From: "Philippe Mathieu-Daudé" <philmd@linaro.org>
To: Richard Henderson <richard.henderson@linaro.org>, qemu-devel@nongnu.org
Cc: Pierrick Bouvier <pierrick.bouvier@linaro.org>,
Peter Xu <peterx@redhat.com>
Subject: Re: [PATCH v2 05/12] accel/tcg: Move post-load tb_flush to vm_change_state hook
Date: Tue, 23 Sep 2025 09:22:11 +0200 [thread overview]
Message-ID: <066df1aa-226f-4cc8-baa8-d7420cd37b72@linaro.org> (raw)
In-Reply-To: <20250923023922.3102471-6-richard.henderson@linaro.org>
On 23/9/25 04:39, Richard Henderson wrote:
> We need not call tb_flush once per cpu, only once per vmload.
>
> By moving the call from cpu_common_post_load to a tcg-specific
> vm_change_state_handler, we do even better than that: we only
> flush when called from HMP triggered loadvm, when we had old
> state to flush.
Nice!
> Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> Cc: Peter Xu <peterx@redhat.com>
> ---
> accel/tcg/tcg-all.c | 21 +++++++++++++++++++++
> hw/core/cpu-system.c | 8 --------
> 2 files changed, 21 insertions(+), 8 deletions(-)
> diff --git a/hw/core/cpu-system.c b/hw/core/cpu-system.c
> index 09c928c1f9..1fd9571017 100644
> --- a/hw/core/cpu-system.c
> +++ b/hw/core/cpu-system.c
> @@ -207,14 +207,6 @@ static int cpu_common_post_load(void *opaque, int version_id)
> cpu_reset_interrupt(cpu, 0x01);
>
> tlb_flush(cpu);
> -
> - /*
> - * loadvm has just updated the content of RAM, bypassing the
> - * usual mechanisms that ensure we flush TBs for writes to
> - * memory we've translated code from. So we must flush all TBs,
> - * which will now be stale.
> - */
> - tb_flush(cpu);
> }
>
To squash:
-- >8 --
--- a/hw/core/cpu-system.c
+++ b/hw/core/cpu-system.c
@@ -25,3 +25,2 @@
#include "system/memory.h"
-#include "exec/tb-flush.h"
#include "qemu/target-info.h"---
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
next prev parent reply other threads:[~2025-09-23 7:22 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-23 2:39 [PATCH v2 00/12] accel/tcg: Improve tb_flush usage Richard Henderson
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 [this message]
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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