Re: [Qemu-devel] [PATCH 2/2] tcg: aarch64: use 32-bit offset for 32-bit user-mode emulation

[Aurelien Jarno <aurelien@aurel32.net>]

On 2015-07-15 17:27, Paolo Bonzini wrote:
> Thanks to the previous patch, it is now easy for tcg_out_qemu_ld and
> tcg_out_qemu_st to use a 32-bit zero extended offset.  However, the
> guest base register x28 must be the base and addr_reg must be the
> index.
> 
> Reported-by: Leon Alrae <leon.alrae@imgtec.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  tcg/aarch64/tcg-target.c | 26 ++++++++++++++++----------
>  1 file changed, 16 insertions(+), 10 deletions(-)
> 
> diff --git a/tcg/aarch64/tcg-target.c b/tcg/aarch64/tcg-target.c
> index 5395202..4aca883 100644
> --- a/tcg/aarch64/tcg-target.c
> +++ b/tcg/aarch64/tcg-target.c
> @@ -1109,10 +1109,10 @@ static void tcg_out_tlb_read(TCGContext *s, TCGReg addr_reg, TCGMemOp s_bits,
>  #endif /* CONFIG_SOFTMMU */
>  
>  static void tcg_out_qemu_ld_direct(TCGContext *s, TCGMemOp memop, TCGType ext,
> -                                   TCGReg data_r, TCGReg addr_r, TCGReg off_r)
> +                                   TCGReg data_r, TCGReg addr_r,
> +                                   TCGType otype, TCGReg off_r)
>  {
>      const TCGMemOp bswap = memop & MO_BSWAP;
> -    const TCGType otype = TCG_TYPE_I64;
>  
>      switch (memop & MO_SSIZE) {
>      case MO_UB:
> @@ -1165,10 +1165,10 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, TCGMemOp memop, TCGType ext,
>  }
>  
>  static void tcg_out_qemu_st_direct(TCGContext *s, TCGMemOp memop,
> -                                   TCGReg data_r, TCGReg addr_r, TCGReg off_r)
> +                                   TCGReg data_r, TCGReg addr_r,
> +                                   TCGType otype, TCGReg off_r)
>  {
>      const TCGMemOp bswap = memop & MO_BSWAP;
> -    const TCGType otype = TCG_TYPE_I64;
>  
>      switch (memop & MO_SIZE) {
>      case MO_8:
> @@ -1210,12 +1210,15 @@ static void tcg_out_qemu_ld(TCGContext *s, TCGReg data_reg, TCGReg addr_reg,
>      tcg_insn_unit *label_ptr;
>  
>      tcg_out_tlb_read(s, addr_reg, s_bits, &label_ptr, mem_index, 1);
> -    tcg_out_qemu_ld_direct(s, memop, ext, data_reg, addr_reg, TCG_REG_X1);
> +    tcg_out_qemu_ld_direct(s, memop, ext, data_reg, addr_reg,
> +                           TCG_TYPE_I64, TCG_REG_X1);
>      add_qemu_ldst_label(s, true, oi, ext, data_reg, addr_reg,
>                          s->code_ptr, label_ptr);
>  #else /* !CONFIG_SOFTMMU */
> -    tcg_out_qemu_ld_direct(s, memop, ext, data_reg, addr_reg,
> -                           GUEST_BASE ? TCG_REG_GUEST_BASE : TCG_REG_XZR);
> +    const TCGType otype = TARGET_LONG_BITS == 64 ? TCG_TYPE_I64 : TCG_TYPE_I32;
> +    tcg_out_qemu_ld_direct(s, memop, ext, data_reg,
> +                           GUEST_BASE ? TCG_REG_GUEST_BASE : TCG_REG_XZR,
> +                           otype, addr_reg);
>  #endif /* CONFIG_SOFTMMU */
>  }
>  
> @@ -1229,12 +1232,15 @@ static void tcg_out_qemu_st(TCGContext *s, TCGReg data_reg, TCGReg addr_reg,
>      tcg_insn_unit *label_ptr;
>  
>      tcg_out_tlb_read(s, addr_reg, s_bits, &label_ptr, mem_index, 0);
> -    tcg_out_qemu_st_direct(s, memop, data_reg, addr_reg, TCG_REG_X1);
> +    tcg_out_qemu_st_direct(s, memop, data_reg, addr_reg,
> +                           TCG_TYPE_I64, TCG_REG_X1);
>      add_qemu_ldst_label(s, false, oi, s_bits == MO_64, data_reg, addr_reg,
>                          s->code_ptr, label_ptr);
>  #else /* !CONFIG_SOFTMMU */
> -    tcg_out_qemu_st_direct(s, memop, data_reg, addr_reg,
> -                           GUEST_BASE ? TCG_REG_GUEST_BASE : TCG_REG_XZR);
> +    const TCGType otype = TARGET_LONG_BITS == 64 ? TCG_TYPE_I64 : TCG_TYPE_I32;
> +    tcg_out_qemu_st_direct(s, memop, data_reg,
> +                           GUEST_BASE ? TCG_REG_GUEST_BASE : TCG_REG_XZR,
> +                           otype, addr_reg);
>  #endif /* CONFIG_SOFTMMU */
>  }
>  

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                 http://www.aurel32.net