Merge remote-tracking branch 'awilliam/tags/vfio-pci-for-qemu-20131206.0' into staging

vfio-pci updates include:
 - Update linux-headers to include KVM-VFIO device support
 - Enable QEMU support for KVM-VFIO device
 - Additional Nvidia x-vga quirk to ACK MSI interrupts
 - Debug options to disable MSI/X KVM acceleration
 - Fix to cleanup MSI-X vectors on shutdown and avoid IRQ route leaks

The KVM-VFIO device support enables KVM to manage how it handles
coherency instructions in the presence of non-coherent I/O.  Dave
Airlie had noted that the Nvidia MSI ACK support here may just be
scratching the surface, but it's better than what we have now and
it's only enabled via the x-vga option, so I'm willing to add since
it does enable some users.

# gpg: Signature made Fri 06 Dec 2013 12:28:19 PM PST using RSA key ID 3BB08B22
# gpg: Can't check signature: public key not found

# By Alex Williamson
# Via Alex Williamson
* awilliam/tags/vfio-pci-for-qemu-20131206.0:
  vfio-pci: Release all MSI-X vectors when disabled
  vfio-pci: Add debug config options to disable MSI/X KVM support
  vfio-pci: Fix Nvidia MSI ACK through 0x88000 quirk
  vfio-pci: Make use of new KVM-VFIO device
  linux-headers: Update from v3.13-rc3

Message-id: 20131206204715.16731.12627.stgit@bling.home
Signed-off-by: Anthony Liguori <aliguori@amazon.com>

1 files changed, 128 insertions, 5 deletions

diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
index f7f8a19..9aecaa8 100644
--- a/hw/misc/vfio.c
+++ b/hw/misc/vfio.c
@@ -52,6 +52,8 @@
 /* Extra debugging, trap acceleration paths for more logging */
 #define VFIO_ALLOW_MMAP 1
 #define VFIO_ALLOW_KVM_INTX 1
+#define VFIO_ALLOW_KVM_MSI 1
+#define VFIO_ALLOW_KVM_MSIX 1
 
 struct VFIODevice;
 
@@ -208,6 +210,17 @@ static QLIST_HEAD(, VFIOContainer)
 static QLIST_HEAD(, VFIOGroup)
     group_list = QLIST_HEAD_INITIALIZER(group_list);
 
+#ifdef CONFIG_KVM
+/*
+ * We have a single VFIO pseudo device per KVM VM.  Once created it lives
+ * for the life of the VM.  Closing the file descriptor only drops our
+ * reference to it and the device's reference to kvm.  Therefore once
+ * initialized, this file descriptor is only released on QEMU exit and
+ * we'll re-use it should another vfio device be attached before then.
+ */
+static int vfio_kvm_device_fd = -1;
+#endif
+
 static void vfio_disable_interrupts(VFIODevice *vdev);
 static uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len);
 static void vfio_pci_write_config(PCIDevice *pdev, uint32_t addr,
@@ -579,9 +592,21 @@ static void vfio_msi_interrupt(void *opaque)
         return;
     }
 
-    DPRINTF("%s(%04x:%02x:%02x.%x) vector %d\n", __func__,
+#ifdef VFIO_DEBUG
+    MSIMessage msg;
+
+    if (vdev->interrupt == VFIO_INT_MSIX) {
+        msg = msi_get_message(&vdev->pdev, nr);
+    } else if (vdev->interrupt == VFIO_INT_MSI) {
+        msg = msix_get_message(&vdev->pdev, nr);
+    } else {
+        abort();
+    }
+
+    DPRINTF("%s(%04x:%02x:%02x.%x) vector %d 0x%"PRIx64"/0x%x\n", __func__,
             vdev->host.domain, vdev->host.bus, vdev->host.slot,
-            vdev->host.function, nr);
+            vdev->host.function, nr, msg.address, msg.data);
+#endif
 
     if (vdev->interrupt == VFIO_INT_MSIX) {
         msix_notify(&vdev->pdev, nr);
@@ -649,7 +674,8 @@ static int vfio_msix_vector_do_use(PCIDevice *pdev, unsigned int nr,
      * Attempt to enable route through KVM irqchip,
      * default to userspace handling if unavailable.
      */
-    vector->virq = msg ? kvm_irqchip_add_msi_route(kvm_state, *msg) : -1;
+    vector->virq = msg && VFIO_ALLOW_KVM_MSIX ?
+                   kvm_irqchip_add_msi_route(kvm_state, *msg) : -1;
     if (vector->virq < 0 ||
         kvm_irqchip_add_irqfd_notifier(kvm_state, &vector->interrupt,
                                        NULL, vector->virq) < 0) {
@@ -816,7 +842,8 @@ retry:
          * Attempt to enable route through KVM irqchip,
          * default to userspace handling if unavailable.
          */
-        vector->virq = kvm_irqchip_add_msi_route(kvm_state, vector->msg);
+        vector->virq = VFIO_ALLOW_KVM_MSI ?
+                       kvm_irqchip_add_msi_route(kvm_state, vector->msg) : -1;
         if (vector->virq < 0 ||
             kvm_irqchip_add_irqfd_notifier(kvm_state, &vector->interrupt,
                                            NULL, vector->virq) < 0) {
@@ -878,8 +905,20 @@ static void vfio_disable_msi_common(VFIODevice *vdev)
 
 static void vfio_disable_msix(VFIODevice *vdev)
 {
+    int i;
+
     msix_unset_vector_notifiers(&vdev->pdev);
 
