Merge tag 'block-pull-request' of https://gitlab.com/stefanha/qemu into staging

Pull request

This pull request includes an important aio=native I/O stall fix, the
experimental vifo-user server, the io_uring_register_ring_fd() optimization for
aio=io_uring, and an update to Vladimir Sementsov-Ogievskiy's maintainership
details.

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# gpg: Signature made Wed 15 Jun 2022 08:50:56 AM PDT
# gpg:                using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]

* tag 'block-pull-request' of https://gitlab.com/stefanha/qemu:
  linux-aio: explain why max batch is checked in laio_io_unplug()
  linux-aio: fix unbalanced plugged counter in laio_io_unplug()
  vfio-user: handle reset of remote device
  vfio-user: handle device interrupts
  vfio-user: handle PCI BAR accesses
  vfio-user: handle DMA mappings
  vfio-user: IOMMU support for remote device
  vfio-user: handle PCI config space accesses
  vfio-user: run vfio-user context
  vfio-user: find and init PCI device
  vfio-user: instantiate vfio-user context
  vfio-user: define vfio-user-server object
  vfio-user: build library
  remote/machine: add vfio-user property
  remote/machine: add HotplugHandler for remote machine
  qdev: unplug blocker for devices
  Use io_uring_register_ring_fd() to skip fd operations
  MAINTAINERS: update Vladimir's address and repositories

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 131 insertions, 0 deletions

diff --git a/hw/remote/iommu.c b/hw/remote/iommu.c
new file mode 100644
index 0000000000..fd723d91f3
--- /dev/null
+++ b/hw/remote/iommu.c
@@ -0,0 +1,131 @@
+/**
+ * IOMMU for remote device
+ *
+ * Copyright © 2022 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+
+#include "hw/remote/iommu.h"
+#include "hw/pci/pci_bus.h"
+#include "hw/pci/pci.h"
+#include "exec/memory.h"
+#include "exec/address-spaces.h"
+#include "trace.h"
+
+/**
+ * IOMMU for TYPE_REMOTE_MACHINE - manages DMA address space isolation
+ *     for remote machine. It is used by TYPE_VFIO_USER_SERVER.
+ *
+ * - Each TYPE_VFIO_USER_SERVER instance handles one PCIDevice on a PCIBus.
+ *   There is one RemoteIommu per PCIBus, so the RemoteIommu tracks multiple
+ *   PCIDevices by maintaining a ->elem_by_devfn mapping.
+ *
+ * - memory_region_init_iommu() is not used because vfio-user MemoryRegions
+ *   will be added to the elem->mr container instead. This is more natural
+ *   than implementing the IOMMUMemoryRegionClass APIs since vfio-user
+ *   provides something that is close to a full-fledged MemoryRegion and
+ *   not like an IOMMU mapping.
+ *
+ * - When a device is hot unplugged, the elem->mr reference is dropped so
+ *   all vfio-user MemoryRegions associated with this vfio-user server are
+ *   destroyed.
+ */
+
+static AddressSpace *remote_iommu_find_add_as(PCIBus *pci_bus,
+                                              void *opaque, int devfn)
+{
+    RemoteIommu *iommu = opaque;
+    RemoteIommuElem *elem = NULL;
+
+    qemu_mutex_lock(&iommu->lock);
+
+    elem = g_hash_table_lookup(iommu->elem_by_devfn, INT2VOIDP(devfn));
+
+    if (!elem) {
+        elem = g_malloc0(sizeof(RemoteIommuElem));
+        g_hash_table_insert(iommu->elem_by_devfn, INT2VOIDP(devfn), elem);
+    }
+
+    if (!elem->mr) {
+        elem->mr = MEMORY_REGION(object_new(TYPE_MEMORY_REGION));
+        memory_region_set_size(elem->mr, UINT64_MAX);
+        address_space_init(&elem->as, elem->mr, NULL);
+    }
+
+    qemu_mutex_unlock(&iommu->lock);
+
+    return &elem->as;
+}
+
+void remote_iommu_unplug_dev(PCIDevice *pci_dev)
+{
+    AddressSpace *as = pci_device_iommu_address_space(pci_dev);
+    RemoteIommuElem *elem = NULL;
+
+    if (as == &address_space_memory) {
+        return;
+    }
+
+    elem = container_of(as, RemoteIommuElem, as);
+
+    address_space_destroy(&elem->as);
+
+    object_unref(elem->mr);
+
+    elem->mr = NULL;
+}
+
+static void remote_iommu_init(Object *obj)
+{
+    RemoteIommu *iommu = REMOTE_IOMMU(obj);
+
+    iommu->elem_by_devfn = g_hash_table_new_full(NULL, NULL, NULL, g_free);
+
+    qemu_mutex_init(&iommu->lock);
+}
+
+static void remote_iommu_finalize(Object *obj)
+{
+    RemoteIommu *iommu = REMOTE_IOMMU(obj);
+
+    qemu_mutex_destroy(&iommu->lock);
+
+    g_hash_table_destroy(iommu->elem_by_devfn);
+
+    iommu->elem_by_devfn = NULL;
+}
+
+void remote_iommu_setup(PCIBus *pci_bus)
+{
+    RemoteIommu *iommu = NULL;
+
+    g_assert(pci_bus);
+
+    iommu = REMOTE_IOMMU(object_new(TYPE_REMOTE_IOMMU));
+
+    pci_setup_iommu(pci_bus, remote_iommu_find_add_as, iommu);
+
+    object_property_add_child(OBJECT(pci_bus), "remote-iommu", OBJECT(iommu));
+
+    object_unref(OBJECT(iommu));
+}
+
+static const TypeInfo remote_iommu_info = {
+    .name = TYPE_REMOTE_IOMMU,
+    .parent = TYPE_OBJECT,
+    .instance_size = sizeof(RemoteIommu),
+    .instance_init = remote_iommu_init,
+    .instance_finalize = remote_iommu_finalize,
+};
+
+static void remote_iommu_register_types(void)
+{
+    type_register_static(&remote_iommu_info);
+}
+
+type_init(remote_iommu_register_types)