[Qemu-devel] [PATCH v8 23/25] 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 7430715..ec1928f 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -2527,6 +2527,21 @@ uint16_t pci_requester_id(PCIDevice *dev)
     return result;
 }
 
+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 351266c..359c22e 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -779,4 +779,6 @@ 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 a9eb366..f4ce357 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1186,15 +1186,7 @@ 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 9051d16..173afd7 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -37,6 +37,7 @@
 #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"
@@ -3360,9 +3361,26 @@ 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) {
@@ -3379,6 +3397,18 @@ 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 6a423fd..8848fe2 100644
--- a/trace-events
+++ b/trace-events
@@ -1951,3 +1951,4 @@ gic_acknowledge_irq(int cpu, int irq) "cpu %d acknowledged irq %d"
 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"
-- 
2.4.11