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 3EB5FC3ABAA for ; Fri, 2 May 2025 12:56:34 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uApvy-00013F-Go; Fri, 02 May 2025 08:56:06 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uApvw-00010Q-8v for qemu-devel@nongnu.org; Fri, 02 May 2025 08:56:04 -0400 Received: from mail-yw1-x1132.google.com ([2607:f8b0:4864:20::1132]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1uApvu-0001Oy-FK for qemu-devel@nongnu.org; Fri, 02 May 2025 08:56:04 -0400 Received: by mail-yw1-x1132.google.com with SMTP id 00721157ae682-7082ad1355bso15491827b3.1 for ; Fri, 02 May 2025 05:56:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1746190561; x=1746795361; darn=nongnu.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=7mXFSvhaukdJK+iayCwvss7NQ9GSRN8lcF0pHMoDFDc=; b=Fw5xpYl1EpK3tKpykaheWFOVHJEDoIzvM2y9fmaZKcTPi3ZVCtyOYGLnnL74nQy3Xy 8LM3duW35TJXiojrCTk+rEutMl+DQk8gF30tC/POdhU0na6lS4kUyA4KM5Ld1cVu1PKy SZAMXrEP/mAY3mbKK3T5GhUmSmEl1ttnniSMgyRqpy7LB+92BYzkM7nEtw8O7v8nJLP2 Jamw0Z55KHVM7YS3s3VVNreO27MILXViJ9YAMMHsTmRogvjnCxj9/lzo9HA+WIv1595m AL46aR7qNx5ODQZzggn5Ck7l7pgjJSB+fXG86e7VCg/CtQzRr8I1pd0GN5US9o69HPTy 2mMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1746190561; x=1746795361; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=7mXFSvhaukdJK+iayCwvss7NQ9GSRN8lcF0pHMoDFDc=; b=YZPGh25el9g/60If3Nf7N1QaKeNPWd0uMf5J4TXKFOxbcwS0D1Sn7BXZMzKbAZDF3g FrghdEWc3SPjqS+MN76fD1GqhWqxIupF9xUXWdS7nbjEh9dnQkoRWV1CPE9Bh+9P+bUG wOzMaT7stH/G6kHTCxzlQm3oeu5qBA7k7ldUoenOEhwkOO2Cc+f6H3Di873OIDwbIt00 LlGkTqs36wzqUtmxKq37gtbxKTd37GfA8R0SJrMjwY9eFDxxnGGIs/WXtpPhuNQmO1YB pDf4ujSi2XIR2hqAVpS7khOR7tji8TJHDkRpIM21Z+bSpYLU9Q3cA0aGAxfWYoHram0g Xzpw== X-Gm-Message-State: AOJu0YzSOkkzdOVuew0PlYU7vliLl6pAsVjyWkghBDG0ypXNuC6LAyf5 TOukhbYfBcwRS9YHbL+HBQc83pZ+YoYjabq08119uL7iWQAejgkScgosVbZpNVCcjCXKP+NnVu5 B72raRvY6nZUHB7iiE+a2/hKQM1dEqrL36yU6eg== X-Gm-Gg: ASbGncu3ImIaBoemzp7kfwMJMVVilBUS2u0idMy4VNvBeKFDzBcyeD1UwRDn7q59AXy BKJ7LEGzq6iRrqtbxaHaTvru0RU5GySzfCMnwn1YxW16HCWhWyiNTrXgy5iQhk4f6mjJNmNO1dL bEq1wsY8A8Aobje3mFHLiyKmE= X-Google-Smtp-Source: AGHT+IH/VWx+ZkU4B7yFZ+VYwLqZZgxbg/rui5KRZGFi6vhrl/cEBh0g8HPNlm6SPDuOsWOMidtf8k229/UNftraBiw= X-Received: by 2002:a81:d849:0:b0:6fe:b88e:4d94 with SMTP id 00721157ae682-708cf167f41mr33323397b3.19.1746190561116; Fri, 02 May 2025 05:56:01 -0700 (PDT) MIME-Version: 1.0 References: <20250402135229.28143-1-mads@ynddal.dk> <20250402135229.28143-3-mads@ynddal.dk> In-Reply-To: <20250402135229.28143-3-mads@ynddal.dk> From: Peter Maydell Date: Fri, 2 May 2025 13:55:48 +0100 X-Gm-Features: ATxdqUFcZ2V1VvpUxM0hFFg8rlhOByQLMDwlT-mOQ6SAD6rycE17-XVo_jBjQO4 Message-ID: Subject: Re: [PATCH 2/2] hvf: only update sysreg from owning thread To: Mads Ynddal Cc: qemu-devel@nongnu.org, qemu-arm@nongnu.org, Phil Dennis-Jordan , Cameron Esfahani , Roman Bolshakov , Alexander Graf , Mads Ynddal , Daniel Gomez Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2607:f8b0:4864:20::1132; envelope-from=peter.maydell@linaro.org; helo=mail-yw1-x1132.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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, RCVD_IN_DNSWL_NONE=-0.0001, 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, 2 Apr 2025 at 14:52, Mads Ynddal wrote: > > From: Mads Ynddal > > hv_vcpu_set_sys_reg should only be called from the owning thread of the > vCPU, so to avoid crashes, the call to hvf_update_guest_debug is > dispatched to the individual threads. > > Tested-by: Daniel Gomez > Signed-off-by: Mads Ynddal > --- > accel/hvf/hvf-all.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/accel/hvf/hvf-all.c b/accel/hvf/hvf-all.c > index d404e01ade..3fc65d6b23 100644 > --- a/accel/hvf/hvf-all.c > +++ b/accel/hvf/hvf-all.c > @@ -58,8 +58,13 @@ int hvf_sw_breakpoints_active(CPUState *cpu) > return !QTAILQ_EMPTY(&hvf_state->hvf_sw_breakpoints); > } > > -int hvf_update_guest_debug(CPUState *cpu) > +static void do_hvf_update_guest_debug(CPUState *cpu, run_on_cpu_data arg) > { > hvf_arch_update_guest_debug(cpu); > +} > + > +int hvf_update_guest_debug(CPUState *cpu) > +{ > + run_on_cpu(cpu, do_hvf_update_guest_debug, RUN_ON_CPU_NULL); > return 0; > } run_on_cpu() implicitly drops the BQL, so it is a potential really nasty footgun in this kind of situation where callers to update_guest_debug aren't expecting the BQL to be dropped on them. But we already use run_on_cpu() in the KVM equivalent kvm_update_guest_debug(), so presumably it's also OK here... -- PMM