From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 8AD9236CE1E for ; Tue, 11 Nov 2025 16:37:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762879055; cv=none; b=JqY++nbktuCvbg7/dKdvzxVP/2Mx2JSk+tOZilSdyWunhWLDNs6+TvzPBRLzeiOdSu6yA85D9VqIf07urCOPKNuIsbeAU78oovlYyA6/9IIxgKw1HLhFb+MZbxvAx8lsSR8PVCmik8RVxzqiMEKb6GrbnwLZ09U+R77IWhveGHc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762879055; c=relaxed/simple; bh=CmB1eUcoNGTFZrhIPIJJSrN0/MRzuZ3tT3YhNKBWw/U=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=B3StLsqqXmvRJ5TwZppkdrEq/7+IihXlIjknv7PkH180/8rIRG0xSDnRb8gxPMhns8zH/uwC4oyW+eNNaRktVtLKkhy7ORFvL2z3Pq/tYlENLCdO8pflk5dOtXHsZk30LnIBvvHiYrceSVBGPOL3OeB5MEuo9Nbh4wFVplOY8S0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=gDAWQdQQ; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=HHeArAuT; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="gDAWQdQQ"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="HHeArAuT" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1762879052; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=HImt604PJ3Z8w/cR0ElYpUFLDlMbNEVlH4hMkZPWNJA=; b=gDAWQdQQWEfS9jRiG77kutSdTKlEz9IRljG9MW5Wd/EKCv1Q299JEboYfrdadN5rf6o3Kz ubdNdayXLa82yobwnsPZ5ZyYFxiqSZy2LMVkRv1P2ji3Soo7tIUMuY8Mq//NitXgBs8I7H gRmGfjAXYyYdjil6mA9SnZXUayCbJ1U= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-448-BwxDBoYKPMm_DVhFzowsdg-1; Tue, 11 Nov 2025 11:37:30 -0500 X-MC-Unique: BwxDBoYKPMm_DVhFzowsdg-1 X-Mimecast-MFC-AGG-ID: BwxDBoYKPMm_DVhFzowsdg_1762879049 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-475e032d81bso26219405e9.3 for ; Tue, 11 Nov 2025 08:37:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1762879049; x=1763483849; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:autocrypt:content-language :from:references:cc:to:subject:user-agent:mime-version:date :message-id:from:to:cc:subject:date:message-id:reply-to; bh=HImt604PJ3Z8w/cR0ElYpUFLDlMbNEVlH4hMkZPWNJA=; b=HHeArAuT7dvpVbfe+tUCgt8FhN+JYkBNGnUFqxK8/zLUOj1bYExDM3Gl70AoIBQrLy DMtsczCC3XFwHkPwf79CNJ/GxM+S++rOxjMU+XJuzfg3uq6vtzfajNd1K0xLqFIli7sT F96sKtPCN/2pRuTkzd73Q3vy14x5E0rUqj9Ga5LJrTWbnnFGTSHj+9XIYYLSOe46Jav7 N3GiQEBja4kyQCSGNRWiP+c1IJZkUu4lzVigSUdEXKqjqzaNQe3HRynCwnnAuo/HEcPO 6Fd2wQQIeYyDbGSxA+wyXAMtOz2z4MT8kvAdcTIc9E5n6t6CmpiN/tbgC7cBJd54gkrS x8Aw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1762879049; x=1763483849; h=content-transfer-encoding:in-reply-to:autocrypt:content-language :from:references:cc:to:subject:user-agent:mime-version:date :message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=HImt604PJ3Z8w/cR0ElYpUFLDlMbNEVlH4hMkZPWNJA=; b=j9yc/l1jIsxYW2YwI8saKVKjiPicPUSaSgQIaGh/GPiUg/HIijkQmK5YqvA2ZNqdEa rfzo811A37WXPgq3aN3cof0FU4yzNygSg7hMBp4hpwNkyV9NeyK5fUfv9BrUjzlLHReF M6WorgMbQJXP55AF0Jco/mOC1Y2LJUIpsk3UyyYgjSHxldRHIzrf9uFBoGdW+QvccKsd dox60UgzwR/4lFzgDDZIjTUGlbY+TGzUmwyhs3BYjfqCitWyG/j0Ew3U8ieB8WIvffrF 