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From: Eric Auger <eric.auger@redhat.com>
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@kernel.org, peter.maydell@linaro.org
Cc: andre.przywara@arm.com, drjones@redhat.com, wei@redhat.com
Subject: [PATCH v4 07/12] KVM: arm/arm64: Helper to register a new redistributor region
Date: Fri, 27 Apr 2018 16:15:00 +0200	[thread overview]
Message-ID: <1524838505-3823-8-git-send-email-eric.auger@redhat.com> (raw)
In-Reply-To: <1524838505-3823-1-git-send-email-eric.auger@redhat.com>

We introduce a new helper that creates and inserts a new redistributor
region into the rdist region list. This helper both handles the case
where the redistributor region size is known at registration time
and the legacy case where it is not (eventually depending on the number
of online vcpus). Depending on pfns, we perform all the possible checks
that we can do:

- end of memory crossing
- incorrect alignment of the base address
- collision with distributor region if already defined
- collision with already registered rdist regions
- check of the new index

Rdist regions must be inserted by increasing order of indices. Indices
must be contiguous.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---

v3 -> v4:
- inversed check in vgic_v3_rdist_overlap
- use list_last_entry in vgic_v3_insert_redist_region
- improve comment in vgic_v3_insert_redist_region
- introduce vgic_dist_overlap
---
 virt/kvm/arm/vgic/vgic-mmio-v3.c | 89 ++++++++++++++++++++++++++++++++--------
 virt/kvm/arm/vgic/vgic.h         |  8 ++++
 2 files changed, 81 insertions(+), 16 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index ce5c927..cbf8f4e 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -680,14 +680,63 @@ static int vgic_register_all_redist_iodevs(struct kvm *kvm)
 	return ret;
 }
 
-int vgic_v3_set_redist_base(struct kvm *kvm, u64 addr)
+/**
+ * vgic_v3_insert_redist_region - Insert a new redistributor region
+ *
+ * Performs various checks before inserting the rdist region in the list.
+ * Those tests depend on whether the size of the rdist region is known
+ * (ie. count != 0). The list is sorted by rdist region index.
+ *
+ * @kvm: kvm handle
+ * @index: redist region index
+ * @base: base of the new rdist region
+ * @count: number of redistributors the region is made of (of 0 in the old style
+ * single region, whose size is induced from the number of vcpus)
+ *
+ * Return 0 on success, < 0 otherwise
+ */
+static int vgic_v3_insert_redist_region(struct kvm *kvm, uint32_t index,
+					gpa_t base, uint32_t count)
 {
-	struct vgic_dist *vgic = &kvm->arch.vgic;
+	struct vgic_dist *d = &kvm->arch.vgic;
 	struct vgic_redist_region *rdreg;
+	struct list_head *rd_regions = &d->rd_regions;
+	struct list_head *last = rd_regions->prev;
+	size_t size = count * KVM_VGIC_V3_REDIST_SIZE;
 	int ret;
 
-	/* vgic_check_ioaddr makes sure we don't do this twice */
-	if (!list_empty(&vgic->rd_regions))
+	/* single rdist region already set ?*/
+	if (!count && !list_empty(rd_regions))
+		return -EINVAL;
+
+	/* cross the end of memory ? */
+	if (base + size < base)
+		return -EINVAL;
+
+	if (list_empty(rd_regions)) {
+		if (index != 0)
+			return -EINVAL;
+	} else {
+		rdreg = list_entry(last, struct vgic_redist_region, list);
+		if (index != rdreg->index + 1)
+			return -EINVAL;
+
+		/* Cannot add an explicitly sized regions after legacy region */
+		if (!rdreg->count)
+			return -EINVAL;
+	}
+
+	/*
+	 * For legacy single-region redistributor regions (!count),
+	 * check that the redistributor region does not overlap with the
+	 * distributor's address space.
+	 */
+	if (!count && !IS_VGIC_ADDR_UNDEF(d->vgic_dist_base) &&
+		vgic_dist_overlap(kvm, base, size))
+		return -EINVAL;
+
+	/* collision with any other rdist region? */
+	if (vgic_v3_rdist_overlap(kvm, base, size))
 		return -EINVAL;
 
 	rdreg = kzalloc(sizeof(*rdreg), GFP_KERNEL);
@@ -696,17 +745,29 @@ int vgic_v3_set_redist_base(struct kvm *kvm, u64 addr)
 
 	rdreg->base = VGIC_ADDR_UNDEF;
 
