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 E544DECF; Thu, 27 Feb 2025 01:14:36 +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=1740618879; cv=none; b=tR2j0e2yJVs/nAhu47zRMkA5g75xjg+g0qWZKPFuKiN7RtP5VJfIMWvAXbU/V05igNZZcc/vAkdLnCJ0H0FBxfUYqdRwfB4ZUBlWjMm0T6H/RnjGKBmrlvyyDhGHzIvYDzd7K65CNzcCuyjget9HC4H0jdupbY49KXOiqdC/dLc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740618879; c=relaxed/simple; bh=Xs/OLWRjVopl+PBKhxfySZxwwvTxhF09wzNSJg4riJU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=inP+Tne5Y8sqvy5EMBi23QrrZLVG5gM0lSv7FbSbRfuSWVq9DyU29+f/hbNUPg2rOiYrYUSrKxietrU1sBkzQ82y/exTLpdX8tLtNjRqk0gVOCbmyM53SopEOAf62yMmXjKsIYcIckPKX/mb/CbIyVko3MM3Su5kxFjXveJHtzE= ARC-Authentication-Results:i=1; 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h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=ct9TI772GPkCMLNGWtqx5yztYlsqCAN59L8juN2tpJ8zhGl676NX2hgL0kWUR4brS BSksI+F8muDwrP5oox1YOsSTnYr0hnSP4k3w1srqI0n5Y+pwQ7uOSK0x/+bljFRsJl n6Qa4Y9fvaJ/Tw405Yzxu5VOew3+vcXo8M/whodutGTPJUocBwxvEA97hGv3sZg99b fQ+Fd1KjGKwwpE/DpQ8uqvjlyG85jXpKQVBm1OC1uEN0ewI1hINNOi7tb6KsXLGGfK haJZUDnpj2yD/D2SJn4qIRyO87JEHJJmt1u1263lMCpND+53xMWAoaMjQaKTcZEB40 hAaipNCOkRpbg== Message-ID: Date: Wed, 26 Feb 2025 17:14:21 -0800 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 1/2] x86/msr: Rename the WRMSRNS opcode macro to ASM_WRMSRNS (for KVM) To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org References: <20250227010111.3222742-1-seanjc@google.com> <20250227010111.3222742-2-seanjc@google.com> Content-Language: en-US From: Xin Li Autocrypt: addr=xin@zytor.com; keydata= xsDNBGUPz1cBDACS/9yOJGojBFPxFt0OfTWuMl0uSgpwk37uRrFPTTLw4BaxhlFL0bjs6q+0 2OfG34R+a0ZCuj5c9vggUMoOLdDyA7yPVAJU0OX6lqpg6z/kyQg3t4jvajG6aCgwSDx5Kzg5 Rj3AXl8k2wb0jdqRB4RvaOPFiHNGgXCs5Pkux/qr0laeFIpzMKMootGa4kfURgPhRzUaM1vy bsMsL8vpJtGUmitrSqe5dVNBH00whLtPFM7IbzKURPUOkRRiusFAsw0a1ztCgoFczq6VfAVu raTye0L/VXwZd+aGi401V2tLsAHxxckRi9p3mc0jExPc60joK+aZPy6amwSCy5kAJ/AboYtY VmKIGKx1yx8POy6m+1lZ8C0q9b8eJ8kWPAR78PgT37FQWKYS1uAroG2wLdK7FiIEpPhCD+zH wlslo2ETbdKjrLIPNehQCOWrT32k8vFNEMLP5G/mmjfNj5sEf3IOKgMTMVl9AFjsINLHcxEQ 6T8nGbX/n3msP6A36FDfdSEAEQEAAc0WWGluIExpIDx4aW5Aenl0b3IuY29tPsLBDQQTAQgA NxYhBIUq/WFSDTiOvUIqv2u9DlcdrjdRBQJlD89XBQkFo5qAAhsDBAsJCAcFFQgJCgsFFgID AQAACgkQa70OVx2uN1HUpgv/cM2fsFCQodLArMTX5nt9yqAWgA5t1srri6EgS8W3F+3Kitge tYTBKu6j5BXuXaX3vyfCm+zajDJN77JHuYnpcKKr13VcZi1Swv6Jx1u0II8DOmoDYLb1Q2ZW v83W55fOWJ2g72x/UjVJBQ0sVjAngazU3ckc0TeNQlkcpSVGa/qBIHLfZraWtdrNAQT4A1fa sWGuJrChBFhtKbYXbUCu9AoYmmbQnsx2EWoJy3h7OjtfFapJbPZql+no5AJ3Mk9eE5oWyLH+ QWqtOeJM7kKvn/dBudokFSNhDUw06e7EoVPSJyUIMbYtUO7g2+Atu44G/EPP0yV0J4lRO6EA wYRXff7+I1jIWEHpj5EFVYO6SmBg7zF2illHEW31JAPtdDLDHYcZDfS41caEKOQIPsdzQkaQ oW2hchcjcMPAfyhhRzUpVHLPxLCetP8vrVhTvnaZUo0xaVYb3+wjP+D5j/3+hwblu2agPsaE vgVbZ8Fx3TUxUPCAdr/p73DGg57oHjgezsDNBGUPz1gBDAD4Mg7hMFRQqlzotcNSxatlAQNL MadLfUTFz8wUUa21LPLrHBkUwm8RujehJrzcVbPYwPXIO0uyL/F///CogMNx7Iwo6by43KOy g89wVFhyy237EY76j1lVfLzcMYmjBoTH95fJC/lVb5Whxil6KjSN/R/y3jfG1dPXfwAuZ/4N cMoOslWkfZKJeEut5aZTRepKKF54T5r49H9F7OFLyxrC/uI9UDttWqMxcWyCkHh0v1Di8176 