Implement PCIIOMMUOPs [set|unset]_iommu_device() callbacks.
In set(), a VirtioHostIOMMUDevice is allocated which holds
a reference to the HostIOMMUDevice. This object is stored in a hash
table indexed by PCI BDF. The handle to the Host IOMMU device
will allow to retrieve information related to the physical IOMMU.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---

v2 -> v3:
- include host_iommu_device.h in virtio-iommu.h header
- introduce hiod_destroy() and fix UAF in
  virtio_iommu_unset_iommu_device()
---
 include/hw/virtio/virtio-iommu.h | 10 ++++
 hw/virtio/virtio-iommu.c         | 90 ++++++++++++++++++++++++++++++++
 2 files changed, 100 insertions(+)

diff --git a/include/hw/virtio/virtio-iommu.h b/include/hw/virtio/virtio-iommu.h
index 83a52cc446..a5926de947 100644
--- a/include/hw/virtio/virtio-iommu.h
+++ b/include/hw/virtio/virtio-iommu.h
@@ -25,6 +25,7 @@
 #include "hw/pci/pci.h"
 #include "qom/object.h"
 #include "qapi/qapi-types-virtio.h"
+#include "sysemu/host_iommu_device.h"
 
 #define TYPE_VIRTIO_IOMMU "virtio-iommu-device"
 #define TYPE_VIRTIO_IOMMU_PCI "virtio-iommu-pci"
@@ -45,6 +46,14 @@ typedef struct IOMMUDevice {
     bool probe_done;
 } IOMMUDevice;
 
+typedef struct VirtioHostIOMMUDevice {
+    void *viommu;
+    PCIBus *bus;
+    uint8_t devfn;
+    HostIOMMUDevice *dev;
+    QLIST_ENTRY(VirtioHostIOMMUDevice) next;
+} VirtioHostIOMMUDevice;
+
 typedef struct IOMMUPciBus {
     PCIBus       *bus;
     IOMMUDevice  *pbdev[]; /* Parent array is sparse, so dynamically alloc */
@@ -57,6 +66,7 @@ struct VirtIOIOMMU {
     struct virtio_iommu_config config;
     uint64_t features;
     GHashTable *as_by_busptr;
+    GHashTable *host_iommu_devices;
     IOMMUPciBus *iommu_pcibus_by_bus_num[PCI_BUS_MAX];
     PCIBus *primary_bus;
     ReservedRegion *prop_resv_regions;
diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
index 1326c6ec41..db842555c8 100644
--- a/hw/virtio/virtio-iommu.c
+++ b/hw/virtio/virtio-iommu.c
@@ -69,6 +69,11 @@ typedef struct VirtIOIOMMUMapping {
     uint32_t flags;
 } VirtIOIOMMUMapping;
 
+struct hiod_key {
+    PCIBus *bus;
+    uint8_t devfn;
+};
+
 static inline uint16_t virtio_iommu_get_bdf(IOMMUDevice *dev)
 {
     return PCI_BUILD_BDF(pci_bus_num(dev->bus), dev->devfn);
@@ -462,8 +467,90 @@ static AddressSpace *virtio_iommu_find_add_as(PCIBus *bus, void *opaque,
     return &sdev->as;
 }
 
