From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f202.google.com (mail-pg1-f202.google.com [209.85.215.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D03D479D1 for ; Fri, 30 Aug 2024 04:42:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724992964; cv=none; b=S0KyV45R87a7yG4bAHpSNjAdDLB9TuonzjsXbnJoLZ+2z3qrbK3QPEITMwRNbHT/Sl9AdUKWwzbBoys9lgnESE+dK2GEP4sxq1U1h2EPjQQGSvs6HxQapwH5IgdQT/aEr1IjHwGjpdw2OAjujhMfdBiGe0Q0S10sb59BrD6JAaE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724992964; c=relaxed/simple; bh=qVZiTEd3P+CV2R2j735WaLbeS9pAFr9F9WZnKfAB2gY=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=NA5jY9Yu/xGBQAfPL64wH4vHHwlOB/RhC/jHIlrmgve5XfdwNl/Erz+XNCy0GTTy6Ewv94Pesp2u6dLjX7JhutzdwcWsu4TCpbIhwIELOq0Bpo3oCMw7oceASFA7PD19BmZtv1Gk5EpmqfovJKIeK64w1eDDURVHrCND/LIbDAc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=NMW8dEAt; arc=none smtp.client-ip=209.85.215.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="NMW8dEAt" Received: by mail-pg1-f202.google.com with SMTP id 41be03b00d2f7-7cf5c296887so1210750a12.3 for ; Thu, 29 Aug 2024 21:42:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1724992962; x=1725597762; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=DuwDmeiQxcz3+jOCRjgsCebKb1su6LiEDyHBdI6Iy3k=; b=NMW8dEAtn0TQYHb0EUZ55Upri64D2i38ahABLdWJNEzKbyu3/TwwSyOEgZ6UpZSbas OmbJhRJMr16QN1wAk9DrBLz71Aqw5iw90WW22bL9klOjH2E2s010GtmLFfK8VbzMdUll T/KDS+etA9akfFmt2glCCP+jyqHfEdRQsnPe1OxoLquADJV/ELcFDaeRjHZWp5ot4tbC VhzY51908dOUCwhRtfbY+UjLFV4I7Nw8chsHO7zOJqs6M3H4TT6mSO11P4XyU0hAczz8 5ecHNunTB/gh1uYbx/H1ugfohjQ0fsDQMHL10imJ7VqUC/yfUB4iO4vmeb5BffZQQrUm RYOg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724992962; x=1725597762; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=DuwDmeiQxcz3+jOCRjgsCebKb1su6LiEDyHBdI6Iy3k=; b=c99YOaCmPiXcG/Sowg/AChXusIF/MT1DsiGNtu8zyhGcHBDy3HD38LmXK1iaFH2qic MRYLLxJRhRLpsiqZTdK+KAneqCbSGPUGt22p1R9wiCzRx0kayclb0Oc5MP7RsN9OS/th bBYtexaYHRWNFIEP4CatLqGAkzLlHUbnCk38Fa5E3UI0KcaC0kUKdG1CpeAEIj0YeXJE IrK/Yrl9rwl/fmK/kQZ9EUbKDRu9P1PyD9PdbRrVD06epyBbzQQV6YrvqFawbfBJZqlZ iOmWWPsDZ5eOrC+e3+GezHKRHSOEH3SIvMcyDuCDWy+VsNSNH5+/v+gMxWAcQUR5VG13 h0vQ== X-Forwarded-Encrypted: i=1; AJvYcCUd2+1s3A6B6q8dAtUdT9mioc2EnQ6UfcYaqJ8Y632IyvH4ZUr2pJR/FRIbSJ4KTSgb/Ck=@vger.kernel.org X-Gm-Message-State: AOJu0Yx5AXZTg2CHRZE92f63yCjxsnGManrZopvnLGYNBg+yo8IZL16p sl8o4j89JjP/4tGT4rJxvSlcI0VBFpQ4sZPN5jjwHP4UHA6IPDSBPWzZVVoMy6JYoxRRB7ZJ4+g pYA== X-Google-Smtp-Source: AGHT+IEpfw0PKgJgqNKTHlMpWyrEsh7CSlO1i5Ro+hb2kbU92lKbF7kt84iFY1/jKRx5JiFvuUhbBUgOPDs= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a63:d70c:0:b0:7cd:8b5f:2567 with SMTP id 41be03b00d2f7-7d4c102e561mr1812a12.4.1724992961954; Thu, 29 Aug 2024 21:42:41 -0700 (PDT) Date: Thu, 29 Aug 2024 21:42:40 -0700 In-Reply-To: <20240829064811.GAZtAZqzWkmF79VOs7@fat_crate.local> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240709175145.9986-1-manali.shukla@amd.com> <20240709175145.9986-2-manali.shukla@amd.com> <20240829064811.GAZtAZqzWkmF79VOs7@fat_crate.local> Message-ID: Subject: Re: [RFC PATCH v1 1/4] x86/cpufeatures: Add CPUID feature bit for the Bus Lock Threshold From: Sean Christopherson To: Borislav Petkov Cc: Manali Shukla , kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, pbonzini@redhat.com, shuah@kernel.org, nikunj@amd.com, thomas.lendacky@amd.com, vkuznets@redhat.com, babu.moger@amd.com Content-Type: text/plain; charset="us-ascii" On Thu, Aug 29, 2024, Borislav Petkov wrote: > On Fri, Aug 16, 2024 at 12:37:52PM -0700, Sean Christopherson wrote: > > I would strongly prefer to enumerate this in /proc/cpuinfo, having to manually > > query CPUID to see if a CPU supports a feature I want to test is beyond annoying. > > Why? > > We have tools/arch/x86/kcpuid/kcpuid.c for that. Ah, sorry, if the platform+kernel supports the feature, not just raw CPU. And because that utility is not available by default on most targets I care about, and having to build and copy over a binary is annoying (though this is a minor gripe). That said, what I really want in most cases is to know if _KVM_ supports a feature. I'll think more on this, I have a few vague ideas for getting a pile of information out of KVM without needing to add more uABI.