ret, TCGReg arg)
>   
>   static void tcg_out_ext16u(TCGContext *s, TCGReg ret, TCGReg arg)
>   {
> -    if (have_zbb) {
> +    if (cpuinfo & CPUINFO_ZBB) {
>           tcg_out_opc_reg(s, OPC_ZEXT_H, ret, arg, TCG_REG_ZERO);
>       } else {
>           tcg_out_opc_imm(s, OPC_SLLIW, ret, arg, 16);
> @@ -604,7 +590,7 @@ static void tcg_out_ext16u(TCGContext *s, TCGReg ret, TCGReg arg)
>   
>   static void tcg_out_ext32u(TCGContext *s, TCGReg ret, TCGReg arg)
>   {
> -    if (have_zba) {
> +    if (cpuinfo & CPUINFO_ZBA) {
>           tcg_out_opc_reg(s, OPC_ADD_UW, ret, arg, TCG_REG_ZERO);
>       } else {
>           tcg_out_opc_imm(s, OPC_SLLI, ret, arg, 32);
> @@ -614,7 +600,7 @@ static void tcg_out_ext32u(TCGContext *s, TCGReg ret, TCGReg arg)
>   
>   static void tcg_out_ext8s(TCGContext *s, TCGType type, TCGReg ret, TCGReg arg)
>   {
> -    if (have_zbb) {
> +    if (cpuinfo & CPUINFO_ZBB) {
>           tcg_out_opc_imm(s, OPC_SEXT_B, ret, arg, 0);
>       } else {
>           tcg_out_opc_imm(s, OPC_SLLIW, ret, arg, 24);
> @@ -624,7 +610,7 @@ static void tcg_out_ext8s(TCGContext *s, TCGType type, TCGReg ret, TCGReg arg)
>   
>   static void tcg_out_ext16s(TCGContext *s, TCGType type, TCGReg ret, TCGReg arg)
>   {
> -    if (have_zbb) {
> +    if (cpuinfo & CPUINFO_ZBB) {
>           tcg_out_opc_imm(s, OPC_SEXT_H, ret, arg, 0);
>       } else {
>           tcg_out_opc_imm(s, OPC_SLLIW, ret, arg, 16);
> @@ -1080,7 +1066,7 @@ static void tcg_out_movcond(TCGContext *s, TCGCond cond, TCGReg ret,
>       int tmpflags;
>       TCGReg t;
>   
> -    if (!have_zicond && (!c_cmp2 || cmp2 == 0)) {
> +    if (!(cpuinfo & CPUINFO_ZICOND) && (!c_cmp2 || cmp2 == 0)) {
>           tcg_out_movcond_br2(s, cond, ret, cmp1, cmp2,
>                               val1, c_val1, val2, c_val2);
>           return;
> @@ -1089,7 +1075,7 @@ static void tcg_out_movcond(TCGContext *s, TCGCond cond, TCGReg ret,
>       tmpflags = tcg_out_setcond_int(s, cond, TCG_REG_TMP0, cmp1, cmp2, c_cmp2);
>       t = tmpflags & ~SETCOND_FLAGS;
>   
> -    if (have_zicond) {
> +    if (cpuinfo & CPUINFO_ZICOND) {
>           if (tmpflags & SETCOND_INV) {
>               tcg_out_movcond_zicond(s, ret, t, val2, c_val2, val1, c_val1);
>           } else {
> @@ -1304,7 +1290,7 @@ static TCGLabelQemuLdst *prepare_host_addr(TCGContext *s, TCGReg *pbase,
>           /* TLB Hit - translate address using addend.  */
>           if (addr_type != TCG_TYPE_I32) {
>               tcg_out_opc_reg(s, OPC_ADD, TCG_REG_TMP0, addr_reg, TCG_REG_TMP2);
> -        } else if (have_zba) {
> +        } else if (cpuinfo & CPUINFO_ZBA) {
>               tcg_out_opc_reg(s, OPC_ADD_UW, TCG_REG_TMP0,
>                               addr_reg, TCG_REG_TMP2);
>           } else {
> @@ -1335,7 +1321,7 @@ static TCGLabelQemuLdst *prepare_host_addr(TCGContext *s, TCGReg *pbase,
>               if (addr_type != TCG_TYPE_I32) {
>                   tcg_out_opc_reg(s, OPC_ADD, base, addr_reg,
>                                   TCG_GUEST_BASE_REG);
> -            } else if (have_zba) {
> +            } else if (cpuinfo & CPUINFO_ZBA) {
>                   tcg_out_opc_reg(s, OPC_ADD_UW, base, addr_reg,
>                                   TCG_GUEST_BASE_REG);
>               } else {
> @@ -2110,62 +2096,8 @@ static void tcg_out_tb_start(TCGContext *s)
>       /* nothing to do */
>   }
>   
> -static volatile sig_atomic_t got_sigill;
> -
> -static void sigill_handler(int signo, siginfo_t *si, void *data)
> -{
> -    /* Skip the faulty instruction */
> -    ucontext_t *uc = (ucontext_t *)data;
> -    uc->uc_mcontext.__gregs[REG_PC] += 4;
> -
> -    got_sigill = 1;
> -}
> -
> -static void tcg_target_detect_isa(void)
> -{
> -#if !defined(have_zba) || !defined(have_zbb) || !defined(have_zicond)
> -    /*
> -     * TODO: It is expected that this will be determinable via
> -     * linux riscv_hwprobe syscall, not yet merged.
> -     * In the meantime, test via sigill.
> -     */
> -
> -    struct sigaction sa_old, sa_new;
> -
> -    memset(&sa_new, 0, sizeof(sa_new));
> -    sa_new.sa_flags = SA_SIGINFO;
> -    sa_new.sa_sigaction = sigill_handler;
> -    sigaction(SIGILL, &sa_new, &sa_old);
> -
> -#ifndef have_zba
> -    /* Probe for Zba: add.uw zero,zero,zero. */
> -    got_sigill = 0;
> -    asm volatile(".insn r 0x3b, 0, 0x04, zero, zero, zero" : : : "memory");
> -    have_zba = !got_sigill;
> -#endif
> -
> -#ifndef have_zbb
> -    /* Probe for Zba: andn zero,zero,zero. */
> -    got_sigill = 0;
> -    asm volatile(".insn r 0x33, 7, 0x20, zero, zero, zero" : : : "memory");
> -    have_zbb = !got_sigill;
> -#endif
> -
> -#ifndef have_zicond
> -    /* Probe for Zicond: czero.eqz zero,zero,zero. */
> -    got_sigill = 0;
> -    asm volatile(".insn r 0x33, 5, 0x07, zero, zero, zero" : : : "memory");
> -    have_zicond = !got_sigill;
> -#endif
> -
> -    sigaction(SIGILL, &sa_old, NULL);
> -#endif
> -}
> -
>   static void tcg_target_init(TCGContext *s)
>   {
> -    tcg_target_detect_isa();
> -
>       tcg_target_available_regs[TCG_TYPE_I32] = 0xffffffff;
>       tcg_target_available_regs[TCG_TYPE_I64] = 0xffffffff;
>   
> diff --git a/util/meson.build b/util/meson.build
> index 72b505df11..5d8bef9891 100644
> --- a/util/meson.build
> +++ b/util/meson.build
> @@ -127,4 +127,6 @@ elif cpu == 'loongarch64'
>     util_ss.add(files('cpuinfo-loongarch.c'))
>   elif cpu in ['ppc', 'ppc64']
>     util_ss.add(files('cpuinfo-ppc.c'))
> +elif cpu in ['riscv32', 'riscv64']
> +  util_ss.add(files('cpuinfo-riscv.c'))
>   endif


^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH 1/3] util/cpuinfo-riscv: Support host/cpuinfo.h for riscv
  2024-07-02 19:55   ` Philippe Mathieu-Daudé
@ 2024-07-02 23:04     ` Richard Henderson
  2024-07-03  7:32       ` Philippe Mathieu-Daudé
  0 siblings, 1 reply; 17+ messages in thread
From: Richard Henderson @ 2024-07-02 23:04 UTC (permalink / raw)
  To: Philippe Mathieu-Daudé, qemu-devel
  Cc: brad, Alistair.Francis, palmer, qemu-riscv

On 7/2/24 12:55, Philippe Mathieu-Daudé wrote:
> On 27/6/24 20:03, Richard Henderson wrote:
...
>> +            info |= !got_sigill * CPUINFO_ZBA;
> 
> A bit too optimized to my taste, 'if (sigill) info|=ZBA' would be simpler to follow. 