+static gboolean hiod_equal(gconstpointer v1, gconstpointer v2)
+{
+    const struct hiod_key *key1 = v1;
+    const struct hiod_key *key2 = v2;
+
+    return (key1->bus == key2->bus) && (key1->devfn == key2->devfn);
+}
+
+static guint hiod_hash(gconstpointer v)
+{
+    const struct hiod_key *key = v;
+    guint value = (guint)(uintptr_t)key->bus;
+
+    return (guint)(value << 8 | key->devfn);
+}
+
+static void hiod_destroy(gpointer v)
+{
+    object_unref(v);
+}
+
+static VirtioHostIOMMUDevice *
+get_host_iommu_device(VirtIOIOMMU *viommu, PCIBus *bus, int devfn) {
+    struct hiod_key key = {
+        .bus = bus,
+        .devfn = devfn,
+    };
+
+    return g_hash_table_lookup(viommu->host_iommu_devices, &key);
+}
+
+static bool virtio_iommu_set_iommu_device(PCIBus *bus, void *opaque, int devfn,
+                                          HostIOMMUDevice *hiod, Error **errp)
+{
+    VirtIOIOMMU *viommu = opaque;
+    VirtioHostIOMMUDevice *vhiod;
+    struct hiod_key *new_key;
+
+    assert(hiod);
+
+    vhiod = get_host_iommu_device(viommu, bus, devfn);
+    if (vhiod) {
+        error_setg(errp, "VirtioHostIOMMUDevice already exists");
+        return false;
+    }
+
+    vhiod = g_malloc0(sizeof(VirtioHostIOMMUDevice));
+    vhiod->bus = bus;
+    vhiod->devfn = (uint8_t)devfn;
+    vhiod->viommu = viommu;
+    vhiod->dev = hiod;
+
+    new_key = g_malloc(sizeof(*new_key));
+    new_key->bus = bus;
+    new_key->devfn = devfn;
+
+    object_ref(hiod);
+    g_hash_table_insert(viommu->host_iommu_devices, new_key, vhiod);
+
+    return true;
+}
+
+static void
+virtio_iommu_unset_iommu_device(PCIBus *bus, void *opaque, int devfn)
+{
+    VirtIOIOMMU *viommu = opaque;
+    VirtioHostIOMMUDevice *vhiod;
+    struct hiod_key key = {
+        .bus = bus,
+        .devfn = devfn,
+    };
+
+    vhiod = g_hash_table_lookup(viommu->host_iommu_devices, &key);
+    if (!vhiod) {
+        return;
+    }
+
+    g_hash_table_remove(viommu->host_iommu_devices, &key);
+}
+
 static const PCIIOMMUOps virtio_iommu_ops = {
     .get_address_space = virtio_iommu_find_add_as,
+    .set_iommu_device = virtio_iommu_set_iommu_device,
+    .unset_iommu_device = virtio_iommu_unset_iommu_device,
 };
 
 static int virtio_iommu_attach(VirtIOIOMMU *s,
@@ -1357,6 +1444,9 @@ static void virtio_iommu_device_realize(DeviceState *dev, Error **errp)
 
     s->as_by_busptr = g_hash_table_new_full(NULL, NULL, NULL, g_free);
 
+    s->host_iommu_devices = g_hash_table_new_full(hiod_hash, hiod_equal,
+                                                  g_free, hiod_destroy);
+
     if (s->primary_bus) {
         pci_setup_iommu(s->primary_bus, &virtio_iommu_ops, s);
     } else {
-- 
2.41.0

