From patchwork Wed Oct 5 13:06:55 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= X-Patchwork-Id: 9362887 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0FB346077E for ; Wed, 5 Oct 2016 13:08:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 00CED28532 for ; Wed, 5 Oct 2016 13:08:01 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E9608285A2; Wed, 5 Oct 2016 13:08:00 +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=-5.9 required=2.0 tests=BAYES_00,HK_RANDOM_FROM, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 83C9D28532 for ; Wed, 5 Oct 2016 13:08:00 +0000 (UTC) Received: from localhost ([::1]:49037 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1brlvT-0002MK-IB for patchwork-qemu-devel@patchwork.kernel.org; Wed, 05 Oct 2016 09:07:59 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40629) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1brluu-0002Jz-JT for qemu-devel@nongnu.org; Wed, 05 Oct 2016 09:07:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1brlut-0004hF-7c for qemu-devel@nongnu.org; Wed, 05 Oct 2016 09:07:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56062) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1brlus-0004h9-Tw for qemu-devel@nongnu.org; Wed, 05 Oct 2016 09:07:23 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 820811C13DF; Wed, 5 Oct 2016 13:07:22 +0000 (UTC) Received: from potion (dhcp-1-247.brq.redhat.com [10.34.1.247]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id u95D7JPx025787; Wed, 5 Oct 2016 09:07:20 -0400 Received: by potion (sSMTP sendmail emulation); Wed, 05 Oct 2016 15:07:19 +0200 From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= To: qemu-devel@nongnu.org Date: Wed, 5 Oct 2016 15:06:55 +0200 Message-Id: <20161005130657.3399-7-rkrcmar@redhat.com> In-Reply-To: <20161005130657.3399-1-rkrcmar@redhat.com> References: <20161005130657.3399-1-rkrcmar@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Wed, 05 Oct 2016 13:07:22 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v4 6/8] intel_iommu: reject broken EIM X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Eduardo Habkost , "Michael S. Tsirkin" , Peter Xu , Paolo Bonzini , Igor Mammedov , Richard Henderson Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Cluster x2APIC cannot work without KVM's x2apic API when the maximal APIC ID is greater than 8 and only KVM's LAPIC can support x2APIC, so we forbid other APICs and also the old KVM case with less than 9, to simplify the code. There is no point in enabling EIM in forbidden APICs, so we keep it enabled only for the KVM APIC; unconditionally, because making the option depend on KVM version would be a maintanance burden. Old QEMUs would enable eim whenever intremap was on, which would trick guests into thinking that they can enable cluster x2APIC even if any interrupt destination would get clamped to 8 bits. Depending on your configuration, QEMU could notice that the destination LAPIC is not present and report it with a very non-obvious: KVM: injection failed, MSI lost (Operation not permitted) Or the guest could say something about unexpected interrupts, because clamping leads to aliasing so interrupts were being delivered to incorrect VCPUs. KVM_X2APIC_API is the feature that allows us to enable eim for KVM. Signed-off-by: Radim Krčmář Reviewed-by: Peter Xu --- v4: be more specific in the comment [Igor] v3: * use error_setg [Paolo] * shorten the code [Peter] v2: * adapt to new intr_eim parameter * provide first linux version that has x2apic api * disable QEMU's LAPIC --- hw/i386/intel_iommu.c | 15 ++++++++++++++- target-i386/kvm-stub.c | 5 +++++ target-i386/kvm.c | 13 +++++++++++++ target-i386/kvm_i386.h | 1 + 4 files changed, 33 insertions(+), 1 deletion(-) diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index 17892b8c336b..efb018b85544 100644 --- a/hw/i386/intel_iommu.c +++ b/hw/i386/intel_iommu.c @@ -33,6 +33,7 @@ #include "hw/pci-host/q35.h" #include "sysemu/kvm.h" #include "hw/i386/apic_internal.h" +#include "kvm_i386.h" /*#define DEBUG_INTEL_IOMMU*/ #ifdef DEBUG_INTEL_IOMMU @@ -2472,10 +2473,22 @@ static bool vtd_decide_config(IntelIOMMUState *s, Error **errp) } if (s->intr_eim == ON_OFF_AUTO_AUTO) { - s->intr_eim = x86_iommu->intr_supported ? + s->intr_eim = x86_iommu->intr_supported && kvm_irqchip_in_kernel() ? ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF; } + if (s->intr_eim == ON_OFF_AUTO_ON) { + if (kvm_irqchip_in_kernel() && !kvm_enable_x2apic()) { + error_setg(errp, "eim=on requires support on the KVM side" + "(X2APIC_API, first shipped in v4.7)"); + return false; + } + if (!kvm_irqchip_in_kernel()) { + error_setg(errp, "eim=on requires accel=kvm,kernel-irqchip=split"); + return false; + } + } + return true; } diff --git a/target-i386/kvm-stub.c b/target-i386/kvm-stub.c index cdf15061091d..bda4dc2f0c57 100644 --- a/target-i386/kvm-stub.c +++ b/target-i386/kvm-stub.c @@ -25,6 +25,11 @@ bool kvm_has_smm(void) return 1; } +bool kvm_enable_x2apic(void) +{ + return false; +} + /* This function is only called inside conditionals which we * rely on the compiler to optimize out when CONFIG_KVM is not * defined. diff --git a/target-i386/kvm.c b/target-i386/kvm.c index ee1f53e56953..0fd664648665 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -122,6 +122,19 @@ bool kvm_allows_irq0_override(void) return !kvm_irqchip_in_kernel() || kvm_has_gsi_routing(); } +static bool kvm_x2apic_api_set_flags(uint64_t flags) +{ + KVMState *s = KVM_STATE(current_machine->accelerator); + + return !kvm_vm_enable_cap(s, KVM_CAP_X2APIC_API, 0, flags); +} + +bool kvm_enable_x2apic(void) +{ + return kvm_x2apic_api_set_flags(KVM_X2APIC_API_USE_32BIT_IDS | + KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK); +} + static int kvm_get_tsc(CPUState *cs) { X86CPU *cpu = X86_CPU(cs); diff --git a/target-i386/kvm_i386.h b/target-i386/kvm_i386.h index 36407e0a5dc7..5c369b1c5b40 100644 --- a/target-i386/kvm_i386.h +++ b/target-i386/kvm_i386.h @@ -43,4 +43,5 @@ int kvm_device_msix_deassign(KVMState *s, uint32_t dev_id); void kvm_put_apicbase(X86CPU *cpu, uint64_t value); +bool kvm_enable_x2apic(void); #endif