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From 2ed38f61f1054e188838bae9244fc1c327f8cda4 Mon Sep 17 00:00:00 2001
From: Marcelo Tosatti <mtosatti@redhat.com>
Date: Mon, 18 Oct 2010 16:17:00 -0200
Subject: [PATCH 42/42] vhost-net patches for qemu-0.13.0 tarball

Justin,

Attached are the patches to fix vhost-net on the 0.13.0 tarball.
Untested.

commit f76cfc6f0882f227101f21d5a5b80804710b88cb
Author: Michael S. Tsirkin <mst@redhat.com>
Date:   Wed Oct 6 07:22:00 2010 +0200

    vhost: fix up irqfd support

    vhost irqfd support: case where many vqs are
    mapped to a single msix vector is currently broken.
    Fix it up.

    	Includes this patch from qemu.git:

    virtio: change set guest notifier to per-device

    When using irqfd with vhost-net to inject interrupts,
    a single evenfd might inject multiple interrupts.
    Implementing this is much easier with a single
    per-device callback to set guest notifiers.

    Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/msix.c       |   82 +++++++++++++++++++++++++++++++-----------------------
 hw/msix.h       |    4 +-
 hw/pci.h        |    3 +-
 hw/virtio-pci.c |   56 +++++++++++++++++++++++++++++++------
 4 files changed, 97 insertions(+), 48 deletions(-)

diff --git a/hw/msix.c b/hw/msix.c
index 3dd0456..c0c6b50 100644
--- a/hw/msix.c
+++ b/hw/msix.c
@@ -300,10 +300,8 @@ static void msix_mmio_writel(void *opaque, target_phys_addr_t addr,
     if (kvm_enabled() && kvm_irqchip_in_kernel()) {
         kvm_msix_update(dev, vector, was_masked, msix_is_masked(dev, vector));
     }
-    if (was_masked != msix_is_masked(dev, vector) &&
-        dev->msix_mask_notifier && dev->msix_mask_notifier_opaque[vector]) {
+    if (was_masked != msix_is_masked(dev, vector) && dev->msix_mask_notifier) {
         int r = dev->msix_mask_notifier(dev, vector,
-					dev->msix_mask_notifier_opaque[vector],
 					msix_is_masked(dev, vector));
         assert(r >= 0);
     }
@@ -351,9 +349,8 @@ static void msix_mask_all(struct PCIDevice *dev, unsigned nentries)
         int was_masked = msix_is_masked(dev, vector);
         dev->msix_table_page[offset] |= MSIX_VECTOR_MASK;
         if (was_masked != msix_is_masked(dev, vector) &&
-            dev->msix_mask_notifier && dev->msix_mask_notifier_opaque[vector]) {
+            dev->msix_mask_notifier) {
             r = dev->msix_mask_notifier(dev, vector,
-                                        dev->msix_mask_notifier_opaque[vector],
                                         msix_is_masked(dev, vector));
             assert(r >= 0);
         }
@@ -379,8 +376,6 @@ int msix_init(struct PCIDevice *dev, unsigned short nentries,
                                             sizeof *dev->msix_irq_entries);
     }
 #endif
-    dev->msix_mask_notifier_opaque =
-        qemu_mallocz(nentries * sizeof *dev->msix_mask_notifier_opaque);
     dev->msix_mask_notifier = NULL;
     dev->msix_entry_used = qemu_mallocz(MSIX_MAX_ENTRIES *
                                         sizeof *dev->msix_entry_used);
@@ -444,8 +439,6 @@ int msix_uninit(PCIDevice *dev)
     dev->msix_entry_used = NULL;
     qemu_free(dev->msix_irq_entries);
     dev->msix_irq_entries = NULL;
-    qemu_free(dev->msix_mask_notifier_opaque);
-    dev->msix_mask_notifier_opaque = NULL;
     dev->cap_present &= ~QEMU_PCI_CAP_MSIX;
     return 0;
 }
@@ -590,46 +583,65 @@ void msix_unuse_all_vectors(PCIDevice *dev)
     msix_free_irq_entries(dev);
 }

