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X-CSE-ConnectionGUID: GIv6gytxR0SdnVSYBmlVxg== X-CSE-MsgGUID: i9exh7tVQ76j+yDWq+5FBg== X-IronPort-AV: E=McAfee;i="6600,9927,11068"; a="11117625" X-IronPort-AV: E=Sophos;i="6.08,149,1712646000"; d="scan'208";a="11117625" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by fmvoesa113.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 May 2024 17:04:38 -0700 X-CSE-ConnectionGUID: xPj8nEPvSy+k+tFEejAmDQ== X-CSE-MsgGUID: T7GrQcT7RYW7Zu8g6GPi0g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,149,1712646000"; d="scan'208";a="33869947" Received: from epinckar-mobl.amr.corp.intel.com (HELO [10.209.98.74]) ([10.209.98.74]) by fmviesa005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 May 2024 17:04:37 -0700 Message-ID: Date: Thu, 9 May 2024 17:04:36 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] x86/entry_32: Move CLEAR_CPU_BUFFERS before CR3 switch To: Pawan Gupta Cc: Borislav Petkov , Dave Hansen , linux-kernel@vger.kernel.org, x86@kernel.org, Robert Gill , "Linux regression tracking (Thorsten Leemhuis)" , antonio.gomez.iglesias@linux.intel.com, daniel.sneddon@linux.intel.com References: <20240426-fix-dosemu-vm86-v1-1-88c826a3f378@linux.intel.com> <5b5e597d-7620-4a5a-9bfa-bae26f0b0fa3@intel.com> <20240509221425.zcl6c45thb7wxyza@desk> From: Dave Hansen Content-Language: en-US Autocrypt: addr=dave.hansen@intel.com; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/9/24 15:17, Pawan Gupta wrote: > It probably can go right before the SWITCH_TO_USER_CR3. I didn't have > 32-bit setup with dosemu to experiment with. I will attach a debug patch to > the bugzilla and request the reporter to test it. There's an enter_from_vm86.c in the kernel selftests. That will at least exercise this path.