[Qemu-devel] [PATCH 0/2] AArch64 TCG User Mode

[Qemu-devel] [PATCH 0/2] AArch64 TCG User Mode

[Claudio Fontana]

This series implements TCG User Mode for Aarch64.

It requires the reviewed but not committed yet series
"[PATCH v4 0/3] ARM aarch64 TCG target" at:
http://lists.nongnu.org/archive/html/qemu-devel/2013-05/msg04200.html

It also requires the reviewed but not committed yet series
"[PATCH 0/4] aarch64 TCG tlb fast lookup prerequisites" at:
http://lists.gnu.org/archive/html/qemu-devel/2013-06/msg00170.html

It also requires Peter's two linux-user changesets:

"[PATCH] linux-user: Allow getdents to be provided by getden" at:
http://lists.gnu.org/archive/html/qemu-devel/2013-06/msg00398.html

"[PATCH 0/2] linux-user: Drop direct use of openat etc sysca" at:
http://lists.gnu.org/archive/html/qemu-devel/2013-06/msg00015.html

Tested running on a x86-64 physical machine running Foundation v8,
running a linux 3.8.0-rc6+ minimal host system based on linaro v8
image 201301271620 for user space.

Tested guest binaries: x86-64 small binary, PPC 'ls' binary from debian

Claudio Fontana (2):
  user-exec.c: aarch64 initial implementation of cpu_signal_handler
  tcg/aarch64: implement user mode qemu ld/st

 configure                |   2 +-
 tcg/aarch64/tcg-target.c | 121 +++++++++++++++++++++++++++++++++++++++++++++--
 user-exec.c              |  15 ++++++
 3 files changed, 132 insertions(+), 6 deletions(-)

-- 
1.8.1

[Qemu-devel] [PATCH 1/2] user-exec.c: aarch64 initial implementation of cpu_signal_handler

[Claudio Fontana]

Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>

---
 user-exec.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/user-exec.c b/user-exec.c
index 71bd6c5..fa7f1f1 100644
--- a/user-exec.c
+++ b/user-exec.c
@@ -448,6 +448,21 @@ int cpu_signal_handler(int host_signum, void *pinfo,
                              &uc->uc_sigmask, puc);
 }
 
+#elif defined(__aarch64__)
+
+int cpu_signal_handler(int host_signum, void *pinfo,
+                       void *puc)
+{
+    siginfo_t *info = pinfo;
+    struct ucontext *uc = puc;
+    uint64_t pc;
+    int is_write = 0; /* XXX how to determine? */
+
+    pc = uc->uc_mcontext.pc;
+    return handle_cpu_signal(pc, (uint64_t)info->si_addr,
+                             is_write, &uc->uc_sigmask, puc);
+}
+
 #elif defined(__mc68000)
 
 int cpu_signal_handler(int host_signum, void *pinfo,
-- 
1.8.1

Re: [Qemu-devel] [PATCH 1/2] user-exec.c: aarch64 initial implementation of cpu_signal_handler

[Peter Maydell]

On 5 June 2013 14:42, Claudio Fontana <claudio.fontana@huawei.com> wrote:
>
> Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>
>
> ---
>  user-exec.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
>
> diff --git a/user-exec.c b/user-exec.c
> index 71bd6c5..fa7f1f1 100644
> --- a/user-exec.c
> +++ b/user-exec.c
> @@ -448,6 +448,21 @@ int cpu_signal_handler(int host_signum, void *pinfo,
>                               &uc->uc_sigmask, puc);
>  }
>
> +#elif defined(__aarch64__)
> +
> +int cpu_signal_handler(int host_signum, void *pinfo,
> +                       void *puc)
> +{
> +    siginfo_t *info = pinfo;
> +    struct ucontext *uc = puc;
> +    uint64_t pc;
> +    int is_write = 0; /* XXX how to determine? */

The long-term answer to this XXX, incidentally, is that
I need to persuade the kernel folk to expose the ESR (or
at a minimum its WnR bit) to userspace. For the moment,
always-0 is what other archs are doing here. (I'd rather
not get into the "read and interpret faulting instruction"
game if we can get the kernel fixed, given we're at a
pretty early stage in aarch64 adoption/rollout.)

> +
> +    pc = uc->uc_mcontext.pc;
> +    return handle_cpu_signal(pc, (uint64_t)info->si_addr,
> +                             is_write, &uc->uc_sigmask, puc);
> +}
> +

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

-- PMM

[Qemu-devel] [PATCH 2/2] tcg/aarch64: implement user mode qemu ld/st

[Claudio Fontana]

From: Jani Kokkonen <jani.kokkonen@huawei.com>

also put aarch64 in the list of archs that do not need an ldscript.

