Re: [PATCH 4/9] pci-assign: Use struct for MSI-X table

["Michael S. Tsirkin" <mst@redhat.com>]

On Sat, Jan 28, 2012 at 07:21:58AM -0700, Alex Williamson wrote:
> This makes access much easier.
> 
> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

Yes but this also makes it easier to forget
to handle endian-ness.
How about using pci_get/pci_set instead?

> ---
> 
>  hw/device-assignment.c |   55 ++++++++++++++++++++++--------------------------
>  hw/device-assignment.h |    9 +++++++-
>  2 files changed, 33 insertions(+), 31 deletions(-)
> 
> diff --git a/hw/device-assignment.c b/hw/device-assignment.c
> index 1fc7ffa..422ee00 100644
> --- a/hw/device-assignment.c
> +++ b/hw/device-assignment.c
> @@ -973,10 +973,9 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
>      AssignedDevice *adev = DO_UPCAST(AssignedDevice, dev, pci_dev);
>      uint16_t entries_nr = 0, entries_max_nr;
>      int pos = 0, i, r = 0;
> -    uint32_t msg_addr, msg_upper_addr, msg_data, msg_ctrl;
>      struct kvm_assigned_msix_nr msix_nr;
>      struct kvm_assigned_msix_entry msix_entry;
> -    void *va = adev->msix_table_page;
> +    MSIXTableEntry *entry = adev->msix_table;
>  
>      pos = pci_find_capability(pci_dev, PCI_CAP_ID_MSIX);
>  
> @@ -985,12 +984,11 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
>      entries_max_nr += 1;
>  
>      /* Get the usable entry number for allocating */
> -    for (i = 0; i < entries_max_nr; i++) {
> -        memcpy(&msg_ctrl, va + i * 16 + 12, 4);
> -        memcpy(&msg_data, va + i * 16 + 8, 4);
> +    for (i = 0; i < entries_max_nr; i++, entry++) {
>          /* Ignore unused entry even it's unmasked */
> -        if (msg_data == 0)
> +        if (entry->data == 0) {
>              continue;
> +        }
>          entries_nr ++;
>      }
>  
> @@ -1013,16 +1011,13 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
>  
>      msix_entry.assigned_dev_id = msix_nr.assigned_dev_id;
>      entries_nr = 0;
> -    for (i = 0; i < entries_max_nr; i++) {
> +    entry = adev->msix_table;
> +    for (i = 0; i < entries_max_nr; i++, entry++) {
>          if (entries_nr >= msix_nr.entry_nr)
>              break;
> -        memcpy(&msg_ctrl, va + i * 16 + 12, 4);
> -        memcpy(&msg_data, va + i * 16 + 8, 4);
> -        if (msg_data == 0)
> +        if (entry->data == 0) {
>              continue;
> -
> -        memcpy(&msg_addr, va + i * 16, 4);
> -        memcpy(&msg_upper_addr, va + i * 16 + 4, 4);
> +        }
>  
>          r = kvm_get_irq_route_gsi();
>          if (r < 0)
> @@ -1031,10 +1026,11 @@ static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
>          adev->entry[entries_nr].gsi = r;
>          adev->entry[entries_nr].type = KVM_IRQ_ROUTING_MSI;
>          adev->entry[entries_nr].flags = 0;
> -        adev->entry[entries_nr].u.msi.address_lo = msg_addr;
> -        adev->entry[entries_nr].u.msi.address_hi = msg_upper_addr;
> -        adev->entry[entries_nr].u.msi.data = msg_data;
> -        DEBUG("MSI-X data 0x%x, MSI-X addr_lo 0x%x\n!", msg_data, msg_addr);
> +        adev->entry[entries_nr].u.msi.address_lo = entry->addr_lo;
> +        adev->entry[entries_nr].u.msi.address_hi = entry->addr_hi;
> +        adev->entry[entries_nr].u.msi.data = entry->data;
> +        DEBUG("MSI-X data 0x%x, MSI-X addr_lo 0x%x\n!",
> +              entry->data, entry->addr_lo);
>  	kvm_add_routing_entry(&adev->entry[entries_nr]);
>  
>          msix_entry.gsi = adev->entry[entries_nr].gsi;