I switched to "info |= got_sigill ? 0 : CPUINFO_ZBA".

> Otherwise,
> 
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Thanks.


r~


^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH 3/3] util/cpuinfo-riscv: Use linux __riscv_hwprobe syscall
  2024-07-02 22:15   ` Daniel Henrique Barboza
@ 2024-07-02 23:08     ` Richard Henderson
  0 siblings, 0 replies; 17+ messages in thread
From: Richard Henderson @ 2024-07-02 23:08 UTC (permalink / raw)
  To: Daniel Henrique Barboza, qemu-devel
  Cc: brad, Alistair.Francis, palmer, qemu-riscv

On 7/2/24 15:15, Daniel Henrique Barboza wrote:
> 
> 
> On 6/27/24 3:03 PM, Richard Henderson wrote:
>> With recent linux kernels, there is a syscall to probe for various
>> ISA extensions.  These bits were phased in over several kernel
>> releases, so we still require checks for symbol availability.
>>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>> ---
>>   meson.build          |  6 ++++++
>>   util/cpuinfo-riscv.c | 26 ++++++++++++++++++++++++++
>>   2 files changed, 32 insertions(+)
>>
>> diff --git a/meson.build b/meson.build
>> index 97e00d6f59..58afd0125d 100644
>> --- a/meson.build
>> +++ b/meson.build
>> @@ -2837,6 +2837,12 @@ have_cpuid_h = cc.links('''
>>     }''')
>>   config_host_data.set('CONFIG_CPUID_H', have_cpuid_h)
>> +# Don't bother to advertise asm/hwprobe.h for old versions that do
>> +# not contain RISCV_HWPROBE_EXT_ZBA.
>> +config_host_data.set('CONFIG_ASM_HWPROBE_H',
>> +                     cc.has_header_symbol('asm/hwprobe.h',
>> +                                          'RISCV_HWPROBE_EXT_ZBA'))
>> +
> 
> FWIW I looked around Linux and I think we can snapshot hwprobe support by
> checking for RISCV_HWPROBE_KEY_IMA_EXT_0 (Linux commit 162e4df137c) if we
> ever need hwprobe for exts earlier than ZBA (C and V).

Sure.  It'll take some effort to use RVV for TCG vector operations.  :-)

> 
> Checking for ZBA is fine for this patch though.
> 
> 
> Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>

Thanks.


r~


^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH 1/3] util/cpuinfo-riscv: Support host/cpuinfo.h for riscv
  2024-06-27 18:03 ` [PATCH 1/3] util/cpuinfo-riscv: Support host/cpuinfo.h " Richard Henderson
  2024-07-02 19:55   ` Philippe Mathieu-Daudé
  2024-07-02 22:17   ` Daniel Henrique Barboza
@ 2024-07-02 23:56   ` Alistair Francis
  2024-07-03  8:46   ` LIU Zhiwei
  3 siblings, 0 replies; 17+ messages in thread
From: Alistair Francis @ 2024-07-02 23:56 UTC (permalink / raw)
  To: Richard Henderson; +Cc: qemu-devel, brad, Alistair.Francis, palmer, qemu-riscv

On Fri, Jun 28, 2024 at 4:06 AM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Move detection code out of tcg, similar to other hosts.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

