KVM: arm/arm64: Enable MSI routing

Up to now, only irqchip routing entries could be set. This patch
adds the capability to insert MSI routing entries.

For ARM64, let's also increase KVM_MAX_IRQ_ROUTES to 4096: this
include SPI irqchip routes plus MSI routes. In the future this
might be extended.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

4 files changed, 28 insertions, 9 deletions

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 7e5f9afcc693..7a04216d7278 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2381,6 +2381,9 @@ On arm/arm64, gsi routing being supported, the following can happen:
 - in case no routing entry is associated to this gsi, injection fails
 - in case the gsi is associated to an irqchip routing entry,
   irqchip.pin + 32 corresponds to the injected SPI ID.
+- in case the gsi is associated to an MSI routing entry, the MSI
+  message and device ID are translated into an LPI (support restricted
+  to GICv3 ITS in-kernel emulation).
 
 4.76 KVM_PPC_ALLOCATE_HTAB
 
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index a7eb5c48251e..a318c3b21608 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1048,6 +1048,8 @@ static inline int mmu_notifier_retry(struct kvm *kvm, unsigned long mmu_seq)
 
 #ifdef CONFIG_S390
 #define KVM_MAX_IRQ_ROUTES 4096 //FIXME: we can have more than that...
+#elif defined(CONFIG_ARM64)
+#define KVM_MAX_IRQ_ROUTES 4096
 #else
 #define KVM_MAX_IRQ_ROUTES 1024
 #endif
diff --git a/virt/kvm/arm/vgic/vgic-irqfd.c b/virt/kvm/arm/vgic/vgic-irqfd.c
index 6e84d530d9f7..683a589711b0 100644
--- a/virt/kvm/arm/vgic/vgic-irqfd.c
+++ b/virt/kvm/arm/vgic/vgic-irqfd.c
@@ -59,6 +59,14 @@ int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
                     (e->irqchip.irqchip >= KVM_NR_IRQCHIPS))
                         goto out;
                 break;
+        case KVM_IRQ_ROUTING_MSI:
+                e->set = kvm_set_msi;
+                e->msi.address_lo = ue->u.msi.address_lo;
+                e->msi.address_hi = ue->u.msi.address_hi;
+                e->msi.data = ue->u.msi.data;
+                e->msi.flags = ue->flags;
+                e->msi.devid = ue->u.msi.devid;
+                break;
         default:
                 goto out;
         }
diff --git a/virt/kvm/irqchip.c b/virt/kvm/irqchip.c
index 0c000546aedc..c6202199e505 100644
--- a/virt/kvm/irqchip.c
+++ b/virt/kvm/irqchip.c
@@ -178,6 +178,7 @@ int kvm_set_irq_routing(struct kvm *kvm,
                         unsigned flags)
 {
         struct kvm_irq_routing_table *new, *old;
+        struct kvm_kernel_irq_routing_entry *e;
         u32 i, j, nr_rt_entries = 0;
         int r;
 
@@ -201,23 +202,25 @@ int kvm_set_irq_routing(struct kvm *kvm,
                         new->chip[i][j] = -1;
 
         for (i = 0; i < nr; ++i) {
-                struct kvm_kernel_irq_routing_entry *e;
-
                 r = -ENOMEM;
                 e = kzalloc(sizeof(*e), GFP_KERNEL);
                 if (!e)
                         goto out;
 
                 r = -EINVAL;
-                if (ue->flags) {
-                        kfree(e);
-                        goto out;
+                switch (ue->type) {
+                case KVM_IRQ_ROUTING_MSI:
+                        if (ue->flags & ~KVM_MSI_VALID_DEVID)
+                                goto free_entry;
+                        break;
+                default:
+                        if (ue->flags)
+                                goto free_entry;
+                        break;
                 }
                 r = setup_routing_entry(new, e, ue);
-                if (r) {
-                        kfree(e);
-                        goto out;
-                }
+                if (r)
+                        goto free_entry;
                 ++ue;
         }
 
@@ -234,7 +237,10 @@ int kvm_set_irq_routing(struct kvm *kvm,
 
         new = old;
         r = 0;
+        goto out;
 
+free_entry:
+        kfree(e);
 out:
         free_irq_routing_table(new);