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 X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69A1FC04AB6 for ; Tue, 28 May 2019 17:40:11 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 368562173B for ; Tue, 28 May 2019 17:40:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 368562173B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([127.0.0.1]:40236 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hVg54-0002JT-5f for qemu-devel@archiver.kernel.org; Tue, 28 May 2019 13:40:10 -0400 Received: from eggs.gnu.org ([209.51.188.92]:41155) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hVfuM-0002LA-Kg for qemu-devel@nongnu.org; Tue, 28 May 2019 13:29:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hVfuI-0001g7-TZ for qemu-devel@nongnu.org; Tue, 28 May 2019 13:29:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51156) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hVfuD-0001Yc-Cq for qemu-devel@nongnu.org; Tue, 28 May 2019 13:28:59 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 00094300183A; Tue, 28 May 2019 17:28:52 +0000 (UTC) Received: from [10.36.116.177] (ovpn-116-177.ams2.redhat.com [10.36.116.177]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0FFEF1017E3C; Tue, 28 May 2019 17:28:51 +0000 (UTC) To: Richard Henderson , qemu-devel@nongnu.org References: <20190522222821.23850-1-richard.henderson@linaro.org> <20190522222821.23850-17-richard.henderson@linaro.org> From: David Hildenbrand Openpgp: preference=signencrypt Autocrypt: addr=david@redhat.com; prefer-encrypt=mutual; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwX4EEwECACgFAljj9eoCGwMFCQlmAYAGCwkI BwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEE3eEPcA/4Na5IIP/3T/FIQMxIfNzZshIq687qgG 8UbspuE/YSUDdv7r5szYTK6KPTlqN8NAcSfheywbuYD9A4ZeSBWD3/NAVUdrCaRP2IvFyELj xoMvfJccbq45BxzgEspg/bVahNbyuBpLBVjVWwRtFCUEXkyazksSv8pdTMAs9IucChvFmmq3 jJ2vlaz9lYt/lxN246fIVceckPMiUveimngvXZw21VOAhfQ+/sofXF8JCFv2mFcBDoa7eYob s0FLpmqFaeNRHAlzMWgSsP80qx5nWWEvRLdKWi533N2vC/EyunN3HcBwVrXH4hxRBMco3jvM m8VKLKao9wKj82qSivUnkPIwsAGNPdFoPbgghCQiBjBe6A75Z2xHFrzo7t1jg7nQfIyNC7ez MZBJ59sqA9EDMEJPlLNIeJmqslXPjmMFnE7Mby/+335WJYDulsRybN+W5rLT5aMvhC6x6POK z55fMNKrMASCzBJum2Fwjf/VnuGRYkhKCqqZ8gJ3OvmR50tInDV2jZ1DQgc3i550T5JDpToh dPBxZocIhzg+MBSRDXcJmHOx/7nQm3iQ6iLuwmXsRC6f5FbFefk9EjuTKcLMvBsEx+2DEx0E UnmJ4hVg7u1PQ+2Oy+Lh/opK/BDiqlQ8Pz2jiXv5xkECvr/3Sv59hlOCZMOaiLTTjtOIU7Tq 7ut6OL64oAq+zsFNBFXLn5EBEADn1959INH2cwYJv0tsxf5MUCghCj/CA/lc/LMthqQ773ga uB9mN+F1rE9cyyXb6jyOGn+GUjMbnq1o121Vm0+neKHUCBtHyseBfDXHA6m4B3mUTWo13nid 0e4AM71r0DS8+KYh6zvweLX/LL5kQS9GQeT+QNroXcC1NzWbitts6TZ+IrPOwT1hfB4WNC+X 2n4AzDqp3+ILiVST2DT4VBc11Gz6jijpC/KI5Al8ZDhRwG47LUiuQmt3yqrmN63V9wzaPhC+ xbwIsNZlLUvuRnmBPkTJwwrFRZvwu5GPHNndBjVpAfaSTOfppyKBTccu2AXJXWAE1Xjh6GOC 8mlFjZwLxWFqdPHR1n2aPVgoiTLk34LR/bXO+e0GpzFXT7enwyvFFFyAS0Nk1q/7EChPcbRb hJqEBpRNZemxmg55zC3GLvgLKd5A09MOM2BrMea+l0FUR+PuTenh2YmnmLRTro6eZ/qYwWkC u8FFIw4pT0OUDMyLgi+GI1aMpVogTZJ70FgV0pUAlpmrzk/bLbRkF3TwgucpyPtcpmQtTkWS gDS50QG9DR/1As3LLLcNkwJBZzBG6PWbvcOyrwMQUF1nl4SSPV0LLH63+BrrHasfJzxKXzqg rW28CTAE2x8qi7e/6M/+XXhrsMYG+uaViM7n2je3qKe7ofum3s4vq7oFCPsOgwARAQABwsFl BBgBAgAPBQJVy5+RAhsMBQkJZgGAAAoJEE3eEPcA/4NagOsP/jPoIBb/iXVbM+fmSHOjEshl KMwEl/m5iLj3iHnHPVLBUWrXPdS7iQijJA/VLxjnFknhaS60hkUNWexDMxVVP/6lbOrs4bDZ NEWDMktAeqJaFtxackPszlcpRVkAs6Msn9tu8hlvB517pyUgvuD7ZS9gGOMmYwFQDyytpepo YApVV00P0u3AaE0Cj/o71STqGJKZxcVhPaZ+LR+UCBZOyKfEyq+ZN311VpOJZ1IvTExf+S/5 lqnciDtbO3I4Wq0ArLX1gs1q1XlXLaVaA3yVqeC8E7kOchDNinD3hJS4OX0e1gdsx/e6COvy qNg5aL5n0Kl4fcVqM0LdIhsubVs4eiNCa5XMSYpXmVi3HAuFyg9dN+x8thSwI836FoMASwOl C7tHsTjnSGufB+D7F7ZBT61BffNBBIm1KdMxcxqLUVXpBQHHlGkbwI+3Ye+nE6HmZH7IwLwV W+Ajl7oYF+jeKaH4DZFtgLYGLtZ1LDwKPjX7VAsa4Yx7S5+EBAaZGxK510MjIx6SGrZWBrrV TEvdV00F2MnQoeXKzD7O4WFbL55hhyGgfWTHwZ457iN9SgYi1JLPqWkZB0JRXIEtjd4JEQcx +8Umfre0Xt4713VxMygW0PnQt5aSQdMD58jHFxTk092mU+yIHj5LeYgvwSgZN4airXk5yRXl SE+xAvmumFBY Organization: Red Hat GmbH Message-ID: Date: Tue, 28 May 2019 19:28:51 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190522222821.23850-17-richard.henderson@linaro.