From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6DD887E0E8 for ; Sun, 23 Feb 2025 04:57:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740286652; cv=none; b=tHIctGoaTM51KRbq/XT6Owf/YkyHba1Xi1FE6JZ8Iq20026WrPtiFSbC80j1Tv1wFRs6RSEP4gjBixrUVBA+4JNin3uzaC1F9WEfQiTtzMuRm0xvvQuWMTC1Fk9XIx8qQYjL5UEKxuM01bEA+AwqecrU4q+vE1CV1stbOaYn3Nc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740286652; c=relaxed/simple; bh=wGfQHdYGTNKFILC4asS/SCxHJUWU5t+CQGfAkXCoeAQ=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=gVXl02OszSfVDsBSUtNLWv5WbwTW8lUVhTa69PfukSt7fxBAe/W7A+Id+WsYjl5etvcUb0YGuYrYqqNDG8WOM5mwxQy1VtKfKeTiJPNd76bmHEhhWzysBblx4GjQ8SlgfFkgVPjG0fUBv6OCWjt5pvz2de7YsXA5Bm6SN/NMTP4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZyrE9Flp; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZyrE9Flp" Received: by smtp.kernel.org (Postfix) with ESMTPS id D1458C4CEEB for ; Sun, 23 Feb 2025 04:57:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740286651; bh=wGfQHdYGTNKFILC4asS/SCxHJUWU5t+CQGfAkXCoeAQ=; h=From:To:Subject:Date:In-Reply-To:References:From; b=ZyrE9FlpgxLt7p7jOvFkkxWyimUC4d7HdaMVuNK26oTETl5Mpr9p8plHpYt/fZSSq eYR8/g5ByBRhiWwelRvK6Sn373wPfGxKkr/xTgrw/riY71PZwWnPOOcMwhzlAh2eME G6/WzaaWEjOVVPAvLK+UxAATlK5TIMqzdtiJ+izbRH6SxhnyHSzrgBjgc7MaumcbSi zH9Ch+Ru7xF8Kz151NLzOAJbmAgckzeJwwccyR25ahWEHce6HoLPFrrBWW7XAopC47 75Cpqq4WDdwmoUEyeC3avi7nKqfiavCajA6w9E0ITw6X/5saAMbQlosHSc5UoW4vw6 Y84UvodKW0ZgA== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id C9345C41606; Sun, 23 Feb 2025 04:57:31 +0000 (UTC) From: bugzilla-daemon@kernel.org To: kvm@vger.kernel.org Subject: [Bug 219787] Guest's applications crash with EXCEPTION_SINGLE_STEP (0x80000004) Date: Sun, 23 Feb 2025 04:57:31 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: AssignedTo virtualization_kvm@kernel-bugs.osdl.org X-Bugzilla-Product: Virtualization X-Bugzilla-Component: kvm X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: high X-Bugzilla-Who: ravi.bangoria@amd.com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: virtualization_kvm@kernel-bugs.osdl.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 https://bugzilla.kernel.org/show_bug.cgi?id=3D219787 --- Comment #16 from Ravi Bangoria (ravi.bangoria@amd.com) --- (In reply to Sean Christopherson from comment #13) > And does AMD do _any_ testing? This doesn't even require a full reproduc= er, > e.g. the existing debug KVM-Unit-Test fails on my system (Turin) without = ever > generating a split/bus lock. AFAICT, the CPU is reporting bus locks in D= R6 > on > #DBs that are most definitely not due to bus locks. It seems, the CPU is preserving SW written DR6[BusLockDetected] while generating the #DB when the CPL is 0 and DEBUGCTL[BusLockTrapEn] is set. Since most of the x86/debug.c KUT tests clears DR6[BusLockDetected] before executing the test, the bit remains cleared at the exception time which cau= ses tests to fail. --=20 You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.=