[PATCH v4 11/14] vfio-user: IOMMU support for remote device

[Jagannathan Raman <jag.raman@oracle.com>]

Assign separate address space for each device in the remote processes.

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
---
 include/hw/pci/pci.h      |   2 +
 include/hw/remote/iommu.h |  24 ++++++++
 hw/pci/pci.c              |   2 +-
 hw/remote/iommu.c         | 117 ++++++++++++++++++++++++++++++++++++++
 hw/remote/machine.c       |   5 ++
 hw/remote/vfio-user-obj.c |  20 ++++++-
 MAINTAINERS               |   2 +
 hw/remote/meson.build     |   1 +
 8 files changed, 169 insertions(+), 4 deletions(-)
 create mode 100644 include/hw/remote/iommu.h
 create mode 100644 hw/remote/iommu.c

diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 5c4016b995..f2fc2d5375 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -734,6 +734,8 @@ void lsi53c8xx_handle_legacy_cmdline(DeviceState *lsi_dev);
 qemu_irq pci_allocate_irq(PCIDevice *pci_dev);
 void pci_set_irq(PCIDevice *pci_dev, int level);
 
+void pci_init_bus_master(PCIDevice *pci_dev);
+
 static inline void pci_irq_assert(PCIDevice *pci_dev)
 {
     pci_set_irq(pci_dev, 1);
diff --git a/include/hw/remote/iommu.h b/include/hw/remote/iommu.h
new file mode 100644
index 0000000000..42ce0ca383
--- /dev/null
+++ b/include/hw/remote/iommu.h
@@ -0,0 +1,24 @@
+/*
+ * IOMMU for remote device
+ *
+ * Copyright © 2021 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.
+ *
+ */
+
+#ifndef REMOTE_IOMMU_H
+#define REMOTE_IOMMU_H
+
+#include "hw/pci/pci_bus.h"
+
+void remote_iommu_free(PCIDevice *pci_dev);
+
+void remote_iommu_init(void);
+
+void remote_iommu_set(PCIBus *bus);
+
+MemoryRegion *remote_iommu_get_ram(PCIDevice *pci_dev);
+
+#endif
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 4a84e478ce..57d561cc03 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -95,7 +95,7 @@ static const VMStateDescription vmstate_pcibus = {
     }
 };
 
-static void pci_init_bus_master(PCIDevice *pci_dev)
+void pci_init_bus_master(PCIDevice *pci_dev)
 {
     AddressSpace *dma_as = pci_device_iommu_address_space(pci_dev);
 
