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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 v6 04/12] KVM: arm/arm64: Helper to locate free rdist index
Date: Mon, 30 Apr 2018 13:48:30 +0200	[thread overview]
Message-ID: <1525088918-8600-5-git-send-email-eric.auger@redhat.com> (raw)
In-Reply-To: <1525088918-8600-1-git-send-email-eric.auger@redhat.com>

We introduce vgic_v3_rdist_free_slot to help identifying
where we can place a new 2x64KB redistributor.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>

---

v3 -> v4:
- add details to vgic_v3_rdist_free_slot kernel doc comment
- Added Christoffer's R-b
---
 virt/kvm/arm/vgic/vgic-mmio-v3.c |  3 +--
 virt/kvm/arm/vgic/vgic-v3.c      | 23 +++++++++++++++++++++++
 virt/kvm/arm/vgic/vgic.h         | 11 +++++++++++
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index d1aab18..49ca176 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -593,8 +593,7 @@ int vgic_register_redist_iodev(struct kvm_vcpu *vcpu)
 	 * function for all VCPUs when the base address is set.  Just return
 	 * without doing any work for now.
 	 */
-	rdreg = list_first_entry(&vgic->rd_regions,
-				 struct vgic_redist_region, list);
+	rdreg = vgic_v3_rdist_free_slot(&vgic->rd_regions);
 	if (!rdreg)
 		return 0;
 
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 94de6cd..f81a63a 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -444,6 +444,29 @@ bool vgic_v3_check_base(struct kvm *kvm)
 	return false;
 }
 
+/**
+ * vgic_v3_rdist_free_slot - Look up registered rdist regions and identify one
+ * which has free space to put a new rdist region.
+ *
+ * @rd_regions: redistributor region list head
+ *
+ * A redistributor regions maps n redistributors, n = region size / (2 x 64kB).
+ * Stride between redistributors is 0 and regions are filled in the index order.
+ *
+ * Return: the redist region handle, if any, that has space to map a new rdist
+ * region.
+ */
+struct vgic_redist_region *vgic_v3_rdist_free_slot(struct list_head *rd_regions)
+{
+	struct vgic_redist_region *rdreg;
+
+	list_for_each_entry(rdreg, rd_regions, list) {
+		if (!vgic_v3_redist_region_full(rdreg))
+			return rdreg;
+	}
+	return NULL;
+}
+
 int vgic_v3_map_resources(struct kvm *kvm)
 {
 	int ret = 0;
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 830e815..fea32cb 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -251,6 +251,17 @@ static inline int vgic_v3_max_apr_idx(struct kvm_vcpu *vcpu)
 	}
 }
 
+static inline bool
+vgic_v3_redist_region_full(struct vgic_redist_region *region)
+{
+	if (!region->count)
+		return false;
+
+	return (region->free_index >= region->count);
+}
+
+struct vgic_redist_region *vgic_v3_rdist_free_slot(struct list_head *rdregs);
+
 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:[~2018-04-30 11:49 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-30 11:48 [PATCH v6 00/12] KVM: arm/arm64: Allow multiple GICv3 redistributor regions Eric Auger
2018-04-30 11:48 ` [PATCH v6 01/12] KVM: arm/arm64: Set dist->spis to NULL after kfree Eric Auger
2018-04-30 11:48 ` [PATCH v6 02/12] KVM: arm/arm64: Document KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION Eric Auger
2018-04-30 11:48 ` [PATCH v6 03/12] KVM: arm/arm64: Replace the single rdist region by a list Eric Auger
2018-04-30 11:48 ` Eric Auger [this message]
2018-04-30 11:48 ` [PATCH v6 05/12] KVM: arm/arm64: Revisit Redistributor TYPER last bit computation Eric Auger
2018-04-30 11:48 ` [PATCH v6 06/12] KVM: arm/arm64: Adapt vgic_v3_check_base to multiple rdist regions Eric Auger
2018-04-30 11:48 ` [PATCH v6 07/12] KVM: arm/arm64: Helper to register a new redistributor region Eric Auger
2018-04-30 11:48 ` [PATCH v6 08/12] KVM: arm/arm64: Check vcpu redist base before registering an iodev Eric Auger
2018-04-30 11:48 ` [PATCH v6 09/12] KVM: arm/arm64: Check all vcpu redistributors are set on map_resources Eric Auger
2018-04-30 11:48 ` [PATCH v6 10/12] KVM: arm/arm64: Add KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION Eric Auger
2018-04-30 11:48 ` [PATCH v6 11/12] KVM: arm/arm64: Implement KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION Eric Auger
2018-04-30 11:48 ` [PATCH v6 12/12] KVM: arm/arm64: Bump VGIC_V3_MAX_CPUS to 512 Eric Auger
2018-05-20 13:43 ` [PATCH v6 00/12] KVM: arm/arm64: Allow multiple GICv3 redistributor regions Marc Zyngier
2018-05-20 21:28   ` Auger Eric

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