>-----Original Message-----
>From: Eric Auger <eric.auger@redhat.com>
>Subject: [PATCH v3 2/7] virtio-iommu: Implement
>set|unset]_iommu_device() callbacks
>
>Implement PCIIOMMUOPs [set|unset]_iommu_device() callbacks.
>In set(), a VirtioHostIOMMUDevice is allocated which holds
>a reference to the HostIOMMUDevice. This object is stored in a hash
>table indexed by PCI BDF. The handle to the Host IOMMU device
>will allow to retrieve information related to the physical IOMMU.
>
>Signed-off-by: Eric Auger <eric.auger@redhat.com>
>
>---
>
>v2 -> v3:
>- include host_iommu_device.h in virtio-iommu.h header
>- introduce hiod_destroy() and fix UAF in
>  virtio_iommu_unset_iommu_device()	
>---
> include/hw/virtio/virtio-iommu.h | 10 ++++
> hw/virtio/virtio-iommu.c         | 90
>++++++++++++++++++++++++++++++++
> 2 files changed, 100 insertions(+)
>
>diff --git a/include/hw/virtio/virtio-iommu.h b/include/hw/virtio/virtio-
>iommu.h
>index 83a52cc446..a5926de947 100644
>--- a/include/hw/virtio/virtio-iommu.h
>+++ b/include/hw/virtio/virtio-iommu.h
>@@ -25,6 +25,7 @@
> #include "hw/pci/pci.h"
> #include "qom/object.h"
> #include "qapi/qapi-types-virtio.h"
>+#include "sysemu/host_iommu_device.h"
>
> #define TYPE_VIRTIO_IOMMU "virtio-iommu-device"
> #define TYPE_VIRTIO_IOMMU_PCI "virtio-iommu-pci"
>@@ -45,6 +46,14 @@ typedef struct IOMMUDevice {
>     bool probe_done;
> } IOMMUDevice;
>
>+typedef struct VirtioHostIOMMUDevice {
>+    void *viommu;
>+    PCIBus *bus;
>+    uint8_t devfn;
>+    HostIOMMUDevice *dev;
>+    QLIST_ENTRY(VirtioHostIOMMUDevice) next;
>+} VirtioHostIOMMUDevice;

Do you have plan to use the elements in VirtioHostIOMMUDevice?

>+
> typedef struct IOMMUPciBus {
>     PCIBus       *bus;
>     IOMMUDevice  *pbdev[]; /* Parent array is sparse, so dynamically alloc
>*/
>@@ -57,6 +66,7 @@ struct VirtIOIOMMU {
>     struct virtio_iommu_config config;
>     uint64_t features;
>     GHashTable *as_by_busptr;
>+    GHashTable *host_iommu_devices;
>     IOMMUPciBus *iommu_pcibus_by_bus_num[PCI_BUS_MAX];
>     PCIBus *primary_bus;
>     ReservedRegion *prop_resv_regions;
>diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
>index 1326c6ec41..db842555c8 100644
>--- a/hw/virtio/virtio-iommu.c
>+++ b/hw/virtio/virtio-iommu.c
>@@ -69,6 +69,11 @@ typedef struct VirtIOIOMMUMapping {
>     uint32_t flags;
> } VirtIOIOMMUMapping;
>
>+struct hiod_key {
>+    PCIBus *bus;
>+    uint8_t devfn;
>+};
>+
> static inline uint16_t virtio_iommu_get_bdf(IOMMUDevice *dev)
> {
>     return PCI_BUILD_BDF(pci_bus_num(dev->bus), dev->devfn);
>@@ -462,8 +467,90 @@ static AddressSpace
>*virtio_iommu_find_add_as(PCIBus *bus, void *opaque,
>     return &sdev->as;
> }
>
>+static gboolean hiod_equal(gconstpointer v1, gconstpointer v2)
>+{
>+    const struct hiod_key *key1 = v1;
>+    const struct hiod_key *key2 = v2;
>+
>+    return (key1->bus == key2->bus) && (key1->devfn == key2->devfn);
>+}
>+
>+static guint hiod_hash(gconstpointer v)
>+{
>+    const struct hiod_key *key = v;
>+    guint value = (guint)(uintptr_t)key->bus;
>+
>+    return (guint)(value << 8 | key->devfn);
>+}
>+
>+static void hiod_destroy(gpointer v)
>+{
>+    object_unref(v);

This is a bit different from intel_iommu, here v represents VirtioHostIOMMUDevice *.

