From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A3F2DC4332F for ; Mon, 29 Nov 2021 14:19:18 +0000 (UTC) Received: from localhost ([::1]:32842 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mrhUz-0007hL-LQ for qemu-devel@archiver.kernel.org; Mon, 29 Nov 2021 09:19:17 -0500 Received: from eggs.gnu.org ([209.51.188.92]:56362) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mrhLk-0001Fz-3a for qemu-devel@nongnu.org; Mon, 29 Nov 2021 09:09:44 -0500 Received: from [2a00:1450:4864:20::32d] (port=37612 helo=mail-wm1-x32d.google.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mrhLd-0006Tx-3C for qemu-devel@nongnu.org; Mon, 29 Nov 2021 09:09:43 -0500 Received: by mail-wm1-x32d.google.com with SMTP id k37-20020a05600c1ca500b00330cb84834fso16939732wms.2 for ; Mon, 29 Nov 2021 06:09:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=1TZ8swcyv0OX5mGYSW/yBjqG9DvFKB22CAAKdZIQEUc=; b=XzTav9bFvkmOT9bE9OZXiGyVLDbkGEJGdCpu9RVRwVcuUqoaxF+zCQoeemiXnPLNrx 2P9gTsTEuxj3wnMkmjp9oNT7rBx4xt5ta/Hf4+9zB3XjmM2vUckTSwI+R7aHdN8EmgSG eseAL95sZbsciQkKAJRZRaircLMNK/2u7TwK37aBdV/EoejgIcGxmRIzNwMJMR34YsrU bQZZlNfffMMshRsMglo2/HiKbhxabRmPvqcZ5p3+ubMlV0J+yiR/uP5/6UjfWnaAUyRA hOmfmBYsAAOwLzAO2d0ilSKYO11KALHO3WqLlXIbmyvSfFm+Vk/S9zj3ASp7GE2jdCQj Pdcg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=1TZ8swcyv0OX5mGYSW/yBjqG9DvFKB22CAAKdZIQEUc=; b=gILoIgYTbnVRJghHGNMD2ShbnPgTUMMaOytBt5urXLxC1lgZqMeZD2x3TL22JB8wmR lQmMAqUL4WOYn9KdLD3OkBQzEiivHtva73Q34ng817tWdzT2HNtDOCAKKC0ARPlN08Ju pi/Hrq0NuXNR7kQ5kt3OXp660EpDl01ZlWZaqA5VoW9gMYbc8ec5uTrZF4kEKljf4k/G S156GyOSOacwgCJJDFk/PvoNc0aYhOsaqS94LFSDlN0YkUWhJje85s1zWyR4VGwXrHLb STTUBS0ke4NBq4E7zbN+wudKcLSEt6oxlQI3NFBOqwdQ0IWReuGEtZyq+o0mfujItSqe LMkA== X-Gm-Message-State: AOAM5321OUfyYZwN+ozoRNt8UAYovEPCYs9UOAmqwHbNVVI1KKEBsVVK SIZLo5A0JRn7l4gwrL2sSkgqGQ== X-Google-Smtp-Source: ABdhPJxx5Hvw9vCKu/PqzgZaxHQw7FyQSEcBiW3/yvNy9Pr7Vm5aZyWV60xyvaA3LGa7lXM5cW8ZtQ== X-Received: by 2002:a05:600c:24d:: with SMTP id 13mr36711515wmj.156.1638194975097; Mon, 29 Nov 2021 06:09:35 -0800 (PST) Received: from zen.linaroharston ([51.148.130.216]) by smtp.gmail.com with ESMTPSA id e18sm14076042wrs.48.2021.11.29.06.09.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 Nov 2021 06:09:34 -0800 (PST) Received: from zen.lan (localhost [127.0.0.1]) by zen.linaroharston (Postfix) with ESMTP id 07FB91FF98; Mon, 29 Nov 2021 14:09:33 +0000 (GMT) From: =?UTF-8?q?Alex=20Benn=C3=A9e?= To: qemu-devel@nongnu.org Subject: [PATCH v3 1/8] accel/tcg: introduce CF_NOIRQ Date: Mon, 29 Nov 2021 14:09:25 +0000 Message-Id: <20211129140932.4115115-2-alex.bennee@linaro.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211129140932.4115115-1-alex.bennee@linaro.org> References: <20211129140932.4115115-1-alex.bennee@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Host-Lookup-Failed: Reverse DNS lookup failed for 2a00:1450:4864:20::32d (failed) Received-SPF: pass client-ip=2a00:1450:4864:20::32d; envelope-from=alex.bennee@linaro.org; helo=mail-wm1-x32d.google.com X-Spam_score_int: -12 X-Spam_score: -1.3 X-Spam_bar: - X-Spam_report: (-1.