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Tue, 28 May 2019 17:28:53 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PULL 16/16] tcg/i386: Use MOVDQA for TCG_TYPE_V128 load/store X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.maydell@linaro.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 23.05.19 00:28, Richard Henderson wrote: > This instruction raises #GP, aka SIGSEGV, if the effective address > is not aligned to 16-bytes. > > We have assertions in tcg-op-gvec.c that the offset from ENV is > aligned, for vector types <= V128. But the offset itself does not > validate that the final pointer is aligned -- one must also remember > to use the QEMU_ALIGNED() attribute on the vector member within ENV. > > PowerPC Altivec has vector load/store instructions that silently > discard the low 4 bits of the address, making alignment mistakes > difficult to discover. Aid that by making the most popular host > visibly signal the error. > > Signed-off-by: Richard Henderson > --- > tcg/i386/tcg-target.inc.c | 24 ++++++++++++++++++++++-- > 1 file changed, 22 insertions(+), 2 deletions(-) > > diff --git a/tcg/i386/tcg-target.inc.c b/tcg/i386/tcg-target.inc.c > index 6ec5e60448..c0443da4af 100644 > --- a/tcg/i386/tcg-target.inc.c > +++ b/tcg/i386/tcg-target.inc.c > @@ -1082,14 +1082,24 @@ static void tcg_out_ld(TCGContext *s, TCGType type, TCGReg ret, > } > /* FALLTHRU */ > case TCG_TYPE_V64: > + /* There is no instruction that can validate 8-byte alignment. */ > tcg_debug_assert(ret >= 16); > tcg_out_vex_modrm_offset(s, OPC_MOVQ_VqWq, ret, 0, arg1, arg2); > break; > case TCG_TYPE_V128: > + /* > + * The gvec infrastructure is asserts that v128 vector loads > + * and stores use a 16-byte aligned offset. Validate that the > + * final pointer is aligned by using an insn that will SIGSEGV. > + */ > tcg_debug_assert(ret >= 16); > - tcg_out_vex_modrm_offset(s, OPC_MOVDQU_VxWx, ret, 0, arg1, arg2); > + tcg_out_vex_modrm_offset(s, OPC_MOVDQA_VxWx, ret, 0, arg1, arg2); > break; > case TCG_TYPE_V256: > + /* > + * The gvec infrastructure only requires 16-byte alignment, > + * so here we must use an unaligned load. > + */ > tcg_debug_assert(ret >= 16); > tcg_out_vex_modrm_offset(s, OPC_MOVDQU_VxWx | P_VEXL, > ret, 0, arg1, arg2); > @@ -1117,14 +1127,24 @@ static void tcg_out_st(TCGContext *s, TCGType type, TCGReg arg, > } > /* FALLTHRU */ > case TCG_TYPE_V64: > + /* There is no instruction that can validate 8-byte alignment. */ > tcg_debug_assert(arg >= 16); > tcg_out_vex_modrm_offset(s, OPC_MOVQ_WqVq, arg, 0, arg1, arg2); > break; > case TCG_TYPE_V128: > + /* > + * The gvec infrastructure is asserts that v128 vector loads > + * and stores use a 16-byte aligned offset. Validate that the > + * final pointer is aligned by using an insn that will SIGSEGV. > + */ > tcg_debug_assert(arg >= 16); > - tcg_out_vex_modrm_offset(s, OPC_MOVDQU_WxVx, arg, 0, arg1, arg2); > + tcg_out_vex_modrm_offset(s, OPC_MOVDQA_WxVx, arg, 0, arg1, arg2); > break; > case TCG_TYPE_V256: > + /* > + * The gvec infrastructure only requires 16-byte alignment, > + * so here we must use an unaligned store. > + */ > tcg_debug_assert(arg >= 16); > tcg_out_vex_modrm_offset(s, OPC_MOVDQU_WxVx | P_VEXL, > arg, 0, arg1, arg2); > This is the problematic patch. Haven't looked into the details yet, so I can't tell what's wrong. Maybe really an alignemnt issue? -- Thanks, David / dhildenb