Thanks
Zhenzhong

>+}
>+
>+static VirtioHostIOMMUDevice *
>+get_host_iommu_device(VirtIOIOMMU *viommu, PCIBus *bus, int devfn) {
>+    struct hiod_key key = {
>+        .bus = bus,
>+        .devfn = devfn,
>+    };
>+
>+    return g_hash_table_lookup(viommu->host_iommu_devices, &key);
>+}
>+
>+static bool virtio_iommu_set_iommu_device(PCIBus *bus, void *opaque,
>int devfn,
>+                                          HostIOMMUDevice *hiod, Error **errp)
>+{
>+    VirtIOIOMMU *viommu = opaque;
>+    VirtioHostIOMMUDevice *vhiod;
>+    struct hiod_key *new_key;
>+
>+    assert(hiod);
>+
>+    vhiod = get_host_iommu_device(viommu, bus, devfn);
>+    if (vhiod) {
>+        error_setg(errp, "VirtioHostIOMMUDevice already exists");
>+        return false;
>+    }
>+
>+    vhiod = g_malloc0(sizeof(VirtioHostIOMMUDevice));
>+    vhiod->bus = bus;
>+    vhiod->devfn = (uint8_t)devfn;
>+    vhiod->viommu = viommu;
>+    vhiod->dev = hiod;
>+
>+    new_key = g_malloc(sizeof(*new_key));
>+    new_key->bus = bus;
>+    new_key->devfn = devfn;
>+
>+    object_ref(hiod);
>+    g_hash_table_insert(viommu->host_iommu_devices, new_key, vhiod);
>+
>+    return true;
>+}
>+
>+static void
>+virtio_iommu_unset_iommu_device(PCIBus *bus, void *opaque, int devfn)
>+{
>+    VirtIOIOMMU *viommu = opaque;
>+    VirtioHostIOMMUDevice *vhiod;
>+    struct hiod_key key = {
>+        .bus = bus,
>+        .devfn = devfn,
>+    };
>+
>+    vhiod = g_hash_table_lookup(viommu->host_iommu_devices, &key);
>+    if (!vhiod) {
>+        return;
>+    }
>+
>+    g_hash_table_remove(viommu->host_iommu_devices, &key);
>+}
>+
> static const PCIIOMMUOps virtio_iommu_ops = {
>     .get_address_space = virtio_iommu_find_add_as,
>+    .set_iommu_device = virtio_iommu_set_iommu_device,
>+    .unset_iommu_device = virtio_iommu_unset_iommu_device,
> };
>
> static int virtio_iommu_attach(VirtIOIOMMU *s,
>@@ -1357,6 +1444,9 @@ static void
>virtio_iommu_device_realize(DeviceState *dev, Error **errp)
>
>     s->as_by_busptr = g_hash_table_new_full(NULL, NULL, NULL, g_free);
>
>+    s->host_iommu_devices = g_hash_table_new_full(hiod_hash,
>hiod_equal,
>+                                                  g_free, hiod_destroy);
>+
>     if (s->primary_bus) {
>         pci_setup_iommu(s->primary_bus, &virtio_iommu_ops, s);
>     } else {
>--
>2.41.0

