From f4a257a355b7913bb956706a774168cdb6631dac Mon Sep 17 00:00:00 2001 From: "Jiahui Cen via groups.io" Date: Tue, 19 Jan 2021 09:13:00 +0800 Subject: OvmfPkg/PciHostBridgeUtilityLib: Extend GetRootBridges() with BusMin/BusMax Extend parameter list of PciHostBridgeUtilityGetRootBridges() with BusMin/ BusMax, so that the utility function could be compatible with ArmVirtPkg who uses mutable bus range [BusMin, BusMax] insteand of [0, PCI_MAX_BUS]. BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3059 Cc: Jordan Justen Cc: Laszlo Ersek Cc: Ard Biesheuvel Signed-off-by: Jiahui Cen Message-Id: <20210119011302.10908-10-cenjiahui@huawei.com> [lersek@redhat.com: fix logging of UINTN values BusMin, BusMax] [lersek@redhat.com: keep zeroing of (*Count) centralized] [lersek@redhat.com: fix typos in ExtraRootBridges comment] Reviewed-by: Laszlo Ersek --- .../PciHostBridgeUtilityLib.c | 29 ++++++++++++++++++---- 1 file changed, 24 insertions(+), 5 deletions(-) (limited to 'OvmfPkg/Library/PciHostBridgeUtilityLib') diff --git a/OvmfPkg/Library/PciHostBridgeUtilityLib/PciHostBridgeUtilityLib.c b/OvmfPkg/Library/PciHostBridgeUtilityLib/PciHostBridgeUtilityLib.c index b59da78700..d2296f3308 100644 --- a/OvmfPkg/Library/PciHostBridgeUtilityLib/PciHostBridgeUtilityLib.c +++ b/OvmfPkg/Library/PciHostBridgeUtilityLib/PciHostBridgeUtilityLib.c @@ -200,6 +200,10 @@ PciHostBridgeUtilityUninitRootBridge ( @param[in] NoExtendedConfigSpace No Extended Config Space. + @param[in] BusMin Minimum Bus number, inclusive. + + @param[in] BusMax Maximum Bus number, inclusive. + @param[in] Io IO aperture. @param[in] Mem MMIO aperture. @@ -220,6 +224,8 @@ PciHostBridgeUtilityGetRootBridges ( IN UINT64 AllocationAttributes, IN BOOLEAN DmaAbove4G, IN BOOLEAN NoExtendedConfigSpace, + IN UINTN BusMin, + IN UINTN BusMax, IN PCI_ROOT_BRIDGE_APERTURE *Io, IN PCI_ROOT_BRIDGE_APERTURE *Mem, IN PCI_ROOT_BRIDGE_APERTURE *MemAbove4G, @@ -238,6 +244,12 @@ PciHostBridgeUtilityGetRootBridges ( *Count = 0; + if (BusMin > BusMax || BusMax > PCI_MAX_BUS) { + DEBUG ((DEBUG_ERROR, "%a: invalid bus range with BusMin %Lu and BusMax " + "%Lu\n", __FUNCTION__, (UINT64)BusMin, (UINT64)BusMax)); + return NULL; + } + // // QEMU provides the number of extra root buses, shortening the exhaustive // search below. If there is no hint, the feature is missing. @@ -249,7 +261,14 @@ PciHostBridgeUtilityGetRootBridges ( QemuFwCfgSelectItem (FwCfgItem); QemuFwCfgReadBytes (FwCfgSize, &ExtraRootBridges); - if (ExtraRootBridges > PCI_MAX_BUS) { + // + // Validate the number of extra root bridges. As BusMax is inclusive, the + // max bus count is (BusMax - BusMin + 1). From that, the "main" root bus + // is always a given, so the max count for the "extra" root bridges is one + // less, i.e. (BusMax - BusMin). If the QEMU hint exceeds that, we have + // invalid behavior. + // + if (ExtraRootBridges > BusMax - BusMin) { DEBUG ((DEBUG_ERROR, "%a: invalid count of extra root buses (%Lu) " "reported by QEMU\n", __FUNCTION__, ExtraRootBridges)); return NULL; @@ -271,15 +290,15 @@ PciHostBridgeUtilityGetRootBridges ( // // The "main" root bus is always there. // - LastRootBridgeNumber = 0; + LastRootBridgeNumber = BusMin; // // Scan all other root buses. If function 0 of any device on a bus returns a // VendorId register value different from all-bits-one, then that bus is // alive. // - for (RootBridgeNumber = 1; - RootBridgeNumber <= PCI_MAX_BUS && Initialized < ExtraRootBridges; + for (RootBridgeNumber = BusMin + 1; + RootBridgeNumber <= BusMax && Initialized < ExtraRootBridges; ++RootBridgeNumber) { UINTN Device; @@ -329,7 +348,7 @@ PciHostBridgeUtilityGetRootBridges ( DmaAbove4G, NoExtendedConfigSpace, (UINT8) LastRootBridgeNumber, - PCI_MAX_BUS, + (UINT8) BusMax, Io, Mem, MemAbove4G, -- cgit v1.2.3