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

Alistair

> ---
>  host/include/riscv/host/cpuinfo.h | 23 +++++++++
>  tcg/riscv/tcg-target.h            | 46 ++++++++---------
>  util/cpuinfo-riscv.c              | 85 +++++++++++++++++++++++++++++++
>  tcg/riscv/tcg-target.c.inc        | 84 +++---------------------------
>  util/meson.build                  |  2 +
>  5 files changed, 139 insertions(+), 101 deletions(-)
>  create mode 100644 host/include/riscv/host/cpuinfo.h
>  create mode 100644 util/cpuinfo-riscv.c
>
> diff --git a/host/include/riscv/host/cpuinfo.h b/host/include/riscv/host/cpuinfo.h
> new file mode 100644
> index 0000000000..2b00660e36
> --- /dev/null
> +++ b/host/include/riscv/host/cpuinfo.h
> @@ -0,0 +1,23 @@
> +/*
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + * Host specific cpu identification for RISC-V.
> + */
> +
> +#ifndef HOST_CPUINFO_H
> +#define HOST_CPUINFO_H
> +
> +#define CPUINFO_ALWAYS          (1u << 0)  /* so cpuinfo is nonzero */
> +#define CPUINFO_ZBA             (1u << 1)
> +#define CPUINFO_ZBB             (1u << 2)
> +#define CPUINFO_ZICOND          (1u << 3)
> +
> +/* Initialized with a constructor. */
> +extern unsigned cpuinfo;
> +
> +/*
> + * We cannot rely on constructor ordering, so other constructors must
> + * use the function interface rather than the variable above.
> + */
> +unsigned cpuinfo_init(void);
> +
> +#endif /* HOST_CPUINFO_H */
> diff --git a/tcg/riscv/tcg-target.h b/tcg/riscv/tcg-target.h
> index 2c1b680b93..1a347eaf6e 100644
> --- a/tcg/riscv/tcg-target.h
> +++ b/tcg/riscv/tcg-target.h
> @@ -25,6 +25,8 @@
>  #ifndef RISCV_TCG_TARGET_H
>  #define RISCV_TCG_TARGET_H
>
> +#include "host/cpuinfo.h"
> +
>  #define TCG_TARGET_INSN_UNIT_SIZE 4
>  #define TCG_TARGET_NB_REGS 32
>  #define MAX_CODE_GEN_BUFFER_SIZE  ((size_t)-1)
> @@ -80,18 +82,12 @@ typedef enum {
>  #define TCG_TARGET_CALL_ARG_I128        TCG_CALL_ARG_NORMAL
>  #define TCG_TARGET_CALL_RET_I128        TCG_CALL_RET_NORMAL
>
> -#if defined(__riscv_arch_test) && defined(__riscv_zbb)
> -# define have_zbb true
> -#else
> -extern bool have_zbb;
> -#endif
> -
>  /* optional instructions */
>  #define TCG_TARGET_HAS_negsetcond_i32   1
>  #define TCG_TARGET_HAS_div_i32          1
>  #define TCG_TARGET_HAS_rem_i32          1
>  #define TCG_TARGET_HAS_div2_i32         0
> -#define TCG_TARGET_HAS_rot_i32          have_zbb
> +#define TCG_TARGET_HAS_rot_i32          (cpuinfo & CPUINFO_ZBB)
>  #define TCG_TARGET_HAS_deposit_i32      0
>  #define TCG_TARGET_HAS_extract_i32      0
>  #define TCG_TARGET_HAS_sextract_i32     0
> @@ -106,17 +102,17 @@ extern bool have_zbb;
>  #define TCG_TARGET_HAS_ext16s_i32       1
>  #define TCG_TARGET_HAS_ext8u_i32        1
>  #define TCG_TARGET_HAS_ext16u_i32       1
> -#define TCG_TARGET_HAS_bswap16_i32      have_zbb
> -#define TCG_TARGET_HAS_bswap32_i32      have_zbb
> +#define TCG_TARGET_HAS_bswap16_i32      (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_bswap32_i32      (cpuinfo & CPUINFO_ZBB)
>  #define TCG_TARGET_HAS_not_i32          1
> -#define TCG_TARGET_HAS_andc_i32         have_zbb
> -#define TCG_TARGET_HAS_orc_i32          have_zbb
> -#define TCG_TARGET_HAS_eqv_i32          have_zbb
> +#define TCG_TARGET_HAS_andc_i32         (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_orc_i32          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_eqv_i32          (cpuinfo & CPUINFO_ZBB)
>  #define TCG_TARGET_HAS_nand_i32         0
>  #define TCG_TARGET_HAS_nor_i32          0
> -#define TCG_TARGET_HAS_clz_i32          have_zbb
> -#define TCG_TARGET_HAS_ctz_i32          have_zbb
> -#define TCG_TARGET_HAS_ctpop_i32        have_zbb
> +#define TCG_TARGET_HAS_clz_i32          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_ctz_i32          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_ctpop_i32        (cpuinfo & CPUINFO_ZBB)
>  #define TCG_TARGET_HAS_brcond2          1
>  #define TCG_TARGET_HAS_setcond2         1
>  #define TCG_TARGET_HAS_qemu_st8_i32     0
> @@ -125,7 +121,7 @@ extern bool have_zbb;
>  #define TCG_TARGET_HAS_div_i64          1
>  #define TCG_TARGET_HAS_rem_i64          1
>  #define TCG_TARGET_HAS_div2_i64         0
> -#define TCG_TARGET_HAS_rot_i64          have_zbb
> +#define TCG_TARGET_HAS_rot_i64          (cpuinfo & CPUINFO_ZBB)
>  #define TCG_TARGET_HAS_deposit_i64      0
>  #define TCG_TARGET_HAS_extract_i64      0
>  #define TCG_TARGET_HAS_sextract_i64     0
> @@ -137,18 +133,18 @@ extern bool have_zbb;
>  #define TCG_TARGET_HAS_ext8u_i64        1
>  #define TCG_TARGET_HAS_ext16u_i64       1
>  #define TCG_TARGET_HAS_ext32u_i64       1
> -#define TCG_TARGET_HAS_bswap16_i64      have_zbb
> -#define TCG_TARGET_HAS_bswap32_i64      have_zbb
> -#define TCG_TARGET_HAS_bswap64_i64      have_zbb
> +#define TCG_TARGET_HAS_bswap16_i64      (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_bswap32_i64      (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_bswap64_i64      (cpuinfo & CPUINFO_ZBB)
>  #define TCG_TARGET_HAS_not_i64          1
> -#define TCG_TARGET_HAS_andc_i64         have_zbb
> -#define TCG_TARGET_HAS_orc_i64          have_zbb
> -#define TCG_TARGET_HAS_eqv_i64          have_zbb
> +#define TCG_TARGET_HAS_andc_i64         (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_orc_i64          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_eqv_i64          (cpuinfo & CPUINFO_ZBB)
>  #define TCG_TARGET_HAS_nand_i64         0
>  #define TCG_TARGET_HAS_nor_i64          0
> -#define TCG_TARGET_HAS_clz_i64          have_zbb
> -#define TCG_TARGET_HAS_ctz_i64          have_zbb
> -#define TCG_TARGET_HAS_ctpop_i64        have_zbb
> +#define TCG_TARGET_HAS_clz_i64          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_ctz_i64          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_ctpop_i64        (cpuinfo & CPUINFO_ZBB)
>  #define TCG_TARGET_HAS_add2_i64         1
>  #define TCG_TARGET_HAS_sub2_i64         1
>  #define TCG_TARGET_HAS_mulu2_i64        0
> diff --git a/util/cpuinfo-riscv.c b/util/cpuinfo-riscv.c
> new file mode 100644
> index 0000000000..6b97100620
> --- /dev/null
> +++ b/util/cpuinfo-riscv.c
> @@ -0,0 +1,85 @@
> +/*
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + * Host specific cpu identification for RISC-V.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "host/cpuinfo.h"
> +
> +unsigned cpuinfo;
> +static volatile sig_atomic_t got_sigill;
> +
> +static void sigill_handler(int signo, siginfo_t *si, void *data)
> +{
> +    /* Skip the faulty instruction */
> +    ucontext_t *uc = (ucontext_t *)data;
> +    uc->uc_mcontext.__gregs[REG_PC] += 4;
> +
> +    got_sigill = 1;
> +}
> +
> +/* Called both as constructor and (possibly) via other constructors. */
> +unsigned __attribute__((constructor)) cpuinfo_init(void)
> +{
> +    unsigned left = CPUINFO_ZBA | CPUINFO_ZBB | CPUINFO_ZICOND;
> +    unsigned info = cpuinfo;
> +
> +    if (info) {
> +        return info;
> +    }
> +
> +    /* Test for compile-time settings. */
> +#if defined(__riscv_arch_test) && defined(__riscv_zba)
> +    info |= CPUINFO_ZBA;
> +#endif
> +#if defined(__riscv_arch_test) && defined(__riscv_zbb)
> +    info |= CPUINFO_ZBB;
> +#endif
> +#if defined(__riscv_arch_test) && defined(__riscv_zicond)
> +    info |= CPUINFO_ZICOND;
> +#endif
> +    left &= ~info;
> +
> +    if (left) {
> +        struct sigaction sa_old, sa_new;
> +
> +        memset(&sa_new, 0, sizeof(sa_new));
> +        sa_new.sa_flags = SA_SIGINFO;
> +        sa_new.sa_sigaction = sigill_handler;