Hi Zhenzhong,

On 6/13/24 11:57, Duan, Zhenzhong wrote:
>
>> -----Original Message-----
>> From: Eric Auger <eric.auger@redhat.com>
>> Subject: [PATCH v3 2/7] virtio-iommu: Implement
>> set|unset]_iommu_device() callbacks
>>
>> Implement PCIIOMMUOPs [set|unset]_iommu_device() callbacks.
>> In set(), a VirtioHostIOMMUDevice is allocated which holds
>> a reference to the HostIOMMUDevice. This object is stored in a hash
>> table indexed by PCI BDF. The handle to the Host IOMMU device
>> will allow to retrieve information related to the physical IOMMU.
>>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>>
>> ---
>>
>> v2 -> v3:
>> - include host_iommu_device.h in virtio-iommu.h header
>> - introduce hiod_destroy() and fix UAF in
>>  virtio_iommu_unset_iommu_device()	
>> ---
>> include/hw/virtio/virtio-iommu.h | 10 ++++
>> hw/virtio/virtio-iommu.c         | 90
>> ++++++++++++++++++++++++++++++++
>> 2 files changed, 100 insertions(+)
>>
>> diff --git a/include/hw/virtio/virtio-iommu.h b/include/hw/virtio/virtio-
>> iommu.h
>> index 83a52cc446..a5926de947 100644
>> --- a/include/hw/virtio/virtio-iommu.h
>> +++ b/include/hw/virtio/virtio-iommu.h
>> @@ -25,6 +25,7 @@
>> #include "hw/pci/pci.h"
>> #include "qom/object.h"
>> #include "qapi/qapi-types-virtio.h"
>> +#include "sysemu/host_iommu_device.h"
>>
>> #define TYPE_VIRTIO_IOMMU "virtio-iommu-device"
>> #define TYPE_VIRTIO_IOMMU_PCI "virtio-iommu-pci"
>> @@ -45,6 +46,14 @@ typedef struct IOMMUDevice {
>>     bool probe_done;
>> } IOMMUDevice;
>>
>> +typedef struct VirtioHostIOMMUDevice {
>> +    void *viommu;
>> +    PCIBus *bus;
>> +    uint8_t devfn;
>> +    HostIOMMUDevice *dev;
>> +    QLIST_ENTRY(VirtioHostIOMMUDevice) next;
>> +} VirtioHostIOMMUDevice;
> Do you have plan to use the elements in VirtioHostIOMMUDevice?
As of now I get rid of this derived object and do something similar as
what you did on vtd.
>
>> +
>> typedef struct IOMMUPciBus {
>>     PCIBus       *bus;
>>     IOMMUDevice  *pbdev[]; /* Parent array is sparse, so dynamically alloc
>> */
>> @@ -57,6 +66,7 @@ struct VirtIOIOMMU {
>>     struct virtio_iommu_config config;
>>     uint64_t features;
>>     GHashTable *as_by_busptr;
>> +    GHashTable *host_iommu_devices;
>>     IOMMUPciBus *iommu_pcibus_by_bus_num[PCI_BUS_MAX];
>>     PCIBus *primary_bus;
>>     ReservedRegion *prop_resv_regions;
>> diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
>> index 1326c6ec41..db842555c8 100644
>> --- a/hw/virtio/virtio-iommu.c
>> +++ b/hw/virtio/virtio-iommu.c
>> @@ -69,6 +69,11 @@ typedef struct VirtIOIOMMUMapping {
>>     uint32_t flags;
>> } VirtIOIOMMUMapping;
>>
>> +struct hiod_key {
>> +    PCIBus *bus;
>> +    uint8_t devfn;
>> +};
>> +
>> static inline uint16_t virtio_iommu_get_bdf(IOMMUDevice *dev)
>> {
>>     return PCI_BUILD_BDF(pci_bus_num(dev->bus), dev->devfn);
>> @@ -462,8 +467,90 @@ static AddressSpace
>> *virtio_iommu_find_add_as(PCIBus *bus, void *opaque,
>>     return &sdev->as;
>> }
>>
>> +static gboolean hiod_equal(gconstpointer v1, gconstpointer v2)
>> +{
>> +    const struct hiod_key *key1 = v1;
>> +    const struct hiod_key *key2 = v2;
>> +
>> +    return (key1->bus == key2->bus) && (key1->devfn == key2->devfn);
>> +}
>> +
>> +static guint hiod_hash(gconstpointer v)
>> +{
>> +    const struct hiod_key *key = v;
>> +    guint value = (guint)(uintptr_t)key->bus;
>> +
>> +    return (guint)(value << 8 | key->devfn);
>> +}
>> +
>> +static void hiod_destroy(gpointer v)
>> +{
>> +    object_unref(v);
> This is a bit different from intel_iommu, here v represents VirtioHostIOMMUDevice *.
damned, you are totally right.

Fixed in next version.

Thank you very much!

