[Qemu-devel] [PATCH v7 21/25] kvm-irqchip: simplify kvm_irqchip_add_msi_route

[Peter Xu <peterx@redhat.com>]

Changing the original MSIMessage parameter in kvm_irqchip_add_msi_route
into the vector number. Vector index provides more information than the
MSIMessage, we can retrieve the MSIMessage using the vector easily. This
will avoid fetching MSIMessage every time before adding MSI routes.

Meanwhile, the vector info will be used in the coming patches to further
enable gsi route update notifications.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 hw/i386/kvm/pci-assign.c |  8 ++------
 hw/misc/ivshmem.c        |  3 +--
 hw/vfio/pci.c            | 11 +++++------
 hw/virtio/virtio-pci.c   |  9 +++------
 include/sysemu/kvm.h     | 13 ++++++++++++-
 kvm-all.c                | 18 ++++++++++++++++--
 kvm-stub.c               |  2 +-
 target-i386/kvm.c        |  3 +--
 8 files changed, 41 insertions(+), 26 deletions(-)

diff --git a/hw/i386/kvm/pci-assign.c b/hw/i386/kvm/pci-assign.c
index c40ab36..9b43332 100644
--- a/hw/i386/kvm/pci-assign.c
+++ b/hw/i386/kvm/pci-assign.c
@@ -974,10 +974,9 @@ static void assigned_dev_update_msi(PCIDevice *pci_dev)
     }
 
     if (ctrl_byte & PCI_MSI_FLAGS_ENABLE) {
-        MSIMessage msg = msi_get_message(pci_dev, 0);
         int virq;
 
-        virq = kvm_irqchip_add_msi_route(kvm_state, msg, pci_dev);
+        virq = kvm_irqchip_add_msi_route(kvm_state, 0, pci_dev);
         if (virq < 0) {
             perror("assigned_dev_update_msi: kvm_irqchip_add_msi_route");
             return;
@@ -1042,7 +1041,6 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
     uint16_t entries_nr = 0;
     int i, r = 0;
     MSIXTableEntry *entry = adev->msix_table;
-    MSIMessage msg;
 
     /* Get the usable entry number for allocating */
     for (i = 0; i < adev->msix_max; i++, entry++) {
@@ -1079,9 +1077,7 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
             continue;
         }
 
-        msg.address = entry->addr_lo | ((uint64_t)entry->addr_hi << 32);
-        msg.data = entry->data;
-        r = kvm_irqchip_add_msi_route(kvm_state, msg, pci_dev);
+        r = kvm_irqchip_add_msi_route(kvm_state, i, pci_dev);
         if (r < 0) {
             return r;
         }
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index e40f23b..6909346 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -444,13 +444,12 @@ static void ivshmem_add_kvm_msi_virq(IVShmemState *s, int vector,
                                      Error **errp)
 {
     PCIDevice *pdev = PCI_DEVICE(s);
-    MSIMessage msg = msix_get_message(pdev, vector);
     int ret;
 
     IVSHMEM_DPRINTF("ivshmem_add_kvm_msi_virq vector:%d\n", vector);
     assert(!s->msi_vectors[vector].pdev);
 
-    ret = kvm_irqchip_add_msi_route(kvm_state, msg, pdev);
+    ret = kvm_irqchip_add_msi_route(kvm_state, vector, pdev);
     if (ret < 0) {
         error_setg(errp, "kvm_irqchip_add_msi_route failed");
         return;
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index d091d8c..2b2f935 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -417,11 +417,11 @@ static int vfio_enable_vectors(VFIOPCIDevice *vdev, bool msix)
 }
 
 static void vfio_add_kvm_msi_virq(VFIOPCIDevice *vdev, VFIOMSIVector *vector,
-                                  MSIMessage *msg, bool msix)
+                                  int vector_n, bool msix)
 {
     int virq;
 
-    if ((msix && vdev->no_kvm_msix) || (!msix && vdev->no_kvm_msi) || !msg) {
+    if ((msix && vdev->no_kvm_msix) || (!msix && vdev->no_kvm_msi)) {
         return;
     }
 
@@ -429,7 +429,7 @@ static void vfio_add_kvm_msi_virq(VFIOPCIDevice *vdev, VFIOMSIVector *vector,
         return;
     }
 
-    virq = kvm_irqchip_add_msi_route(kvm_state, *msg, &vdev->pdev);
+    virq = kvm_irqchip_add_msi_route(kvm_state, vector_n, &vdev->pdev);
     if (virq < 0) {
         event_notifier_cleanup(&vector->kvm_interrupt);
         return;
@@ -495,7 +495,7 @@ static int vfio_msix_vector_do_use(PCIDevice *pdev, unsigned int nr,
             vfio_update_kvm_msi_virq(vector, *msg, pdev);
         }
     } else {
-        vfio_add_kvm_msi_virq(vdev, vector, msg, true);
+        vfio_add_kvm_msi_virq(vdev, vector, nr, true);
     }
 
     /*
@@ -639,7 +639,6 @@ retry:
 
     for (i = 0; i < vdev->nr_vectors; i++) {
         VFIOMSIVector *vector = &vdev->msi_vectors[i];
-        MSIMessage msg = msi_get_message(&vdev->pdev, i);
 
         vector->vdev = vdev;
         vector->virq = -1;
@@ -656,7 +655,7 @@ retry:
          * Attempt to enable route through KVM irqchip,
          * default to userspace handling if unavailable.
          */
-        vfio_add_kvm_msi_virq(vdev, vector, &msg, false);
+        vfio_add_kvm_msi_virq(vdev, vector, i, false);
     }
 
