From nobody Mon Feb 9 15:47:02 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=ispras.ru Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1636624606504747.0933654802667; Thu, 11 Nov 2021 01:56:46 -0800 (PST) Received: from localhost ([::1]:41638 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ml6p3-0000sA-6W for importer@patchew.org; Thu, 11 Nov 2021 04:56:45 -0500 Received: from eggs.gnu.org ([209.51.188.92]:33960) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ml6nZ-0007JN-Ci for qemu-devel@nongnu.org; Thu, 11 Nov 2021 04:55:14 -0500 Received: from mail.ispras.ru ([83.149.199.84]:44968) by eggs.gnu.org with esmtps (TLS1.2:DHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ml6nX-0008OB-Dv for qemu-devel@nongnu.org; Thu, 11 Nov 2021 04:55:13 -0500 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id 1D48740755CE; Thu, 11 Nov 2021 09:55:09 +0000 (UTC) Subject: [PATCH v2 1/3] icount: preserve cflags when custom tb is about to execute From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Thu, 11 Nov 2021 12:55:08 +0300 Message-ID: <163662450891.125458.6706022775465303586.stgit@pasha-ThinkPad-X280> In-Reply-To: <163662450348.125458.5494710452733592356.stgit@pasha-ThinkPad-X280> References: <163662450348.125458.5494710452733592356.stgit@pasha-ThinkPad-X280> User-Agent: StGit/0.23 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=83.149.199.84; envelope-from=pavel.dovgalyuk@ispras.ru; helo=mail.ispras.ru X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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: pavel.dovgalyuk@ispras.ru, david@redhat.com, richard.henderson@linaro.org, peterx@redhat.com, pbonzini@redhat.com, alex.bennee@linaro.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZM-MESSAGEID: 1636624608854100003 When debugging with the watchpoints, qemu may need to create TB with single instruction. This is achieved by setting cpu->cflags_next_tb. But when this block is about to execute, it may be interrupted by another thread. In this case cflags will be lost and next executed TB will not be the special one. This patch checks TB exit reason and restores cflags_next_tb to allow finding the interrupted block. Signed-off-by: Pavel Dovgalyuk --- accel/tcg/cpu-exec.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c index 2d14d02f6c..df12452b8f 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -846,6 +846,16 @@ static inline void cpu_loop_exec_tb(CPUState *cpu, Tra= nslationBlock *tb, * cpu_handle_interrupt. cpu_handle_interrupt will also * clear cpu->icount_decr.u16.high. */ + if (cpu->cflags_next_tb =3D=3D -1 + && (!use_icount || !(tb->cflags & CF_USE_ICOUNT) + || cpu_neg(cpu)->icount_decr.u16.low >=3D tb->icount)) { + /* + * icount is disabled or there are enough instructions + * in the budget, do not retranslate this block with + * different parameters. + */ + cpu->cflags_next_tb =3D tb->cflags; + } return; } =20 From nobody Mon Feb 9 15:47:02 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=ispras.ru Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1636624703163458.2956422277116; Thu, 11 Nov 2021 01:58:23 -0800 (PST) Received: from localhost ([::1]:47060 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ml6qb-0004cV-Ot for importer@patchew.org; Thu, 11 Nov 2021 04:58:21 -0500 Received: from eggs.gnu.org ([209.51.188.92]:33984) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ml6ne-0007L2-H5 for qemu-devel@nongnu.org; Thu, 11 Nov 2021 04:55:19 -0500 Received: from mail.ispras.ru ([83.149.199.84]:44988) by eggs.gnu.org with esmtps (TLS1.2:DHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ml6nb-0008Oh-VS for qemu-devel@nongnu.org; Thu, 11 Nov 2021 04:55:17 -0500 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id 7E03840A2BC1; Thu, 11 Nov 2021 09:55:14 +0000 (UTC) Subject: [PATCH v2 2/3] softmmu: fix watchpoint-interrupt races From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Thu, 11 Nov 2021 12:55:14 +0300 Message-ID: <163662451431.125458.14945698834107669531.stgit@pasha-ThinkPad-X280> In-Reply-To: <163662450348.125458.5494710452733592356.stgit@pasha-ThinkPad-X280> References: <163662450348.125458.5494710452733592356.stgit@pasha-ThinkPad-X280> User-Agent: StGit/0.23 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=83.149.199.84; envelope-from=pavel.dovgalyuk@ispras.ru; helo=mail.ispras.ru X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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: pavel.dovgalyuk@ispras.ru, david@redhat.com, richard.henderson@linaro.org, peterx@redhat.com, pbonzini@redhat.com, alex.bennee@linaro.