qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Richard Henderson <richard.henderson@linaro.org>
To: Alistair Francis <alistair.francis@wdc.com>,
	qemu-devel@nongnu.org, qemu-riscv@nongnu.org
Cc: alistair23@gmail.com, bmeng.cn@gmail.com, palmer@dabbelt.com
Subject: Re: [PATCH v1 4/8] target/riscv: Remove the hardcoded MSTATUS_SD macro
Date: Mon, 5 Apr 2021 08:10:35 -0700	[thread overview]
Message-ID: <81cbeace-c357-1ef3-1a1c-f1b266e66a98@linaro.org> (raw)
In-Reply-To: <7efb55362999a5b709ea8e7fa0ea188e740d9c67.1617393702.git.alistair.francis@wdc.com>

On 4/2/21 1:02 PM, Alistair Francis wrote:
> @@ -369,6 +369,9 @@ static void gen_jal(DisasContext *ctx, int rd, target_ulong imm)
>   static void mark_fs_dirty(DisasContext *ctx)
>   {
>       TCGv tmp;
> +    CPUState *cpu = ctx->cs;
> +    CPURISCVState *env = cpu->env_ptr;
> +
>       if (ctx->mstatus_fs == MSTATUS_FS) {
>           return;
>       }
> @@ -377,12 +380,24 @@ static void mark_fs_dirty(DisasContext *ctx)
>   
>       tmp = tcg_temp_new();
>       tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus));
> -    tcg_gen_ori_tl(tmp, tmp, MSTATUS_FS | MSTATUS_SD);
> +    if (riscv_cpu_is_32bit(env)) {

This is less than ideal, and will be incorrect long term.
You should check ctx->misa instead.

Eventually you'll need to change riscv_tr_init_disas_context to not just copy 
ctx->misa from env.  At present we flush all translation blocks when misa 
changes, which works.  But you won't want to do that when the hypervisor is 
64-bit and the guest is 32-bit.

Anyway, I think it would be a good idea to create a helper local to translate, 
akin to has_ext().

> +        tcg_gen_ori_tl(tmp, tmp, MSTATUS_FS | MSTATUS32_SD);
> +    } else {
> +#if defined(TARGET_RISCV64)
> +        tcg_gen_ori_tl(tmp, tmp, MSTATUS_FS | MSTATUS64_SD);
> +#endif

The ifdefs are ugly.  I presume there's some sort of compiler warning here? 
Does it go away if you cast to target_ulong?

How about

     target_ulong sd = is_32bit(ctx) ? MSTATUS32_SD : MSTATUS64_SD;
     tcg_gen_ori_tl(tmp, tmp, MSTATUS_FS | sd);


r~


  reply	other threads:[~2021-04-05 15:25 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-02 20:02 [PATCH v1 0/8] RISC-V: Steps towards running 32-bit guests on Alistair Francis
2021-04-02 20:02 ` [PATCH v1 1/8] target/riscv: Remove the hardcoded RVXLEN macro Alistair Francis
2021-04-05 14:48   ` Richard Henderson
2021-04-12  9:10   ` Bin Meng
2021-04-02 20:02 ` [PATCH v1 2/8] target/riscv: Remove the hardcoded SSTATUS_SD macro Alistair Francis
2021-04-05 14:49   ` Richard Henderson
2021-04-12  9:10   ` Bin Meng
2021-04-02 20:02 ` [PATCH v1 3/8] target/riscv: Remove the hardcoded HGATP_MODE macro Alistair Francis
2021-04-05 14:54   ` Richard Henderson
2021-04-02 20:02 ` [PATCH v1 4/8] target/riscv: Remove the hardcoded MSTATUS_SD macro Alistair Francis
2021-04-05 15:10   ` Richard Henderson [this message]
2021-04-07 17:11     ` Alistair Francis
2021-04-08 15:20     ` Alistair Francis
2021-04-08 18:51       ` Richard Henderson
2021-04-02 20:02 ` [PATCH v1 5/8] target/riscv: Remove the hardcoded SATP_MODE macro Alistair Francis
2021-04-05 15:14   ` Richard Henderson
2021-04-02 20:02 ` [PATCH v1 6/8] target/riscv: Remove the unused HSTATUS_WPRI macro Alistair Francis
2021-04-05 15:15   ` Richard Henderson
2021-04-12  9:10   ` Bin Meng
2021-04-02 20:02 ` [PATCH v1 7/8] target/riscv: Remove an unused CASE_OP_32_64 macro Alistair Francis
2021-04-05 15:15   ` Richard Henderson
2021-04-12  9:10   ` Bin Meng
2021-04-02 20:03 ` [PATCH v1 8/8] target/riscv: Include RV32 instructions in RV64 build Alistair Francis
2021-04-06 14:57   ` Richard Henderson

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=81cbeace-c357-1ef3-1a1c-f1b266e66a98@linaro.org \
    --to=richard.henderson@linaro.org \
    --cc=alistair.francis@wdc.com \
    --cc=alistair23@gmail.com \
    --cc=bmeng.cn@gmail.com \
    --cc=palmer@dabbelt.com \
    --cc=qemu-devel@nongnu.org \
    --cc=qemu-riscv@nongnu.org \
    --subject='Re: [PATCH v1 4/8] target/riscv: Remove the hardcoded MSTATUS_SD macro' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).