diff --git a/hw/remote/iommu.c b/hw/remote/iommu.c
new file mode 100644
index 0000000000..30c866badb
--- /dev/null
+++ b/hw/remote/iommu.c
@@ -0,0 +1,117 @@
+/*
+ * Remote IOMMU
+ *
+ * Copyright © 2021 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 "qemu-common.h"
+
+#include "hw/remote/iommu.h"
+#include "hw/pci/pci_bus.h"
+#include "exec/memory.h"
+#include "exec/address-spaces.h"
+#include "trace.h"
+
+struct VFUIOMMU {
+    AddressSpace  as;
+    MemoryRegion  mr;
+};
+
+typedef struct VFUPciBus {
+    PCIBus           *bus;
+    struct VFUIOMMU  *iommu[];
+} VFUPciBus;
+
+GHashTable *remote_as_table;
+
+static AddressSpace *remote_iommu_get_as(PCIBus *bus, void *opaque, int devfn)
+{
+    VFUPciBus *vfu_pci_bus = NULL;
+    struct VFUIOMMU *iommu = NULL;
+
+    if (!remote_as_table) {
+        return &address_space_memory;
+    }
+
+    vfu_pci_bus = g_hash_table_lookup(remote_as_table, bus);
+
+    if (!vfu_pci_bus) {
+        vfu_pci_bus = g_malloc0(sizeof(VFUPciBus));
+        vfu_pci_bus->bus = bus;
+        g_hash_table_insert(remote_as_table, bus, vfu_pci_bus);
+    }
+
+    iommu = vfu_pci_bus->iommu[devfn];
+
+    if (!iommu) {
+        g_autofree char *mr_name = g_strdup_printf("vfu-ram-%d", devfn);
+        g_autofree char *as_name = g_strdup_printf("vfu-as-%d", devfn);
+
+        iommu = g_malloc0(sizeof(struct VFUIOMMU));
+
+        memory_region_init(&iommu->mr, NULL, mr_name, UINT64_MAX);
+        address_space_init(&iommu->as, &iommu->mr, as_name);
+
+        vfu_pci_bus->iommu[devfn] = iommu;
+    }
+
+    return &iommu->as;
+}
+
+void remote_iommu_free(PCIDevice *pci_dev)
+{
+    VFUPciBus *vfu_pci_bus = NULL;
+    struct VFUIOMMU *iommu = NULL;
+
+    if (!remote_as_table) {
+        return;
+    }
+
+    vfu_pci_bus = g_hash_table_lookup(remote_as_table, pci_get_bus(pci_dev));
+
+    if (!vfu_pci_bus) {
+        return;
+    }
+
+    iommu = vfu_pci_bus->iommu[pci_dev->devfn];
+
+    vfu_pci_bus->iommu[pci_dev->devfn] = NULL;
+
+    if (iommu) {
+        memory_region_unref(&iommu->mr);
+        address_space_destroy(&iommu->as);
+        g_free(iommu);
+    }
+}
+
+void remote_iommu_init(void)
+{
+    remote_as_table = g_hash_table_new_full(NULL, NULL, NULL, NULL);
+}
+
+void remote_iommu_set(PCIBus *bus)
+{
+    pci_setup_iommu(bus, remote_iommu_get_as, NULL);
+}
+
+MemoryRegion *remote_iommu_get_ram(PCIDevice *pci_dev)
+{
+    PCIBus *bus = pci_get_bus(pci_dev);
+    VFUPciBus *vfu_pci_bus;
+
+    if (!remote_as_table) {
+        return get_system_memory();
+    }
+
+    vfu_pci_bus = g_hash_table_lookup(remote_as_table, bus);
+    if (!vfu_pci_bus) {
+        return get_system_memory();
+    }
+
+    return &vfu_pci_bus->iommu[pci_dev->devfn]->mr;
+}
diff --git a/hw/remote/machine.c b/hw/remote/machine.c
index 952105eab5..023be0491e 100644
--- a/hw/remote/machine.c
+++ b/hw/remote/machine.c
@@ -21,6 +21,7 @@
 #include "qapi/error.h"
 #include "hw/pci/pci_host.h"
 #include "hw/remote/iohub.h"
+#include "hw/remote/iommu.h"
 
 static void remote_machine_init(MachineState *machine)
 {
@@ -52,6 +53,10 @@ static void remote_machine_init(MachineState *machine)
 
     remote_iohub_init(&s->iohub);
 
+    remote_iommu_init();
+
+    remote_iommu_set(pci_host->bus);
+
     pci_bus_irqs(pci_host->bus, remote_iohub_set_irq, remote_iohub_map_irq,
                  &s->iohub, REMOTE_IOHUB_NB_PIRQS);
 }
diff --git a/hw/remote/vfio-user-obj.c b/hw/remote/vfio-user-obj.c
index 9399e87cbe..ae375e69b9 100644
--- a/hw/remote/vfio-user-obj.c
+++ b/hw/remote/vfio-user-obj.c
@@ -49,6 +49,7 @@
 #include "hw/qdev-core.h"
 #include "hw/pci/pci.h"
 #include "qemu/timer.h"
+#include "hw/remote/iommu.h"
 
