From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E41D2C43219 for ; Wed, 9 Nov 2022 14:54:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231661AbiKIOyM (ORCPT ); Wed, 9 Nov 2022 09:54:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230072AbiKIOyA (ORCPT ); Wed, 9 Nov 2022 09:54:00 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E89C31C136 for ; Wed, 9 Nov 2022 06:52:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1668005523; 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=rDPg823+ssgoo9QOHHChyrv6cfKJarSq3LFy2v+O4Og=; b=Nycd0DBCEJz/yxqUbPwxzdGSfPCNy/3J7ac/KI2QB/idtAXzKmt0Cpb+nYK9VfGXcV1mnq RPMfTIKg7ZAvvpE7BIPmUlVquvDpTkzUwLPVpdf7e0UM7Cj3UQv05GNfJjZzM+xG67Z0Np +CYtiwOAQ5h91HZt+WPHYEs7lopBBR8= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-147-nGbcBkZFMwmsKOgK8rOuFg-1; Wed, 09 Nov 2022 09:51:58 -0500 X-MC-Unique: nGbcBkZFMwmsKOgK8rOuFg-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 95DC72815216; Wed, 9 Nov 2022 14:51:57 +0000 (UTC) Received: from virtlab511.virt.lab.eng.bos.redhat.com (virtlab511.virt.lab.eng.bos.redhat.com [10.19.152.198]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6B43E1401C2E; Wed, 9 Nov 2022 14:51:57 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: thomas.lendacky@amd.com, jmattson@google.com, seanjc@google.com Subject: [PATCH v3 00/11] KVM: SVM: fixes for vmentry code Date: Wed, 9 Nov 2022 09:51:45 -0500 Message-Id: <20221109145156.84714-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This series comprises two related fixes: - the FILL_RETURN_BUFFER macro in -next needs to access percpu data, hence the GS segment base needs to be loaded before FILL_RETURN_BUFFER. This means moving guest vmload/vmsave and host vmload to assembly (patches 8 and 9). - because AMD wants the OS to set STIBP to 1 before executing the return thunk (un)training sequence, IA32_SPEC_CTRL must be restored before UNTRAIN_RET, too. This must also be moved to assembly and, for consistency, the guest SPEC_CTRL is also loaded in there (patch 10). Neither is particularly hard, however because of 32-bit systems one needs to keep the number of arguments to __svm_vcpu_run to three or fewer. Therefore, patches 2 to 7 move various accesses to the vcpu_svm struct and to percpu data to vmenter.S, cleaning up various bits along the way to keep the assembly code nice. I think the code is simpler than before after these prerequisites, and even at the end of the series it is not much harder to follow despite doing a lot more stuff. Care has been taken to keep the "normal" and SEV-ES code as similar as possible, even though the latter would not hit the three argument barrier; even the prototype is the same. The above summary leaves patch 1, which introduces a separate asm-offsets.c file for KVM, so that kernel/asm-offsets.c does not have to do ugly includes with ../ paths; and patch 11, which is just more dead code removal. Thanks, Paolo v2->v3: store SME-adjusted save_area physical address in svm_cpu_data, access it with PER_CPU_VAR instead of an argument [Sean, sort of] split out-of-line spec-ctrl restore macro in two parts [Sean] adjust comments to point out clobbered registers [Sean] Paolo Bonzini (11): KVM: x86: use a separate asm-offsets.c file KVM: SVM: replace regs argument of __svm_vcpu_run with vcpu_svm KVM: SVM: adjust register allocation for __svm_vcpu_run KVM: SVM: retrieve VMCB from assembly KVM: SVM: remove unused field from struct vcpu_svm KVM: SVM: remove dead field from struct svm_cpu_data KVM: SVM: do not allocate struct svm_cpu_data dynamically KVM: SVM: move guest vmsave/vmload back to assembly KVM: SVM: restore host save area from assembly KVM: SVM: move MSR_IA32_SPEC_CTRL save/restore to assembly x86, KVM: remove unnecessary argument to x86_virt_spec_ctrl and callers arch/x86/include/asm/spec-ctrl.h | 10 +- arch/x86/kernel/asm-offsets.c | 6 - arch/x86/kernel/cpu/bugs.c | 15 +- arch/x86/kvm/.gitignore | 2 + arch/x86/kvm/Makefile | 12 ++ arch/x86/kvm/kvm-asm-offsets.c | 29 ++++ arch/x86/kvm/svm/sev.c | 4 +- arch/x86/kvm/svm/svm.c | 105 +++++-------- arch/x86/kvm/svm/svm.h | 11 +- arch/x86/kvm/svm/svm_ops.h | 5 - arch/x86/kvm/svm/vmenter.S | 260 +++++++++++++++++++++++++------ arch/x86/kvm/vmx/vmenter.S | 2 +- 12 files changed, 305 insertions(+), 156 deletions(-) create mode 100644 arch/x86/kvm/.gitignore create mode 100644 arch/x86/kvm/kvm-asm-offsets.c -- 2.31.1