From a371975ef6f634a2322b3dd19682dc0d12d4c77a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Thu, 16 Feb 2023 10:09:48 +0100 Subject: [PATCH] hw/cpu: Extend CPUState::cluster_index documentation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Copy part of the description of commit f7b78602fd ("accel/tcg: Add cluster number to TCG TB hash") in tcg_cpu_init_cflags(), improving a bit CPUState::cluster_index documentation. Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Peter Maydell Message-Id: <20230216142338.82982-2-philmd@linaro.org> --- accel/tcg/tcg-accel-ops.c | 13 ++++++++++++- include/hw/core/cpu.h | 2 ++ 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/accel/tcg/tcg-accel-ops.c b/accel/tcg/tcg-accel-ops.c index d9228fd403..aeb1cbaf65 100644 --- a/accel/tcg/tcg-accel-ops.c +++ b/accel/tcg/tcg-accel-ops.c @@ -44,7 +44,18 @@ void tcg_cpu_init_cflags(CPUState *cpu, bool parallel) { - uint32_t cflags = cpu->cluster_index << CF_CLUSTER_SHIFT; + uint32_t cflags; + + /* + * Include the cluster number in the hash we use to look up TBs. + * This is important because a TB that is valid for one cluster at + * a given physical address and set of CPU flags is not necessarily + * valid for another: + * the two clusters may have different views of physical memory, or + * may have different CPU features (eg FPU present or absent). + */ + cflags = cpu->cluster_index << CF_CLUSTER_SHIFT; + cflags |= parallel ? CF_PARALLEL : 0; cflags |= icount_enabled() ? CF_USE_ICOUNT : 0; cpu->tcg_cflags = cflags; diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h index 5b2792d937..fb5d9667ca 100644 --- a/include/hw/core/cpu.h +++ b/include/hw/core/cpu.h @@ -272,6 +272,8 @@ struct qemu_work_item; * to a cluster this will be UNASSIGNED_CLUSTER_INDEX; otherwise it will * be the same as the cluster-id property of the CPU object's TYPE_CPU_CLUSTER * QOM parent. + * Under TCG this value is propagated to @tcg_cflags. + * See TranslationBlock::TCG CF_CLUSTER_MASK. * @tcg_cflags: Pre-computed cflags for this cpu. * @nr_cores: Number of cores within this CPU package. * @nr_threads: Number of threads within this CPU.