From nobody Sun Dec 14 11:36:24 2025 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 9403C1714D7 for ; Wed, 11 Dec 2024 01:33:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733880792; cv=none; b=knEXGElP+IH91SHvs+cCyQJ7L61YIFDCsa7k1joJFO9acLzBICz28q74qNzHdWHzzk/Open4/6XcMUJmu4uI4eYKmoanuOaQwTj5qEmHAikfvw5ZQBkDgziZP59AiMsal696XWuszmHlm8PEFmXniDmgEkmAPA/VPETrr68F+cc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733880792; c=relaxed/simple; bh=MEVW6xDzLLQfv9y9OXgkK6FmeeyEKbPbGZpDIKqPQkk=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=GvKg9MgLDuXe1va62Z7iNRWYnWUSwDJ+5l7ZIgq26PpASzSkAtilH8Y6IcYfrY6Y2EXc8jtgK3WquKjGszwHE3o2qn8aXmxJuCQPeSaQpUmtembko3qqyz6k/8AyInsaWuNIHelyev/exk25w8n3Aqo5uaw2Mesn9z98ahNiURE= 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=IZ6TOzIO; arc=none smtp.client-ip=209.85.216.74 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="IZ6TOzIO" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-2ef91d5c863so3422758a91.2 for ; Tue, 10 Dec 2024 17:33:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1733880790; x=1734485590; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=cL3NRVkBfZBJU3o2RWiXYFqfXEQDl3zXojuDagzC/0c=; b=IZ6TOzIOQvGBH83BDvXv2u1PeruzxdX5qpwBGsgZ9BAJMrIeXaP87bqxWdmLBX4ZC5 sCB8xBxLpq70sYr5hINj6hdHHoniCDDJ+zEr80ss/WGvsoe7q8lJdlQjQTBO0NTdgdEU k+3W32niR8oDMep3bbPPUWesNATE1QKGEpp3IkCWX2Ts3JoKa5Ze6M0snSj8Wt04v1kc fgnW37Di+2pihN8lshttc0GKs37kojvd/FSO4w2Tcwln2iNFUM7Ng7nqqlCWyYOdwaoj aHupjFYwz8n8aGtzl7lPUPdA8vOCgGwXGsml5ls30UspEq/JV0Egz9uwrinhwjEYPJF0 5Mwg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1733880790; x=1734485590; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=cL3NRVkBfZBJU3o2RWiXYFqfXEQDl3zXojuDagzC/0c=; b=uZ0d2nVi/I8/RL9G4wc7SX+7KDpbAezJkn00kk1dwgxjQ3Nfvh7iX0buKmSXHNFOr+ vTH71Gb5dikb0p0DCs8m+6H9ENOxWiVs2bliCa+SbesCaGLKkFYWj4ntoPLK4w8YNSyY WZusRplbhcC3h1LkU03NjKIdno3urnnxDDB5fQaBREXEAY7+9LnKDafsAAmmWKOTLZ4O tNsLNKhMoB9UsHgYABFEUpw+n+xmagEZDsUtE+zoI/aJl950uSeLMyUKx8/QRI7KbK/5 GoJt1OLeDXOIG5iWnKRBSJaTgurWjdHbOXRYLmVfxbnmKIusLpws5lItf7EXZft0nSYv ne1A== X-Forwarded-Encrypted: i=1; AJvYcCULionMKf5o+LXZ7nL/NqN+GuXCgXOBl2GhBbwdfCFFsU3Y1CfuLnJjw52JcfagIrgK7qakW0YkR9p3uek=@vger.kernel.org X-Gm-Message-State: AOJu0Yx+8+1FKISot2nxXYfGzIxJlMFTu9vBolXbyMd5MK1U1buUq3bx NH3zci+Hg2uC05qXToNDUMYR6BsVubtttSHHUAEbx8dhNNMIynVZLv76VZR54ri6ZivOi7SLGN2 ulg== X-Google-Smtp-Source: AGHT+IHE/2gxSbX+S+9LU/gh8HaW14iyj5UQ7k4tSNCWmJQgUFrk9t8D9rOA16e9oYsL7aftQDmDCAMD5+A= X-Received: from pjbqx8.prod.google.com ([2002:a17:90b:3e48:b0:2e2:9021:cf53]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:3e82:b0:2ee:94d1:7a9d with SMTP id 98e67ed59e1d1-2f12804a1cdmr1552457a91.32.1733880789942; Tue, 10 Dec 2024 17:33:09 -0800 (PST) Reply-To: Sean Christopherson Date: Tue, 10 Dec 2024 17:33:00 -0800 In-Reply-To: <20241211013302.1347853-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241211013302.1347853-1-seanjc@google.com> X-Mailer: git-send-email 2.47.0.338.g60cca15819-goog Message-ID: <20241211013302.1347853-4-seanjc@google.com> Subject: [PATCH 3/5] KVM: x86: Apply TSX_CTRL_CPUID_CLEAR if and only if the vCPU has RTM or HLE From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Jim Mattson Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When emulating CPUID, retrieve MSR_IA32_TSX_CTRL.TSX_CTRL_CPUID_CLEAR if and only if RTM and/or HLE feature bits need to be cleared. Getting the MSR value is unnecessary if neither bit is set, and avoiding the lookup saves ~80 cycles for vCPUs without RTM or HLE. Cc: Jim Mattson Signed-off-by: Sean Christopherson Reviewed-by: Jim Mattson --- arch/x86/kvm/cpuid.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index f73af4a98c35..7f5fa6665969 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -1998,7 +1998,8 @@ bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *= ebx, *edx =3D entry->edx; if (function =3D=3D 7 && index =3D=3D 0) { u64 data; - if (!__kvm_get_msr(vcpu, MSR_IA32_TSX_CTRL, &data, true) && + if ((*ebx & (feature_bit(RTM) | feature_bit(HLE))) && + !__kvm_get_msr(vcpu, MSR_IA32_TSX_CTRL, &data, true) && (data & TSX_CTRL_CPUID_CLEAR)) *ebx &=3D ~(feature_bit(RTM) | feature_bit(HLE)); } else if (function =3D=3D 0x80000007) { --=20 2.47.0.338.g60cca15819-goog