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, PDS_HP_HELO_NORDNS=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: fam@euphon.net, berrange@redhat.com, Richard Henderson , f4bug@amsat.org, stefanha@redhat.com, crosa@redhat.com, pbonzini@redhat.com, =?UTF-8?q?Alex=20Benn=C3=A9e?= , aurelien@aurel32.net Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Here we introduce a new compiler flag to disable the checking of exit request (icount_decr.u32). This is useful when we want to ensure the next block cannot be preempted by an asynchronous event. Suggested-by: Richard Henderson Signed-off-by: Alex Bennée Reviewed-by: Richard Henderson --- v2 - split from larger patch - reword the check in cpu_handle_interrupt and scope to CF_NOIRQ only --- include/exec/exec-all.h | 1 + include/exec/gen-icount.h | 21 +++++++++++++++++---- 2 files changed, 18 insertions(+), 4 deletions(-) diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index 6bb2a0f7ec..35d8e93976 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -503,6 +503,7 @@ struct TranslationBlock { #define CF_USE_ICOUNT 0x00020000 #define CF_INVALID 0x00040000 /* TB is stale. Set with @jmp_lock held */ #define CF_PARALLEL 0x00080000 /* Generate code for a parallel context */ +#define CF_NOIRQ 0x00100000 /* Generate an uninterruptible TB */ #define CF_CLUSTER_MASK 0xff000000 /* Top 8 bits are cluster ID */ #define CF_CLUSTER_SHIFT 24 diff --git a/include/exec/gen-icount.h b/include/exec/gen-icount.h index 610cba58fe..c57204ddad 100644 --- a/include/exec/gen-icount.h +++ b/include/exec/gen-icount.h @@ -21,7 +21,6 @@ static inline void gen_tb_start(const TranslationBlock *tb) { TCGv_i32 count; - tcg_ctx->exitreq_label = gen_new_label(); if (tb_cflags(tb) & CF_USE_ICOUNT) { count = tcg_temp_local_new_i32(); } else { @@ -42,7 +41,19 @@ static inline void gen_tb_start(const TranslationBlock *tb) icount_start_insn = tcg_last_op(); } - tcg_gen_brcondi_i32(TCG_COND_LT, count, 0, tcg_ctx->exitreq_label); + /* + * Emit the check against icount_decr.u32 to see if we should exit + * unless we suppress the check with CF_NOIRQ. If we are using + * icount and have suppressed interruption the higher level code + * should have ensured we don't run more instructions than the + * budget. + */ + if (tb_cflags(tb) & CF_NOIRQ) { + tcg_ctx->exitreq_label = NULL; + } else { + tcg_ctx->exitreq_label = gen_new_label(); + tcg_gen_brcondi_i32(TCG_COND_LT, count, 0, tcg_ctx->exitreq_label); + } if (tb_cflags(tb) & CF_USE_ICOUNT) { tcg_gen_st16_i32(count, cpu_env, @@ -74,8 +85,10 @@ static inline void gen_tb_end(const TranslationBlock *tb, int num_insns) tcgv_i32_arg(tcg_constant_i32(num_insns))); } - gen_set_label(tcg_ctx->exitreq_label); - tcg_gen_exit_tb(tb, TB_EXIT_REQUESTED); + if (tcg_ctx->exitreq_label) { + gen_set_label(tcg_ctx->exitreq_label); + tcg_gen_exit_tb(tb, TB_EXIT_REQUESTED); + } } #endif -- 2.30.2