Signed-off-by: Jani Kokkoken <jani.kokkonen@huawei.com>
Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>
---
 configure                |   2 +-
 tcg/aarch64/tcg-target.c | 121 +++++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 117 insertions(+), 6 deletions(-)

diff --git a/configure b/configure
index f021bdd..d98a9a6 100755
--- a/configure
+++ b/configure
@@ -4499,7 +4499,7 @@ fi
 
 if test "$target_linux_user" = "yes" -o "$target_bsd_user" = "yes" ; then
   case "$ARCH" in
-  alpha | s390x)
+  alpha | s390x | aarch64)
     # The default placement of the application is fine.
     ;;
   *)
diff --git a/tcg/aarch64/tcg-target.c b/tcg/aarch64/tcg-target.c
index 5d0f300..8bb195e 100644
--- a/tcg/aarch64/tcg-target.c
+++ b/tcg/aarch64/tcg-target.c
@@ -24,10 +24,16 @@ static const char * const tcg_target_reg_names[TCG_TARGET_NB_REGS] = {
 };
 #endif /* NDEBUG */
 
+#ifdef TARGET_WORDS_BIGENDIAN
+ #define TCG_LDST_BSWAP 1
+#else
+ #define TCG_LDST_BSWAP 0
+#endif
+
 static const int tcg_target_reg_alloc_order[] = {
     TCG_REG_X20, TCG_REG_X21, TCG_REG_X22, TCG_REG_X23,
     TCG_REG_X24, TCG_REG_X25, TCG_REG_X26, TCG_REG_X27,
-    TCG_REG_X28,
+    TCG_REG_X28, /* we will reserve this for GUEST_BASE if configured */
 
     TCG_REG_X9, TCG_REG_X10, TCG_REG_X11, TCG_REG_X12,
     TCG_REG_X13, TCG_REG_X14, TCG_REG_X15,
@@ -51,6 +57,14 @@ static const int tcg_target_call_oarg_regs[1] = {
 
 #define TCG_REG_TMP TCG_REG_X8
 
+#ifndef CONFIG_SOFTMMU
+# if defined(CONFIG_USE_GUEST_BASE)
+# define TCG_REG_GUEST_BASE TCG_REG_X28
+# else
+# define TCG_REG_GUEST_BASE TCG_REG_XZR
+# endif
+#endif
+
 static inline void reloc_pc26(void *code_ptr, tcg_target_long target)
 {
     tcg_target_long offset; uint32_t insn;
@@ -713,6 +727,94 @@ static const void * const qemu_st_helpers[4] = {
     helper_stq_mmu,
 };
 
+#else /* !CONFIG_SOFTMMU */
+
+static void tcg_out_qemu_ld_direct(TCGContext *s, int opc, TCGReg data_r,
+                                   TCGReg addr_r, TCGReg off_r)
+{
+    switch (opc) {
+    case 0:
+        tcg_out_ldst_r(s, LDST_8, LDST_LD, data_r, addr_r, off_r);
+        break;
+    case 0 | 4:
+        tcg_out_ldst_r(s, LDST_8, LDST_LD_S_X, data_r, addr_r, off_r);
+        break;
+    case 1:
+        tcg_out_ldst_r(s, LDST_16, LDST_LD, data_r, addr_r, off_r);
+        if (TCG_LDST_BSWAP) {
+            tcg_out_rev16(s, 0, data_r, data_r);
+        }
+        break;
+    case 1 | 4:
+        if (TCG_LDST_BSWAP) {
+            tcg_out_ldst_r(s, LDST_16, LDST_LD, data_r, addr_r, off_r);
+            tcg_out_rev16(s, 0, data_r, data_r);
+            tcg_out_sxt(s, 1, 1, data_r, data_r);
+        } else {
+            tcg_out_ldst_r(s, LDST_16, LDST_LD_S_X, data_r, addr_r, off_r);
+        }
+        break;
+    case 2:
+        tcg_out_ldst_r(s, LDST_32, LDST_LD, data_r, addr_r, off_r);
+        if (TCG_LDST_BSWAP) {
+            tcg_out_rev(s, 0, data_r, data_r);
+        }
+        break;
+    case 2 | 4:
+        if (TCG_LDST_BSWAP) {
+            tcg_out_ldst_r(s, LDST_32, LDST_LD, data_r, addr_r, off_r);
+            tcg_out_rev(s, 0, data_r, data_r);
+            tcg_out_sxt(s, 1, 2, data_r, data_r);
+        } else {
+            tcg_out_ldst_r(s, LDST_32, LDST_LD_S_X, data_r, addr_r, off_r);
+        }
+        break;
+    case 3:
+        tcg_out_ldst_r(s, LDST_64, LDST_LD, data_r, addr_r, off_r);
+        if (TCG_LDST_BSWAP) {
+            tcg_out_rev(s, 1, data_r, data_r);
+        }
+        break;
+    default:
+        tcg_abort();
+    }
+}
+
+static void tcg_out_qemu_st_direct(TCGContext *s, int opc, TCGReg data_r,
+                                   TCGReg addr_r, TCGReg off_r)
+{
+    switch (opc) {
+    case 0:
+        tcg_out_ldst_r(s, LDST_8, LDST_ST, data_r, addr_r, off_r);
+        break;
+    case 1:
+        if (TCG_LDST_BSWAP) {
+            tcg_out_rev16(s, 0, TCG_REG_TMP, data_r);
+            tcg_out_ldst_r(s, LDST_16, LDST_ST, TCG_REG_TMP, addr_r, off_r);
+        } else {
+            tcg_out_ldst_r(s, LDST_16, LDST_ST, data_r, addr_r, off_r);
+        }
+        break;
+    case 2:
+        if (TCG_LDST_BSWAP) {
+            tcg_out_rev(s, 0, TCG_REG_TMP, data_r);
+            tcg_out_ldst_r(s, LDST_32, LDST_ST, TCG_REG_TMP, addr_r, off_r);
+        } else {
+            tcg_out_ldst_r(s, LDST_32, LDST_ST, data_r, addr_r, off_r);
+        }
+        break;
+    case 3:
+        if (TCG_LDST_BSWAP) {
+            tcg_out_rev(s, 1, TCG_REG_TMP, data_r);
+            tcg_out_ldst_r(s, LDST_64, LDST_ST, TCG_REG_TMP, addr_r, off_r);
+        } else {
+            tcg_out_ldst_r(s, LDST_64, LDST_ST, data_r, addr_r, off_r);
+        }
+        break;
+    default:
+        tcg_abort();
+    }
+}
 #endif /* CONFIG_SOFTMMU */
 
