Re: [Qemu-devel] [PATCH] xen_pt: Present the size of 64 bit BARs correctly

[Anthony PERARD]

On Mon, May 14, 2018 at 10:57:46AM +0100, Ross Lagerwall wrote:
> The full size of the BAR is stored in the lower PCIIORegion.size. The
> upper PCIIORegion.size is 0.  Calculate the size of the upper half
> correctly from the lower half otherwise the size read by the guest will
> be incorrect.
> 
> Signed-off-by: Ross Lagerwall 

Acked-by: Anthony PERARD 

> ---
>  hw/xen/xen_pt_config_init.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c
> index a3ce33e..aee31c6 100644
> --- a/hw/xen/xen_pt_config_init.c
> +++ b/hw/xen/xen_pt_config_init.c
> @@ -504,6 +504,8 @@ static int xen_pt_bar_reg_write(XenPCIPassthroughState 
> *s, XenPTReg *cfg_entry,
>  bar_ro_mask = XEN_PT_BAR_IO_RO_MASK | (r_size - 1);
>  break;
>  case XEN_PT_BAR_FLAG_UPPER:
> +assert(index > 0);
> +r_size = d->io_regions[index - 1].size >> 32;
>  bar_emu_mask = XEN_PT_BAR_ALLF;
>  bar_ro_mask = r_size ? r_size - 1 : 0;
>  break;


-- 
Anthony PERARD

[Qemu-devel] [PATCH] xen_pt: Present the size of 64 bit BARs correctly

[Ross Lagerwall]

The full size of the BAR is stored in the lower PCIIORegion.size. The
upper PCIIORegion.size is 0.  Calculate the size of the upper half
correctly from the lower half otherwise the size read by the guest will
be incorrect.

Signed-off-by: Ross Lagerwall 
---
 hw/xen/xen_pt_config_init.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c
index a3ce33e..aee31c6 100644
--- a/hw/xen/xen_pt_config_init.c
+++ b/hw/xen/xen_pt_config_init.c
@@ -504,6 +504,8 @@ static int xen_pt_bar_reg_write(XenPCIPassthroughState *s, 
XenPTReg *cfg_entry,
 bar_ro_mask = XEN_PT_BAR_IO_RO_MASK | (r_size - 1);
 break;
 case XEN_PT_BAR_FLAG_UPPER:
+assert(index > 0);
+r_size = d->io_regions[index - 1].size >> 32;
 bar_emu_mask = XEN_PT_BAR_ALLF;
 bar_ro_mask = r_size ? r_size - 1 : 0;
 break;
-- 
2.9.5