From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (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 7293050A95 for ; Thu, 25 Jan 2024 13:08:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706188116; cv=none; b=rQzabYUPFmxwrQSRSi1XDipomshzB2MPb5G1GKGnqHtS+pqsOEEvezWKwoEPLl9TY1gI9uyd8CU7L64NsTFN/oAP8wRjIXKP35zVFLMBU4xB5BHR3I4QZfAENb6rdOc5n8/IyWUGT52nbZN4FwX8fMYtr4L5i7YSM/FNQiJssTw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706188116; c=relaxed/simple; bh=DQw6SkbRWKUw+mEBZpF+BrHQJGhjrIcRv8sDzH/zTLY=; h=Date:From:To:CC:Subject:In-Reply-To:References:Message-ID: MIME-Version:Content-Type; b=O8vdwBX2jnV9nk/3y/zRKBc4kFuGMlV2raHvGHYu7YTa567dpv/cwa3p7TUnztQ0Ef3xIhdjOjydRa8VFNhr5RBUh5DAenpD5UqbMMYiNRxpT/mXjTPNwuxdEbGuV+MqoNPf4zSyVQdwSyRdzVzIb4EfyOd94vqu5tW/vSi5jzY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=Rfedy4bS; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="Rfedy4bS" Received: from [127.0.0.1] ([76.133.66.138]) (authenticated bits=0) by mail.zytor.com (8.17.2/8.17.1) with ESMTPSA id 40PD7ohH017921 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Thu, 25 Jan 2024 05:07:51 -0800 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 40PD7ohH017921 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2024011201; t=1706188071; bh=aI9WJx+jYvQnEIH6Q4cNpzmMxlGwehYlGZIFWqI/BWw=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=Rfedy4bS6fJrYJhVwO0eqYNK7BQP/zUgo78ry7Yr0XwJ/z0GYR+jw0elS1t+7qCWH 8jYPWWx353vfXtxz0fwzh6DmXxtGax3lWkP6ubcNm7/3hSjbdwSg+IIq4u52f/6Xqm LQk/AGVLDC0LpVfmwfoPPnLEdFQKRRce8Csw+vAu5q9Q6IZ0DT05i7lpvtEAKxGFRi BBFCAY/BSVeceaGljlVQAXzLTlxiENwcU1R69l62KrL3V8tzF4v1xonvmRFz1gMejh q2Egm2lH+Mp1L9GWFfPTTjMrLJOxNyktGMpWiJTNNZyfZF+Ock1ycy2/XIwtHNAMcz Pt4KCLg3iqLHw== Date: Thu, 25 Jan 2024 05:07:47 -0800 From: "H. Peter Anvin" To: Andi Kleen , "Kirill A. Shutemov" CC: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, linux-kernel@vger.kernel.org, Kai Huang , Sean Christopherson Subject: =?US-ASCII?Q?Re=3A_=5BPATCHv3=2C_RESEND=5D_x86/trampoline=3A_Bypass_co?= =?US-ASCII?Q?mpat_mode_in_trampoline=5Fstart64=28=29_if_not_needed?= User-Agent: K-9 Mail for Android In-Reply-To: References: <20240124131510.496803-1-kirill.shutemov@linux.intel.com> Message-ID: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On January 25, 2024 1:57:18 AM PST, Andi Kleen wro= te: >> + /* Paging mode is correct proceed in 64-bit mode */ >> + >> + LOCK_AND_LOAD_REALMODE_ESP lock_rip=3D1 >> + >> + movw $__KERNEL_DS, %dx >> + movl %edx, %ss >> + addl $pa_real_mode_base, %esp >> + movl %edx, %ds >> + movl %edx, %es >> + movl %edx, %fs >> + movl %edx, %gs >> + >> + movl $pa_trampoline_pgd, %eax >> + movq %rax, %cr3 >> + >> + jmpq *tr_start(%rip) > >Still think we should add a far jump here so that we run on a defined >code segment=2E It probably doesn't matter since there are likely no >IRETs before reloading anyways, but it seems cleaner=2E > >-Andi > Agreed=2E