> +        sigaction(SIGILL, &sa_new, &sa_old);
> +
> +        if (left & CPUINFO_ZBA) {
> +            /* Probe for Zba: add.uw zero,zero,zero. */
> +            got_sigill = 0;
> +            asm volatile(".insn r 0x3b, 0, 0x04, zero, zero, zero"
> +                         : : : "memory");
> +            info |= !got_sigill * CPUINFO_ZBA;
> +            left &= ~CPUINFO_ZBA;
> +        }
> +
> +        if (left & CPUINFO_ZBB) {
> +            /* Probe for Zba: andn zero,zero,zero. */
> +            got_sigill = 0;
> +            asm volatile(".insn r 0x33, 7, 0x20, zero, zero, zero"
> +                         : : : "memory");
> +            info |= !got_sigill * CPUINFO_ZBB;
> +            left &= ~CPUINFO_ZBB;
> +        }
> +
> +        if (left & CPUINFO_ZICOND) {
> +            /* Probe for Zicond: czero.eqz zero,zero,zero. */
> +            got_sigill = 0;
> +            asm volatile(".insn r 0x33, 5, 0x07, zero, zero, zero"
> +                         : : : "memory");
> +            info |= !got_sigill * CPUINFO_ZICOND;
> +            left &= ~CPUINFO_ZICOND;
> +        }
> +
> +        sigaction(SIGILL, &sa_old, NULL);
> +        assert(left == 0);
> +    }
> +
> +    info |= CPUINFO_ALWAYS;
> +    cpuinfo = info;
> +    return info;
> +}
> diff --git a/tcg/riscv/tcg-target.c.inc b/tcg/riscv/tcg-target.c.inc
> index 639363039b..d334857226 100644
> --- a/tcg/riscv/tcg-target.c.inc
> +++ b/tcg/riscv/tcg-target.c.inc
> @@ -113,20 +113,6 @@ static const int tcg_target_call_iarg_regs[] = {
>      TCG_REG_A7,
>  };
>
> -#ifndef have_zbb
> -bool have_zbb;
> -#endif
> -#if defined(__riscv_arch_test) && defined(__riscv_zba)
> -# define have_zba true
> -#else
> -static bool have_zba;
> -#endif
> -#if defined(__riscv_arch_test) && defined(__riscv_zicond)
> -# define have_zicond true
> -#else
> -static bool have_zicond;
> -#endif
> -
>  static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot)
>  {
>      tcg_debug_assert(kind == TCG_CALL_RET_NORMAL);
> @@ -594,7 +580,7 @@ static void tcg_out_ext8u(TCGContext *s, TCGReg ret, TCGReg arg)
>
>  static void tcg_out_ext16u(TCGContext *s, TCGReg ret, TCGReg arg)
>  {
> -    if (have_zbb) {
> +    if (cpuinfo & CPUINFO_ZBB) {
>          tcg_out_opc_reg(s, OPC_ZEXT_H, ret, arg, TCG_REG_ZERO);
>      } else {
>          tcg_out_opc_imm(s, OPC_SLLIW, ret, arg, 16);
> @@ -604,7 +590,7 @@ static void tcg_out_ext16u(TCGContext *s, TCGReg ret, TCGReg arg)
>
>  static void tcg_out_ext32u(TCGContext *s, TCGReg ret, TCGReg arg)
>  {
> -    if (have_zba) {
> +    if (cpuinfo & CPUINFO_ZBA) {
>          tcg_out_opc_reg(s, OPC_ADD_UW, ret, arg, TCG_REG_ZERO);
>      } else {
>          tcg_out_opc_imm(s, OPC_SLLI, ret, arg, 32);
> @@ -614,7 +600,7 @@ static void tcg_out_ext32u(TCGContext *s, TCGReg ret, TCGReg arg)
>
>  static void tcg_out_ext8s(TCGContext *s, TCGType type, TCGReg ret, TCGReg arg)
>  {
> -    if (have_zbb) {
> +    if (cpuinfo & CPUINFO_ZBB) {
>          tcg_out_opc_imm(s, OPC_SEXT_B, ret, arg, 0);
>      } else {
>          tcg_out_opc_imm(s, OPC_SLLIW, ret, arg, 24);
> @@ -624,7 +610,7 @@ static void tcg_out_ext8s(TCGContext *s, TCGType type, TCGReg ret, TCGReg arg)
>
>  static void tcg_out_ext16s(TCGContext *s, TCGType type, TCGReg ret, TCGReg arg)
>  {
> -    if (have_zbb) {
> +    if (cpuinfo & CPUINFO_ZBB) {
>          tcg_out_opc_imm(s, OPC_SEXT_H, ret, arg, 0);
>      } else {
>          tcg_out_opc_imm(s, OPC_SLLIW, ret, arg, 16);
> @@ -1080,7 +1066,7 @@ static void tcg_out_movcond(TCGContext *s, TCGCond cond, TCGReg ret,
>      int tmpflags;
>      TCGReg t;
>
> -    if (!have_zicond && (!c_cmp2 || cmp2 == 0)) {
> +    if (!(cpuinfo & CPUINFO_ZICOND) && (!c_cmp2 || cmp2 == 0)) {
>          tcg_out_movcond_br2(s, cond, ret, cmp1, cmp2,
>                              val1, c_val1, val2, c_val2);
>          return;
> @@ -1089,7 +1075,7 @@ static void tcg_out_movcond(TCGContext *s, TCGCond cond, TCGReg ret,
>      tmpflags = tcg_out_setcond_int(s, cond, TCG_REG_TMP0, cmp1, cmp2, c_cmp2);
>      t = tmpflags & ~SETCOND_FLAGS;
>
> -    if (have_zicond) {
> +    if (cpuinfo & CPUINFO_ZICOND) {
>          if (tmpflags & SETCOND_INV) {
>              tcg_out_movcond_zicond(s, ret, t, val2, c_val2, val1, c_val1);
>          } else {
> @@ -1304,7 +1290,7 @@ static TCGLabelQemuLdst *prepare_host_addr(TCGContext *s, TCGReg *pbase,
>          /* TLB Hit - translate address using addend.  */
>          if (addr_type != TCG_TYPE_I32) {
>              tcg_out_opc_reg(s, OPC_ADD, TCG_REG_TMP0, addr_reg, TCG_REG_TMP2);
> -        } else if (have_zba) {
> +        } else if (cpuinfo & CPUINFO_ZBA) {
>              tcg_out_opc_reg(s, OPC_ADD_UW, TCG_REG_TMP0,
>                              addr_reg, TCG_REG_TMP2);
>          } else {
> @@ -1335,7 +1321,7 @@ static TCGLabelQemuLdst *prepare_host_addr(TCGContext *s, TCGReg *pbase,
>              if (addr_type != TCG_TYPE_I32) {
>                  tcg_out_opc_reg(s, OPC_ADD, base, addr_reg,
>                                  TCG_GUEST_BASE_REG);
> -            } else if (have_zba) {
> +            } else if (cpuinfo & CPUINFO_ZBA) {
>                  tcg_out_opc_reg(s, OPC_ADD_UW, base, addr_reg,
>                                  TCG_GUEST_BASE_REG);
>              } else {
> @@ -2110,62 +2096,8 @@ static void tcg_out_tb_start(TCGContext *s)
>      /* nothing to do */
>  }
>
> -static volatile sig_atomic_t got_sigill;
> -
> -static void sigill_handler(int signo, siginfo_t *si, void *data)
> -{
> -    /* Skip the faulty instruction */
> -    ucontext_t *uc = (ucontext_t *)data;
> -    uc->uc_mcontext.__gregs[REG_PC] += 4;
> -
> -    got_sigill = 1;
> -}
> -
> -static void tcg_target_detect_isa(void)
> -{
> -#if !defined(have_zba) || !defined(have_zbb) || !defined(have_zicond)
> -    /*
> -     * TODO: It is expected that this will be determinable via
> -     * linux riscv_hwprobe syscall, not yet merged.
> -     * In the meantime, test via sigill.
> -     */
> -
> -    struct sigaction sa_old, sa_new;
> -
> -    memset(&sa_new, 0, sizeof(sa_new));
> -    sa_new.sa_flags = SA_SIGINFO;
> -    sa_new.sa_sigaction = sigill_handler;
> -    sigaction(SIGILL, &sa_new, &sa_old);
> -
> -#ifndef have_zba
> -    /* Probe for Zba: add.uw zero,zero,zero. */
> -    got_sigill = 0;
> -    asm volatile(".insn r 0x3b, 0, 0x04, zero, zero, zero" : : : "memory");
> -    have_zba = !got_sigill;
> -#endif
> -
> -#ifndef have_zbb
> -    /* Probe for Zba: andn zero,zero,zero. */
> -    got_sigill = 0;
> -    asm volatile(".insn r 0x33, 7, 0x20, zero, zero, zero" : : : "memory");
> -    have_zbb = !got_sigill;
> -#endif
> -
> -#ifndef have_zicond
> -    /* Probe for Zicond: czero.eqz zero,zero,zero. */
> -    got_sigill = 0;
> -    asm volatile(".insn r 0x33, 5, 0x07, zero, zero, zero" : : : "memory");
> -    have_zicond = !got_sigill;
> -#endif
> -
> -    sigaction(SIGILL, &sa_old, NULL);
> -#endif
> -}
> -
>  static void tcg_target_init(TCGContext *s)
>  {
> -    tcg_target_detect_isa();
> -
>      tcg_target_available_regs[TCG_TYPE_I32] = 0xffffffff;
>      tcg_target_available_regs[TCG_TYPE_I64] = 0xffffffff;
>
> diff --git a/util/meson.build b/util/meson.build
> index 72b505df11..5d8bef9891 100644
> --- a/util/meson.build
> +++ b/util/meson.build
> @@ -127,4 +127,6 @@ elif cpu == 'loongarch64'
>    util_ss.add(files('cpuinfo-loongarch.c'))
>  elif cpu in ['ppc', 'ppc64']
>    util_ss.add(files('cpuinfo-ppc.c'))
> +elif cpu in ['riscv32', 'riscv64']
> +  util_ss.add(files('cpuinfo-riscv.c'))
>  endif
> --
> 2.34.1
>
>


