RE: [PATCH v6 18/19] intel_iommu: Implement [set|unset]_iommu_device() callbacks

[Duan, Zhenzhong]

>-----Original Message-----
>From: Eric Auger <eric.auger@redhat.com>
>Subject: Re: [PATCH v6 18/19] intel_iommu: Implement
>[set|unset]_iommu_device() callbacks
>
>Hi Zhenzhong,
>
>On 6/3/24 08:10, Zhenzhong Duan wrote:
>> From: Yi Liu <yi.l.liu@intel.com>
>>
>> Implement [set|unset]_iommu_device() callbacks in Intel vIOMMU.
>> In set call, a new structure VTDHostIOMMUDevice which holds
>> a reference to HostIOMMUDevice is stored in hash table
>> indexed by PCI BDF.
>maybe precise that this is not the aliased one?

Sure.

>>
>> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
>> Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
>> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
>> ---
>>  hw/i386/intel_iommu_internal.h |  9 ++++
>>  include/hw/i386/intel_iommu.h  |  2 +
>>  hw/i386/intel_iommu.c          | 76
>++++++++++++++++++++++++++++++++++
>>  3 files changed, 87 insertions(+)
>>
>> diff --git a/hw/i386/intel_iommu_internal.h
>b/hw/i386/intel_iommu_internal.h
>> index f8cf99bddf..b800d62ca0 100644
>> --- a/hw/i386/intel_iommu_internal.h
>> +++ b/hw/i386/intel_iommu_internal.h
>> @@ -28,6 +28,7 @@
>>  #ifndef HW_I386_INTEL_IOMMU_INTERNAL_H
>>  #define HW_I386_INTEL_IOMMU_INTERNAL_H
>>  #include "hw/i386/intel_iommu.h"
>> +#include "sysemu/host_iommu_device.h"
>>
>>  /*
>>   * Intel IOMMU register specification
>> @@ -537,4 +538,12 @@ typedef struct VTDRootEntry VTDRootEntry;
>>  #define VTD_SL_IGN_COM              0xbff0000000000000ULL
>>  #define VTD_SL_TM                   (1ULL << 62)
>>
>> +
>> +typedef struct VTDHostIOMMUDevice {
>> +    IntelIOMMUState *iommu_state;
>Why do you need the iommu_state?

It is used in nesting series.

>> +    PCIBus *bus;
>> +    uint8_t devfn;
>> +    HostIOMMUDevice *dev;
>> +    QLIST_ENTRY(VTDHostIOMMUDevice) next;
>> +} VTDHostIOMMUDevice;
>How VTD specific is it?

In nesting series, it has element iommu_state and errata
which are VTD specific.

>>  #endif
>> diff --git a/include/hw/i386/intel_iommu.h
>b/include/hw/i386/intel_iommu.h
>> index 7d694b0813..2bbde41e45 100644
>> --- a/include/hw/i386/intel_iommu.h
>> +++ b/include/hw/i386/intel_iommu.h
>> @@ -293,6 +293,8 @@ struct IntelIOMMUState {
>>      /* list of registered notifiers */
>>      QLIST_HEAD(, VTDAddressSpace) vtd_as_with_notifiers;
>>
>> +    GHashTable *vtd_host_iommu_dev;             /* VTDHostIOMMUDevice
>*/
>> +
>>      /* interrupt remapping */
>>      bool intr_enabled;              /* Whether guest enabled IR */
>>      dma_addr_t intr_root;           /* Interrupt remapping table pointer */
>> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
>> index 519063c8f8..747c988bc4 100644
>> --- a/hw/i386/intel_iommu.c
>> +++ b/hw/i386/intel_iommu.c
>> @@ -237,6 +237,13 @@ static gboolean vtd_as_equal(gconstpointer v1,
>gconstpointer v2)
>>             (key1->pasid == key2->pasid);
>>  }
>>
>> +static gboolean vtd_as_idev_equal(gconstpointer v1, gconstpointer v2)
>> +{
>> +    const struct vtd_as_key *key1 = v1;
>> +    const struct vtd_as_key *key2 = v2;
>> +
>> +    return (key1->bus == key2->bus) && (key1->devfn == key2->devfn);
>> +}
>can't you reuse the key with pasid?

s->vtd_host_iommu_dev isn't indexed by pasid but only BDF.
Maybe I'd better to define its own key struct, hash() and equal() functions.

