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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 B7508C5ACC6 for ; Tue, 16 Oct 2018 16:50:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D60E21470 for ; Tue, 16 Oct 2018 16:50:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8D60E21470 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727724AbeJQAlz (ORCPT ); Tue, 16 Oct 2018 20:41:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40448 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727272AbeJQAly (ORCPT ); Tue, 16 Oct 2018 20:41:54 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 783AE285B0; Tue, 16 Oct 2018 16:50:38 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.43.2.58]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2FD326BF7B; Tue, 16 Oct 2018 16:50:36 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org Cc: Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Roman Kagan , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , "Michael Kelley (EOSG)" , linux-kernel@vger.kernel.org, Jim Mattson , Liran Alon Subject: [PATCH v6 08/13] x86/kvm/lapic: preserve gfn_to_hva_cache len on cache reinit Date: Tue, 16 Oct 2018 18:50:06 +0200 Message-Id: <20181016165011.6607-9-vkuznets@redhat.com> In-Reply-To: <20181016165011.6607-1-vkuznets@redhat.com> References: <20181016165011.6607-1-vkuznets@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Tue, 16 Oct 2018 16:50:38 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org vcpu->arch.pv_eoi is accessible through both HV_X64_MSR_VP_ASSIST_PAGE and MSR_KVM_PV_EOI_EN so on migration userspace may try to restore them in any order. Values match, however, kvm_lapic_enable_pv_eoi() uses different length: for Hyper-V case it's the whole struct hv_vp_assist_page, for KVM native case it is 8. In case we restore KVM-native MSR last cache will be reinitialized with len=8 so trying to access VP assist page beyond 8 bytes with kvm_read_guest_cached() will fail. Check if we re-initializing cache for the same address and preserve length in case it was greater. Signed-off-by: Vitaly Kuznetsov --- arch/x86/kvm/lapic.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 79358fd6a71c..3cd227ff807f 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2647,14 +2647,22 @@ int kvm_hv_vapic_msr_read(struct kvm_vcpu *vcpu, u32 reg, u64 *data) int kvm_lapic_enable_pv_eoi(struct kvm_vcpu *vcpu, u64 data, unsigned long len) { u64 addr = data & ~KVM_MSR_ENABLED; + struct gfn_to_hva_cache *ghc = &vcpu->arch.pv_eoi.data; + unsigned long new_len; + if (!IS_ALIGNED(addr, 4)) return 1; vcpu->arch.pv_eoi.msr_val = data; if (!pv_eoi_enabled(vcpu)) return 0; - return kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.pv_eoi.data, - addr, len); + + if (addr == ghc->gpa && len <= ghc->len) + new_len = ghc->len; + else + new_len = len; + + return kvm_gfn_to_hva_cache_init(vcpu->kvm, ghc, addr, new_len); } void kvm_apic_accept_events(struct kvm_vcpu *vcpu) -- 2.17.1