From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758770AbbA2Vtw (ORCPT ); Thu, 29 Jan 2015 16:49:52 -0500 Received: from mx1.redhat.com ([209.132.183.28]:40893 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758714AbbA2Vtr (ORCPT ); Thu, 29 Jan 2015 16:49:47 -0500 From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, Paolo Bonzini , Nadav Amit , Gleb Natapov Subject: [PATCH 7/8] KVM: x86: avoid logical_map when it is invalid Date: Thu, 29 Jan 2015 22:48:54 +0100 Message-Id: <1422568135-28402-8-git-send-email-rkrcmar@redhat.com> In-Reply-To: <1422568135-28402-1-git-send-email-rkrcmar@redhat.com> References: <1422568135-28402-1-git-send-email-rkrcmar@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We want to support mixed modes and the easiest solution is to avoid optimizing those weird and unlikely scenarios. Signed-off-by: Radim Krčmář --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/lapic.c | 16 ++++++++++++++++ arch/x86/kvm/lapic.h | 4 ++++ 3 files changed, 21 insertions(+) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 26d0f0f646d3..fec3188cabbb 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -554,6 +554,7 @@ struct kvm_arch_memory_slot { struct kvm_apic_map { struct rcu_head rcu; + u8 mode; u8 ldr_bits; /* fields bellow are used to decode ldr values in different modes */ u32 cid_shift, cid_mask, lid_mask; diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index fab007509047..621d9df6ac63 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -162,16 +162,19 @@ static void recalculate_apic_map(struct kvm *kvm) new->ldr_bits = 32; new->cid_shift = 16; new->cid_mask = new->lid_mask = 0xffff; + new->mode |= KVM_APIC_MODE_X2APIC; } else if (kvm_apic_get_reg(apic, APIC_LDR)) { if (kvm_apic_get_reg(apic, APIC_DFR) == APIC_DFR_CLUSTER) { new->cid_shift = 4; new->cid_mask = 0xf; new->lid_mask = 0xf; + new->mode |= KVM_APIC_MODE_XAPIC_CLUSTER; } else { new->cid_shift = 8; new->cid_mask = 0; new->lid_mask = 0xff; + new->mode |= KVM_APIC_MODE_XAPIC_FLAT; } } @@ -201,6 +204,13 @@ static void recalculate_apic_map(struct kvm *kvm) if (aid < ARRAY_SIZE(new->phys_map)) new->phys_map[aid] = apic; + + /* The logical map is definitely wrong if we have multiple + * modes at the same time. Physical is still right though. + */ + if (hweight8(new->mode) != 1) + continue; + if (lid && cid < ARRAY_SIZE(new->logical_map)) new->logical_map[cid][ffs(lid) - 1] = apic; } @@ -720,6 +730,12 @@ bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src, if (cid >= ARRAY_SIZE(map->logical_map)) goto out; + if (hweight8(map->mode) != 1) { + /* Not deliverable with optimized map. */ + ret = false; + goto out; + } + dst = map->logical_map[cid]; bitmap = apic_logical_id(map, mda); diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h index c1ef25c89508..fd0197a93862 100644 --- a/arch/x86/kvm/lapic.h +++ b/arch/x86/kvm/lapic.h @@ -8,6 +8,10 @@ #define KVM_APIC_INIT 0 #define KVM_APIC_SIPI 1 +#define KVM_APIC_MODE_XAPIC_FLAT (1 << 0) +#define KVM_APIC_MODE_XAPIC_CLUSTER (1 << 1) +#define KVM_APIC_MODE_X2APIC (1 << 2) + struct kvm_timer { struct hrtimer timer; s64 period; /* unit: ns */ -- 2.2.2