-int msix_set_mask_notifier(PCIDevice *dev, unsigned vector, void *opaque)
+/* Invoke the notifier if vector entry is used and unmasked. */
+static int msix_notify_if_unmasked(PCIDevice *dev, unsigned vector, int masked)
 {
-    int r = 0;
-    if (vector >= dev->msix_entries_nr || !dev->msix_entry_used[vector])
+    assert(dev->msix_mask_notifier);
+    if (!dev->msix_entry_used[vector] || msix_is_masked(dev, vector)) {
         return 0;
+    }
+    return dev->msix_mask_notifier(dev, vector, masked);
+}

-    assert(dev->msix_mask_notifier);
-    assert(opaque);
-    assert(!dev->msix_mask_notifier_opaque[vector]);
+static int msix_set_mask_notifier_for_vector(PCIDevice *dev, unsigned vector)
+{
+	/* Notifier has been set. Invoke it on unmasked vectors. */
+	return msix_notify_if_unmasked(dev, vector, 0);
+}
+
+static int msix_unset_mask_notifier_for_vector(PCIDevice *dev, unsigned vector)
+{
+	/* Notifier will be unset. Invoke it to mask unmasked entries. */
+	return msix_notify_if_unmasked(dev, vector, 1);
+}

-    /* Unmask the new notifier unless vector is masked. */
-    if (!msix_is_masked(dev, vector)) {
-        r = dev->msix_mask_notifier(dev, vector, opaque, false);
+int msix_set_mask_notifier(PCIDevice *dev, msix_mask_notifier_func f)
+{
+    int r, n;
+    assert(!dev->msix_mask_notifier);
+    dev->msix_mask_notifier = f;
+    for (n = 0; n < dev->msix_entries_nr; ++n) {
+        r = msix_set_mask_notifier_for_vector(dev, n);
         if (r < 0) {
-            return r;
+            goto undo;
         }
     }
-    dev->msix_mask_notifier_opaque[vector] = opaque;
+    return 0;
+
+undo:
+    while (--n >= 0) {
+        msix_unset_mask_notifier_for_vector(dev, n);
+    }
+    dev->msix_mask_notifier = NULL;
     return r;
 }

-int msix_unset_mask_notifier(PCIDevice *dev, unsigned vector)
+int msix_unset_mask_notifier(PCIDevice *dev)
 {
-    int r = 0;
-    void *opaque;
-    if (vector >= dev->msix_entries_nr || !dev->msix_entry_used[vector])
-        return 0;
-
-    opaque = dev->msix_mask_notifier_opaque[vector];
-
+    int r, n;
     assert(dev->msix_mask_notifier);
-    assert(opaque);
-
-    /* Mask the old notifier unless it is already masked. */
-    if (!msix_is_masked(dev, vector)) {
-        r = dev->msix_mask_notifier(dev, vector, opaque, true);
+    for (n = 0; n < dev->msix_entries_nr; ++n) {
+        r = msix_unset_mask_notifier_for_vector(dev, n);
         if (r < 0) {
-            return r;
+            goto undo;
         }
     }
-    dev->msix_mask_notifier_opaque[vector] = NULL;
+    dev->msix_mask_notifier = NULL;
+    return 0;
+
+undo:
+    while (--n >= 0) {
+        msix_set_mask_notifier_for_vector(dev, n);
+    }
     return r;
 }
diff --git a/hw/msix.h b/hw/msix.h
index 6b21ffb..5a81df5 100644
--- a/hw/msix.h
+++ b/hw/msix.h
@@ -33,6 +33,6 @@ void msix_reset(PCIDevice *dev);

 extern int msix_supported;

-int msix_set_mask_notifier(PCIDevice *dev, unsigned vector, void *opaque);
-int msix_unset_mask_notifier(PCIDevice *dev, unsigned vector);
+int msix_set_mask_notifier(PCIDevice *dev, msix_mask_notifier_func);
+int msix_unset_mask_notifier(PCIDevice *dev);
 #endif
diff --git a/hw/pci.h b/hw/pci.h
index ccb99d0..a40dc14 100644
--- a/hw/pci.h
+++ b/hw/pci.h
@@ -131,7 +131,7 @@ enum {
 #define PCI_CAPABILITY_CONFIG_MSIX_LENGTH 0x10

 typedef int (*msix_mask_notifier_func)(PCIDevice *, unsigned vector,
-				       void *opaque, int masked);
+				       int masked);

 struct PCIDevice {
     DeviceState qdev;
@@ -198,7 +198,6 @@ struct PCIDevice {

     struct kvm_irq_routing_entry *msix_irq_entries;