Eric
>
> Thanks
> Zhenzhong
>
>> +}
>> +
>> +static VirtioHostIOMMUDevice *
>> +get_host_iommu_device(VirtIOIOMMU *viommu, PCIBus *bus, int devfn) {
>> +    struct hiod_key key = {
>> +        .bus = bus,
>> +        .devfn = devfn,
>> +    };
>> +
>> +    return g_hash_table_lookup(viommu->host_iommu_devices, &key);
>> +}
>> +
>> +static bool virtio_iommu_set_iommu_device(PCIBus *bus, void *opaque,
>> int devfn,
>> +                                          HostIOMMUDevice *hiod, Error **errp)
>> +{
>> +    VirtIOIOMMU *viommu = opaque;
>> +    VirtioHostIOMMUDevice *vhiod;
>> +    struct hiod_key *new_key;
>> +
>> +    assert(hiod);
>> +
>> +    vhiod = get_host_iommu_device(viommu, bus, devfn);
>> +    if (vhiod) {
>> +        error_setg(errp, "VirtioHostIOMMUDevice already exists");
>> +        return false;
>> +    }
>> +
>> +    vhiod = g_malloc0(sizeof(VirtioHostIOMMUDevice));
>> +    vhiod->bus = bus;
>> +    vhiod->devfn = (uint8_t)devfn;
>> +    vhiod->viommu = viommu;
>> +    vhiod->dev = hiod;
>> +
>> +    new_key = g_malloc(sizeof(*new_key));
>> +    new_key->bus = bus;
>> +    new_key->devfn = devfn;
>> +
>> +    object_ref(hiod);
>> +    g_hash_table_insert(viommu->host_iommu_devices, new_key, vhiod);
>> +
>> +    return true;
>> +}
>> +
>> +static void
>> +virtio_iommu_unset_iommu_device(PCIBus *bus, void *opaque, int devfn)
>> +{
>> +    VirtIOIOMMU *viommu = opaque;
>> +    VirtioHostIOMMUDevice *vhiod;
>> +    struct hiod_key key = {
>> +        .bus = bus,
>> +        .devfn = devfn,
>> +    };
>> +
>> +    vhiod = g_hash_table_lookup(viommu->host_iommu_devices, &key);
>> +    if (!vhiod) {
>> +        return;
>> +    }
>> +
>> +    g_hash_table_remove(viommu->host_iommu_devices, &key);
>> +}
>> +
>> static const PCIIOMMUOps virtio_iommu_ops = {
>>     .get_address_space = virtio_iommu_find_add_as,
>> +    .set_iommu_device = virtio_iommu_set_iommu_device,
>> +    .unset_iommu_device = virtio_iommu_unset_iommu_device,
>> };
>>
>> static int virtio_iommu_attach(VirtIOIOMMU *s,
>> @@ -1357,6 +1444,9 @@ static void
>> virtio_iommu_device_realize(DeviceState *dev, Error **errp)
>>
>>     s->as_by_busptr = g_hash_table_new_full(NULL, NULL, NULL, g_free);
>>
>> +    s->host_iommu_devices = g_hash_table_new_full(hiod_hash,
>> hiod_equal,
>> +                                                  g_free, hiod_destroy);
>> +
>>     if (s->primary_bus) {
>>         pci_setup_iommu(s->primary_bus, &virtio_iommu_ops, s);
>>     } else {
>> --
>> 2.41.0