jjYRNTrGEfYfGxSp+3jYL3PoNceIMkqM9haXjjGl0W1B4BidK1LVYBNov0rTEzyr0a1riUrp Qk+6z/LHxCM9lFFXnqH7KWeToTOPQebD2B/Ah5CZlft41i8L6LOF/LCuDBuYlu/fI2nuCc8d m4wwtkou1Y/kIwbEsE/6RQwRXUZhzO6llfoN96Fczr/RwvPIK5SVMixqWq4QGFAyK0m/1ap4 bhIRrdCLVQcgU4glo17vqfEaRcTW5SgX+pGs4KIPPBE5J/ABD6pBnUUAEQEAAcLA/AQYAQgA JhYhBIUq/WFSDTiOvUIqv2u9DlcdrjdRBQJlD89ZBQkFo5qAAhsMAAoJEGu9DlcdrjdR4C0L /RcjolEjoZW8VsyxWtXazQPnaRvzZ4vhmGOsCPr2BPtMlSwDzTlri8BBG1/3t/DNK4JLuwEj OAIE3fkkm+UG4Kjud6aNeraDI52DRVCSx6xff3bjmJsJJMb12mWglN6LjdF6K+PE+OTJUh2F dOhslN5C2kgl0dvUuevwMgQF3IljLmi/6APKYJHjkJpu1E6luZec/lRbetHuNFtbh3xgFIJx 2RpgVDP4xB3f8r0I+y6ua+p7fgOjDLyoFjubRGed0Be45JJQEn7A3CSb6Xu7NYobnxfkwAGZ Q81a2XtvNS7Aj6NWVoOQB5KbM4yosO5+Me1V1SkX2jlnn26JPEvbV3KRFcwV5RnDxm4OQTSk PYbAkjBbm+tuJ/Sm+5Yp5T/BnKz21FoCS8uvTiziHj2H7Cuekn6F8EYhegONm+RVg3vikOpn gao85i4HwQTK9/D1wgJIQkdwWXVMZ6q/OALaBp82vQ2U9sjTyFXgDjglgh00VRAHP7u1Rcu4 l75w1xInsg== In-Reply-To: <20250227010111.3222742-2-seanjc@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2/26/2025 5:01 PM, Sean Christopherson wrote: > Rename the WRMSRNS instruction opcode macro so that it doesn't collide > with X86_FEATURE_WRMSRNS when using token pasting to generate references > to X86_FEATURE_WRMSRNS. KVM heavily uses token pasting to generate KVM's > set of support feature bits, and adding WRMSRNS support in KVM will run > will run afoul of the opcode macro. > > arch/x86/kvm/cpuid.c:719:37: error: pasting "X86_FEATURE_" and "" "" does not > give a valid preprocessing token > 719 | u32 __leaf = __feature_leaf(X86_FEATURE_##name); \ > | ^~~~~~~~~~~~ > > KVM has worked around one such collision in the past by #undef'ing the > problematic macro in order to avoid blocking a KVM rework, but such games > are generally undesirable, e.g. requires bleeding macro details into KVM, > risks weird behavior if what KVM is #undef'ing changes, etc. > > Signed-off-by: Sean Christopherson > --- > arch/x86/include/asm/msr.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h > index 001853541f1e..60b80a36d045 100644 > --- a/arch/x86/include/asm/msr.h > +++ b/arch/x86/include/asm/msr.h > @@ -300,7 +300,7 @@ do { \ > #endif /* !CONFIG_PARAVIRT_XXL */ > > /* Instruction opcode for WRMSRNS supported in binutils >= 2.40 */ > -#define WRMSRNS _ASM_BYTES(0x0f,0x01,0xc6) > +#define ASM_WRMSRNS _ASM_BYTES(0x0f,0x01,0xc6) > > /* Non-serializing WRMSR, when available. Falls back to a serializing WRMSR. */ > static __always_inline void wrmsrns(u32 msr, u64 val) > @@ -309,7 +309,7 @@ static __always_inline void wrmsrns(u32 msr, u64 val) > * WRMSR is 2 bytes. WRMSRNS is 3 bytes. Pad WRMSR with a redundant > * DS prefix to avoid a trailing NOP. > */ > - asm volatile("1: " ALTERNATIVE("ds wrmsr", WRMSRNS, X86_FEATURE_WRMSRNS) > + asm volatile("1: " ALTERNATIVE("ds wrmsr", ASM_WRMSRNS, X86_FEATURE_WRMSRNS) > "2: " _ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_WRMSR) > : : "c" (msr), "a" ((u32)val), "d" ((u32)(val >> 32))); > } I hit the same build issue, thanks for fixing it. Reviewed-by: Xin Li (Intel)