^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH 2/3] util/cpuinfo-riscv: Support OpenBSD signal frame
  2024-06-27 18:03 ` [PATCH 2/3] util/cpuinfo-riscv: Support OpenBSD signal frame Richard Henderson
  2024-07-02 19:58   ` Philippe Mathieu-Daudé
  2024-07-02 22:16   ` Daniel Henrique Barboza
@ 2024-07-02 23:56   ` Alistair Francis
  2 siblings, 0 replies; 17+ messages in thread
From: Alistair Francis @ 2024-07-02 23:56 UTC (permalink / raw)
  To: Richard Henderson; +Cc: qemu-devel, brad, Alistair.Francis, palmer, qemu-riscv

On Fri, Jun 28, 2024 at 4:06 AM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Reported-by: Brad Smith <brad@comstyle.com>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

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

Alistair

> ---
>  util/cpuinfo-riscv.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/util/cpuinfo-riscv.c b/util/cpuinfo-riscv.c
> index 6b97100620..abf799794f 100644
> --- a/util/cpuinfo-riscv.c
> +++ b/util/cpuinfo-riscv.c
> @@ -13,7 +13,14 @@ static void sigill_handler(int signo, siginfo_t *si, void *data)
>  {
>      /* Skip the faulty instruction */
>      ucontext_t *uc = (ucontext_t *)data;
> +
> +#ifdef __linux__
>      uc->uc_mcontext.__gregs[REG_PC] += 4;
> +#elif defined(__OpenBSD__)
> +    uc->sc_sepc += 4;
> +#else
> +# error Unsupported OS
> +#endif
>
>      got_sigill = 1;
>  }
> --
> 2.34.1
>
>


^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH 3/3] util/cpuinfo-riscv: Use linux __riscv_hwprobe syscall
  2024-06-27 18:03 ` [PATCH 3/3] util/cpuinfo-riscv: Use linux __riscv_hwprobe syscall Richard Henderson
  2024-07-02 22:15   ` Daniel Henrique Barboza
@ 2024-07-02 23:58   ` Alistair Francis
  1 sibling, 0 replies; 17+ messages in thread
From: Alistair Francis @ 2024-07-02 23:58 UTC (permalink / raw)
  To: Richard Henderson; +Cc: qemu-devel, brad, Alistair.Francis, palmer, qemu-riscv

On Fri, Jun 28, 2024 at 4:06 AM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> With recent linux kernels, there is a syscall to probe for various
> ISA extensions.  These bits were phased in over several kernel
> releases, so we still require checks for symbol availability.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

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

Alistair

> ---
>  meson.build          |  6 ++++++
>  util/cpuinfo-riscv.c | 26 ++++++++++++++++++++++++++
>  2 files changed, 32 insertions(+)
>
> diff --git a/meson.build b/meson.build
> index 97e00d6f59..58afd0125d 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -2837,6 +2837,12 @@ have_cpuid_h = cc.links('''
>    }''')
>  config_host_data.set('CONFIG_CPUID_H', have_cpuid_h)
>
> +# Don't bother to advertise asm/hwprobe.h for old versions that do
> +# not contain RISCV_HWPROBE_EXT_ZBA.
> +config_host_data.set('CONFIG_ASM_HWPROBE_H',
> +                     cc.has_header_symbol('asm/hwprobe.h',
> +                                          'RISCV_HWPROBE_EXT_ZBA'))
> +
>  config_host_data.set('CONFIG_AVX2_OPT', get_option('avx2') \
>    .require(have_cpuid_h, error_message: 'cpuid.h not available, cannot enable AVX2') \
>    .require(cc.links('''
> diff --git a/util/cpuinfo-riscv.c b/util/cpuinfo-riscv.c
> index abf799794f..cf59ce83a3 100644
> --- a/util/cpuinfo-riscv.c
> +++ b/util/cpuinfo-riscv.c
> @@ -6,6 +6,11 @@
>  #include "qemu/osdep.h"
>  #include "host/cpuinfo.h"
>
> +#ifdef CONFIG_ASM_HWPROBE_H
> +#include <asm/hwprobe.h>
> +#include <sys/syscall.h>
> +#endif
> +
>  unsigned cpuinfo;
>  static volatile sig_atomic_t got_sigill;
>
> @@ -47,6 +52,27 @@ unsigned __attribute__((constructor)) cpuinfo_init(void)
>  #endif
>      left &= ~info;
>
> +#ifdef CONFIG_ASM_HWPROBE_H
> +    if (left) {
> +        /*
> +         * TODO: glibc 2.40 will introduce <sys/hwprobe.h>, which
> +         * provides __riscv_hwprobe and __riscv_hwprobe_one,
> +         * which is a slightly cleaner interface.
> +         */
> +        struct riscv_hwprobe pair = { .key = RISCV_HWPROBE_KEY_IMA_EXT_0 };
> +        if (syscall(__NR_riscv_hwprobe, &pair, 1, 0, NULL, 0) == 0
> +            && pair.key >= 0) {
> +            info |= pair.value & RISCV_HWPROBE_EXT_ZBA ? CPUINFO_ZBA : 0;
> +            info |= pair.value & RISCV_HWPROBE_EXT_ZBB ? CPUINFO_ZBB : 0;
> +            left &= ~(CPUINFO_ZBA | CPUINFO_ZBB);
> +#ifdef RISCV_HWPROBE_EXT_ZICOND
> +            info |= pair.value & RISCV_HWPROBE_EXT_ZICOND ? CPUINFO_ZICOND : 0;
> +            left &= ~CPUINFO_ZICOND;
> +#endif
> +        }
> +    }
> +#endif /* CONFIG_ASM_HWPROBE_H */
> +
>      if (left) {
>          struct sigaction sa_old, sa_new;
>
> --
> 2.34.1
>
>


^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH 1/3] util/cpuinfo-riscv: Support host/cpuinfo.h for riscv
  2024-07-02 23:04     ` Richard Henderson
@ 2024-07-03  7:32       ` Philippe Mathieu-Daudé
  0 siblings, 0 replies; 17+ messages in thread
From: Philippe Mathieu-Daudé @ 2024-07-03  7:32 UTC (permalink / raw)
  To: Richard Henderson, qemu-devel; +Cc: brad, Alistair.Francis, palmer, qemu-riscv

On 3/7/24 01:04, Richard Henderson wrote:
> On 7/2/24 12:55, Philippe Mathieu-Daudé wrote:
>> On 27/6/24 20:03, Richard Henderson wrote:
> ...
>>> +            info |= !got_sigill * CPUINFO_ZBA;
>>
>> A bit too optimized to my taste, 'if (sigill) info|=ZBA' would be 
>> simpler to follow. 
> 
> I switched to "info |= got_sigill ? 0 : CPUINFO_ZBA".

