x86/dpci: EOI interrupt regardless of its masking status

Modify hvm_pirq_eoi to always EOI the interrupt if required, instead
of not doing such EOI if the interrupt is routed through the vIO-APIC
and the entry is masked at the time the EOI is performed.

Further unmask of the vIO-APIC pin won't EOI the interrupt, and thus
the guest OS has to wait for the timeout to expire and the automatic
EOI to be performed.

This allows to simplify the helpers and drop the vioapic_redir_entry
parameter from all of them.

Fixes: ccfe4e0845 ('Intel vt-d specific changes in arch/x86/hvm/vmx/vtd.')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: eb298f32fa
master date: 2021-01-07 15:10:29 +0100

xen/arch/x86/hvm/vioapic.c

@@ -539,7 +539,7 @@ void vioapic_update_EOI(struct domain *d, u8 vector)
             if ( is_iommu_enabled(d) )
             {
                 spin_unlock(&d->arch.hvm.irq_lock);
-                hvm_dpci_eoi(d, vioapic->base_gsi + pin, ent);
+                hvm_dpci_eoi(d, vioapic->base_gsi + pin);
                 spin_lock(&d->arch.hvm.irq_lock);
             }
 

xen/arch/x86/hvm/vpic.c

@@ -261,8 +261,7 @@ static void vpic_ioport_write(
                 vpic_update_int_output(vpic);
                 vpic_unlock(vpic);
                 hvm_dpci_eoi(current->domain,
-                             hvm_isa_irq_to_gsi((addr >> 7) ? (irq|8) : irq),
-                             NULL);
+                             hvm_isa_irq_to_gsi((addr >> 7) ? (irq | 8) : irq));
                 return; /* bail immediately */
             case 6: /* Set Priority                */
                 vpic->priority_add = (val + 1) & 7;

xen/drivers/passthrough/io.c

@@ -950,8 +950,7 @@ static void hvm_dirq_assist(struct domain *d, struct hvm_pirq_dpci *pirq_dpci)
     spin_unlock(&d->event_lock);
 }
 
-static void hvm_pirq_eoi(struct pirq *pirq,
-                         const union vioapic_redir_entry *ent)
+static void hvm_pirq_eoi(struct pirq *pirq)
 {
     struct hvm_pirq_dpci *pirq_dpci;
 
@@ -968,7 +967,6 @@ static void hvm_pirq_eoi(struct pirq *pirq,
      * since interrupt is still not EOIed
      */
     if ( --pirq_dpci->pending ||
-         (ent && ent->fields.mask) ||
          !pt_irq_need_timer(pirq_dpci->flags) )
         return;
 
@@ -977,19 +975,17 @@ static void hvm_pirq_eoi(struct pirq *pirq,
 }
 
 static void __hvm_dpci_eoi(struct domain *d,
-                           const struct hvm_girq_dpci_mapping *girq,
-                           const union vioapic_redir_entry *ent)
+                           const struct hvm_girq_dpci_mapping *girq)
 {
     struct pirq *pirq = pirq_info(d, girq->machine_gsi);
 
     if ( !hvm_domain_use_pirq(d, pirq) )
         hvm_pci_intx_deassert(d, girq->device, girq->intx);
 
-    hvm_pirq_eoi(pirq, ent);
+    hvm_pirq_eoi(pirq);
 }
 
-static void hvm_gsi_eoi(struct domain *d, unsigned int gsi,
-                        const union vioapic_redir_entry *ent)
+static void hvm_gsi_eoi(struct domain *d, unsigned int gsi)
 {
     struct pirq *pirq = pirq_info(d, gsi);
 
@@ -998,11 +994,10 @@ static void hvm_gsi_eoi(struct domain *d, unsigned int gsi,
         return;
 
     hvm_gsi_deassert(d, gsi);
-    hvm_pirq_eoi(pirq, ent);
+    hvm_pirq_eoi(pirq);
 }
 
-void hvm_dpci_eoi(struct domain *d, unsigned int guest_gsi,
-                  const union vioapic_redir_entry *ent)
+void hvm_dpci_eoi(struct domain *d, unsigned int guest_gsi)
 {
     const struct hvm_irq_dpci *hvm_irq_dpci;
     const struct hvm_girq_dpci_mapping *girq;
@@ -1013,7 +1008,7 @@ void hvm_dpci_eoi(struct domain *d, unsigned int guest_gsi,
     if ( is_hardware_domain(d) )
     {
         spin_lock(&d->event_lock);
-        hvm_gsi_eoi(d, guest_gsi, ent);
+        hvm_gsi_eoi(d, guest_gsi);
         goto unlock;
     }
 
@@ -1030,7 +1025,7 @@ void hvm_dpci_eoi(struct domain *d, unsigned int guest_gsi,
         goto unlock;
 
     list_for_each_entry ( girq, &hvm_irq_dpci->girq[guest_gsi], list )
-        __hvm_dpci_eoi(d, girq, ent);
+        __hvm_dpci_eoi(d, girq);
 
 unlock:
     spin_unlock(&d->event_lock);

xen/include/asm-x86/hvm/io.h

@@ -118,8 +118,7 @@ bool handle_mmio_with_translation(unsigned long gla, unsigned long gpfn,
                                   struct npfec);
 bool handle_pio(uint16_t port, unsigned int size, int dir);
 void hvm_interrupt_post(struct vcpu *v, int vector, int type);
-void hvm_dpci_eoi(struct domain *d, unsigned int guest_irq,
-                  const union vioapic_redir_entry *ent);
+void hvm_dpci_eoi(struct domain *d, unsigned int guest_irq);
 void msix_write_completion(struct vcpu *);
 
 #ifdef CONFIG_HVM