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 X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DA7E4C04AA7 for ; Mon, 13 May 2019 14:40:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 99DFA2084A for ; Mon, 13 May 2019 14:40:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="m2arcl/O" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730633AbfEMOk3 (ORCPT ); Mon, 13 May 2019 10:40:29 -0400 Received: from aserp2130.oracle.com ([141.146.126.79]:37798 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730623AbfEMOk0 (ORCPT ); Mon, 13 May 2019 10:40:26 -0400 Received: from pps.filterd (aserp2130.oracle.com [127.0.0.1]) by aserp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x4DEdHlv193231; Mon, 13 May 2019 14:39:53 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2018-07-02; bh=LfHNGKdGVZ8SXafCfcR3Zof+WadTo/bKWh5zIaesw/M=; b=m2arcl/OoSz25ufQlPkSDyXa5f1frMRq2QeB0JzA4PV/uhaSpAPsJfmP6YeH0R+Y7+PC 50HJ+Yx7Z8gUn3m69WqI9tJvyt5ZPxzpbW+60gErtelRwYfFJw+X3V78E3pi6uU708Zl uEVUq4MhUxXUf1DFx84dYgGV/93RXZwfztVCXTVvknZhM6YZw2KSvN8qBdHsbd2ELVmx /7qs4qjDnvxh+fcskoo9PGQvTX2vY0RinWTrcvKjzeXlWoP9/wWiom7xFgGIssxbulhP IvPfd4bMncK92V8msleNSWffh5EcxE1AX3Pw6AsvfuevV3vA7E7XlcOF1Gt+oJHTRqAq Ww== Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by aserp2130.oracle.com with ESMTP id 2sdkwdfm13-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 13 May 2019 14:39:53 +0000 Received: from achartre-desktop.fr.oracle.com (dhcp-10-166-106-34.fr.oracle.com [10.166.106.34]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id x4DEcZQS022780; Mon, 13 May 2019 14:39:50 GMT From: Alexandre Chartre To: pbonzini@redhat.com, rkrcmar@redhat.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, kvm@vger.kernel.org, x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: konrad.wilk@oracle.com, jan.setjeeilers@oracle.com, liran.alon@oracle.com, jwadams@google.com, alexandre.chartre@oracle.com Subject: [RFC KVM 25/27] kvm/isolation: implement actual KVM isolation enter/exit Date: Mon, 13 May 2019 16:38:33 +0200 Message-Id: <1557758315-12667-26-git-send-email-alexandre.chartre@oracle.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1557758315-12667-1-git-send-email-alexandre.chartre@oracle.com> References: <1557758315-12667-1-git-send-email-alexandre.chartre@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9255 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905130103 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Liran Alon KVM isolation enter/exit is done by switching between the KVM address space and the kernel address space. Signed-off-by: Liran Alon Signed-off-by: Alexandre Chartre --- arch/x86/kvm/isolation.c | 30 ++++++++++++++++++++++++------ arch/x86/mm/tlb.c | 1 + include/linux/sched.h | 1 + 3 files changed, 26 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/isolation.c b/arch/x86/kvm/isolation.c index db0a7ce..b0c789f 100644 --- a/arch/x86/kvm/isolation.c +++ b/arch/x86/kvm/isolation.c @@ -1383,11 +1383,13 @@ static bool kvm_page_fault(struct pt_regs *regs, unsigned long error_code, printk(KERN_DEFAULT "KVM isolation: page fault %ld at %pS on %lx (%pS) while switching mm\n" " cr3=%lx\n" " kvm_mm=%px pgd=%px\n" - " active_mm=%px pgd=%px\n", + " active_mm=%px pgd=%px\n" + " kvm_prev_mm=%px pgd=%px\n", error_code, (void *)regs->ip, address, (void *)address, cr3, &kvm_mm, kvm_mm.pgd, - active_mm, active_mm->pgd); + active_mm, active_mm->pgd, + current->kvm_prev_mm, current->kvm_prev_mm->pgd); dump_stack(); return false; @@ -1649,11 +1651,27 @@ void kvm_may_access_sensitive_data(struct kvm_vcpu *vcpu) kvm_isolation_exit(); } +static void kvm_switch_mm(struct mm_struct *mm) +{ + unsigned long flags; + + /* + * Disable interrupt before updating active_mm, otherwise if an + * interrupt occurs during the switch then the interrupt handler + * can be mislead about the mm effectively in use. + */ + local_irq_save(flags); + current->kvm_prev_mm = current->active_mm; + current->active_mm = mm; + switch_mm_irqs_off(current->kvm_prev_mm, mm, NULL); + local_irq_restore(flags); +} + void kvm_isolation_enter(void) { int err; - if (kvm_isolation()) { + if (kvm_isolation() && current->active_mm != &kvm_mm) { /* * Switches to kvm_mm should happen from vCPU thread, * which should not be a kernel thread with no mm @@ -1666,14 +1684,14 @@ void kvm_isolation_enter(void) current); return; } - /* TODO: switch to kvm_mm */ + kvm_switch_mm(&kvm_mm); } } void kvm_isolation_exit(void) { - if (kvm_isolation()) { + if (kvm_isolation() && current->active_mm == &kvm_mm) { /* TODO: Kick sibling hyperthread before switch to host mm */ - /* TODO: switch back to original mm */ + kvm_switch_mm(current->kvm_prev_mm); } } diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index a4db7f5..7ad5ad1 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -444,6 +444,7 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next, switch_ldt(real_prev, next); } } +EXPORT_SYMBOL_GPL(switch_mm_irqs_off); /* * Please ignore the name of this function. It should be called diff --git a/include/linux/sched.h b/include/linux/sched.h index 80e1d75..b03680d 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1202,6 +1202,7 @@ struct task_struct { #ifdef CONFIG_HAVE_KVM /* Is the task mapped into the KVM address space? */ bool kvm_mapped; + struct mm_struct *kvm_prev_mm; #endif /* -- 1.7.1