Thanks :)



^ permalink raw reply	[flat|nested] 17+ messages in thread

* Re: [PATCH 1/3] util/cpuinfo-riscv: Support host/cpuinfo.h for riscv
  2024-06-27 18:03 ` [PATCH 1/3] util/cpuinfo-riscv: Support host/cpuinfo.h " Richard Henderson
                     ` (2 preceding siblings ...)
  2024-07-02 23:56   ` Alistair Francis
@ 2024-07-03  8:46   ` LIU Zhiwei
  3 siblings, 0 replies; 17+ messages in thread
From: LIU Zhiwei @ 2024-07-03  8:46 UTC (permalink / raw)
  To: Richard Henderson, qemu-devel; +Cc: brad, Alistair.Francis, palmer, qemu-riscv


On 2024/6/28 2:03, Richard Henderson wrote:
> Move detection code out of tcg, similar to other hosts.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>

Zhiwei

> ---
>   host/include/riscv/host/cpuinfo.h | 23 +++++++++
>   tcg/riscv/tcg-target.h            | 46 ++++++++---------
>   util/cpuinfo-riscv.c              | 85 +++++++++++++++++++++++++++++++
>   tcg/riscv/tcg-target.c.inc        | 84 +++---------------------------
>   util/meson.build                  |  2 +
>   5 files changed, 139 insertions(+), 101 deletions(-)
>   create mode 100644 host/include/riscv/host/cpuinfo.h
>   create mode 100644 util/cpuinfo-riscv.c
>
> diff --git a/host/include/riscv/host/cpuinfo.h b/host/include/riscv/host/cpuinfo.h
> new file mode 100644
> index 0000000000..2b00660e36
> --- /dev/null
> +++ b/host/include/riscv/host/cpuinfo.h
> @@ -0,0 +1,23 @@
> +/*
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + * Host specific cpu identification for RISC-V.
> + */
> +
> +#ifndef HOST_CPUINFO_H
> +#define HOST_CPUINFO_H
> +
> +#define CPUINFO_ALWAYS          (1u << 0)  /* so cpuinfo is nonzero */
> +#define CPUINFO_ZBA             (1u << 1)
> +#define CPUINFO_ZBB             (1u << 2)
> +#define CPUINFO_ZICOND          (1u << 3)
> +
> +/* Initialized with a constructor. */
> +extern unsigned cpuinfo;
> +
> +/*
> + * We cannot rely on constructor ordering, so other constructors must
> + * use the function interface rather than the variable above.
> + */
> +unsigned cpuinfo_init(void);
> +
> +#endif /* HOST_CPUINFO_H */
> diff --git a/tcg/riscv/tcg-target.h b/tcg/riscv/tcg-target.h
> index 2c1b680b93..1a347eaf6e 100644
> --- a/tcg/riscv/tcg-target.h
> +++ b/tcg/riscv/tcg-target.h
> @@ -25,6 +25,8 @@
>   #ifndef RISCV_TCG_TARGET_H
>   #define RISCV_TCG_TARGET_H
>   
> +#include "host/cpuinfo.h"
> +
>   #define TCG_TARGET_INSN_UNIT_SIZE 4
>   #define TCG_TARGET_NB_REGS 32
>   #define MAX_CODE_GEN_BUFFER_SIZE  ((size_t)-1)
> @@ -80,18 +82,12 @@ typedef enum {
>   #define TCG_TARGET_CALL_ARG_I128        TCG_CALL_ARG_NORMAL
>   #define TCG_TARGET_CALL_RET_I128        TCG_CALL_RET_NORMAL
>   
> -#if defined(__riscv_arch_test) && defined(__riscv_zbb)
> -# define have_zbb true
> -#else
> -extern bool have_zbb;
> -#endif
> -
>   /* optional instructions */
>   #define TCG_TARGET_HAS_negsetcond_i32   1
>   #define TCG_TARGET_HAS_div_i32          1
>   #define TCG_TARGET_HAS_rem_i32          1
>   #define TCG_TARGET_HAS_div2_i32         0
> -#define TCG_TARGET_HAS_rot_i32          have_zbb
> +#define TCG_TARGET_HAS_rot_i32          (cpuinfo & CPUINFO_ZBB)
>   #define TCG_TARGET_HAS_deposit_i32      0
>   #define TCG_TARGET_HAS_extract_i32      0
>   #define TCG_TARGET_HAS_sextract_i32     0
> @@ -106,17 +102,17 @@ extern bool have_zbb;
>   #define TCG_TARGET_HAS_ext16s_i32       1
>   #define TCG_TARGET_HAS_ext8u_i32        1
>   #define TCG_TARGET_HAS_ext16u_i32       1
> -#define TCG_TARGET_HAS_bswap16_i32      have_zbb
> -#define TCG_TARGET_HAS_bswap32_i32      have_zbb
> +#define TCG_TARGET_HAS_bswap16_i32      (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_bswap32_i32      (cpuinfo & CPUINFO_ZBB)
>   #define TCG_TARGET_HAS_not_i32          1
> -#define TCG_TARGET_HAS_andc_i32         have_zbb
> -#define TCG_TARGET_HAS_orc_i32          have_zbb
> -#define TCG_TARGET_HAS_eqv_i32          have_zbb
> +#define TCG_TARGET_HAS_andc_i32         (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_orc_i32          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_eqv_i32          (cpuinfo & CPUINFO_ZBB)
>   #define TCG_TARGET_HAS_nand_i32         0
>   #define TCG_TARGET_HAS_nor_i32          0
> -#define TCG_TARGET_HAS_clz_i32          have_zbb
> -#define TCG_TARGET_HAS_ctz_i32          have_zbb
> -#define TCG_TARGET_HAS_ctpop_i32        have_zbb
> +#define TCG_TARGET_HAS_clz_i32          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_ctz_i32          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_ctpop_i32        (cpuinfo & CPUINFO_ZBB)
>   #define TCG_TARGET_HAS_brcond2          1
>   #define TCG_TARGET_HAS_setcond2         1
>   #define TCG_TARGET_HAS_qemu_st8_i32     0
> @@ -125,7 +121,7 @@ extern bool have_zbb;
>   #define TCG_TARGET_HAS_div_i64          1
>   #define TCG_TARGET_HAS_rem_i64          1
>   #define TCG_TARGET_HAS_div2_i64         0
> -#define TCG_TARGET_HAS_rot_i64          have_zbb
> +#define TCG_TARGET_HAS_rot_i64          (cpuinfo & CPUINFO_ZBB)
>   #define TCG_TARGET_HAS_deposit_i64      0
>   #define TCG_TARGET_HAS_extract_i64      0
>   #define TCG_TARGET_HAS_sextract_i64     0
> @@ -137,18 +133,18 @@ extern bool have_zbb;
>   #define TCG_TARGET_HAS_ext8u_i64        1
>   #define TCG_TARGET_HAS_ext16u_i64       1
>   #define TCG_TARGET_HAS_ext32u_i64       1
> -#define TCG_TARGET_HAS_bswap16_i64      have_zbb
> -#define TCG_TARGET_HAS_bswap32_i64      have_zbb
> -#define TCG_TARGET_HAS_bswap64_i64      have_zbb
> +#define TCG_TARGET_HAS_bswap16_i64      (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_bswap32_i64      (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_bswap64_i64      (cpuinfo & CPUINFO_ZBB)
>   #define TCG_TARGET_HAS_not_i64          1
> -#define TCG_TARGET_HAS_andc_i64         have_zbb
> -#define TCG_TARGET_HAS_orc_i64          have_zbb
> -#define TCG_TARGET_HAS_eqv_i64          have_zbb
> +#define TCG_TARGET_HAS_andc_i64         (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_orc_i64          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_eqv_i64          (cpuinfo & CPUINFO_ZBB)
>   #define TCG_TARGET_HAS_nand_i64         0
>   #define TCG_TARGET_HAS_nor_i64          0
> -#define TCG_TARGET_HAS_clz_i64          have_zbb
> -#define TCG_TARGET_HAS_ctz_i64          have_zbb
> -#define TCG_TARGET_HAS_ctpop_i64        have_zbb
> +#define TCG_TARGET_HAS_clz_i64          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_ctz_i64          (cpuinfo & CPUINFO_ZBB)
> +#define TCG_TARGET_HAS_ctpop_i64        (cpuinfo & CPUINFO_ZBB)
>   #define TCG_TARGET_HAS_add2_i64         1
>   #define TCG_TARGET_HAS_sub2_i64         1
>   #define TCG_TARGET_HAS_mulu2_i64        0
> diff --git a/util/cpuinfo-riscv.c b/util/cpuinfo-riscv.c
> new file mode 100644
> index 0000000000..6b97100620
> --- /dev/null
> +++ b/util/cpuinfo-riscv.c
> @@ -0,0 +1,85 @@
> +/*
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + * Host specific cpu identification for RISC-V.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "host/cpuinfo.h"
> +
> +unsigned cpuinfo;
> +static volatile sig_atomic_t got_sigill;
> +
> +static void sigill_handler(int signo, siginfo_t *si, void *data)
> +{
> +    /* Skip the faulty instruction */
> +    ucontext_t *uc = (ucontext_t *)data;
> +    uc->uc_mcontext.__gregs[REG_PC] += 4;
> +
> +    got_sigill = 1;
> +}
> +
> +/* Called both as constructor and (possibly) via other constructors. */
> +unsigned __attribute__((constructor)) cpuinfo_init(void)
> +{
> +    unsigned left = CPUINFO_ZBA | CPUINFO_ZBB | CPUINFO_ZICOND;
> +    unsigned info = cpuinfo;
> +
> +    if (info) {
> +        return info;
> +    }
> +
> +    /* Test for compile-time settings. */
> +#if defined(__riscv_arch_test) && defined(__riscv_zba)
> +    info |= CPUINFO_ZBA;
> +#endif
> +#if defined(__riscv_arch_test) && defined(__riscv_zbb)
> +    info |= CPUINFO_ZBB;
> +#endif