3O9GmfrsfIojysz778GZ4w690aqGAPJIEgObdsl74cI6jsO52+yg+iv1+cbzMmXtjyvO 1eTQ== X-Forwarded-Encrypted: i=1; AJvYcCVmi4/Ba65X/p23suggnKnSlDJqJRBCWZD4ooqETbwthWv2HlLDudjsBGOsJVrJFF31LzWNcDwPN/8RbFc=@vger.kernel.org X-Gm-Message-State: AOJu0Yw01Jr761zzlrUP1JNbaVa8HV/1nWzXLY2MTeJING3UGPGto2ZM A3eReT3GumGUDguJG75Kurd6Oikr3eCq9glKu5qcQVLcy+NkFKNW+Tx0LjKb9ypMesA1ThmakiI uLNK8nQ302Q+Vd21tEhFZzRZF0LSSqjnPyzoczAaYLaW8KqSI7osMD1X6UgUVPNAUmQ== X-Gm-Gg: ASbGncsKL3m0LyjCnPaV9oF2HWi6rCFj9aBn68XTzJtBIO7X3m37jNXXmriF0jAyeyS YpOyyHX23ZHzdyPQrWuA/kqUfPlk5h0zeuwpVjZPV/c0ZaFMvSr3UsIj6vjJMyfvbRsfmGUchsd FVONMXj8/yEULwOcDleg3f3tqKx2gDtWaitCA+tHmiwowNrNVXxgbc+3DrvyQ/SYwQVjnux8VM/ hGm2xtm9Hw8CIuWHtBDW5FPxQDFBbNijZvqof1XvXDUxH/AbW3aFVq5N8M6zdm8bsBXgU4j0bLN 0nHuEbrdnndercCYA0+hh4X+aDtzc+fZrPJ2vS3hdEVFF2CCLTm7QQhOsBZpJ4ACxswgFMND5ol QoD3nAF9mbTxHjdgLEK+abZYPooRFZxKnarIwIuMVcX+C7yLsNaeIloPBNanMXi75twuLuk5yEy cOcQc1dA== X-Received: by 2002:a05:600c:4593:b0:475:dd7f:f6cd with SMTP id 5b1f17b1804b1-477870b92f6mr263345e9.35.1762879049507; Tue, 11 Nov 2025 08:37:29 -0800 (PST) X-Google-Smtp-Source: AGHT+IH0FFQqiFEcuP0QuOZESv6esXKON7IZgxgQeWvfeD0418RmgbA8MrtmypbihbYyHq3QGSegyg== X-Received: by 2002:a05:600c:4593:b0:475:dd7f:f6cd with SMTP id 5b1f17b1804b1-477870b92f6mr263125e9.35.1762879049128; Tue, 11 Nov 2025 08:37:29 -0800 (PST) Received: from [192.168.10.81] ([176.206.111.214]) by smtp.googlemail.com with ESMTPSA id 5b1f17b1804b1-4777d9447eesm122367945e9.16.2025.11.11.08.37.23 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 11 Nov 2025 08:37:24 -0800 (PST) Message-ID: <896debcd-f0d3-4f75-b090-c59b0ac1fa57@redhat.com> Date: Tue, 11 Nov 2025 17:37:21 +0100 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 RFC v1 15/20] KVM: x86: Reject EVEX-prefix instructions in the emulator To: "Chang S. Bae" , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: seanjc@google.com, chao.gao@intel.com, zhao1.liu@intel.com References: <20251110180131.28264-1-chang.seok.bae@intel.com> <20251110180131.28264-16-chang.seok.bae@intel.com> From: Paolo Bonzini Content-Language: en-US Autocrypt: addr=pbonzini@redhat.com; keydata= xsEhBFRCcBIBDqDGsz4K0zZun3jh+U6Z9wNGLKQ0kSFyjN38gMqU1SfP+TUNQepFHb/Gc0E2 CxXPkIBTvYY+ZPkoTh5xF9oS1jqI8iRLzouzF8yXs3QjQIZ2SfuCxSVwlV65jotcjD2FTN04 hVopm9llFijNZpVIOGUTqzM4U55sdsCcZUluWM6x4HSOdw5F5Utxfp1wOjD/v92Lrax0hjiX DResHSt48q+8FrZzY+AUbkUS+Jm34qjswdrgsC5uxeVcLkBgWLmov2kMaMROT0YmFY6A3m1S P/kXmHDXxhe23gKb3dgwxUTpENDBGcfEzrzilWueOeUWiOcWuFOed/C3SyijBx3Av/lbCsHU Vx6pMycNTdzU1BuAroB+Y3mNEuW56Yd44jlInzG2UOwt9XjjdKkJZ1g0P9dwptwLEgTEd3Fo UdhAQyRXGYO8oROiuh+RZ1lXp6AQ4ZjoyH8WLfTLf5g1EKCTc4C1sy1vQSdzIRu3rBIjAvnC tGZADei1IExLqB3uzXKzZ1BZ+Z8hnt2og9hb7H0y8diYfEk2w3R7wEr+Ehk5NQsT2MPI2QBd wEv1/Aj1DgUHZAHzG1QN9S8wNWQ6K9DqHZTBnI1hUlkp22zCSHK/6FwUCuYp1zcAEQEAAc0j UGFvbG8gQm9uemluaSA8cGJvbnppbmlAcmVkaGF0LmNvbT7CwU0EEwECACMFAlRCcBICGwMH CwkIBwMCAQYVCAIJCgsEFgIDAQIeAQIXgAAKCRB+FRAMzTZpsbceDp9IIN6BIA0Ol7MoB15E 