-    void **msix_mask_notifier_opaque;
     msix_mask_notifier_func msix_mask_notifier;

     /* Device capability configuration space */
diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index 83b7871..72bc80e 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -427,11 +427,10 @@ static void virtio_pci_guest_notifier_read(void *opaque)
     }
 }

-static int virtio_pci_mask_notifier(PCIDevice *dev, unsigned vector,
-                                    void *opaque, int masked)
+static int virtio_pci_mask_vq(PCIDevice *dev, unsigned vector,
+                              VirtQueue *vq, int masked)
 {
 #ifdef CONFIG_KVM
-    VirtQueue *vq = opaque;
     EventNotifier *notifier = virtio_queue_get_guest_notifier(vq);
     int r = kvm_set_irqfd(dev->msix_irq_entries[vector].gsi,
                           event_notifier_get_fd(notifier),
@@ -452,6 +451,34 @@ static int virtio_pci_mask_notifier(PCIDevice *dev, unsigned vector,
 #endif
 }

+static int virtio_pci_mask_notifier(PCIDevice *dev, unsigned vector,
+                                    int masked)
+{
+    VirtIOPCIProxy *proxy = container_of(dev, VirtIOPCIProxy, pci_dev);
+    VirtIODevice *vdev = proxy->vdev;
+    int r, n;
+
+    for (n = 0; n < VIRTIO_PCI_QUEUE_MAX; n++) {
+        if (!virtio_queue_get_num(vdev, n)) {
+            break;
+        }
+        if (virtio_queue_vector(vdev, n) != vector) {
+            continue;
+        }
+        r = virtio_pci_mask_vq(dev, vector, virtio_get_queue(vdev, n), masked);
+        if (r < 0) {
+            goto undo;
+        }
+    }
+    return 0;
+undo:
+    while (--n >= 0) {
+        virtio_pci_mask_vq(dev, vector, virtio_get_queue(vdev, n), !masked);
+    }
+    return r;
+}
+
+
 static int virtio_pci_set_guest_notifier(void *opaque, int n, bool assign)
 {
     VirtIOPCIProxy *proxy = opaque;
@@ -465,11 +492,7 @@ static int virtio_pci_set_guest_notifier(void *opaque, int n, bool assign)
         }
         qemu_set_fd_handler(event_notifier_get_fd(notifier),
                             virtio_pci_guest_notifier_read, NULL, vq);
-        msix_set_mask_notifier(&proxy->pci_dev,
-                               virtio_queue_vector(proxy->vdev, n), vq);
     } else {
-        msix_unset_mask_notifier(&proxy->pci_dev,
-				 virtio_queue_vector(proxy->vdev, n));
         qemu_set_fd_handler(event_notifier_get_fd(notifier),
                             NULL, NULL, NULL);
         /* Test and clear notifier before closing it,
@@ -487,6 +510,13 @@ static int virtio_pci_set_guest_notifiers(void *opaque, bool assign)
     VirtIODevice *vdev = proxy->vdev;
     int r, n;

+    /* Must unset mask notifier while guest notifier
+     * is still assigned */
+    if (!assign) {
+	    r = msix_unset_mask_notifier(&proxy->pci_dev);
+            assert(r >= 0);
+    }
+
     for (n = 0; n < VIRTIO_PCI_QUEUE_MAX; n++) {
         if (!virtio_queue_get_num(vdev, n)) {
             break;
@@ -498,6 +528,16 @@ static int virtio_pci_set_guest_notifiers(void *opaque, bool assign)
         }
     }

+    /* Must set mask notifier after guest notifier
+     * has been assigned */
+    if (assign) {
+        r = msix_set_mask_notifier(&proxy->pci_dev,
+                                   virtio_pci_mask_notifier);
+        if (r < 0) {
+            goto assign_error;
+        }
+    }
+
     return 0;

 assign_error:
@@ -583,8 +623,6 @@ static void virtio_init_pci(VirtIOPCIProxy *proxy, VirtIODevice *vdev,

     proxy->pci_dev.config_write = virtio_write_config;

-    proxy->pci_dev.msix_mask_notifier = virtio_pci_mask_notifier;
-
     size = VIRTIO_PCI_REGION_SIZE(&proxy->pci_dev) + vdev->config_len;
     if (size & (size-1))
         size = 1 << qemu_fls(size);
-- 
1.7.2.3