From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: mx.groups.io; dkim=missing; spf=pass (domain: citrix.com, ip: 162.221.156.55, mailfrom: prvs=9977b2ae1=anthony.perard@citrix.com) Received: from SMTP03.CITRIX.COM (SMTP03.CITRIX.COM [162.221.156.55]) by groups.io with SMTP; Thu, 11 Apr 2019 06:07:58 -0700 X-IronPort-AV: E=Sophos;i="5.60,337,1549929600"; d="scan'208";a="83328320" Date: Thu, 11 Apr 2019 14:07:32 +0100 From: "Anthony PERARD" To: Igor Druzhinin CC: , , , , , , Subject: Re: [PATCH v2 1/3] OvmfPkg/XenSupport: remove usage of prefetchable PCI host bridge aperture Message-ID: <20190411130732.GK1435@perard.uk.xensource.com> References: <1554779560-26204-1-git-send-email-igor.druzhinin@citrix.com> <1554779560-26204-2-git-send-email-igor.druzhinin@citrix.com> MIME-Version: 1.0 In-Reply-To: <1554779560-26204-2-git-send-email-igor.druzhinin@citrix.com> User-Agent: Mutt/1.11.4 (2019-03-13) Return-Path: anthony.perard@citrix.com Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline 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 > --- > Changes in v2: > * remove usage of prefetchable aperture entirely > * explained rationale for the change in the description > --- Reviewed-by: Anthony PERARD Thanks, -- Anthony PERARD