Re: [PATCH v2 0/3] Xen PCI passthrough fixes

Re: [PATCH v2 0/3] Xen PCI passthrough fixes

[Laszlo Ersek]

Hi Igor,

On 04/09/19 05:12, Igor Druzhinin wrote:
> Igor Druzhinin (3):
>   OvmfPkg/XenSupport: remove usage of prefetchable PCI host bridge
>     aperture
>   OvmfPkg/XenSupport: use a correct PCI host bridge aperture for BAR64
>   OvmfPkg/XenSupport: turn off address decoding before BAR sizing
> 
>  OvmfPkg/Library/PciHostBridgeLib/XenSupport.c | 44 ++++++++++++++++++++++-----
>  1 file changed, 37 insertions(+), 7 deletions(-)
> 

some general administrativa:

(1) the edk2-devel mailing list has moved. Please subscribe at
<https://edk2.groups.io/g/devel>, and resend the series. Apologies about
the inconvenience.

(2) By the time we push this series,
<https://bugzilla.tianocore.org/show_bug.cgi?id=1373> will have been
fixed most likely. That means that you will no longer need to add the
"Contributed-under" line to your signoffs, on all patches.

Thanks!
Laszlo

Re: [PATCH v2 1/3] OvmfPkg/XenSupport: remove usage of prefetchable PCI host bridge aperture

[Anthony PERARD]

On Tue, Apr 09, 2019 at 04:12:38AM +0100, Igor Druzhinin wrote:
> This aperture doesn't exist in QEMU-XEN and hvmloader places BARs
> in arbitrary order disregarding prefetchable bit. This makes
> prefetchable and non-prefetchable BARs to follow each other that's
> quite likely with PCI passthrough devices. In that case, the existing
> code, that tries to work out aperture boundaries by reading hvmloader
> BAR placement, will report a bogus prefetchable aperture which overlaps
> with the regular one. It will eventually trigger an assertion in
> DXE PCI initialization code.
> 
> Do the same thing as OVMF on QEMU-KVM and pass a non-existing aperture
> there. It's not necessary to pass additional allocation flags as we set
> ResourceAssigned flag on the root bridge which means they will be ignored.
> 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
> ---
> Changes in v2:
> * remove usage of prefetchable aperture entirely
> * explained rationale for the change in the description
> ---

Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>

Thanks,

-- 
Anthony PERARD