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZM-MESSAGEID: 1636624704849100001 Watchpoint may be processed in two phases. First one is detecting the instruction with target memory access. And the second one is executing only one instruction and setting the debug interrupt flag. Hardware interrupts can break this sequence when they happen after the first watchpoint phase. This patch postpones the interrupt request until watchpoint is processed. Signed-off-by: Pavel Dovgalyuk Reviewed-by: Alex Benn=C3=A9e Reviewed-by: David Hildenbrand --- accel/tcg/cpu-exec.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c index df12452b8f..e4526c2f5e 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -742,6 +742,11 @@ static inline bool cpu_handle_interrupt(CPUState *cpu, qemu_mutex_unlock_iothread(); return true; } + /* Process watchpoints first, or interrupts will ruin everything */ + if (cpu->watchpoint_hit) { + qemu_mutex_unlock_iothread(); + return false; + } #if !defined(CONFIG_USER_ONLY) if (replay_mode =3D=3D REPLAY_MODE_PLAY && !replay_has_interrupt()= ) { /* Do nothing */ From nobody Mon Feb 9 15:47:02 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=ispras.ru Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1636624612192938.0287980539035; Thu, 11 Nov 2021 01:56:52 -0800 (PST) Received: from localhost ([::1]:42166 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ml6p9-0001Dd-3S for importer@patchew.org; Thu, 11 Nov 2021 04:56:51 -0500 Received: from eggs.gnu.org ([209.51.188.92]:34042) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ml6nt-0007Rh-J6 for qemu-devel@nongnu.org; Thu, 11 Nov 2021 04:55:35 -0500 Received: from mail.ispras.ru ([83.149.199.84]:45008) by eggs.gnu.org with esmtps (TLS1.2:DHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ml6ni-0008T4-7j for qemu-devel@nongnu.org; Thu, 11 Nov 2021 04:55:32 -0500 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id E7B7D40A2BC1; Thu, 11 Nov 2021 09:55:19 +0000 (UTC) Subject: [PATCH v2 3/3] softmmu: fix watchpoints on memory used by vCPU internals From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Thu, 11 Nov 2021 12:55:19 +0300 Message-ID: <163662451972.125458.8046031260136838656.stgit@pasha-ThinkPad-X280> In-Reply-To: <163662450348.125458.5494710452733592356.stgit@pasha-ThinkPad-X280> References: <163662450348.125458.5494710452733592356.stgit@pasha-ThinkPad-X280> User-Agent: StGit/0.23 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=83.149.199.84; envelope-from=pavel.dovgalyuk@ispras.ru; helo=mail.ispras.ru X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_PASS=-0.001, T_SPF_HELO_TEMPERROR=0.01 autolearn=ham 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: pavel.dovgalyuk@ispras.ru, david@redhat.com, richard.henderson@linaro.org, peterx@redhat.com, pbonzini@redhat.com, alex.bennee@linaro.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZM-MESSAGEID: 1636624612759100001 When vCPU processes interrupt request or exception, it can save register values to the memory. Watchpoints may also be set on these memory cells. In this case watchpoint processing code should not retranslate the block which accessed the memory, because there is no such block at all. "After access" watchpoint also can't be used in such case. This patch adds some conditions to prevent failures when watchpoint is set on memory used for saving the registers on interrupt request. Signed-off-by: Pavel Dovgalyuk --- softmmu/physmem.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/softmmu/physmem.c b/softmmu/physmem.c index 314f8b439c..53edcf9a51 100644 --- a/softmmu/physmem.c +++ b/softmmu/physmem.c @@ -886,6 +886,14 @@ void cpu_check_watchpoint(CPUState *cpu, vaddr addr, v= addr len, =20 assert(tcg_enabled()); if (cpu->watchpoint_hit) { + if (!ra) { + /* + * Another memory access after hitting the watchpoint. + * There is no translation block and interrupt request + * is already set. + */ + return; + } /* * We re-entered the check after replacing the TB. * Now raise the debug interrupt so that it will @@ -936,6 +944,12 @@ void cpu_check_watchpoint(CPUState *cpu, vaddr addr, v= addr len, continue; } cpu->watchpoint_hit =3D wp; + if (!ra) { + /* We're not in the TB, can't stop before the access. */ + g_assert(!(wp->flags & BP_STOP_BEFORE_ACCESS)); + cpu_interrupt(cpu, CPU_INTERRUPT_DEBUG); + return; + } =20 mmap_lock(); /* This call also restores vCPU state */