From patchwork Fri Sep 21 10:01:40 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Mackerras X-Patchwork-Id: 10609645 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E1018112B for ; Fri, 21 Sep 2018 10:03:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D1F6026D08 for ; Fri, 21 Sep 2018 10:03:01 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C66FD2811E; Fri, 21 Sep 2018 10:03:01 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3D2E428793 for ; Fri, 21 Sep 2018 10:03:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389628AbeIUPub (ORCPT ); Fri, 21 Sep 2018 11:50:31 -0400 Received: from ozlabs.org ([203.11.71.1]:33301 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389591AbeIUPub (ORCPT ); Fri, 21 Sep 2018 11:50:31 -0400 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPSA id 42Gpzy1ZSNz9sBn; Fri, 21 Sep 2018 20:02:22 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ozlabs.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ozlabs.org; s=201707; t=1537524142; bh=exYMnWJGd0qjHtbb9609NfoAbWBTfpdHQ0cW0g2lEig=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ChKs0L7SebFCddzNbSGF3JB6pNgwwOKXfO8TKRhNiT3BktRLEmiZqBpKltGaUAqGA MEwpaW8aRUVwSI4KpUSegWHfnBnw704H0If9AOp21L97BMhCOYC8WJ/ucFCZ4nHje8 7CUQnX1YmLyhLiS8is24NdTn3h8WGHiUcBNxnbKTU6Y8raON/eaDZUYw71tu1CRZTB euEngTPtPRbMLO8JK2mIoDLNo0Sf8oCrnNFkmgyhLs2nhZCWZobIRBZHhzL/otOOfm fQHuKvR62dAZDOnk4EKkK2is6NDmR7fdl4yO2QZuhdMTXgsNO8eryxglDRrCbI83Yc xce9+EYkjVgeA== From: Paul Mackerras To: kvm-ppc@vger.kernel.org, kvm@vger.kernel.org Cc: David Gibson Subject: [RFC PATCH 09/32] KVM: PPC: Book3S HV: Handle hypervisor instruction faults better Date: Fri, 21 Sep 2018 20:01:40 +1000 Message-Id: <1537524123-9578-10-git-send-email-paulus@ozlabs.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1537524123-9578-1-git-send-email-paulus@ozlabs.org> References: <1537524123-9578-1-git-send-email-paulus@ozlabs.org> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently the code for handling hypervisor instruction page faults passes 0 for the flags indicating the type of fault, which is OK in the usual case that the page is not mapped in the partition-scoped page tables. However, there are other causes for hypervisor instruction page faults, such as not being to update a reference (R) or change (C) bit. The cause is indicated in bits in HSRR1, including a bit which indicates that the fault is due to not being able to write to a page (for example to update an R or C bit). Not handling these other kinds of faults correctly can lead to a loop of continual faults without forward progress in the guest. In order to handle these faults better, this patch constructs a "DSISR-like" value from the bits which DSISR and SRR1 (for a HISI) have in common, and passes it to kvmppc_book3s_hv_page_fault() so that it knows what caused the fault. Signed-off-by: Paul Mackerras Reviewed-by: David Gibson --- arch/powerpc/include/asm/reg.h | 1 + arch/powerpc/kvm/book3s_hv.c | 5 ++++- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index e5b314e..6fda746 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -766,6 +766,7 @@ #define SPRN_HSRR0 0x13A /* Save/Restore Register 0 */ #define SPRN_HSRR1 0x13B /* Save/Restore Register 1 */ #define HSRR1_DENORM 0x00100000 /* Denorm exception */ +#define HSRR1_HISI_WRITE 0x00010000 /* HISI bcs couldn't update mem */ #define SPRN_TBCTL 0x35f /* PA6T Timebase control register */ #define TBCTL_FREEZE 0x0000000000000000ull /* Freeze all tbs */ diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 8576a7b..e0e92f2 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -1188,7 +1188,10 @@ static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu, break; case BOOK3S_INTERRUPT_H_INST_STORAGE: vcpu->arch.fault_dar = kvmppc_get_pc(vcpu); - vcpu->arch.fault_dsisr = 0; + vcpu->arch.fault_dsisr = vcpu->arch.shregs.msr & + DSISR_SRR1_MATCH_64S; + if (vcpu->arch.shregs.msr & HSRR1_HISI_WRITE) + vcpu->arch.fault_dsisr |= DSISR_ISSTORE; r = RESUME_PAGE_FAULT; break; /*