> +#if defined(__riscv_arch_test) && defined(__riscv_zicond)
> +    info |= CPUINFO_ZICOND;
> +#endif
> +    left &= ~info;
> +
> +    if (left) {
> +        struct sigaction sa_old, sa_new;
> +
> +        memset(&sa_new, 0, sizeof(sa_new));
> +        sa_new.sa_flags = SA_SIGINFO;
> +        sa_new.sa_sigaction = sigill_handler;
> +        sigaction(SIGILL, &sa_new, &sa_old);
> +
> +        if (left & CPUINFO_ZBA) {
> +            /* Probe for Zba: add.uw zero,zero,zero. */
> +            got_sigill = 0;
> +            asm volatile(".insn r 0x3b, 0, 0x04, zero, zero, zero"
> +                         : : : "memory");
> +            info |= !got_sigill * CPUINFO_ZBA;
> +            left &= ~CPUINFO_ZBA;
> +        }
> +
> +        if (left & CPUINFO_ZBB) {
> +            /* Probe for Zba: andn zero,zero,zero. */
> +            got_sigill = 0;
> +            asm volatile(".insn r 0x33, 7, 0x20, zero, zero, zero"
> +                         : : : "memory");
> +            info |= !got_sigill * CPUINFO_ZBB;
> +            left &= ~CPUINFO_ZBB;
> +        }
> +
> +        if (left & CPUINFO_ZICOND) {
> +            /* Probe for Zicond: czero.eqz zero,zero,zero. */
> +            got_sigill = 0;
> +            asm volatile(".insn r 0x33, 5, 0x07, zero, zero, zero"
> +                         : : : "memory");
> +            info |= !got_sigill * CPUINFO_ZICOND;
> +            left &= ~CPUINFO_ZICOND;
> +        }
> +
> +        sigaction(SIGILL, &sa_old, NULL);
> +        assert(left == 0);
> +    }
> +
> +    info |= CPUINFO_ALWAYS;
> +    cpuinfo = info;
> +    return info;
> +}
> diff --git a/tcg/riscv/tcg-target.c.inc b/tcg/riscv/tcg-target.c.inc
> index 639363039b..d334857226 100644
> --- a/tcg/riscv/tcg-target.c.inc
> +++ b/tcg/riscv/tcg-target.c.inc
> @@ -113,20 +113,6 @@ static const int tcg_target_call_iarg_regs[] = {
>       TCG_REG_A7,
>   };
>   
> -#ifndef have_zbb
> -bool have_zbb;
> -#endif
> -#if defined(__riscv_arch_test) && defined(__riscv_zba)
> -# define have_zba true
> -#else
> -static bool have_zba;
> -#endif
> -#if defined(__riscv_arch_test) && defined(__riscv_zicond)
> -# define have_zicond true
> -#else
> -static bool have_zicond;
> -#endif
> -
>   static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot)
>   {
>       tcg_debug_assert(kind == TCG_CALL_RET_NORMAL);
> @@ -594,7 +580,7 @@ static void tcg_out_ext8u(TCGContext *s, TCGReg ret, TCGReg arg)
>   
>   static void tcg_out_ext16u(TCGContext *s, TCGReg ret, TCGReg arg)
>   {
> -    if (have_zbb) {
> +    if (cpuinfo & CPUINFO_ZBB) {
>           tcg_out_opc_reg(s, OPC_ZEXT_H, ret, arg, TCG_REG_ZERO);
>       } else {
>           tcg_out_opc_imm(s, OPC_SLLIW, ret, arg, 16);
> @@ -604,7 +590,7 @@ static void tcg_out_ext16u(TCGContext *s, TCGReg ret, TCGReg arg)
>   
>   static void tcg_out_ext32u(TCGContext *s, TCGReg ret, TCGReg arg)
>   {
> -    if (have_zba) {
> +    if (cpuinfo & CPUINFO_ZBA) {
>           tcg_out_opc_reg(s, OPC_ADD_UW, ret, arg, TCG_REG_ZERO);
>       } else {
>           tcg_out_opc_imm(s, OPC_SLLI, ret, arg, 32);
> @@ -614,7 +600,7 @@ static void tcg_out_ext32u(TCGContext *s, TCGReg ret, TCGReg arg)
>   
>   static void tcg_out_ext8s(TCGContext *s, TCGType type, TCGReg ret, TCGReg arg)
>   {
> -    if (have_zbb) {
> +    if (cpuinfo & CPUINFO_ZBB) {
>           tcg_out_opc_imm(s, OPC_SEXT_B, ret, arg, 0);
>       } else {
>           tcg_out_opc_imm(s, OPC_SLLIW, ret, arg, 24);
> @@ -624,7 +610,7 @@ static void tcg_out_ext8s(TCGContext *s, TCGType type, TCGReg ret, TCGReg arg)
>   
>   static void tcg_out_ext16s(TCGContext *s, TCGType type, TCGReg ret, TCGReg arg)
>   {
> -    if (have_zbb) {
> +    if (cpuinfo & CPUINFO_ZBB) {
>           tcg_out_opc_imm(s, OPC_SEXT_H, ret, arg, 0);
>       } else {
>           tcg_out_opc_imm(s, OPC_SLLIW, ret, arg, 16);
> @@ -1080,7 +1066,7 @@ static void tcg_out_movcond(TCGContext *s, TCGCond cond, TCGReg ret,
>       int tmpflags;
>       TCGReg t;
>   
> -    if (!have_zicond && (!c_cmp2 || cmp2 == 0)) {
> +    if (!(cpuinfo & CPUINFO_ZICOND) && (!c_cmp2 || cmp2 == 0)) {
>           tcg_out_movcond_br2(s, cond, ret, cmp1, cmp2,
>                               val1, c_val1, val2, c_val2);
>           return;
> @@ -1089,7 +1075,7 @@ static void tcg_out_movcond(TCGContext *s, TCGCond cond, TCGReg ret,
>       tmpflags = tcg_out_setcond_int(s, cond, TCG_REG_TMP0, cmp1, cmp2, c_cmp2);
>       t = tmpflags & ~SETCOND_FLAGS;
>   
> -    if (have_zicond) {
> +    if (cpuinfo & CPUINFO_ZICOND) {
>           if (tmpflags & SETCOND_INV) {
>               tcg_out_movcond_zicond(s, ret, t, val2, c_val2, val1, c_val1);
>           } else {
> @@ -1304,7 +1290,7 @@ static TCGLabelQemuLdst *prepare_host_addr(TCGContext *s, TCGReg *pbase,
>           /* TLB Hit - translate address using addend.  */
>           if (addr_type != TCG_TYPE_I32) {
>               tcg_out_opc_reg(s, OPC_ADD, TCG_REG_TMP0, addr_reg, TCG_REG_TMP2);
> -        } else if (have_zba) {
> +        } else if (cpuinfo & CPUINFO_ZBA) {
>               tcg_out_opc_reg(s, OPC_ADD_UW, TCG_REG_TMP0,
>                               addr_reg, TCG_REG_TMP2);
>           } else {
> @@ -1335,7 +1321,7 @@ static TCGLabelQemuLdst *prepare_host_addr(TCGContext *s, TCGReg *pbase,
>               if (addr_type != TCG_TYPE_I32) {
>                   tcg_out_opc_reg(s, OPC_ADD, base, addr_reg,
>                                   TCG_GUEST_BASE_REG);
> -            } else if (have_zba) {
> +            } else if (cpuinfo & CPUINFO_ZBA) {
>                   tcg_out_opc_reg(s, OPC_ADD_UW, base, addr_reg,
>                                   TCG_GUEST_BASE_REG);
>               } else {
> @@ -2110,62 +2096,8 @@ static void tcg_out_tb_start(TCGContext *s)
>       /* nothing to do */
>   }
>   
> -static volatile sig_atomic_t got_sigill;
> -
> -static void sigill_handler(int signo, siginfo_t *si, void *data)
> -{
> -    /* Skip the faulty instruction */
> -    ucontext_t *uc = (ucontext_t *)data;
> -    uc->uc_mcontext.__gregs[REG_PC] += 4;
> -
> -    got_sigill = 1;
> -}
> -
> -static void tcg_target_detect_isa(void)
> -{
> -#if !defined(have_zba) || !defined(have_zbb) || !defined(have_zicond)
> -    /*
> -     * TODO: It is expected that this will be determinable via
> -     * linux riscv_hwprobe syscall, not yet merged.
> -     * In the meantime, test via sigill.
> -     */
> -
> -    struct sigaction sa_old, sa_new;
> -
> -    memset(&sa_new, 0, sizeof(sa_new));
> -    sa_new.sa_flags = SA_SIGINFO;
> -    sa_new.sa_sigaction = sigill_handler;
> -    sigaction(SIGILL, &sa_new, &sa_old);
> -
> -#ifndef have_zba
> -    /* Probe for Zba: add.uw zero,zero,zero. */
> -    got_sigill = 0;
> -    asm volatile(".insn r 0x3b, 0, 0x04, zero, zero, zero" : : : "memory");
> -    have_zba = !got_sigill;
> -#endif
> -
> -#ifndef have_zbb
> -    /* Probe for Zba: andn zero,zero,zero. */
> -    got_sigill = 0;
> -    asm volatile(".insn r 0x33, 7, 0x20, zero, zero, zero" : : : "memory");
> -    have_zbb = !got_sigill;
> -#endif
> -
> -#ifndef have_zicond
> -    /* Probe for Zicond: czero.eqz zero,zero,zero. */
> -    got_sigill = 0;
> -    asm volatile(".insn r 0x33, 5, 0x07, zero, zero, zero" : : : "memory");
> -    have_zicond = !got_sigill;
> -#endif
> -
> -    sigaction(SIGILL, &sa_old, NULL);
> -#endif
> -}
> -
>   static void tcg_target_init(TCGContext *s)
>   {
> -    tcg_target_detect_isa();
> -
>       tcg_target_available_regs[TCG_TYPE_I32] = 0xffffffff;
>       tcg_target_available_regs[TCG_TYPE_I64] = 0xffffffff;
>   
> diff --git a/util/meson.build b/util/meson.build
> index 72b505df11..5d8bef9891 100644
> --- a/util/meson.build
> +++ b/util/meson.build
> @@ -127,4 +127,6 @@ elif cpu == 'loongarch64'
>     util_ss.add(files('cpuinfo-loongarch.c'))
>   elif cpu in ['ppc', 'ppc64']
>     util_ss.add(files('cpuinfo-ppc.c'))
> +elif cpu in ['riscv32', 'riscv64']
> +  util_ss.add(files('cpuinfo-riscv.c'))
>   endif


