[Qemu-devel] [PATCH v10 23/26] kvm-irqchip: x86: add msi route notify fn

[Peter Xu <peterx@redhat.com>]

One more IEC notifier is added to let msi routes know about the IEC
changes. When interrupt invalidation happens, all registered msi routes
will be updated for all PCI devices.

Since both vfio and vhost are possible gsi route consumers, this patch
will go one step further to keep them safe in split irqchip mode and
when irqfd is enabled.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 hw/pci/pci.c         | 15 +++++++++++++++
 include/hw/pci/pci.h |  2 ++
 kvm-all.c            | 10 +---------
 target-i386/kvm.c    | 30 ++++++++++++++++++++++++++++++
 trace-events         |  1 +
 5 files changed, 49 insertions(+), 9 deletions(-)

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 3b02888..4ed119e 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -2598,6 +2598,21 @@ PCIDevice *pci_get_function_0(PCIDevice *pci_dev)
     }
 }
 
+MSIMessage pci_get_msi_message(PCIDevice *dev, int vector)
+{
+    MSIMessage msg;
+    if (msix_enabled(dev)) {
+        msg = msix_get_message(dev, vector);
+    } else if (msi_enabled(dev)) {
+        msg = msi_get_message(dev, vector);
+    } else {
+        /* Should never happen */
+        error_report("%s: unknown interrupt type", __func__);
+        abort();
+    }
+    return msg;
+}
+
 static const TypeInfo pci_device_type_info = {
     .name = TYPE_PCI_DEVICE,
     .parent = TYPE_DEVICE,
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 9ed1624..74d797d 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -805,4 +805,6 @@ extern const VMStateDescription vmstate_pci_device;
     .offset     = vmstate_offset_pointer(_state, _field, PCIDevice), \
 }
 
+MSIMessage pci_get_msi_message(PCIDevice *dev, int vector);
+
 #endif
diff --git a/kvm-all.c b/kvm-all.c
index 69ff658..ca30a58 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1246,15 +1246,7 @@ int kvm_irqchip_add_msi_route(KVMState *s, int vector, PCIDevice *dev)
     MSIMessage msg = {0, 0};
 
     if (dev) {
-        if (msix_enabled(dev)) {
-            msg = msix_get_message(dev, vector);
-        } else if (msi_enabled(dev)) {
-            msg = msi_get_message(dev, vector);
-        } else {
-            /* Should never happen */
-            error_report("%s: unknown interrupt type", __func__);
-            abort();
-        }
+        msg = pci_get_msi_message(dev, vector);
     }
 
     if (kvm_gsi_direct_mapping()) {
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 5d7a7a7..f02ba0a 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -36,6 +36,7 @@
 #include "hw/i386/apic_internal.h"
 #include "hw/i386/apic-msidef.h"
 #include "hw/i386/intel_iommu.h"
+#include "hw/i386/x86-iommu.h"
 
 #include "exec/ioport.h"
 #include "standard-headers/asm-x86/hyperv.h"
@@ -3365,9 +3366,26 @@ struct MSIRouteEntry {
 static QLIST_HEAD(, MSIRouteEntry) msi_route_list = \
     QLIST_HEAD_INITIALIZER(msi_route_list);
 
+static void kvm_update_msi_routes_all(void *private, bool global,
+                                      uint32_t index, uint32_t mask)
+{
+    int cnt = 0;
+    MSIRouteEntry *entry;
+    MSIMessage msg;
+    /* TODO: explicit route update */
+    QLIST_FOREACH(entry, &msi_route_list, list) {
+        cnt++;
+        msg = pci_get_msi_message(entry->dev, entry->vector);
+        kvm_irqchip_update_msi_route(kvm_state, entry->virq,
+                                     msg, entry->dev);
+    }
+    trace_kvm_x86_update_msi_routes(cnt);
+}
+
 int kvm_arch_add_msi_route_post(struct kvm_irq_routing_entry *route,
                                 int vector, PCIDevice *dev)
 {
+    static bool notify_list_inited = false;
     MSIRouteEntry *entry;
 
     if (!dev) {
@@ -3384,6 +3402,18 @@ int kvm_arch_add_msi_route_post(struct kvm_irq_routing_entry *route,
     QLIST_INSERT_HEAD(&msi_route_list, entry, list);
 
     trace_kvm_x86_add_msi_route(route->gsi);
+
+    if (!notify_list_inited) {
+        /* For the first time we do add route, add ourselves into
+         * IOMMU's IEC notify list if needed. */
+        X86IOMMUState *iommu = x86_iommu_get_default();
+        if (iommu) {
+            x86_iommu_iec_register_notifier(iommu,
+                                            kvm_update_msi_routes_all,
+                                            NULL);
+        }
+        notify_list_inited = true;
+    }
     return 0;
 }
 
diff --git a/trace-events b/trace-events
index 1ca0842..9ce3514 100644
--- a/trace-events
+++ b/trace-events
@@ -2211,6 +2211,7 @@ gicv3_redist_send_sgi(uint32_t cpu, int irq) "GICv3 redistributor %x pending SGI
 kvm_x86_fixup_msi_error(uint32_t gsi) "VT-d failed to remap interrupt for GSI %" PRIu32
 kvm_x86_add_msi_route(int virq) "Adding route entry for virq %d"
 kvm_x86_remove_msi_route(int virq) "Removing route entry for virq %d"
+kvm_x86_update_msi_routes(int num) "Updated %d MSI routes"
 
 # hw/i386/x86-iommu.c
 x86_iommu_iec_notify(bool global, uint32_t index, uint32_t mask) "Notify IEC invalidation: global=%d index=%" PRIu32 " mask=%" PRIu32
-- 
2.4.11