+    /*
+     * MSI-X will only release vectors if MSI-X is still enabled on the
+     * device, check through the rest and release it ourselves if necessary.
+     */
+    for (i = 0; i < vdev->nr_vectors; i++) {
+        if (vdev->msi_vectors[i].use) {
+            vfio_msix_vector_release(&vdev->pdev, i);
+        }
+    }
+
     if (vdev->nr_vectors) {
         vfio_disable_irqindex(vdev, VFIO_PCI_MSIX_IRQ_INDEX);
     }
@@ -1800,6 +1839,34 @@ static void vfio_probe_nvidia_bar5_window_quirk(VFIODevice *vdev, int nr)
             vdev->host.function);
 }
 
+static void vfio_nvidia_88000_quirk_write(void *opaque, hwaddr addr,
+                                          uint64_t data, unsigned size)
+{
+    VFIOQuirk *quirk = opaque;
+    VFIODevice *vdev = quirk->vdev;
+    PCIDevice *pdev = &vdev->pdev;
+    hwaddr base = quirk->data.address_match & TARGET_PAGE_MASK;
+
+    vfio_generic_quirk_write(opaque, addr, data, size);
+
+    /*
+     * Nvidia seems to acknowledge MSI interrupts by writing 0xff to the
+     * MSI capability ID register.  Both the ID and next register are
+     * read-only, so we allow writes covering either of those to real hw.
+     * NB - only fixed for the 0x88000 MMIO window.
+     */
+    if ((pdev->cap_present & QEMU_PCI_CAP_MSI) &&
+        vfio_range_contained(addr, size, pdev->msi_cap, PCI_MSI_FLAGS)) {
+        vfio_bar_write(&vdev->bars[quirk->data.bar], addr + base, data, size);
+    }
+}
+
+static const MemoryRegionOps vfio_nvidia_88000_quirk = {
+    .read = vfio_generic_quirk_read,
+    .write = vfio_nvidia_88000_quirk_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
 /*
  * Finally, BAR0 itself.  We want to redirect any accesses to either
  * 0x1800 or 0x88000 through the PCI config space access functions.
@@ -1826,7 +1893,7 @@ static void vfio_probe_nvidia_bar0_88000_quirk(VFIODevice *vdev, int nr)
     quirk->data.address_mask = PCIE_CONFIG_SPACE_SIZE - 1;
     quirk->data.bar = nr;
 
-    memory_region_init_io(&quirk->mem, OBJECT(vdev), &vfio_generic_quirk,
+    memory_region_init_io(&quirk->mem, OBJECT(vdev), &vfio_nvidia_88000_quirk,
                           quirk, "vfio-nvidia-bar0-88000-quirk",
                           TARGET_PAGE_ALIGN(quirk->data.address_mask + 1));
     memory_region_add_subregion_overlap(&vdev->bars[nr].mem,
@@ -3041,6 +3108,59 @@ static void vfio_pci_reset_handler(void *opaque)
     }
 }
 
+static void vfio_kvm_device_add_group(VFIOGroup *group)
+{
+#ifdef CONFIG_KVM
+    struct kvm_device_attr attr = {
+        .group = KVM_DEV_VFIO_GROUP,
+        .attr = KVM_DEV_VFIO_GROUP_ADD,
+        .addr = (uint64_t)(unsigned long)&group->fd,
+    };
+
+    if (!kvm_enabled()) {
+        return;
+    }
+
+    if (vfio_kvm_device_fd < 0) {
+        struct kvm_create_device cd = {
+            .type = KVM_DEV_TYPE_VFIO,
+        };
+
+        if (kvm_vm_ioctl(kvm_state, KVM_CREATE_DEVICE, &cd)) {
+            DPRINTF("KVM_CREATE_DEVICE: %m\n");
+            return;
+        }
+
+        vfio_kvm_device_fd = cd.fd;
+    }
+
+    if (ioctl(vfio_kvm_device_fd, KVM_SET_DEVICE_ATTR, &attr)) {
+        error_report("Failed to add group %d to KVM VFIO device: %m",
+                     group->groupid);
+    }
+#endif
+}
+
+static void vfio_kvm_device_del_group(VFIOGroup *group)
+{
+#ifdef CONFIG_KVM
+    struct kvm_device_attr attr = {
+        .group = KVM_DEV_VFIO_GROUP,
+        .attr = KVM_DEV_VFIO_GROUP_DEL,
+        .addr = (uint64_t)(unsigned long)&group->fd,
+    };
+
+    if (vfio_kvm_device_fd < 0) {
+        return;
+    }
+
+    if (ioctl(vfio_kvm_device_fd, KVM_SET_DEVICE_ATTR, &attr)) {
+        error_report("Failed to remove group %d to KVM VFIO device: %m",
+                     group->groupid);
+    }
+#endif
+}
+
 static int vfio_connect_container(VFIOGroup *group)
 {
     VFIOContainer *container;
@@ -3189,6 +3309,8 @@ static VFIOGroup *vfio_get_group(int groupid)
 
     QLIST_INSERT_HEAD(&group_list, group, next);
 
+    vfio_kvm_device_add_group(group);
+
     return group;
 }
 
@@ -3198,6 +3320,7 @@ static void vfio_put_group(VFIOGroup *group)
         return;
     }
 
+    vfio_kvm_device_del_group(group);
     vfio_disconnect_container(group);
     QLIST_REMOVE(group, next);
     DPRINTF("vfio_put_group: close group->fd\n");