xen/arm/gic: Allow adding interrupt to running VMs

Currently, adding physical interrupts are only allowed at
the domain creation time. For use cases such as dynamic device
tree overlay addition, the adding of physical IRQ to
running domains should be allowed.

Drop the above-mentioned domain creation check. Since this
will introduce interrupt state unsync issues for cases when the
interrupt is active or pending in the guest, therefore for these
cases we simply reject the operation. Do it for both new and old
vGIC implementations.

Signed-off-by: Henry Wang <xin.wang2@amd.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>

diff --git a/xen/arch/arm/gic-vgic.c b/xen/arch/arm/gic-vgic.c
index 56490dbc436d4ae8ece2bc48270d0c8066191901..b99e2872242562ec9faa50776335cf07c6f265b5 100644 (file)
--- a/xen/arch/arm/gic-vgic.c
+++ b/xen/arch/arm/gic-vgic.c
@@ -442,9 +442,14 @@ int vgic_connect_hw_irq(struct domain *d, struct vcpu *v, unsigned int virq,
 
     if ( connect )
     {
-        /* The VIRQ should not be already enabled by the guest */
+        /*
+         * The VIRQ should not be already enabled by the guest nor
+         * active/pending in the guest.
+         */
         if ( !p->desc &&
-             !test_bit(GIC_IRQ_GUEST_ENABLED, &p->status) )
+             !test_bit(GIC_IRQ_GUEST_ENABLED, &p->status) &&
+             !test_bit(GIC_IRQ_GUEST_VISIBLE, &p->status) &&
+             !test_bit(GIC_IRQ_GUEST_ACTIVE, &p->status) )
             p->desc = desc;
         else
             ret = -EBUSY;

diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index 44c40e86defe44418ea393639fb8c8c376fa3353..b3467a76ae751806a22006edbdd26f6e92b58c84 100644 (file)
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -135,14 +135,6 @@ int gic_route_irq_to_guest(struct domain *d, unsigned int virq,
     ASSERT(virq < vgic_num_irqs(d));
     ASSERT(!is_lpi(virq));
 
-    /*
-     * When routing an IRQ to guest, the virtual state is not synced
-     * back to the physical IRQ. To prevent get unsync, restrict the
-     * routing to when the Domain is been created.
-     */
-    if ( d->creation_finished )
-        return -EBUSY;
-
     ret = vgic_connect_hw_irq(d, NULL, virq, desc, true);
     if ( ret )
         return ret;

diff --git a/xen/arch/arm/vgic/vgic.c b/xen/arch/arm/vgic/vgic.c
index b9463a5f2714541fcfebbd7225c972751bdb0633..6cabd0496dfa6111f6a91599bfea3b409f97d35e 100644 (file)
--- a/xen/arch/arm/vgic/vgic.c
+++ b/xen/arch/arm/vgic/vgic.c
@@ -876,8 +876,11 @@ int vgic_connect_hw_irq(struct domain *d, struct vcpu *vcpu,
 
     if ( connect )                      /* assign a mapped IRQ */
     {
-        /* The VIRQ should not be already enabled by the guest */
-        if ( !irq->hw && !irq->enabled )
+        /*
+         * The VIRQ should not be already enabled by the guest nor
+         * active/pending in the guest.
+         */
+        if ( !irq->hw && !irq->enabled && !irq->active && !irq->pending_latch )
         {
             irq->hw = true;
             irq->hwintid = desc->irq;