From patchwork Tue Dec 1 08:52:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 336844 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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 35530C64E7B for ; Tue, 1 Dec 2020 09:09:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7FD2221FF for ; Tue, 1 Dec 2020 09:08:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="rGpOLu8V" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389277AbgLAJIi (ORCPT ); Tue, 1 Dec 2020 04:08:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:46058 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389266AbgLAJIg (ORCPT ); Tue, 1 Dec 2020 04:08:36 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BDE2D22245; Tue, 1 Dec 2020 09:07:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606813675; bh=OIl2PaLR6m+mUydIo7T59Uy4mlHqDn+kQDtyLPEktvA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rGpOLu8VQqTynyZLFGZkUaUiJHkgcZo8T8r2iJUqVsyMGsfeXRCSmzLBmjmLJ9WCw Yvwz7XY73iQhAwgQUiSrdZJfoLUbLooaNY6QuhfKILZrqw1kXfpsU8BSlHsmq/Ugfy LJizv9BpRIZ+KF8XRzNPewUiT9+xLgGQPyKcKHe4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nicholas Piggin , Michael Ellerman Subject: [PATCH 5.9 021/152] powerpc/64s/exception: KVM Fix for host DSI being taken in HPT guest MMU context Date: Tue, 1 Dec 2020 09:52:16 +0100 Message-Id: <20201201084714.627633394@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201201084711.707195422@linuxfoundation.org> References: <20201201084711.707195422@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Nicholas Piggin commit cd81acc600a9684ea4b4d25a47900d38a3890eab upstream. Commit 2284ffea8f0c ("powerpc/64s/exception: Only test KVM in SRR interrupts when PR KVM is supported") removed KVM guest tests from interrupts that do not set HV=1, when PR-KVM is not configured. This is wrong for HV-KVM HPT guest MMIO emulation case which attempts to load the faulting instruction word with MSR[DR]=1 and MSR[HV]=1 with the guest MMU context loaded. This can cause host DSI, DSLB interrupts which must test for KVM guest. Restore this and add a comment. Fixes: 2284ffea8f0c ("powerpc/64s/exception: Only test KVM in SRR interrupts when PR KVM is supported") Cc: stable@vger.kernel.org # v5.7+ Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201117135617.3521127-1-npiggin@gmail.com Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/exceptions-64s.S | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -1410,6 +1410,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) * If none is found, do a Linux page fault. Linux page faults can happen in * kernel mode due to user copy operations of course. * + * KVM: The KVM HDSI handler may perform a load with MSR[DR]=1 in guest + * MMU context, which may cause a DSI in the host, which must go to the + * KVM handler. MSR[IR] is not enabled, so the real-mode handler will + * always be used regardless of AIL setting. + * * - Radix MMU * The hardware loads from the Linux page table directly, so a fault goes * immediately to Linux page fault. @@ -1420,10 +1425,8 @@ INT_DEFINE_BEGIN(data_access) IVEC=0x300 IDAR=1 IDSISR=1 -#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE IKVM_SKIP=1 IKVM_REAL=1 -#endif INT_DEFINE_END(data_access) EXC_REAL_BEGIN(data_access, 0x300, 0x80) @@ -1462,6 +1465,8 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TY * ppc64_bolted_size (first segment). The kernel handler must avoid stomping * on user-handler data structures. * + * KVM: Same as 0x300, DSLB must test for KVM guest. + * * A dedicated save area EXSLB is used (XXX: but it actually need not be * these days, we could use EXGEN). */ @@ -1470,10 +1475,8 @@ INT_DEFINE_BEGIN(data_access_slb) IAREA=PACA_EXSLB IRECONCILE=0 IDAR=1 -#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE IKVM_SKIP=1 IKVM_REAL=1 -#endif INT_DEFINE_END(data_access_slb) EXC_REAL_BEGIN(data_access_slb, 0x380, 0x80)