Thread (72 messages) 72 messages, 4 authors, 2017-05-06
STALE3329d

[PATCH v6 15/24] KVM: arm64: vgic-its: Read config and pending bit in add_lpi()

From: Christoffer Dall <hidden>
Date: 2017-05-05 09:57:08
Also in: kvm, kvmarm

On Thu, May 04, 2017 at 01:44:35PM +0200, Eric Auger wrote:
quoted hunk ↗ jump to hunk
When creating the lpi we now ask the redistributor what is the state
of the LPI (priority, enabled, pending).

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

---

v6: creation
---
 virt/kvm/arm/vgic/vgic-its.c | 35 ++++++++++++++++++++++++-----------
 1 file changed, 24 insertions(+), 11 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index f43ea30c..3ad615a 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -38,6 +38,8 @@
 
 static int vgic_its_set_abi(struct vgic_its *its, int rev);
 static const struct vgic_its_abi *vgic_its_get_abi(struct vgic_its *its);
+static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
+			     struct kvm_vcpu *filter_vcpu);
 
 /*
  * Creates a new (reference to a) struct vgic_irq for a given LPI.
@@ -46,10 +48,12 @@ static const struct vgic_its_abi *vgic_its_get_abi(struct vgic_its *its);
  * If this is a "new" LPI, we allocate and initialize a new struct vgic_irq.
  * This function returns a pointer to the _unlocked_ structure.
  */
-static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid)
+static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid,
+				     struct kvm_vcpu *vcpu)
 {
 	struct vgic_dist *dist = &kvm->arch.vgic;
 	struct vgic_irq *irq = vgic_get_irq(kvm, NULL, intid), *oldirq;
+	int ret;
 
 	/* In this case there is no put, since we keep the reference. */
 	if (irq)
@@ -66,6 +70,7 @@ static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid)
 	irq->config = VGIC_CONFIG_EDGE;
 	kref_init(&irq->refcount);
 	irq->intid = intid;
+	irq->target_vcpu = vcpu;
 
 	spin_lock(&dist->lpi_list_lock);
 
@@ -97,6 +102,19 @@ static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid)
 out_unlock:
 	spin_unlock(&dist->lpi_list_lock);
 
+	/*
+	 * We "cache" the configuration table entries in out struct vgic_irq's.
s/out/our/ ?
quoted hunk ↗ jump to hunk
+	 * However we only have those structs for mapped IRQs, so we read in
+	 * the respective config data from memory here upon mapping the LPI.
+	 */
+	ret = update_lpi_config(kvm, irq, NULL);
+	if (ret)
+		return ERR_PTR(ret);
+
+	ret = vgic_v3_lpi_sync_pending_status(kvm, irq);
+	if (ret)
+		return ERR_PTR(ret);
+
 	return irq;
 }
 
@@ -769,6 +787,7 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
 	u32 event_id = its_cmd_get_id(its_cmd);
 	u32 coll_id = its_cmd_get_collection(its_cmd);
 	struct its_ite *ite;
+	struct kvm_vcpu *vcpu = NULL;
 	struct its_device *device;
 	struct its_collection *collection, *new_coll = NULL;
 	int lpi_nr;
@@ -814,7 +833,10 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
 	ite->collection = collection;
 	ite->lpi = lpi_nr;
 
-	irq = vgic_add_lpi(kvm, lpi_nr);
+	if (its_is_collection_mapped(collection))
+		vcpu = kvm_get_vcpu(kvm, collection->target_addr);
+
+	irq = vgic_add_lpi(kvm, lpi_nr, vcpu);
So, if we don't have the collection and therefore end up with irq->vcpu
== NULL, how do we ever read the pending bit from memory as the affinity
may later change?

Is this a problem with our idea of only looking at the pending bit on
vgic_add_lpi, or does it just mean that we should sample the pending bit
whenever we move LPIs around to VCPUs and if the bit is set, then also
set the pennding_latch (if not already set), or what should happen here?

I think in any case, we should have a comment here explaining that vcpu
configuration data gets picked up later?

Thanks,
-Christoffer
quoted hunk ↗ jump to hunk
 	if (IS_ERR(irq)) {
 		if (new_coll)
 			vgic_its_free_collection(its, coll_id);
@@ -823,15 +845,6 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
 	}
 	ite->irq = irq;
 
-	update_affinity_ite(kvm, ite);
-
-	/*
-	 * We "cache" the configuration table entries in out struct vgic_irq's.
-	 * However we only have those structs for mapped IRQs, so we read in
-	 * the respective config data from memory here upon mapping the LPI.
-	 */
-	update_lpi_config(kvm, ite->irq, NULL);
-
 	return 0;
 }
 
-- 
2.5.5
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