11kRz/ewzryFY54tQlMnd4xxfH8MTQ/mm9I482YoSwPMdcWFAKnUX6Yo30tbLiNB8hzaHeRj jx12K+ptqYbg+cevgOtbLAlL9kNgLLcsGqC2829jBCUTVeMSZDrzS97ole/YEez2qFpPnTV0 VrRWClWVfYh+JfzpXmgyhbkuwUxNFk421s4Ajp3d8nPPFUGgBG5HOxzkAm7xb1cjAuJ+oi/K CHfkuN+fLZl/u3E/fw7vvOESApLU5o0icVXeakfSz0LsygEnekDbxPnE5af/9FEkXJD5EoYG SEahaEtgNrR4qsyxyAGYgZlS70vkSSYJ+iT2rrwEiDlo31MzRo6Ba2FfHBSJ7lcYdPT7bbk9 AO3hlNMhNdUhoQv7M5HsnqZ6unvSHOKmReNaS9egAGdRN0/GPDWr9wroyJ65ZNQsHl9nXBqE AukZNr5oJO5vxrYiAuuTSd6UI/xFkjtkzltG3mw5ao2bBpk/V/YuePrJsnPFHG7NhizrxttB nTuOSCMo45pfHQ+XYd5K1+Cv/NzZFNWscm5htJ0HznY+oOsZvHTyGz3v91pn51dkRYN0otqr bQ4tlFFuVjArBZcapSIe6NV8C4cEiSTOwE0EVEJx7gEIAMeHcVzuv2bp9HlWDp6+RkZe+vtl KwAHplb/WH59j2wyG8V6i33+6MlSSJMOFnYUCCL77bucx9uImI5nX24PIlqT+zasVEEVGSRF m8dgkcJDB7Tps0IkNrUi4yof3B3shR+vMY3i3Ip0e41zKx0CvlAhMOo6otaHmcxr35sWq1Jk tLkbn3wG+fPQCVudJJECvVQ//UAthSSEklA50QtD2sBkmQ14ZryEyTHQ+E42K3j2IUmOLriF dNr9NvE1QGmGyIcbw2NIVEBOK/GWxkS5+dmxM2iD4Jdaf2nSn3jlHjEXoPwpMs0KZsgdU0pP JQzMUMwmB1wM8JxovFlPYrhNT9MAEQEAAcLBMwQYAQIACQUCVEJx7gIbDAAKCRB+FRAMzTZp sadRDqCctLmYICZu4GSnie4lKXl+HqlLanpVMOoFNnWs9oRP47MbE2wv8OaYh5pNR9VVgyhD OG0AU7oidG36OeUlrFDTfnPYYSF/mPCxHttosyt8O5kabxnIPv2URuAxDByz+iVbL+RjKaGM GDph56ZTswlx75nZVtIukqzLAQ5fa8OALSGum0cFi4ptZUOhDNz1onz61klD6z3MODi0sBZN Aj6guB2L/+2ZwElZEeRBERRd/uommlYuToAXfNRdUwrwl9gRMiA0WSyTb190zneRRDfpSK5d usXnM/O+kr3Dm+Ui+UioPf6wgbn3T0o6I5BhVhs4h4hWmIW7iNhPjX1iybXfmb1gAFfjtHfL xRUr64svXpyfJMScIQtBAm0ihWPltXkyITA92ngCmPdHa6M1hMh4RDX+Jf1fiWubzp1voAg0 JBrdmNZSQDz0iKmSrx8xkoXYfA3bgtFN8WJH2xgFL28XnqY4M6dLhJwV3z08tPSRqYFm4NMP dRsn0/7oymhneL8RthIvjDDQ5ktUjMe8LtHr70OZE/TT88qvEdhiIVUogHdo4qBrk41+gGQh b906Dudw5YhTJFU3nC6bbF2nrLlB4C/XSiH76ZvqzV0Z/cAMBo5NF/w= In-Reply-To: <20251110180131.28264-16-chang.seok.bae@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 11/10/25 19:01, Chang S. Bae wrote: > Explicitly mark EVEX-prefixed opcodes (0x62) as unsupported, clarifying > current decoding behavior. > > While new prefixes like REX2 extend GPR handling, EVEX emulation should > be addressed separately once after VEX support is implemented. > > Signed-off-by: Chang S. Bae > --- > arch/x86/kvm/emulate.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c > index 03f8e007b14e..9bd61ea496e5 100644 > --- a/arch/x86/kvm/emulate.c > +++ b/arch/x86/kvm/emulate.c > @@ -4952,8 +4952,8 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len, int > if (ctxt->d & ModRM) > ctxt->modrm = insn_fetch(u8, ctxt); > > - /* vex-prefix instructions are not implemented */ > - if (ctxt->opcode_len == 1 && (ctxt->b == 0xc5 || ctxt->b == 0xc4) && > + /* VEX and EVEX-prefixed instructions are not implemented */ > + if (ctxt->opcode_len == 1 && (ctxt->b == 0xc5 || ctxt->b == 0xc4 || ctxt->b == 0x62) && > (mode == X86EMUL_MODE_PROT64 || (ctxt->modrm & 0xc0) == 0xc0)) { > ctxt->d = NotImpl; > } VEX support is coming (will post tomorrow I think) so the patches around decode are going to need changes, but nothing major. Paolo