Re: [Xen-devel] [PATCH v3] qemu/xen: Add 64 bits big bar support on qemu

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

On Thu, 27 Sep 2012, Xudong Hao wrote:
> v3 changes from v2:
> - Refine code following by the qemu code style
> - As suggestion by Stefano, cheanup code, add some code comment
> 
> v2 changes from v1:
> - Rebase to qemu upstream from qemu-xen
> 
> Currently it is assumed PCI device BAR access < 4G memory. If there is such a
> device whose BAR size is larger than 4G, it must access > 4G memory address.
> This patch enable the 64bits big BAR support on qemu.
> 
> Signed-off-by: Xudong Hao <xudong.hao@xxxxxxxxx>
> Signed-off-by: Xiantao Zhang <xiantao.zhang@xxxxxxxxx>

Acked-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>


>  hw/xen_pt.c             |    7 +++++--
>  hw/xen_pt_config_init.c |   39 ++++++++++++++++++++++++++-------------
>  2 files changed, 31 insertions(+), 15 deletions(-)
> 
> diff --git a/hw/xen_pt.c b/hw/xen_pt.c
> index 307119a..838bcea 100644
> --- a/hw/xen_pt.c
> +++ b/hw/xen_pt.c
> @@ -410,14 +410,17 @@ static int 
> xen_pt_register_regions(XenPCIPassthroughState *s)
>              if (r->type & XEN_HOST_PCI_REGION_TYPE_PREFETCH) {
>                  type |= PCI_BASE_ADDRESS_MEM_PREFETCH;
>              }
> +            if (r->type & XEN_HOST_PCI_REGION_TYPE_MEM_64) {
> +                type |= PCI_BASE_ADDRESS_MEM_TYPE_64;
> +            }
>          }
>  
>          memory_region_init_io(&s->bar[i], &ops, &s->dev,
>                                "xen-pci-pt-bar", r->size);
>          pci_register_bar(&s->dev, i, type, &s->bar[i]);
>  
> -        XEN_PT_LOG(&s->dev, "IO region %i registered (size=0x%08"PRIx64
> -                   " base_addr=0x%08"PRIx64" type: %#x)\n",
> +        XEN_PT_LOG(&s->dev, "IO region %i registered (size=0x%lx"PRIx64
> +                   " base_addr=0x%lx"PRIx64" type: %#x)\n",
>                     i, r->size, r->base_addr, type);
>      }
>  
> diff --git a/hw/xen_pt_config_init.c b/hw/xen_pt_config_init.c
> index e524a40..0a5f82c 100644
> --- a/hw/xen_pt_config_init.c
> +++ b/hw/xen_pt_config_init.c
> @@ -342,6 +342,23 @@ static int xen_pt_cmd_reg_write(XenPCIPassthroughState 
> *s, XenPTReg *cfg_entry,
>  #define XEN_PT_BAR_IO_RO_MASK     0x00000003  /* BAR ReadOnly mask(I/O) */
>  #define XEN_PT_BAR_IO_EMU_MASK    0xFFFFFFFC  /* BAR emul mask(I/O) */
>  
> +static bool is_64bit_bar(PCIIORegion *r)
> +{
> +    return !!(r->type & PCI_BASE_ADDRESS_MEM_TYPE_64);
> +}
> +
> +static uint64_t xen_pt_get_bar_size(PCIIORegion *r)
> +{
> +    if (is_64bit_bar(r)) {
> +        uint64_t size64;
> +        size64 = (r + 1)->size;
> +        size64 <<= 32;
> +        size64 += r->size;
> +        return size64;
> +    }
> +    return r->size;
> +}
> +
>  static XenPTBarFlag xen_pt_bar_reg_parse(XenPCIPassthroughState *s,
>                                           XenPTRegInfo *reg)
>  {
> @@ -366,7 +383,7 @@ static XenPTBarFlag 
> xen_pt_bar_reg_parse(XenPCIPassthroughState *s,
>  
>      /* check unused BAR */
>      r = &d->io_regions[index];
> -    if (r->size == 0) {
> +    if (!xen_pt_get_bar_size(r)) {
>          return XEN_PT_BAR_FLAG_UNUSED;
>      }
>  
> @@ -481,7 +498,12 @@ static int xen_pt_bar_reg_write(XenPCIPassthroughState 
> *s, XenPTReg *cfg_entry,
>      switch (s->bases[index].bar_flag) {
>      case XEN_PT_BAR_FLAG_MEM:
>          bar_emu_mask = XEN_PT_BAR_MEM_EMU_MASK;
> -        bar_ro_mask = XEN_PT_BAR_MEM_RO_MASK | (r_size - 1);
> +        if (!r_size) {
> +            /* low 32 bits mask for 64 bit bars */
> +            bar_ro_mask = XEN_PT_BAR_ALLF;
> +        } else {
> +            bar_ro_mask = XEN_PT_BAR_MEM_RO_MASK | (r_size - 1);
> +        }
>          break;
>      case XEN_PT_BAR_FLAG_IO:
>          bar_emu_mask = XEN_PT_BAR_IO_EMU_MASK;
> @@ -489,7 +511,7 @@ static int xen_pt_bar_reg_write(XenPCIPassthroughState 
> *s, XenPTReg *cfg_entry,
>          break;
>      case XEN_PT_BAR_FLAG_UPPER:
>          bar_emu_mask = XEN_PT_BAR_ALLF;
> -        bar_ro_mask = 0;    /* all upper 32bit are R/W */
> +        bar_ro_mask = r_size ? r_size - 1 : 0;
>          break;
>      default:
>          break;
> @@ -501,22 +523,13 @@ static int xen_pt_bar_reg_write(XenPCIPassthroughState 
> *s, XenPTReg *cfg_entry,
>  
>      /* check whether we need to update the virtual region address or not */
>      switch (s->bases[index].bar_flag) {
> +    case XEN_PT_BAR_FLAG_UPPER:
>      case XEN_PT_BAR_FLAG_MEM:
>          /* nothing to do */
>          break;
>      case XEN_PT_BAR_FLAG_IO:
>          /* nothing to do */
>          break;
> -    case XEN_PT_BAR_FLAG_UPPER:
> -        if (cfg_entry->data) {
> -            if (cfg_entry->data != (XEN_PT_BAR_ALLF & ~bar_ro_mask)) {
> -                XEN_PT_WARN(d, "Guest attempt to set high MMIO Base Address. 
> "
> -                            "Ignore mapping. "
> -                            "(offset: 0x%02x, high address: 0x%08x)\n",
> -                            reg->offset, cfg_entry->data);
> -            }
> -        }
> -        break;
>      default:
>          break;
>      }
> -- 
> 1.5.5
> 

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