On 6/13/24 11:57 AM, Duan, Zhenzhong wrote:
> 
> 
>> -----Original Message-----
>> From: Eric Auger <eric.auger@redhat.com>
>> Subject: [PATCH v3 2/7] virtio-iommu: Implement
>> set|unset]_iommu_device() callbacks
>>
>> Implement PCIIOMMUOPs [set|unset]_iommu_device() callbacks.
>> In set(), a VirtioHostIOMMUDevice is allocated which holds
>> a reference to the HostIOMMUDevice. This object is stored in a hash
>> table indexed by PCI BDF. The handle to the Host IOMMU device
>> will allow to retrieve information related to the physical IOMMU.
>>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>>
>> ---
>>
>> v2 -> v3:
>> - include host_iommu_device.h in virtio-iommu.h header
>> - introduce hiod_destroy() and fix UAF in
>>   virtio_iommu_unset_iommu_device()	
>> ---
>> include/hw/virtio/virtio-iommu.h | 10 ++++
>> hw/virtio/virtio-iommu.c         | 90
>> ++++++++++++++++++++++++++++++++
>> 2 files changed, 100 insertions(+)
>>
>> diff --git a/include/hw/virtio/virtio-iommu.h b/include/hw/virtio/virtio-
>> iommu.h
>> index 83a52cc446..a5926de947 100644
>> --- a/include/hw/virtio/virtio-iommu.h
>> +++ b/include/hw/virtio/virtio-iommu.h
>> @@ -25,6 +25,7 @@
>> #include "hw/pci/pci.h"
>> #include "qom/object.h"
>> #include "qapi/qapi-types-virtio.h"
>> +#include "sysemu/host_iommu_device.h"
>>
>> #define TYPE_VIRTIO_IOMMU "virtio-iommu-device"
>> #define TYPE_VIRTIO_IOMMU_PCI "virtio-iommu-pci"
>> @@ -45,6 +46,14 @@ typedef struct IOMMUDevice {
>>      bool probe_done;
>> } IOMMUDevice;
>>
>> +typedef struct VirtioHostIOMMUDevice {
>> +    void *viommu;
>> +    PCIBus *bus;
>> +    uint8_t devfn;
>> +    HostIOMMUDevice *dev;
>> +    QLIST_ENTRY(VirtioHostIOMMUDevice) next;
>> +} VirtioHostIOMMUDevice;
> 
> Do you have plan to use the elements in VirtioHostIOMMUDevice?

Indeed.

It would be better to avoid the unused struct definition. If removed,
the new vtd and virtio un/set_iommu_device ops become very similar and
there could be a common shared framework. Some of it could be handled
in the PCI subsystem probably ?

Thanks,

C.


