Re: [Qemu-devel] [PATCH v2 02/10] intel-iommu: remove IntelIOMMUNotifierNode

[Auger Eric <eric.auger@redhat.com>]

Hi Peter,

On 05/04/2018 05:08 AM, Peter Xu wrote:
> That is not really necessary.  Removing that node struct and put the
> list entry directly into VTDAddressSpace.  It simplfies the code a lot.
> 
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
>  include/hw/i386/intel_iommu.h |  9 ++------
>  hw/i386/intel_iommu.c         | 41 ++++++++++-------------------------
>  2 files changed, 14 insertions(+), 36 deletions(-)
> 
> diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
> index 45ec8919b6..220697253f 100644
> --- a/include/hw/i386/intel_iommu.h
> +++ b/include/hw/i386/intel_iommu.h
> @@ -67,7 +67,6 @@ typedef union VTD_IR_TableEntry VTD_IR_TableEntry;
>  typedef union VTD_IR_MSIAddress VTD_IR_MSIAddress;
>  typedef struct VTDIrq VTDIrq;
>  typedef struct VTD_MSIMessage VTD_MSIMessage;
> -typedef struct IntelIOMMUNotifierNode IntelIOMMUNotifierNode;
>  
>  /* Context-Entry */
>  struct VTDContextEntry {
> @@ -93,6 +92,7 @@ struct VTDAddressSpace {
>      MemoryRegion iommu_ir;      /* Interrupt region: 0xfeeXXXXX */
>      IntelIOMMUState *iommu_state;
>      VTDContextCacheEntry context_cache_entry;
> +    QLIST_ENTRY(VTDAddressSpace) next;
>  };
>  
>  struct VTDBus {
> @@ -253,11 +253,6 @@ struct VTD_MSIMessage {
>  /* When IR is enabled, all MSI/MSI-X data bits should be zero */
>  #define VTD_IR_MSI_DATA          (0)
>  
> -struct IntelIOMMUNotifierNode {
> -    VTDAddressSpace *vtd_as;
> -    QLIST_ENTRY(IntelIOMMUNotifierNode) next;
> -};
> -
>  /* The iommu (DMAR) device state struct */
>  struct IntelIOMMUState {
>      X86IOMMUState x86_iommu;
> @@ -295,7 +290,7 @@ struct IntelIOMMUState {
>      GHashTable *vtd_as_by_busptr;   /* VTDBus objects indexed by PCIBus* reference */
>      VTDBus *vtd_as_by_bus_num[VTD_PCI_BUS_MAX]; /* VTDBus objects indexed by bus number */
>      /* list of registered notifiers */
> -    QLIST_HEAD(, IntelIOMMUNotifierNode) notifiers_list;
> +    QLIST_HEAD(, VTDAddressSpace) notifiers_list;
Wouldn't it make sense to rename notifiers_list into something more
understandable like address_spaces?
>  
>      /* interrupt remapping */
>      bool intr_enabled;              /* Whether guest enabled IR */
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index b359efd6f9..5987b48d43 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -1248,10 +1248,10 @@ static void vtd_interrupt_remap_table_setup(IntelIOMMUState *s)
>  
>  static void vtd_iommu_replay_all(IntelIOMMUState *s)
>  {
> -    IntelIOMMUNotifierNode *node;
> +    VTDAddressSpace *vtd_as;
>  
> -    QLIST_FOREACH(node, &s->notifiers_list, next) {
> -        memory_region_iommu_replay_all(&node->vtd_as->iommu);
> +    QLIST_FOREACH(vtd_as, &s->notifiers_list, next) {
> +        memory_region_iommu_replay_all(&vtd_as->iommu);
>      }
>  }
>  
> @@ -1372,7 +1372,6 @@ static void vtd_iotlb_global_invalidate(IntelIOMMUState *s)
>  
>  static void vtd_iotlb_domain_invalidate(IntelIOMMUState *s, uint16_t domain_id)
>  {
> -    IntelIOMMUNotifierNode *node;
>      VTDContextEntry ce;
>      VTDAddressSpace *vtd_as;
>  
