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[2620:137:e000::1:20]) by mx.google.com with ESMTP id 3-20020a170906328300b0078db6f488cesi7831007ejw.112.2022.11.07.07.00.57; Mon, 07 Nov 2022 07:01:25 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=iTvFg8Dj; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232653AbiKGO5Q (ORCPT + 99 others); Mon, 7 Nov 2022 09:57:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36544 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232621AbiKGO4g (ORCPT ); Mon, 7 Nov 2022 09:56:36 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 070FD1DF2F for ; Mon, 7 Nov 2022 06:54:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1667832883; 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=TlMjd/2CU7uAhpVg7cB+yVdFYGEY40Ps8qhqieVo7Po=; b=iTvFg8DjtXWtXV876KX/X4En+HTs9jtKpnaO24PI3J+9uVg6nR5KtR5wUYV5eGEALPZdMA zSkvAUBt4/LvCr8TVVypThzIV+3A88Bv1kPA5qZ/gWv9+uFec6nSrfoUhD4vlE8ZDdJwAq YWbA6XFF6z6Vgx5qDI55B6lVTRvhC6U= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-564-UTqozkQ5NdyG5uvXMHhq8w-1; Mon, 07 Nov 2022 09:54:38 -0500 X-MC-Unique: UTqozkQ5NdyG5uvXMHhq8w-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 77F7685A59D; Mon, 7 Nov 2022 14:54:37 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id 40AF62028CE4; Mon, 7 Nov 2022 14:54:37 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: nathan@kernel.org, thomas.lendacky@amd.com, andrew.cooper3@citrix.com, peterz@infradead.org, jmattson@google.com, seanjc@google.com Subject: [PATCH 0/8] KVM: SVM: fixes for vmentry code Date: Mon, 7 Nov 2022 09:54:28 -0500 Message-Id: <20221107145436.276079-1-pbonzini@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1748849955818490538?= X-GMAIL-MSGID: =?utf-8?q?1748849955818490538?= 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 4 and 6). - 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 7). 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. One is taken for whether IA32_SPEC_CTRL is intercepted, and one for the host save area, so all accesses to the vcpu_svm struct have to be done from assembly too. This is done in patches 2, 3 and 5 and it turns out not to be that bad; in fact I don't think the code is much harder to follow than before despite doing a lot more stuff. Care has been taken to keep the "normal" and SEV-ES code as similar as possible, too. The above summary leaves out the more mundane patches 1 and 8. They are respectively preparation for adding more asm-offsets, and dead code removal. Most of the scary diffstat comes from patch 1, which is purely moving inline functions to a separate header file than svm.h. Peter Zijlstra had already sent a similar patch for the first issue last Friday. Unfortunately it did not take care of the 32-bit issue with the number of arguments. This series is independent of his, but I did steal his organization of the exception fixup code because it's pretty. Tested on 64-bit bare metal including SEV-ES, and on 32-bit nested. On top of this I also spent way too much time comparing the output of the compiler code before the patch with the assembly code after. Paolo Supersedes: <20221028230723.3254250-1-pbonzini@redhat.com> Paolo Bonzini (8): KVM: SVM: extract VMCB accessors to a new file KVM: SVM: replace regs argument of __svm_vcpu_run with vcpu_svm KVM: SVM: adjust register allocation for __svm_vcpu_run KVM: SVM: move guest vmsave/vmload to assembly KVM: SVM: retrieve VMCB from 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 | 10 ++ arch/x86/kernel/cpu/bugs.c | 15 +- arch/x86/kvm/svm/avic.c | 1 + arch/x86/kvm/svm/nested.c | 1 + arch/x86/kvm/svm/sev.c | 1 + arch/x86/kvm/svm/svm.c | 54 +++----- arch/x86/kvm/svm/svm.h | 204 +-------------------------- arch/x86/kvm/svm/svm_onhyperv.c | 1 + arch/x86/kvm/svm/svm_ops.h | 5 - arch/x86/kvm/svm/vmcb.h | 211 ++++++++++++++++++++++++++++ arch/x86/kvm/svm/vmenter.S | 231 ++++++++++++++++++++++++------- 12 files changed, 434 insertions(+), 310 deletions(-) create mode 100644 arch/x86/kvm/svm/vmcb.h Acked-by: Peter Zijlstra (Intel)