 #define TYPE_VFU_OBJECT "x-vfio-user-server"
 OBJECT_DECLARE_TYPE(VfuObject, VfuObjectClass, VFU_OBJECT)
@@ -210,6 +211,7 @@ static ssize_t vfu_object_cfg_access(vfu_ctx_t *vfu_ctx, char * const buf,
 
 static void dma_register(vfu_ctx_t *vfu_ctx, vfu_dma_info_t *info)
 {
+    VfuObject *o = vfu_get_private(vfu_ctx);
     MemoryRegion *subregion = NULL;
     g_autofree char *name = NULL;
     static unsigned int suffix;
@@ -226,14 +228,15 @@ static void dma_register(vfu_ctx_t *vfu_ctx, vfu_dma_info_t *info)
     memory_region_init_ram_ptr(subregion, NULL, name,
                                iov->iov_len, info->vaddr);
 
-    memory_region_add_subregion(get_system_memory(), (hwaddr)iov->iov_base,
-                                subregion);
+    memory_region_add_subregion(remote_iommu_get_ram(o->pci_dev),
+                                (hwaddr)iov->iov_base, subregion);
 
     trace_vfu_dma_register((uint64_t)iov->iov_base, iov->iov_len);
 }
 
 static void dma_unregister(vfu_ctx_t *vfu_ctx, vfu_dma_info_t *info)
 {
+    VfuObject *o = vfu_get_private(vfu_ctx);
     MemoryRegion *mr = NULL;
     ram_addr_t offset;
 
@@ -242,7 +245,7 @@ static void dma_unregister(vfu_ctx_t *vfu_ctx, vfu_dma_info_t *info)
         return;
     }
 
-    memory_region_del_subregion(get_system_memory(), mr);
+    memory_region_del_subregion(remote_iommu_get_ram(o->pci_dev), mr);
 
     object_unparent((OBJECT(mr)));
 
@@ -320,6 +323,7 @@ static vfu_region_access_cb_t *vfu_object_bar_handlers[PCI_NUM_REGIONS] = {
  */
 static void vfu_object_register_bars(vfu_ctx_t *vfu_ctx, PCIDevice *pdev)
 {
+    VfuObject *o = vfu_get_private(vfu_ctx);
     int i;
 
     for (i = 0; i < PCI_NUM_REGIONS; i++) {
@@ -332,6 +336,12 @@ static void vfu_object_register_bars(vfu_ctx_t *vfu_ctx, PCIDevice *pdev)
                          vfu_object_bar_handlers[i],
                          VFU_REGION_FLAG_RW, NULL, 0, -1, 0);
 
+        if ((o->pci_dev->io_regions[i].type & PCI_BASE_ADDRESS_SPACE) == 0) {
+            memory_region_unref(o->pci_dev->io_regions[i].address_space);
+            o->pci_dev->io_regions[i].address_space =
+                remote_iommu_get_ram(o->pci_dev);
+        }
+
         trace_vfu_bar_register(i, pdev->io_regions[i].addr,
                                pdev->io_regions[i].size);
     }
@@ -490,6 +500,10 @@ static void vfu_object_finalize(Object *obj)
 
     o->device = NULL;
 
+    if (o->pci_dev) {
+        remote_iommu_free(o->pci_dev);
+    }
+
     o->pci_dev = NULL;
 
     if (!k->nr_devs && !k->daemon) {
diff --git a/MAINTAINERS b/MAINTAINERS
index b5eb306662..5dc67d79a1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3466,6 +3466,8 @@ F: hw/remote/iohub.c
 F: include/hw/remote/iohub.h
 F: subprojects/libvfio-user
 F: hw/remote/vfio-user-obj.c
+F: include/hw/remote/iommu.h
+F: hw/remote/iommu.c
 
 EBPF:
 M: Jason Wang <jasowang@redhat.com>
diff --git a/hw/remote/meson.build b/hw/remote/meson.build
index 534ac5df79..bcef83c8cc 100644
--- a/hw/remote/meson.build
+++ b/hw/remote/meson.build
@@ -6,6 +6,7 @@ remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('message.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('remote-obj.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('proxy.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('iohub.c'))
+remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('iommu.c'))
 remote_ss.add(when: 'CONFIG_VFIO_USER_SERVER', if_true: files('vfio-user-obj.c'))
 
 remote_ss.add(when: 'CONFIG_VFIO_USER_SERVER', if_true: vfiouser)
-- 
2.20.1