     /* Set interrupt type prior to possible interrupts */
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index bfedbbf..df85f28 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -727,14 +727,13 @@ static uint32_t virtio_read_config(PCIDevice *pci_dev,
 
 static int kvm_virtio_pci_vq_vector_use(VirtIOPCIProxy *proxy,
                                         unsigned int queue_no,
-                                        unsigned int vector,
-                                        MSIMessage msg)
+                                        unsigned int vector)
 {
     VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
     int ret;
 
     if (irqfd->users == 0) {
-        ret = kvm_irqchip_add_msi_route(kvm_state, msg, &proxy->pci_dev);
+        ret = kvm_irqchip_add_msi_route(kvm_state, vector, &proxy->pci_dev);
         if (ret < 0) {
             return ret;
         }
@@ -787,7 +786,6 @@ static int kvm_virtio_pci_vector_use(VirtIOPCIProxy *proxy, int nvqs)
     VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
     unsigned int vector;
     int ret, queue_no;
-    MSIMessage msg;
 
     for (queue_no = 0; queue_no < nvqs; queue_no++) {
         if (!virtio_queue_get_num(vdev, queue_no)) {
@@ -797,8 +795,7 @@ static int kvm_virtio_pci_vector_use(VirtIOPCIProxy *proxy, int nvqs)
         if (vector >= msix_nr_vectors_allocated(dev)) {
             continue;
         }
-        msg = msix_get_message(dev, vector);
-        ret = kvm_virtio_pci_vq_vector_use(proxy, queue_no, vector, msg);
+        ret = kvm_virtio_pci_vq_vector_use(proxy, queue_no, vector);
         if (ret < 0) {
             goto undo;
         }
diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index 0e18f15..20b52f0 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -470,7 +470,18 @@ static inline void cpu_synchronize_post_init(CPUState *cpu)
     }
 }
 
-int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg, PCIDevice *dev);
+/**
+ * kvm_irqchip_add_msi_route - Add MSI route for specific vector
+ * @s:      KVM state
+ * @vector: which vector to add. This can be either MSI/MSIX
+ *          vector. The function will automatically detect whether
+ *          MSI/MSIX is enabled, and fetch corresponding MSI
+ *          message.
+ * @dev:    Owner PCI device to add the route. If @dev is specified
+ *          as @NULL, an empty MSI message will be inited.
+ * @return: virq (>=0) when success, errno (<0) when failed.
+ */
+int kvm_irqchip_add_msi_route(KVMState *s, int vector, PCIDevice *dev);
 int kvm_irqchip_update_msi_route(KVMState *s, int virq, MSIMessage msg,
                                  PCIDevice *dev);
 void kvm_irqchip_release_virq(KVMState *s, int virq);
diff --git a/kvm-all.c b/kvm-all.c
index e7b66df..f0dc769 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -26,6 +26,7 @@
 #include "qemu/error-report.h"
 #include "hw/hw.h"
 #include "hw/pci/msi.h"
+#include "hw/pci/msix.h"
 #include "hw/s390x/adapter.h"
 #include "exec/gdbstub.h"
 #include "sysemu/kvm_int.h"
@@ -1177,10 +1178,23 @@ int kvm_irqchip_send_msi(KVMState *s, MSIMessage msg)
     return kvm_set_irq(s, route->kroute.gsi, 1);
 }
 
-int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg, PCIDevice *dev)
+int kvm_irqchip_add_msi_route(KVMState *s, int vector, PCIDevice *dev)
 {
     struct kvm_irq_routing_entry kroute = {};
     int virq;
+    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();
+        }
+    }
 
     if (kvm_gsi_direct_mapping()) {
         return kvm_arch_msi_data_to_gsi(msg.data);
@@ -1330,7 +1344,7 @@ int kvm_irqchip_send_msi(KVMState *s, MSIMessage msg)
     abort();
 }
 
-int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg)
+int kvm_irqchip_add_msi_route(KVMState *s, int vector, PCIDevice *dev)
 {
     return -ENOSYS;
 }
diff --git a/kvm-stub.c b/kvm-stub.c
index b962b24..421c9ce 100644
--- a/kvm-stub.c
+++ b/kvm-stub.c
@@ -112,7 +112,7 @@ int kvm_on_sigbus(int code, void *addr)
 }
 
 #ifndef CONFIG_USER_ONLY
-int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg, PCIDevice *dev)
+int kvm_irqchip_add_msi_route(KVMState *s, int vector, PCIDevice *dev)
 {
     return -ENOSYS;
 }
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 693d1c1..3ce568c 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -3158,8 +3158,7 @@ void kvm_arch_init_irq_routing(KVMState *s)
         /* If the ioapic is in QEMU and the lapics are in KVM, reserve
            MSI routes for signaling interrupts to the local apics. */
         for (i = 0; i < IOAPIC_NUM_PINS; i++) {
-            struct MSIMessage msg = { 0x0, 0x0 };
-            if (kvm_irqchip_add_msi_route(s, msg, NULL) < 0) {
+            if (kvm_irqchip_add_msi_route(s, 0, NULL) < 0) {
                 error_report("Could not enable split IRQ mode.");
                 exit(1);
             }
-- 
2.4.11