>>  /*
>>   * Note that we use pointer to PCIBus as the key, so hashing/shifting
>>   * based on the pointer value is intended. Note that we deal with
>> @@ -3812,6 +3819,70 @@ VTDAddressSpace
>*vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus,
>>      return vtd_dev_as;
>>  }
>>
>> +static bool vtd_dev_set_iommu_device(PCIBus *bus, void *opaque, int
>devfn,
>> +                                     HostIOMMUDevice *hiod, Error **errp)
>> +{
>> +    IntelIOMMUState *s = opaque;
>> +    VTDHostIOMMUDevice *vtd_hdev;
>> +    struct vtd_as_key key = {
>> +        .bus = bus,
>> +        .devfn = devfn,
>> +    };
>> +    struct vtd_as_key *new_key;
>> +
>> +    assert(hiod);
>> +
>> +    vtd_iommu_lock(s);
>> +
>> +    vtd_hdev = g_hash_table_lookup(s->vtd_host_iommu_dev, &key);
>> +
>> +    if (vtd_hdev) {
>> +        error_setg(errp, "IOMMUFD device already exist");
>s/IOMMUFD/Host IOMMU device?

Good catch, will fix.

Thanks
Zhenzhong

>> +        vtd_iommu_unlock(s);
>> +        return false;
>> +    }
>> +
>> +    vtd_hdev = g_malloc0(sizeof(VTDHostIOMMUDevice));
>> +    vtd_hdev->bus = bus;
>> +    vtd_hdev->devfn = (uint8_t)devfn;
>> +    vtd_hdev->iommu_state = s;
>> +    vtd_hdev->dev = hiod;
>> +
>> +    new_key = g_malloc(sizeof(*new_key));
>> +    new_key->bus = bus;
>> +    new_key->devfn = devfn;
>> +
>> +    object_ref(hiod);
>> +    g_hash_table_insert(s->vtd_host_iommu_dev, new_key, vtd_hdev);
>> +
>> +    vtd_iommu_unlock(s);
>> +
>> +    return true;
>> +}
>> +
>> +static void vtd_dev_unset_iommu_device(PCIBus *bus, void *opaque, int
>devfn)
>> +{
>> +    IntelIOMMUState *s = opaque;
>> +    VTDHostIOMMUDevice *vtd_hdev;
>> +    struct vtd_as_key key = {
>> +        .bus = bus,
>> +        .devfn = devfn,
>> +    };
>> +
>> +    vtd_iommu_lock(s);
>> +
>> +    vtd_hdev = g_hash_table_lookup(s->vtd_host_iommu_dev, &key);
>> +    if (!vtd_hdev) {
>> +        vtd_iommu_unlock(s);
>> +        return;
>> +    }
>> +
>> +    g_hash_table_remove(s->vtd_host_iommu_dev, &key);
>> +    object_unref(vtd_hdev->dev);
>> +
>> +    vtd_iommu_unlock(s);
>> +}
>> +
>>  /* Unmap the whole range in the notifier's scope. */
>>  static void vtd_address_space_unmap(VTDAddressSpace *as,
>IOMMUNotifier *n)
>>  {
>> @@ -4116,6 +4187,8 @@ static AddressSpace
>*vtd_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
>>
>>  static PCIIOMMUOps vtd_iommu_ops = {
>>      .get_address_space = vtd_host_dma_iommu,
>> +    .set_iommu_device = vtd_dev_set_iommu_device,
>> +    .unset_iommu_device = vtd_dev_unset_iommu_device,
>>  };
>>
>>  static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
>> @@ -4235,6 +4308,9 @@ static void vtd_realize(DeviceState *dev, Error
>**errp)
>>                                       g_free, g_free);
>>      s->vtd_address_spaces = g_hash_table_new_full(vtd_as_hash,
>vtd_as_equal,
>>                                        g_free, g_free);
>> +    s->vtd_host_iommu_dev = g_hash_table_new_full(vtd_as_hash,
>> +                                                  vtd_as_idev_equal,
>> +                                                  g_free, g_free);
>>      vtd_init(s);
>>      pci_setup_iommu(bus, &vtd_iommu_ops, dev);
>>      /* Pseudo address space under root PCI bus. */
>Thanks
>
>Eric