^ permalink raw reply	[flat|nested] 17+ messages in thread

end of thread, other threads:[~2024-07-03  8:48 UTC | newest]

Thread overview: 17+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-06-27 18:03 [PATCH 0/3] util: Add cpuinfo support for riscv Richard Henderson
2024-06-27 18:03 ` [PATCH 1/3] util/cpuinfo-riscv: Support host/cpuinfo.h " Richard Henderson
2024-07-02 19:55   ` Philippe Mathieu-Daudé
2024-07-02 23:04     ` Richard Henderson
2024-07-03  7:32       ` Philippe Mathieu-Daudé
2024-07-02 22:17   ` Daniel Henrique Barboza
2024-07-02 23:56   ` Alistair Francis
2024-07-03  8:46   ` LIU Zhiwei
2024-06-27 18:03 ` [PATCH 2/3] util/cpuinfo-riscv: Support OpenBSD signal frame Richard Henderson
2024-07-02 19:58   ` Philippe Mathieu-Daudé
2024-07-02 22:16   ` Daniel Henrique Barboza
2024-07-02 23:56   ` Alistair Francis
2024-06-27 18:03 ` [PATCH 3/3] util/cpuinfo-riscv: Use linux __riscv_hwprobe syscall Richard Henderson
2024-07-02 22:15   ` Daniel Henrique Barboza
2024-07-02 23:08     ` Richard Henderson
2024-07-02 23:58   ` Alistair Francis
2024-07-02 16:26 ` [PATCH 0/3] util: Add cpuinfo support for riscv Richard Henderson

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