[xen staging] xen/arm/gic: Allow adding interrupt to running VMs

[patchbot@xxxxxxx]

commit 1c77496bc84391a946f5a00b21ffa9c5d71335c9
Author:     Henry Wang <xin.wang2@xxxxxxx>
AuthorDate: Thu May 23 15:40:35 2024 +0800
Commit:     Stefano Stabellini <stefano.stabellini@xxxxxxx>
CommitDate: Fri May 24 16:26:22 2024 -0700

    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@xxxxxxx>
    Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxx>
    Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>
---
 xen/arch/arm/gic-vgic.c  | 9 +++++++--
 xen/arch/arm/gic.c       | 8 --------
 xen/arch/arm/vgic/vgic.c | 7 +++++--
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/xen/arch/arm/gic-vgic.c b/xen/arch/arm/gic-vgic.c
index 56490dbc43..b99e287224 100644
--- 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 44c40e86de..b3467a76ae 100644
--- 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 b9463a5f27..6cabd0496d 100644
--- 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;
--
generated by git-patchbot for /home/xen/git/xen.git#staging