> @@ -1381,8 +1380,7 @@ static void vtd_iotlb_domain_invalidate(IntelIOMMUState *s, uint16_t domain_id)
>      g_hash_table_foreach_remove(s->iotlb, vtd_hash_remove_by_domain,
>                                  &domain_id);
>  
> -    QLIST_FOREACH(node, &s->notifiers_list, next) {
> -        vtd_as = node->vtd_as;
> +    QLIST_FOREACH(vtd_as, &s->notifiers_list, next) {
>          if (!vtd_dev_to_context_entry(s, pci_bus_num(vtd_as->bus),
>                                        vtd_as->devfn, &ce) &&
>              domain_id == VTD_CONTEXT_ENTRY_DID(ce.hi)) {
> @@ -1402,12 +1400,11 @@ static void vtd_iotlb_page_invalidate_notify(IntelIOMMUState *s,
>                                             uint16_t domain_id, hwaddr addr,
>                                             uint8_t am)
>  {
> -    IntelIOMMUNotifierNode *node;
> +    VTDAddressSpace *vtd_as;
>      VTDContextEntry ce;
>      int ret;
>  
> -    QLIST_FOREACH(node, &(s->notifiers_list), next) {
> -        VTDAddressSpace *vtd_as = node->vtd_as;
> +    QLIST_FOREACH(vtd_as, &(s->notifiers_list), next) {
>          ret = vtd_dev_to_context_entry(s, pci_bus_num(vtd_as->bus),
>                                         vtd_as->devfn, &ce);
>          if (!ret && domain_id == VTD_CONTEXT_ENTRY_DID(ce.hi)) {
> @@ -2344,8 +2341,6 @@ static void vtd_iommu_notify_flag_changed(IOMMUMemoryRegion *iommu,
>  {
>      VTDAddressSpace *vtd_as = container_of(iommu, VTDAddressSpace, iommu);
>      IntelIOMMUState *s = vtd_as->iommu_state;
> -    IntelIOMMUNotifierNode *node = NULL;
> -    IntelIOMMUNotifierNode *next_node = NULL;
>  
>      if (!s->caching_mode && new & IOMMU_NOTIFIER_MAP) {
>          error_report("We need to set caching-mode=1 for intel-iommu to enable "
> @@ -2354,21 +2349,11 @@ static void vtd_iommu_notify_flag_changed(IOMMUMemoryRegion *iommu,
>      }
>  
>      if (old == IOMMU_NOTIFIER_NONE) {
> -        node = g_malloc0(sizeof(*node));
> -        node->vtd_as = vtd_as;
> -        QLIST_INSERT_HEAD(&s->notifiers_list, node, next);
> -        return;
> -    }
> -
> -    /* update notifier node with new flags */
> -    QLIST_FOREACH_SAFE(node, &s->notifiers_list, next, next_node) {
> -        if (node->vtd_as == vtd_as) {
> -            if (new == IOMMU_NOTIFIER_NONE) {
> -                QLIST_REMOVE(node, next);
> -                g_free(node);
> -            }
> -            return;
> -        }
> +        /* Insert new ones */
s/ones/one

> +        QLIST_INSERT_HEAD(&s->notifiers_list, vtd_as, next);
> +    } else if (new == IOMMU_NOTIFIER_NONE) {
> +        /* Remove old ones */
same. Not sure the comments are worth.
> +        QLIST_REMOVE(vtd_as, next);
>      }
>  }
>  
> @@ -2838,12 +2823,10 @@ static void vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier *n)
>  
>  static void vtd_address_space_unmap_all(IntelIOMMUState *s)
>  {
> -    IntelIOMMUNotifierNode *node;
>      VTDAddressSpace *vtd_as;
>      IOMMUNotifier *n;
>  
> -    QLIST_FOREACH(node, &s->notifiers_list, next) {
> -        vtd_as = node->vtd_as;
> +    QLIST_FOREACH(vtd_as, &s->notifiers_list, next) {
>          IOMMU_NOTIFIER_FOREACH(n, &vtd_as->iommu) {
>              vtd_address_space_unmap(vtd_as, n);
>          }
> 
Thanks

Eric