From: Richard Henderson <richard.henderson@linaro.org>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-devel@nongnu.org
Subject: Re: [PATCH for-8.0 07/29] accel/tcg: Honor atomicity of loads
Date: Tue, 22 Nov 2022 10:04:01 -0800 [thread overview]
Message-ID: <ee02113c-0321-86a7-f23f-835a02a5ef94@linaro.org> (raw)
In-Reply-To: <CAFEAcA_6PHdEPBFqyHC+z8Xz8FcJw1wgDu-R+ynm+Qv04WS1Xg@mail.gmail.com>
On 11/22/22 06:35, Peter Maydell wrote:
>> + /*
>> + * Here we have the architectural atomicity of the operation.
>> + * However, when executing in a serial context, we need no extra
>> + * host atomicity in order to avoid racing. This reduction
>> + * avoids looping with cpu_loop_exit_atomic.
>> + */
>> + if (cpu_in_serial_context(env_cpu(env))) {
>
> Is it OK to use cpu_in_serial_context() here ? Even if
> there's no other vCPU executing in parallel, there might
> be device model code doing a memory write in the iothread,
> I think.
Well, it's no different from how we currently treat compare-and-swap expansion. But you
have a point -- we should probably be doing something with the iothread lock for both
EXCP_ATOMIC and round-robin mode.
r~
next prev parent reply other threads:[~2022-11-22 18:04 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-18 9:47 [PATCH for-8.0 00/29] tcg: Improve atomicity support Richard Henderson
2022-11-18 9:47 ` [PATCH for-8.0 01/29] include/qemu/cpuid: Introduce xgetbv_low Richard Henderson
2022-11-21 12:15 ` Philippe Mathieu-Daudé
2022-11-18 9:47 ` [PATCH for-8.0 02/29] include/exec/memop: Add bits describing atomicity Richard Henderson
2022-11-18 9:47 ` [PATCH for-8.0 03/29] accel/tcg: Add cpu_in_serial_context Richard Henderson
2022-11-18 9:47 ` [PATCH for-8.0 04/29] accel/tcg: Introduce tlb_read_idx Richard Henderson
2022-11-21 12:25 ` Philippe Mathieu-Daudé
2022-11-18 9:47 ` [PATCH for-8.0 05/29] accel/tcg: Reorg system mode load helpers Richard Henderson
2022-11-18 9:47 ` [PATCH for-8.0 06/29] accel/tcg: Reorg system mode store helpers Richard Henderson
2022-11-18 9:47 ` [PATCH for-8.0 07/29] accel/tcg: Honor atomicity of loads Richard Henderson
2022-11-22 14:35 ` Peter Maydell
2022-11-22 18:04 ` Richard Henderson [this message]
2022-11-18 9:47 ` [PATCH for-8.0 08/29] accel/tcg: Honor atomicity of stores Richard Henderson
2022-11-18 9:47 ` [PATCH for-8.0 09/29] tcg/tci: Use cpu_{ld,st}_mmu Richard Henderson
2022-11-21 12:40 ` Philippe Mathieu-Daudé
2022-11-18 9:47 ` [PATCH for-8.0 10/29] tcg: Unify helper_{be,le}_{ld,st}* Richard Henderson
2022-11-21 12:48 ` Philippe Mathieu-Daudé
2022-11-18 9:47 ` [PATCH for-8.0 11/29] accel/tcg: Implement helper_{ld, st}*_mmu for user-only Richard Henderson
2022-11-18 9:47 ` [PATCH for-8.0 12/29] tcg: Add 128-bit guest memory primitives Richard Henderson
2022-11-22 3:30 ` Richard Henderson
2022-11-18 9:47 ` [PATCH for-8.0 13/29] meson: Detect atomic128 support with optimization Richard Henderson
2022-11-18 9:47 ` [PATCH for-8.0 14/29] tcg/i386: Add have_atomic16 Richard Henderson
2022-11-18 9:47 ` [PATCH for-8.0 15/29] include/qemu/int128: Add vector type to Int128Alias Richard Henderson
2022-11-21 23:45 ` Philippe Mathieu-Daudé
2022-11-22 18:21 ` Philippe Mathieu-Daudé
2022-11-22 18:31 ` Philippe Mathieu-Daudé
2022-11-18 9:47 ` [PATCH for-8.0 16/29] accel/tcg: Use have_atomic16 in ldst_atomicity.c.inc Richard Henderson
2022-11-18 9:47 ` [PATCH for-8.0 17/29] tcg/aarch64: Add have_lse, have_lse2 Richard Henderson
2022-11-21 23:10 ` Philippe Mathieu-Daudé
2022-11-21 23:14 ` Philippe Mathieu-Daudé
2022-11-18 9:47 ` [PATCH for-8.0 18/29] accel/tcg: Add aarch64 specific support in ldst_atomicity Richard Henderson
2022-11-18 9:47 ` [PATCH for-8.0 19/29] tcg: Introduce TCG_OPF_TYPE_MASK Richard Henderson
2022-11-21 16:12 ` Philippe Mathieu-Daudé
2022-11-18 9:47 ` [PATCH for-8.0 20/29] tcg: Add INDEX_op_qemu_{ld,st}_i128 Richard Henderson
2022-11-21 22:59 ` Philippe Mathieu-Daudé
2022-11-18 9:47 ` [PATCH for-8.0 21/29] tcg/i386: Introduce tcg_out_mov2 Richard Henderson
2022-11-21 16:21 ` Philippe Mathieu-Daudé
2022-11-18 9:47 ` [PATCH for-8.0 22/29] tcg/i386: Introduce tcg_out_testi Richard Henderson
2022-11-21 16:22 ` Philippe Mathieu-Daudé
2022-11-18 9:47 ` [PATCH for-8.0 23/29] tcg/i386: Use full load/store helpers in user-only mode Richard Henderson
2022-11-18 9:47 ` [PATCH for-8.0 24/29] tcg/i386: Replace is64 with type in qemu_ld/st routines Richard Henderson
2022-11-21 16:27 ` Philippe Mathieu-Daudé
2022-11-18 9:47 ` [PATCH for-8.0 25/29] tcg/i386: Mark Win64 call-saved vector regs as reserved Richard Henderson
2022-11-21 16:28 ` Philippe Mathieu-Daudé
2022-11-18 9:47 ` [PATCH for-8.0 26/29] tcg/i386: Examine MemOp for atomicity and alignment Richard Henderson
2022-11-18 9:47 ` [PATCH for-8.0 27/29] tcg/i386: Support 128-bit load/store with have_atomic16 Richard Henderson
2022-11-18 9:47 ` [PATCH for-8.0 28/29] tcg/i386: Add vex_v argument to tcg_out_vex_modrm_pool Richard Henderson
2022-11-18 9:47 ` [PATCH for-8.0 29/29] tcg/i386: Honor 64-bit atomicity in 32-bit mode Richard Henderson
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