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 023111CBE8D for ; Thu, 31 Oct 2024 19:54:03 +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=1730404445; cv=none; b=iEfLePNPZ/s/X4dTXWFzptL+cLqZNOAozCS2yhzcmECbqrlRXSl6ug7XMMCEbdAZm2lKUZlPs6QAliBncqTYYcA55zFZV2RTPAM799KiWzO6A08mzdIpsNtF1lHq2dKFbwFl5selXLy/ieY+ZOLz/hV0/cJ1om1srGRiWMLqovg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730404445; c=relaxed/simple; bh=YkBRNFEsN35dGfxgWRIwToGQglmdje/bR992AmSVZ2o=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=RipyAd7QlhYcSo4Bi+XH12ksw4qWPqjVxP1ESfSrpY4j4Hn+eeKi3Hs63JkQKKwV5h8SSPCpJmwfwFDvmryBda3M4J+meEIH4vYcWMERdeyIuKKjGNfK3ia/FHhszztR4NzBpBAOM67GdG+PUR4U9c+lt5pdE5lTLymHkmP3S14= 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=rf1dY3lO; 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="rf1dY3lO" Received: by mail-pg1-f202.google.com with SMTP id 41be03b00d2f7-7cbe272efa6so1484709a12.3 for ; Thu, 31 Oct 2024 12:54:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1730404443; x=1731009243; 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=tMWwOWR8YlKBIDqnosPHW958i6emqG1WTA/8O+fCvsI=; b=rf1dY3lORaeWFkqbnf4zpb6HSwlpXXhCjenwOa7KG4sKjuop7nd9dpiLNRPxmPO8bp I2Us7KEdcyI6A0jPjnnqdkIgP0qzimfnT6FKPtB0kYLH9LDz+2ROKHXPSjYdW2YYmMxg gObfUfIgb8yE95U9JImyfm74GgBfmlfaFjUlUepqouroQESl2ww+ofIPmv1Kuk8oFlSz fjCI6FYHDeZMVapP0w+BZUoBO/UQlddw2JzSjms8Ju+97YCEEIJfooneNbetQGN2IB7n hKvDlhUpsGD16hOe4sfwp+eVmFB37G+3RlpnKRHbVG9Aisp8v/xNh/AEME/GrjS2lxxC fWkw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730404443; x=1731009243; 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=tMWwOWR8YlKBIDqnosPHW958i6emqG1WTA/8O+fCvsI=; b=WJ/IL8qa2gcqbgqIm6Q/XNPp/5mOoSKpGQKI9xDZGpEQYOxKYv6GA1l+/Rv3tpNj5b 3dXdEssCjRa5mWuMNbXBtudyhIzAo/LraXL15vExRDh6r/ovYyvB6Vz/0JPf0rDw2e2q bHtvW6c3PzzaIBhBjWkkIvbJx1w1/dswx5m18EYcrACr0hTM1eBiD3KgpZExIt8SEeHE qvs67oLO/tsI3oIrY2E8blQk8MVlrN3JWwVLAx7bJlxODmO4A/Dae1STDmcUSPn6f+bq hQ8zxuGKENYI8mLfGW8bfecubyd42Hdl2deiOwZASf/ifogFvFaNpqvBPWwAL0+tlbxt ns9g== X-Forwarded-Encrypted: i=1; AJvYcCXELbNkt1WlDv8s+KQ/cAsnvYxOLbCvirkaj7QEPraSzKMcevVyJsVdoLQflwkolua1XUsLopEFqlprlyc=@vger.kernel.org X-Gm-Message-State: AOJu0YxrElTpS2BWBaSQAhnQVu2Cnj1Q8Oz3jDGLFE8vUx83YL0DVlws QB4eGGH57pQ+ndqIVkWVnQXoGHLFUz6e0UUQapFWzcNyExaxiXNKZCFPJabZjx25Lu8E5dRXAm1 2ag== X-Google-Smtp-Source: AGHT+IHkmW04UVeplfmm6k9u29eDQmh1Q5dvhWh8Q5TKZvWf4BSK1EHAifK51R77vzNuuNteTnsMapgSrJE= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:9d:3983:ac13:c240]) (user=seanjc job=sendgmr) by 2002:a17:903:2310:b0:20c:686e:28c6 with SMTP id d9443c01a7336-210f729e85fmr710135ad.0.1730404443326; Thu, 31 Oct 2024 12:54:03 -0700 (PDT) Date: Thu, 31 Oct 2024 12:51:33 -0700 In-Reply-To: <20241011214353.1625057-1-jmattson@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241011214353.1625057-1-jmattson@google.com> X-Mailer: git-send-email 2.47.0.163.g1226f6d8fa-goog Message-ID: <173039500211.1507616.16831780895322741303.b4-ty@google.com> Subject: Re: [PATCH v5 0/4] Distinguish between variants of IBPB From: Sean Christopherson To: Sean Christopherson , kvm@vger.kernel.org, Jim Mattson Cc: bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, jpoimboe@kernel.org, kai.huang@intel.com, linux-kernel@vger.kernel.org, mingo@redhat.com, pawan.kumar.gupta@linux.intel.com, pbonzini@redhat.com, sandipan.das@amd.com, tglx@linutronix.de, x86@kernel.org Content-Type: text/plain; charset="utf-8" On Fri, 11 Oct 2024 14:43:49 -0700, Jim Mattson wrote: > Prior to Zen4, AMD's IBPB did not flush the RAS (or, in Intel > terminology, the RSB). Hence, the older version of AMD's IBPB was not > equivalent to Intel's IBPB. However, KVM has been treating them as > equivalent, synthesizing Intel's CPUID.(EAX=7,ECX=0):EDX[bit 26] on any > platform that supports the synthetic features X86_FEATURE_IBPB and > X86_FEATURE_IBRS. > > [...] Applied to kvm-x86 misc, thanks! [1/4] x86/cpufeatures: Clarify semantics of X86_FEATURE_IBPB https://github.com/kvm-x86/linux/commit/43801a0dbb38 [2/4] x86/cpufeatures: Define X86_FEATURE_AMD_IBPB_RET https://github.com/kvm-x86/linux/commit/99d252e3ae3e [3/4] KVM: x86: Advertise AMD_IBPB_RET to userspace https://github.com/kvm-x86/linux/commit/df9328b0ef66 [4/4] KVM: x86: AMD's IBPB is not equivalent to Intel's IBPB https://github.com/kvm-x86/linux/commit/d66e266427e4 -- https://github.com/kvm-x86/linux/tree/next