From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: mx.groups.io; dkim=missing; spf=pass (domain: redhat.com, ip: 209.132.183.28, mailfrom: lersek@redhat.com) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by groups.io with SMTP; Wed, 29 May 2019 08:12:41 -0700 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D4EAEC05FF80; Wed, 29 May 2019 15:12:40 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com (ovpn-120-170.rdu2.redhat.com [10.10.120.170]) by smtp.corp.redhat.com (Postfix) with ESMTP id 172201715C; Wed, 29 May 2019 15:12:37 +0000 (UTC) From: "Laszlo Ersek" To: edk2-devel-groups-io Cc: Ard Biesheuvel , Gerd Hoffmann , Jordan Justen Subject: [PATCH for-edk2-stable201905 5/6] OvmfPkg: raise the PCIEXBAR base to 2816 MB on Q35 Date: Wed, 29 May 2019 17:12:08 +0200 Message-Id: <20190529151209.17503-6-lersek@redhat.com> In-Reply-To: <20190529151209.17503-1-lersek@redhat.com> References: <20190529151209.17503-1-lersek@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Wed, 29 May 2019 15:12:40 +0000 (UTC) Content-Transfer-Encoding: quoted-printable (This is a replacement for commit 75136b29541b, "OvmfPkg/PlatformPei: reorder the 32-bit PCI window vs. the PCIEXBAR on q35", 2019-05-16). Commit 7b8fe63561b4 ("OvmfPkg: PlatformPei: enable PCIEXBAR (aka MMCONFIG / ECAM) on Q35", 2016-03-10) claimed that, On Q35 machine types that QEMU intends to support in the long term, QEM= U never lets the RAM below 4 GB exceed 2 GB. Alas, this statement came from a misunderstanding that occurred while we worked out the interface contract. In fact QEMU does allow the 32-bit RAM extend up to 0xB000_0000 (exclusive), in case the RAM size falls in the range (0x8000_0000, 0xB000_0000) (i.e., the RAM size is greater than 2048MB and smaller than 2816MB). In turn, such a RAM size (justifiedly) triggers ASSERT (TopOfLowRam <=3D PciExBarBase); in MemMapInitialization(), because we placed the 256MB PCIEXBAR at 0x8000_0000 (2GB) exactly, relying on the interface contract. (And, the 32-bit PCI window would follow the PCIEXBAR, covering the [0x9000_0000, 0xFC00_0000) range.) In order to fix this, place the PCIEXBAR at 2816MB (0xB000_0000), and start the 32-bit PCI window at 3 GB (0xC000_0000). This shrinks the 32-bi= t PCI window to 0xFC00_0000 - 0xC000_0000 =3D 0x3C00_0000 =3D 960 MB. Cc: Ard Biesheuvel Cc: Gerd Hoffmann Cc: Jordan Justen Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3D1859 Signed-off-by: Laszlo Ersek --- OvmfPkg/OvmfPkgIa32.dsc | 4 ++-- OvmfPkg/OvmfPkgIa32X64.dsc | 4 ++-- OvmfPkg/OvmfPkgX64.dsc | 4 ++-- 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc index 578fc6c98ec8..e74a9d5a5149 100644 --- a/OvmfPkg/OvmfPkgIa32.dsc +++ b/OvmfPkg/OvmfPkgIa32.dsc @@ -492,8 +492,8 @@ [PcdsFixedAtBuild] # the PCIEXBAR register. # # On Q35 machine types that QEMU intends to support in the long term, = QEMU - # never lets the RAM below 4 GB exceed 2 GB. - gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0x80000000 + # never lets the RAM below 4 GB exceed 2816 MB. + gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xB0000000 =20 !ifdef $(SOURCE_DEBUG_ENABLE) gEfiSourceLevelDebugPkgTokenSpaceGuid.PcdDebugLoadImageMethod|0x2 diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc index eade8f62d3de..67ac015991fd 100644 --- a/OvmfPkg/OvmfPkgIa32X64.dsc +++ b/OvmfPkg/OvmfPkgIa32X64.dsc @@ -497,8 +497,8 @@ [PcdsFixedAtBuild] # the PCIEXBAR register. # # On Q35 machine types that QEMU intends to support in the long term, = QEMU - # never lets the RAM below 4 GB exceed 2 GB. - gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0x80000000 + # never lets the RAM below 4 GB exceed 2816 MB. + gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xB0000000 =20 !ifdef $(SOURCE_DEBUG_ENABLE) gEfiSourceLevelDebugPkgTokenSpaceGuid.PcdDebugLoadImageMethod|0x2 diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc index 733a4c9d8a43..68073ef55b4d 100644 --- a/OvmfPkg/OvmfPkgX64.dsc +++ b/OvmfPkg/OvmfPkgX64.dsc @@ -497,8 +497,8 @@ [PcdsFixedAtBuild] # the PCIEXBAR register. # # On Q35 machine types that QEMU intends to support in the long term, = QEMU - # never lets the RAM below 4 GB exceed 2 GB. - gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0x80000000 + # never lets the RAM below 4 GB exceed 2816 MB. + gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress|0xB0000000 =20 !ifdef $(SOURCE_DEBUG_ENABLE) gEfiSourceLevelDebugPkgTokenSpaceGuid.PcdDebugLoadImageMethod|0x2 --=20 2.19.1.3.g30247aa5d201