From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger Subject: [PATCH v5 08/10] KVM: arm/arm64: vgic-its: Free caches when GITS_BASER Valid bit is cleared Date: Mon, 23 Oct 2017 16:08:27 +0200 Message-ID: <1508767709-15256-9-git-send-email-eric.auger@redhat.com> References: <1508767709-15256-1-git-send-email-eric.auger@redhat.com> Return-path: In-Reply-To: <1508767709-15256-1-git-send-email-eric.auger@redhat.com> Sender: kvm-owner@vger.kernel.org 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 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 --- v4 -> v5: - add comment about locking v2 -> v3: - add a comment and clear cache in if block --- virt/kvm/arm/vgic/vgic-its.c | 27 +++++++++++++++++++++++---- 1 file changed, 23 insertions(+), 4 deletions(-) diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index 8098f91..bdfceb4 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -1434,8 +1434,9 @@ 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; u64 reg, *regptr, clearbits = 0; + int type; /* When GITS_CTLR.Enable is 1, we ignore write accesses. */ if (its->enabled) @@ -1445,12 +1446,12 @@ 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; + type = GITS_BASER_TYPE_DEVICE; break; case 1: regptr = &its->baser_coll_table; entry_size = abi->cte_esz; - device_type = GITS_BASER_TYPE_COLLECTION; + type = GITS_BASER_TYPE_COLLECTION; clearbits = GITS_BASER_INDIRECT; break; default: @@ -1462,10 +1463,28 @@ 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 |= (u64)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)) { + switch (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; + default: + break; + } + } } static unsigned long vgic_mmio_read_its_ctlr(struct kvm *vcpu, -- 2.5.5