From: Jon Derrick jonathan.derrick@intel.com
[ Upstream commit 3e5095eebe015d5a4d566aa5e03c8621add5f0a7 ]
Versions of VMD with the Host Physical Address shadow register use this register to calculate the bus address offset needed to do guest passthrough of the domain. This register shadows the Host Physical Address registers including the resource type bits. After calculating the offset, the extra resource type bits lead to the VMD resources being over-provisioned at the front and under-provisioned at the back.
Example: pci 10000:80:02.0: reg 0x10: [mem 0xf801fffc-0xf803fffb 64bit]
Expected: pci 10000:80:02.0: reg 0x10: [mem 0xf8020000-0xf803ffff 64bit]
If other devices are mapped in the over-provisioned front, it could lead to resource conflict issues with VMD or those devices.
Link: https://lore.kernel.org/r/20200528030240.16024-3-jonathan.derrick@intel.com Fixes: a1a30170138c9 ("PCI: vmd: Fix shadow offsets to reflect spec changes") Signed-off-by: Jon Derrick jonathan.derrick@intel.com Signed-off-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/controller/vmd.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index dac91d60701de..e386d4eac4070 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -445,9 +445,11 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features) if (!membar2) return -ENOMEM; offset[0] = vmd->dev->resource[VMD_MEMBAR1].start - - readq(membar2 + MB2_SHADOW_OFFSET); + (readq(membar2 + MB2_SHADOW_OFFSET) & + PCI_BASE_ADDRESS_MEM_MASK); offset[1] = vmd->dev->resource[VMD_MEMBAR2].start - - readq(membar2 + MB2_SHADOW_OFFSET + 8); + (readq(membar2 + MB2_SHADOW_OFFSET + 8) & + PCI_BASE_ADDRESS_MEM_MASK); pci_iounmap(vmd->dev, membar2); } }