-	ret = vgic_check_ioaddr(kvm, &rdreg->base, addr, SZ_64K);
+	ret = vgic_check_ioaddr(kvm, &rdreg->base, base, SZ_64K);
 	if (ret)
-		goto out;
+		goto free;
 
-	rdreg->base = addr;
-	if (!vgic_v3_check_base(kvm)) {
-		ret = -EINVAL;
-		goto out;
-	}
+	rdreg->base = base;
+	rdreg->count = count;
+	rdreg->free_index = 0;
+	rdreg->index = index;
 
-	list_add(&rdreg->list, &vgic->rd_regions);
+	list_add_tail(&rdreg->list, rd_regions);
+	return 0;
+free:
+	kfree(rdreg);
+	return ret;
+}
+
+int vgic_v3_set_redist_base(struct kvm *kvm, u64 addr)
+{
+	int ret;
+
+	ret = vgic_v3_insert_redist_region(kvm, 0, addr, 0);
+	if (ret)
+		return ret;
 
 	/*
 	 * Register iodevs for each existing VCPU.  Adding more VCPUs
@@ -717,10 +778,6 @@ int vgic_v3_set_redist_base(struct kvm *kvm, u64 addr)
 		return ret;
 
 	return 0;
-
-out:
-	kfree(rdreg);
-	return ret;
 }
 
 int vgic_v3_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr)
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index e6e3ae9..6af7d8a 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -272,6 +272,14 @@ vgic_v3_rd_region_size(struct kvm *kvm, struct vgic_redist_region *rdreg)
 }
 bool vgic_v3_rdist_overlap(struct kvm *kvm, gpa_t base, size_t size);
 
+static inline bool vgic_dist_overlap(struct kvm *kvm, gpa_t base, size_t size)
+{
+	struct vgic_dist *d = &kvm->arch.vgic;
+
+	return (base + size > d->vgic_dist_base) &&
+		(base < d->vgic_dist_base + KVM_VGIC_V3_DIST_SIZE);
+}
+
 int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
 			 u32 devid, u32 eventid, struct vgic_irq **irq);
 struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);
-- 
2.5.5

  parent reply	other threads:[~2018-04-27 14:15 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-27 14:14 [PATCH v4 00/12] KVM: arm/arm64: Allow multiple GICv3 redistributor regions Eric Auger
2018-04-27 14:14 ` [PATCH v4 01/12] KVM: arm/arm64: Set dist->spis to NULL after kfree Eric Auger
2018-04-27 14:14 ` [PATCH v4 02/12] KVM: arm/arm64: Document KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION Eric Auger
2018-04-27 19:15   ` Christoffer Dall
2018-04-27 14:14 ` [PATCH v4 03/12] KVM: arm/arm64: Replace the single rdist region by a list Eric Auger
2018-04-27 14:14 ` [PATCH v4 04/12] KVM: arm/arm64: Helper to locate free rdist index Eric Auger
2018-04-27 14:14 ` [PATCH v4 05/12] KVM: arm/arm64: Revisit Redistributor TYPER last bit computation Eric Auger
2018-04-27 14:14 ` [PATCH v4 06/12] KVM: arm/arm64: Adapt vgic_v3_check_base to multiple rdist regions Eric Auger
2018-04-29 12:35   ` Christoffer Dall
2018-04-27 14:15 ` Eric Auger [this message]
2018-04-27 14:15 ` [PATCH v4 08/12] KVM: arm/arm64: Check vcpu redist base before registering an iodev Eric Auger
2018-04-29 12:35   ` Christoffer Dall
2018-04-27 14:15 ` [PATCH v4 09/12] KVM: arm/arm64: Check all vcpu redistributors are set on map_resources Eric Auger
2018-04-29 12:35   ` Christoffer Dall
2018-04-27 14:15 ` [PATCH v4 10/12] KVM: arm/arm64: Add KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION Eric Auger
2018-04-27 14:15 ` [PATCH v4 11/12] KVM: arm/arm64: Implement KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION Eric Auger
2018-04-27 19:17   ` Christoffer Dall
2018-04-27 14:15 ` [PATCH v4 12/12] KVM: arm/arm64: Bump VGIC_V3_MAX_CPUS to 512 Eric Auger
2018-04-29 12:35   ` Christoffer Dall

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