From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932626AbdJZPYV (ORCPT ); Thu, 26 Oct 2017 11:24:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58840 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932333AbdJZPYR (ORCPT ); Thu, 26 Oct 2017 11:24:17 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 19687883BD Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=eric.auger@redhat.com From: Eric Auger To: eric.auger.pro@gmail.com, eric.auger@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, marc.zyngier@arm.com, cdall@linaro.org, peter.maydell@linaro.org, andre.przywara@arm.com, wanghaibin.wang@huawei.com Cc: wu.wubin@huawei.com, drjones@redhat.com, wei@redhat.com Subject: [PATCH v6 7/9] KVM: arm/arm64: vgic-its: Free caches when GITS_BASER Valid bit is cleared Date: Thu, 26 Oct 2017 17:23:09 +0200 Message-Id: <1509031391-4407-8-git-send-email-eric.auger@redhat.com> In-Reply-To: <1509031391-4407-1-git-send-email-eric.auger@redhat.com> References: <1509031391-4407-1-git-send-email-eric.auger@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Thu, 26 Oct 2017 15:24:17 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When the GITS_BASER.Valid gets cleared, the data structures in guest RAM are not valid anymore. The device, collection and LPI lists stored in the in-kernel ITS represent the same information in some form of cache. So let's void the cache. Signed-off-by: Eric Auger --- v5 -> v6: - rename type into device_type and revert tthe u64 -> int change - remove the default clause - take the its mutex lock around vgic_its_free_device/collection_list v4 -> v5: - add comment about locking v2 -> v3: - add a comment and clear cache in if block --- virt/kvm/arm/vgic/vgic-its.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index 5b7be85..2a92d4d 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -1428,7 +1428,7 @@ static void vgic_mmio_write_its_baser(struct kvm *kvm, unsigned long val) { const struct vgic_its_abi *abi = vgic_its_get_abi(its); - u64 entry_size, device_type; + u64 entry_size, table_type; u64 reg, *regptr, clearbits = 0; /* When GITS_CTLR.Enable is 1, we ignore write accesses. */ @@ -1439,12 +1439,12 @@ static void vgic_mmio_write_its_baser(struct kvm *kvm, case 0: regptr = &its->baser_device_table; entry_size = abi->dte_esz; - device_type = GITS_BASER_TYPE_DEVICE; + table_type = GITS_BASER_TYPE_DEVICE; break; case 1: regptr = &its->baser_coll_table; entry_size = abi->cte_esz; - device_type = GITS_BASER_TYPE_COLLECTION; + table_type = GITS_BASER_TYPE_COLLECTION; clearbits = GITS_BASER_INDIRECT; break; default: @@ -1456,10 +1456,28 @@ static void vgic_mmio_write_its_baser(struct kvm *kvm, reg &= ~clearbits; reg |= (entry_size - 1) << GITS_BASER_ENTRY_SIZE_SHIFT; - reg |= device_type << GITS_BASER_TYPE_SHIFT; + reg |= table_type << GITS_BASER_TYPE_SHIFT; reg = vgic_sanitise_its_baser(reg); *regptr = reg; + + /* + * If the table is no longer valid, we clear the associated cached data. + * Note: there cannot be any race with save/restore code which locks + * all vcpus. + */ + if (!(reg & GITS_BASER_VALID)) { + mutex_lock(&its->its_lock); + switch (table_type) { + case GITS_BASER_TYPE_DEVICE: + vgic_its_free_device_list(kvm, its); + break; + case GITS_BASER_TYPE_COLLECTION: + vgic_its_free_collection_list(kvm, its); + break; + } + mutex_unlock(&its->its_lock); + } } static unsigned long vgic_mmio_read_its_ctlr(struct kvm *vcpu, -- 2.5.5