From mboxrd@z Thu Jan 1 00:00:00 1970 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 DEC40194132 for ; Tue, 10 Sep 2024 14:05:43 +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=1725977145; cv=none; b=j2KlmjPUNpfJ6rzJ5yAi+Bhmgq1spZV65fElP6bcdLlNek1zw4H6DJmT2yaY0DxyBwnJoOCimSEalrpgf0olUajx/5PJJTWHpwVZ4xknmNguoGRnA/k/kyRgyEtlIrwC4el14p7A09+ScTwFII+vkjkeWKr5cD69sgyMHPa4b0E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725977145; c=relaxed/simple; bh=t8ErVB8odQun7D6nqubwrwdq8/LVz3C4A6u9HDCxsy8=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=VFCDPrOEksEtsLn2w7SNnVKWGZSoyXmAwjbJZ7PDIVIVWj9IuQfwSjkbdrKUdhCriAoNKRjEYG5wdgPIV2+CNZoms52qRS+XZLa4DTiVryHI7Zw0ED4FQvDYXO/Eg5MsOBLZRddrikbqwY1ygGxgTJjkkg2T1J8n0K2oOpajMjY= 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=Lf9Bu8Gq; 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="Lf9Bu8Gq" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-2db24468f94so2407366a91.1 for ; Tue, 10 Sep 2024 07:05:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1725977143; x=1726581943; 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=hXOmTeRY6PomLyhOcA86DkilxkGrIMLpe4RY7rDX+4M=; b=Lf9Bu8GqS63SHyJvJjvrM9mFaV9892up9U5SPwSAP9tlUMCEk3xH6e32iIPc8UR78L fYkJMSrDOtIp5uHca+vko3y1r4dcT8e1u284AVtfL4Sny0X/cfV5ghNBc1g8aomttv/Y fo98l3Cf3bt6RO8bOZh9/xlv7sEvb9bvr3LF/YGnGDAvvoKd8nLjV5rrB3+2x4lQ0Tbe LnJOoANZPA8cQV+IXQeJSNrTYi/y0B7Y2T/TRtCEpuAoLXFLqWFDP1YaboPHw/pwYKR5 SGqyq6nD1X7LfF1EdWjb/3WBLp6oTxLkXpYC3QmZeAjqugMiQKDJY5s77qUBxNA7i9/R oAqQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725977143; x=1726581943; 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=hXOmTeRY6PomLyhOcA86DkilxkGrIMLpe4RY7rDX+4M=; b=KtWAZaNXByHOZURZ4RokgqeQgQiYWGxHQ+vD1q1XiSEOw+InE2Buc0dUDTFifKqhOX kudtyhZ8OPOCSri2y44vG8aOBF2OwMtZxgT/LB9sKetmK6+BQiR0yEt6NEsPhyvqIRhd JK5eqd29E0sTUhISuJx9zlWKP9dwBG2qzf9jMWHAe277JHmCNY7/Bhg1luT4q9cW2beV G/ofFYqZhA1dzvF3yYIPCD8qIzrYbmenDixkkiv4RAy+B7kYtZ9HEonsmMmwsYqi3jUe fSVeFub7VxvHqV3GuAMqU6z/IA/kYfI3otOLif4mVzi6iofJYzJnlXqVuGL4K8d1i3Ux 6bAA== X-Forwarded-Encrypted: i=1; AJvYcCVc9ybSJIXIc4x16Lmmvd1OX3al6GWz1VuLspwVZddGtsyaqUQRwtdTtQ0ELoaOLAx8FVPNOgRd5pxuIVk=@vger.kernel.org X-Gm-Message-State: AOJu0YzodF9nFWrH0AxrjxGdknlekuVa3p7Pst7VRLeVHiM2W/CwFdS0 OGuEy/sBiqKP+IgAvFbUZ/Wm/3iYwKMwNNY25PAQn1p0vTmyRtMI1E98heZLpf024JtrM8HC4EP Lig== X-Google-Smtp-Source: AGHT+IHY7Zm41nQugrtyi3XpGw9nez+eUwT1LK7XarrI7Y/zK4pfY2UZwEEv9rY2QWqJJ5NBxwihpUJRBhE= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:90b:4a45:b0:2d8:8f24:bd8c with SMTP id 98e67ed59e1d1-2dad4b8d9edmr308985a91.0.1725977143145; Tue, 10 Sep 2024 07:05:43 -0700 (PDT) Date: Tue, 10 Sep 2024 07:05:41 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240904030751.117579-1-rick.p.edgecombe@intel.com> <20240904030751.117579-18-rick.p.edgecombe@intel.com> Message-ID: Subject: Re: [PATCH 17/21] KVM: TDX: MTRR: implement get_mt_mask() for TDX From: Sean Christopherson To: Paolo Bonzini Cc: Rick Edgecombe , kvm@vger.kernel.org, kai.huang@intel.com, dmatlack@google.com, isaku.yamahata@gmail.com, yan.y.zhao@intel.com, nik.borisov@suse.com, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" On Tue, Sep 10, 2024, Paolo Bonzini wrote: > On 9/4/24 05:07, Rick Edgecombe wrote: > > From: Isaku Yamahata > > > > Although TDX supports only WB for private GPA, it's desirable to support > > MTRR for shared GPA. Always honor guest PAT for shared EPT as what's done > > for normal VMs. > > > > Suggested-by: Kai Huang > > Co-developed-by: Yan Zhao > > Signed-off-by: Yan Zhao > > Signed-off-by: Isaku Yamahata > > Signed-off-by: Rick Edgecombe > > --- > > TDX MMU part 2 v1: > > - Align with latest vmx code in kvm/queue. > > - Updated patch log. > > - Dropped KVM_BUG_ON() in vt_get_mt_mask(). (Rick) > > The only difference at this point is > > if (!static_cpu_has(X86_FEATURE_SELFSNOOP) && > !kvm_arch_has_noncoherent_dma(vcpu->kvm)) > return (MTRR_TYPE_WRBACK << VMX_EPT_MT_EPTE_SHIFT) | > VMX_EPT_IPAT_BIT; > > > which should never be true. I think this patch can simply be dropped. And we can/should do what we've done for SEV, and make it a hard dependency to enable TDX, e.g. similar to this: /* * SEV must obviously be supported in hardware. Sanity check that the * CPU supports decode assists, which is mandatory for SEV guests to * support instruction emulation. Ditto for flushing by ASID, as SEV * guests are bound to a single ASID, i.e. KVM can't rotate to a new * ASID to effect a TLB flush. */ if (!boot_cpu_has(X86_FEATURE_SEV) || WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_DECODEASSISTS)) || WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_FLUSHBYASID))) goto out;