  
> 
>> +
>> typedef struct IOMMUPciBus {
>>      PCIBus       *bus;
>>      IOMMUDevice  *pbdev[]; /* Parent array is sparse, so dynamically alloc
>> */
>> @@ -57,6 +66,7 @@ struct VirtIOIOMMU {
>>      struct virtio_iommu_config config;
>>      uint64_t features;
>>      GHashTable *as_by_busptr;
>> +    GHashTable *host_iommu_devices;
>>      IOMMUPciBus *iommu_pcibus_by_bus_num[PCI_BUS_MAX];
>>      PCIBus *primary_bus;
>>      ReservedRegion *prop_resv_regions;
>> diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
>> index 1326c6ec41..db842555c8 100644
>> --- a/hw/virtio/virtio-iommu.c
>> +++ b/hw/virtio/virtio-iommu.c
>> @@ -69,6 +69,11 @@ typedef struct VirtIOIOMMUMapping {
>>      uint32_t flags;
>> } VirtIOIOMMUMapping;
>>
>> +struct hiod_key {
>> +    PCIBus *bus;
>> +    uint8_t devfn;
>> +};
>> +
>> static inline uint16_t virtio_iommu_get_bdf(IOMMUDevice *dev)
>> {
>>      return PCI_BUILD_BDF(pci_bus_num(dev->bus), dev->devfn);
>> @@ -462,8 +467,90 @@ static AddressSpace
>> *virtio_iommu_find_add_as(PCIBus *bus, void *opaque,
>>      return &sdev->as;
>> }
>>
>> +static gboolean hiod_equal(gconstpointer v1, gconstpointer v2)
>> +{
>> +    const struct hiod_key *key1 = v1;
>> +    const struct hiod_key *key2 = v2;
>> +
>> +    return (key1->bus == key2->bus) && (key1->devfn == key2->devfn);
>> +}
>> +
>> +static guint hiod_hash(gconstpointer v)
>> +{
>> +    const struct hiod_key *key = v;
>> +    guint value = (guint)(uintptr_t)key->bus;
>> +
>> +    return (guint)(value << 8 | key->devfn);
>> +}
>> +
>> +static void hiod_destroy(gpointer v)
>> +{
>> +    object_unref(v);
> 
> This is a bit different from intel_iommu, here v represents VirtioHostIOMMUDevice *.
> 
> Thanks
> Zhenzhong
> 
>> +}
>> +
>> +static VirtioHostIOMMUDevice *
>> +get_host_iommu_device(VirtIOIOMMU *viommu, PCIBus *bus, int devfn) {
>> +    struct hiod_key key = {
>> +        .bus = bus,
>> +        .devfn = devfn,
>> +    };
>> +
>> +    return g_hash_table_lookup(viommu->host_iommu_devices, &key);
>> +}
>> +
>> +static bool virtio_iommu_set_iommu_device(PCIBus *bus, void *opaque,
>> int devfn,
>> +                                          HostIOMMUDevice *hiod, Error **errp)
>> +{
>> +    VirtIOIOMMU *viommu = opaque;
>> +    VirtioHostIOMMUDevice *vhiod;
>> +    struct hiod_key *new_key;
>> +
>> +    assert(hiod);
>> +
>> +    vhiod = get_host_iommu_device(viommu, bus, devfn);
>> +    if (vhiod) {
>> +        error_setg(errp, "VirtioHostIOMMUDevice already exists");
>> +        return false;
>> +    }
>> +
>> +    vhiod = g_malloc0(sizeof(VirtioHostIOMMUDevice));
>> +    vhiod->bus = bus;
>> +    vhiod->devfn = (uint8_t)devfn;
>> +    vhiod->viommu = viommu;
>> +    vhiod->dev = hiod;
>> +
>> +    new_key = g_malloc(sizeof(*new_key));
>> +    new_key->bus = bus;
>> +    new_key->devfn = devfn;
>> +
>> +    object_ref(hiod);
>> +    g_hash_table_insert(viommu->host_iommu_devices, new_key, vhiod);
>> +
>> +    return true;
>> +}
>> +
>> +static void
>> +virtio_iommu_unset_iommu_device(PCIBus *bus, void *opaque, int devfn)
>> +{
>> +    VirtIOIOMMU *viommu = opaque;
>> +    VirtioHostIOMMUDevice *vhiod;
>> +    struct hiod_key key = {
>> +        .bus = bus,
>> +        .devfn = devfn,
>> +    };
>> +
>> +    vhiod = g_hash_table_lookup(viommu->host_iommu_devices, &key);
>> +    if (!vhiod) {
>> +        return;
>> +    }
>> +
>> +    g_hash_table_remove(viommu->host_iommu_devices, &key);
>> +}
>> +
>> static const PCIIOMMUOps virtio_iommu_ops = {
>>      .get_address_space = virtio_iommu_find_add_as,
>> +    .set_iommu_device = virtio_iommu_set_iommu_device,
>> +    .unset_iommu_device = virtio_iommu_unset_iommu_device,
>> };
>>
>> static int virtio_iommu_attach(VirtIOIOMMU *s,
>> @@ -1357,6 +1444,9 @@ static void
>> virtio_iommu_device_realize(DeviceState *dev, Error **errp)
>>
>>      s->as_by_busptr = g_hash_table_new_full(NULL, NULL, NULL, g_free);
>>
>> +    s->host_iommu_devices = g_hash_table_new_full(hiod_hash,
>> hiod_equal,
>> +                                                  g_free, hiod_destroy);
>> +
>>      if (s->primary_bus) {
>>          pci_setup_iommu(s->primary_bus, &virtio_iommu_ops, s);
>>      } else {
>> --
>> 2.41.0
>