From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Subject: [PATCH v2 00/12] accel/tcg: Improve tb_flush usage
Date: Mon, 22 Sep 2025 19:39:04 -0700 [thread overview]
Message-ID: <20250923023922.3102471-1-richard.henderson@linaro.org> (raw)
It is too easy to mis-use tb_flush(). For instance, because of
the cpu argument, some parts assumed that it needed to call the
global flush function for every cpu. It is easy to forget that
the flush is not complete when the call returns: we have merely
queued work to the cpu run loop. So: remove tb_flush and expose
only the core as tb_flush__exclusive, to be used only when we
are already within an exclusive context.
In some cases (gdbstub, alpha, riscv, ppc spapr),
we can eliminate the need for tb_flush completely.
Changes for v2:
- Assert exclusivity in tb_flush__exclusive (pbo)
r~
Richard Henderson (12):
gdbstub: Remove tb_flush uses
accel/tcg: Split out tb_flush__exclusive
target/alpha: Simplify call_pal implementation
target/riscv: Record misa_ext in TCGTBCPUState.cs_base
accel/tcg: Move post-load tb_flush to vm_change_state hook
hw/ppc/spapr: Use tb_invalidate_phys_range in h_page_init
linux-user: Use tb_flush_exclusive to start second thread
plugins: Use tb_flush__exclusive
accel/tcg: Introduce EXCP_TB_FLUSH
accel/tcg: Use EXCP_TB_FLUSH in tb_gen_code
accel/tcg: Remove tb_flush
accel/tcg: Tighten assert in tb_flush__exclusive
include/exec/cpu-common.h | 1 +
include/exec/tb-flush.h | 18 ++++++--------
target/alpha/helper.h | 1 -
accel/tcg/tb-maint.c | 43 +++++++++++----------------------
accel/tcg/tcg-accel-ops-mttcg.c | 7 ++++++
accel/tcg/tcg-accel-ops-rr.c | 9 +++++--
accel/tcg/tcg-all.c | 21 ++++++++++++++++
accel/tcg/translate-all.c | 5 +---
gdbstub/system.c | 4 ---
gdbstub/user.c | 3 ---
hw/core/cpu-system.c | 8 ------
hw/ppc/spapr_hcall.c | 4 +--
linux-user/mmap.c | 4 +--
linux-user/syscall.c | 2 +-
plugins/core.c | 6 ++---
plugins/loader.c | 2 +-
target/alpha/sys_helper.c | 6 -----
target/alpha/translate.c | 21 +++++-----------
target/riscv/csr.c | 3 ---
target/riscv/tcg/tcg-cpu.c | 3 ++-
20 files changed, 75 insertions(+), 96 deletions(-)
--
2.43.0
next reply other threads:[~2025-09-23 2:41 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-23 2:39 Richard Henderson [this message]
2025-09-23 2:39 ` [PATCH v2 01/12] gdbstub: Remove tb_flush uses Richard Henderson
2025-09-23 9:11 ` Philippe Mathieu-Daudé
2025-09-23 16:23 ` Richard Henderson
2025-09-23 2:39 ` [PATCH v2 02/12] accel/tcg: Split out tb_flush__exclusive Richard Henderson
2025-09-23 7:17 ` Philippe Mathieu-Daudé
2025-09-23 9:16 ` Philippe Mathieu-Daudé
2025-09-23 2:39 ` [PATCH v2 03/12] target/alpha: Simplify call_pal implementation Richard Henderson
2025-09-23 7:30 ` Philippe Mathieu-Daudé
2025-09-23 9:05 ` Philippe Mathieu-Daudé
2025-09-23 2:39 ` [PATCH v2 04/12] target/riscv: Record misa_ext in TCGTBCPUState.cs_base Richard Henderson
2025-09-24 6:17 ` LIU Zhiwei
2025-09-24 12:23 ` Daniel Henrique Barboza
2025-09-28 23:10 ` Alistair Francis
2025-09-23 2:39 ` [PATCH v2 05/12] accel/tcg: Move post-load tb_flush to vm_change_state hook Richard Henderson
2025-09-23 7:22 ` Philippe Mathieu-Daudé
2025-09-23 2:39 ` [PATCH v2 06/12] hw/ppc/spapr: Use tb_invalidate_phys_range in h_page_init Richard Henderson
2025-09-23 4:49 ` Harsh Prateek Bora
2025-09-23 8:55 ` Philippe Mathieu-Daudé
2025-09-23 9:45 ` Harsh Prateek Bora
2025-09-23 16:59 ` Richard Henderson
2025-09-23 2:39 ` [PATCH v2 07/12] linux-user: Use tb_flush_exclusive to start second thread Richard Henderson
2025-09-23 8:50 ` Philippe Mathieu-Daudé
2025-09-23 2:39 ` [PATCH v2 08/12] plugins: Use tb_flush__exclusive Richard Henderson
2025-09-23 7:33 ` Philippe Mathieu-Daudé
2025-09-23 13:35 ` Philippe Mathieu-Daudé
2025-09-23 20:28 ` Richard Henderson
2025-09-24 3:18 ` Philippe Mathieu-Daudé
2025-09-23 2:39 ` [PATCH v2 09/12] accel/tcg: Introduce EXCP_TB_FLUSH Richard Henderson
2025-09-23 7:10 ` Paolo Bonzini
2025-09-23 20:02 ` Richard Henderson
2025-09-23 2:39 ` [PATCH v2 10/12] accel/tcg: Use EXCP_TB_FLUSH in tb_gen_code Richard Henderson
2025-09-23 9:15 ` Philippe Mathieu-Daudé
2025-09-23 2:39 ` [PATCH v2 11/12] accel/tcg: Remove tb_flush Richard Henderson
2025-09-23 7:24 ` Philippe Mathieu-Daudé
2025-09-23 2:39 ` [PATCH v2 12/12] accel/tcg: Tighten assert in tb_flush__exclusive Richard Henderson
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