> @@ -1443,7 +1439,7 @@ static uint64_t msix_mmio_read(void *opaque, target_phys_addr_t addr,
>      AssignedDevice *adev = opaque;
>      uint64_t val;
>  
> -    memcpy(&val, (void *)((uint8_t *)adev->msix_table_page + addr), size);
> +    memcpy(&val, (void *)((uint8_t *)adev->msix_table + addr), size);
>  
>      return val;
>  }
> @@ -1456,7 +1452,7 @@ static void msix_mmio_write(void *opaque, target_phys_addr_t addr,
>      DEBUG("write to MSI-X entry table mmio offset 0x%lx, val 0x%lx\n",
>            addr, val);
>  
> -    memcpy((void *)((uint8_t *)adev->msix_table_page + addr), &val, size);
> +    memcpy((void *)((uint8_t *)adev->msix_table + addr), &val, size);
>  }
>  
>  static const MemoryRegionOps msix_mmio_ops = {
> @@ -1471,15 +1467,13 @@ static const MemoryRegionOps msix_mmio_ops = {
>  
>  static int assigned_dev_register_msix_mmio(AssignedDevice *dev)
>  {
> -    dev->msix_table_page = mmap(NULL, 0x1000,
> -                                PROT_READ|PROT_WRITE,
> -                                MAP_ANONYMOUS|MAP_PRIVATE, 0, 0);
> -    if (dev->msix_table_page == MAP_FAILED) {
> -        fprintf(stderr, "fail allocate msix_table_page! %s\n",
> -                strerror(errno));
> +    dev->msix_table = mmap(NULL, 0x1000, PROT_READ|PROT_WRITE,
> +                           MAP_ANONYMOUS|MAP_PRIVATE, 0, 0);
> +    if (dev->msix_table == MAP_FAILED) {
> +        fprintf(stderr, "fail allocate msix_table! %s\n", strerror(errno));
>          return -EFAULT;
>      }
> -    memset(dev->msix_table_page, 0, 0x1000);
> +    memset(dev->msix_table, 0, 0x1000);
>      memory_region_init_io(&dev->mmio, &msix_mmio_ops, dev,
>                            "assigned-dev-msix", MSIX_PAGE_SIZE);
>      return 0;
> @@ -1487,16 +1481,17 @@ static int assigned_dev_register_msix_mmio(AssignedDevice *dev)
>  
>  static void assigned_dev_unregister_msix_mmio(AssignedDevice *dev)
>  {
> -    if (!dev->msix_table_page)
> +    if (!dev->msix_table) {
>          return;
> +    }
>  
>      memory_region_destroy(&dev->mmio);
>  
> -    if (munmap(dev->msix_table_page, 0x1000) == -1) {
> -        fprintf(stderr, "error unmapping msix_table_page! %s\n",
> +    if (munmap(dev->msix_table, 0x1000) == -1) {
> +        fprintf(stderr, "error unmapping msix_table! %s\n",
>                  strerror(errno));
>      }
> -    dev->msix_table_page = NULL;
> +    dev->msix_table = NULL;
>  }
>  
>  static const VMStateDescription vmstate_assigned_device = {
> diff --git a/hw/device-assignment.h b/hw/device-assignment.h
> index 8ee2274..e229303 100644
> --- a/hw/device-assignment.h
> +++ b/hw/device-assignment.h
> @@ -82,6 +82,13 @@ typedef struct {
>  #define ASSIGNED_DEVICE_PREFER_MSI_MASK	(1 << ASSIGNED_DEVICE_PREFER_MSI_BIT)
>  #define ASSIGNED_DEVICE_USE_MEM64_MASK	(1 << ASSIGNED_DEVICE_USE_MEM64_BIT)
>  
> +typedef struct {
> +    uint32_t addr_lo;
> +    uint32_t addr_hi;
> +    uint32_t data;
> +    uint32_t ctrl;
> +} MSIXTableEntry;
> +
>  typedef struct AssignedDevice {
>      PCIDevice dev;
>      PCIHostDevice host;
> @@ -110,7 +117,7 @@ typedef struct AssignedDevice {
>      uint8_t emulate_config_write[PCI_CONFIG_SPACE_SIZE];
>      int irq_entries_nr;
>      struct kvm_irq_routing_entry *entry;
> -    void *msix_table_page;
> +    MSIXTableEntry *msix_table;
>      target_phys_addr_t msix_table_addr;
>      MemoryRegion mmio;
>      char *configfd_name;
> 
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