 static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, int opc)
@@ -745,8 +847,9 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, int opc)
     }
 
 #else /* !CONFIG_SOFTMMU */
-    tcg_abort(); /* TODO */
-#endif
+    tcg_out_qemu_ld_direct(s, opc, data_reg, addr_reg,
+                           GUEST_BASE ? TCG_REG_GUEST_BASE : TCG_REG_XZR);
+#endif /* CONFIG_SOFTMMU */
 }
 
 static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, int opc)
@@ -774,8 +877,9 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, int opc)
     tcg_out_callr(s, TCG_REG_TMP);
 
 #else /* !CONFIG_SOFTMMU */
-    tcg_abort(); /* TODO */
-#endif
+    tcg_out_qemu_st_direct(s, opc, data_reg, addr_reg,
+                           GUEST_BASE ? TCG_REG_GUEST_BASE : TCG_REG_XZR);
+#endif /* CONFIG_SOFTMMU */
 }
 
 static uint8_t *tb_ret_addr;
@@ -1270,6 +1374,13 @@ static void tcg_target_qemu_prologue(TCGContext *s)
     tcg_set_frame(s, TCG_REG_SP, TCG_STATIC_CALL_ARGS_SIZE,
                   CPU_TEMP_BUF_NLONGS * sizeof(long));
 
+#if defined(CONFIG_USE_GUEST_BASE)
+    if (GUEST_BASE) {
+        tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_GUEST_BASE, GUEST_BASE);
+        tcg_regset_set_reg(s->reserved_regs, TCG_REG_GUEST_BASE);
+    }
+#endif
+
     tcg_out_mov(s, TCG_TYPE_PTR, TCG_AREG0, tcg_target_call_iarg_regs[0]);
     tcg_out_gotor(s, tcg_target_call_iarg_regs[1]);
 
-- 
1.8.1

Re: [Qemu-devel] [PATCH 0/2] AArch64 TCG User Mode

[Richard Henderson]

On 06/05/2013 06:37 AM, Claudio Fontana wrote:
> 
> This series implements TCG User Mode for Aarch64.
> 
> It requires the reviewed but not committed yet series
> "[PATCH v4 0/3] ARM aarch64 TCG target" at:
> http://lists.nongnu.org/archive/html/qemu-devel/2013-05/msg04200.html
> 
> It also requires the reviewed but not committed yet series
> "[PATCH 0/4] aarch64 TCG tlb fast lookup prerequisites" at:
> http://lists.gnu.org/archive/html/qemu-devel/2013-06/msg00170.html
> 
> It also requires Peter's two linux-user changesets:
> 
> "[PATCH] linux-user: Allow getdents to be provided by getden" at:
> http://lists.gnu.org/archive/html/qemu-devel/2013-06/msg00398.html
> 
> "[PATCH 0/2] linux-user: Drop direct use of openat etc sysca" at:
> http://lists.gnu.org/archive/html/qemu-devel/2013-06/msg00015.html
> 
> Tested running on a x86-64 physical machine running Foundation v8,
> running a linux 3.8.0-rc6+ minimal host system based on linaro v8
> image 201301271620 for user space.
> 
> Tested guest binaries: x86-64 small binary, PPC 'ls' binary from debian
> 
> Claudio Fontana (2):
>   user-exec.c: aarch64 initial implementation of cpu_signal_handler
>   tcg/aarch64: implement user mode qemu ld/st
> 
>  configure                |   2 +-
>  tcg/aarch64/tcg-target.c | 121 +++++++++++++++++++++++++++++++++++++++++++++--
>  user-exec.c              |  15 ++++++
>  3 files changed, 132 insertions(+), 6 deletions(-)
> 

Reviewed-by: Richard Henderson <rth@twiddle.net>


r~