From patchwork Tue Mar 4 06:06:41 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 13999955 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 F09731F5845 for ; Tue, 4 Mar 2025 06:07:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741068424; cv=none; b=Z8m4Iy3e9zJk6VnLV2DwomTRxc5gqIFEvLCIZNS6qZ3XfXO1q1E/0yBUqgFTNwnOMNuMbr2XpDDLtKEIqKkabCCvTk7yDuCzby8h5UXEWyryEa5WBrgi8wcgyAcaCknwCXLlGWWyEI5PSstOxpeY8vgo2kiaFBKy2TLRmv8jz90= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741068424; c=relaxed/simple; bh=H3yi31HVokcXJOCubsppmA5t1sFMy5S8K3VED2TAarI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=o0TpLdyGbkgTli2O3z46yTflFg7UWsLdXhbCx6zq9PlXgCPwVdk0j6W3uZW3nLMr14QYPdLa4a0/rvVGKz3z3WnbpJa29t/cGE1UhBlQaxx6d+kDwe4Bmdj8TlH79mYkqsij/0YXrvQpjtga8a27B6bRPnI9OFVvsE57vusRO28= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=GzBtxZF3; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GzBtxZF3" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1741068422; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=Gh8Xe3wJDPflxFCDUNvREYtPLwvRg7q/ggCpf5a4R/o=; b=GzBtxZF3/SLYtB7ENcArB0M8axZqYkI34EEAAXshCF2po+fugMhzdwSjZmu+RzRevk02iv geOZQn9NyCNkq6NxC/AWV3py4W8Miz5ejIj7ukHqlcqEpLP0uiorFK5tzAQlOvgyP2crBI NYbs1yQlu98CuoJ0f7YuPq/0Wyo1oEo= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-230-m7A5iEGUNZ-MxK0My6uWjA-1; Tue, 04 Mar 2025 01:06:50 -0500 X-MC-Unique: m7A5iEGUNZ-MxK0My6uWjA-1 X-Mimecast-MFC-AGG-ID: m7A5iEGUNZ-MxK0My6uWjA_1741068409 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3367F180087E; Tue, 4 Mar 2025 06:06:49 +0000 (UTC) Received: from virtlab1023.lab.eng.rdu2.redhat.com (virtlab1023.lab.eng.rdu2.redhat.com [10.8.1.187]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 50A6919560A3; Tue, 4 Mar 2025 06:06:48 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: xiaoyao.li@intel.com, seanjc@google.com, yan.y.zhao@intel.com Subject: [PATCH v3 0/4] KVM: x86: Introduce quirk KVM_X86_QUIRK_IGNORE_GUEST_PAT Date: Tue, 4 Mar 2025 01:06:41 -0500 Message-ID: <20250304060647.2903469-1-pbonzini@redhat.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 This series is my evolution of Yan's patches at https://patchew.org/linux/20250224070716.31360-1-yan.y.zhao@intel.com/. The implementation of the quirk is unchanged, but the concepts in kvm_caps are a bit different. In particular: - if a quirk is not applicable to some hardware, it is still included in KVM_CAP_DISABLE_QUIRKS2. This way userspace knows that KVM is *aware* of a particular issue - even if disabling it has no effect because the quirk is not a problem on a specific hardware, userspace may want to know that it can rely on the problematic behavior not being present. Therefore, KVM_X86_QUIRK_EPT_IGNORE_GUEST_PAT is simply auto-disabled on TDX machines. - if instead a quirk cannot be disabled due to limitations, for example KVM_X86_QUIRK_EPT_IGNORE_GUEST_PAT if self-snoop is not present on the CPU, the quirk is removed completely from kvm_caps.supported_quirks and therefore from KVM_CAP_DISABLE_QUIRKS2. This series does not introduce a way to query always-disabled quirks, which could be for example KVM_CAP_DISABLED_QUIRKS. This could be added if we wanted for example to get rid of hypercall patching; it's a trivial addition. The main semantic change with respect to v2 is to prevent re-enabling quirks that have been disabled with KVM_ENABLE_CAP. This in turn makes it possible to just use kvm->arch.disabled_quirks for TDX-enabled Paolo Supersedes: <20250301073428.2435768-1-pbonzini@redhat.com> Paolo Bonzini (3): KVM: x86: do not allow re-enabling quirks KVM: x86: Allow vendor code to disable quirks KVM: x86: remove shadow_memtype_mask Yan Zhao (3): KVM: x86: Introduce supported_quirks to block disabling quirks KVM: x86: Introduce Intel specific quirk KVM_X86_QUIRK_IGNORE_GUEST_PAT KVM: TDX: Always honor guest PAT on TDX enabled guests Documentation/virt/kvm/api.rst | 22 +++++++++++++++++ arch/x86/include/asm/kvm_host.h | 7 +++++- arch/x86/include/uapi/asm/kvm.h | 1 + arch/x86/kvm/mmu.h | 2 +- arch/x86/kvm/mmu/mmu.c | 13 ---------- arch/x86/kvm/mmu/spte.c | 19 ++------------- arch/x86/kvm/mmu/spte.h | 1 - arch/x86/kvm/svm/svm.c | 1 + arch/x86/kvm/vmx/tdx.c | 6 +++++ arch/x86/kvm/vmx/vmx.c | 43 +++++++++++++++++++++++++++------ arch/x86/kvm/x86.c | 13 +++++++--- arch/x86/kvm/x86.h | 3 +++ 12 files changed, 87 insertions(+), 44 deletions(-)