From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger 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> References: <1509031391-4407-1-git-send-email-eric.auger@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 08A9A49D36 for ; Thu, 26 Oct 2017 11:22:56 -0400 (EDT) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ONh0fcCfTWiW for ; Thu, 26 Oct 2017 11:22:55 -0400 (EDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id E2AB340651 for ; Thu, 26 Oct 2017 11:22:54 -0400 (EDT) In-Reply-To: <1509031391-4407-1-git-send-email-eric.auger@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu 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 List-Id: kvmarm@lists.cs.columbia.edu 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