Re: [PATCH rfcv1 3/6] intel_iommu: add set/unset_iommu_device callback

[Eric Auger]

Hi Zhenzhong,

On 1/15/24 11:13, Zhenzhong Duan wrote:
> From: Yi Liu <yi.l.liu@intel.com>
>
> This adds set/unset_iommu_device() implementation in Intel vIOMMU.
> In set call, IOMMUFDDevice is recorded in hash table indexed by
> PCI BDF.
>
> 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>
> ---
>  include/hw/i386/intel_iommu.h | 10 +++++
>  hw/i386/intel_iommu.c         | 79 +++++++++++++++++++++++++++++++++++
>  2 files changed, 89 insertions(+)
>
> diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
> index 7fa0a695c8..c65fdde56f 100644
> --- a/include/hw/i386/intel_iommu.h
> +++ b/include/hw/i386/intel_iommu.h
> @@ -62,6 +62,7 @@ typedef union VTD_IR_TableEntry VTD_IR_TableEntry;
>  typedef union VTD_IR_MSIAddress VTD_IR_MSIAddress;
>  typedef struct VTDPASIDDirEntry VTDPASIDDirEntry;
>  typedef struct VTDPASIDEntry VTDPASIDEntry;
> +typedef struct VTDIOMMUFDDevice VTDIOMMUFDDevice;
>  
>  /* Context-Entry */
>  struct VTDContextEntry {
> @@ -148,6 +149,13 @@ struct VTDAddressSpace {
>      IOVATree *iova_tree;
>  };
>  
> +struct VTDIOMMUFDDevice {
> +    PCIBus *bus;
> +    uint8_t devfn;
> +    IOMMUFDDevice *idev;
> +    IntelIOMMUState *iommu_state;
> +};
> +
Just wondering whether we shouldn't reuse the VTDAddressSpace to store
the idev, if any. How have you made your choice. What will it become
when PASID gets added?
>  struct VTDIOTLBEntry {
>      uint64_t gfn;
>      uint16_t domain_id;
> @@ -292,6 +300,8 @@ struct IntelIOMMUState {
>      /* list of registered notifiers */
>      QLIST_HEAD(, VTDAddressSpace) vtd_as_with_notifiers;
>  
> +    GHashTable *vtd_iommufd_dev;             /* VTDIOMMUFDDevice */
> +
>      /* 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 ed5677c0ae..95faf697eb 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);
> +}
>  /*
>   * 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 +3819,74 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, 
> PCIBus *bus,
>      return vtd_dev_as;
>  }
>  
> +static int vtd_dev_set_iommu_device(PCIBus *bus, void *opaque, int32_t devfn,
> +                                    IOMMUFDDevice *idev, Error **errp)
> +{
> +    IntelIOMMUState *s = opaque;
> +    VTDIOMMUFDDevice *vtd_idev;
> +    struct vtd_as_key key = {
> +        .bus = bus,
> +        .devfn = devfn,
> +    };
> +    struct vtd_as_key *new_key;
> +
> +    assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
> +
> +    /* None IOMMUFD case */
> +    if (!idev) {
> +        return 0;
> +    }
> +
> +    vtd_iommu_lock(s);
> +
> +    vtd_idev = g_hash_table_lookup(s->vtd_iommufd_dev, &key);
> +
> +    if (vtd_idev) {
> +        error_setg(errp, "IOMMUFD device already exist");
> +        return -1;
> +    }
> +
> +    new_key = g_malloc(sizeof(*new_key));
> +    new_key->bus = bus;
> +    new_key->devfn = devfn;
> +
> +    vtd_idev = g_malloc0(sizeof(VTDIOMMUFDDevice));
> +    vtd_idev->bus = bus;
> +    vtd_idev->devfn = (uint8_t)devfn;
> +    vtd_idev->iommu_state = s;
> +    vtd_idev->idev = idev;
> +
> +    g_hash_table_insert(s->vtd_iommufd_dev, new_key, vtd_idev);
> +
> +    vtd_iommu_unlock(s);
> +
> +    return 0;
> +}
> +
> +static void vtd_dev_unset_iommu_device(PCIBus *bus, void *opaque, int32_t 
> devfn)
> +{
> +    IntelIOMMUState *s = opaque;
> +    VTDIOMMUFDDevice *vtd_idev;
> +    struct vtd_as_key key = {
> +        .bus = bus,
> +        .devfn = devfn,
> +    };
> +
> +    assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
> +
> +    vtd_iommu_lock(s);
> +
> +    vtd_idev = g_hash_table_lookup(s->vtd_iommufd_dev, &key);
> +    if (!vtd_idev) {
> +        vtd_iommu_unlock(s);
> +        return;
> +    }
> +
> +    g_hash_table_remove(s->vtd_iommufd_dev, &key);
> +
> +    vtd_iommu_unlock(s);
> +}
> +
>  /* Unmap the whole range in the notifier's scope. */
>  static void vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier *n)
>  {
> @@ -4107,6 +4182,8 @@ 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)
> @@ -4230,6 +4307,8 @@ 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_iommufd_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