From: Michael S. Tsirkin <m...@redhat.com> KVM does not virtualize low address bits for memory accesses, so we must require that PCI BAR size is a multiple of 4K for passthrough to work (this also guarantees that address is 4K aligned).
Users of recent linux kernels can force resource size up to 4K using: commit 32a9a682bef2f6fce7026bd94d1ce20028b0e52d Author: Yuji Shimada <shimada-...@necst.nec.co.jp> Date: Mon Mar 16 17:13:39 2009 +0900 PCI: allow assignment of memory resources with a specified alignment Signed-off-by: Michael S. Tsirkin <m...@redhat.com> Signed-off-by: Marcelo Tosatti <mtosa...@redhat.com> diff --git a/hw/device-assignment.c b/hw/device-assignment.c index 6f792db..516cf14 100644 --- a/hw/device-assignment.c +++ b/hw/device-assignment.c @@ -384,6 +384,14 @@ static int assigned_dev_register_regions(PCIRegion *io_regions, int t = cur_region->type & IORESOURCE_PREFETCH ? PCI_ADDRESS_SPACE_MEM_PREFETCH : PCI_ADDRESS_SPACE_MEM; + if (cur_region->size & 0xFFF) { + fprintf(stderr, "Unable to assign device: PCI region %d " + "at address 0x%llx has size 0x%x, " + " which is not a multiple of 4K\n", + i, (unsigned long long)cur_region->base_addr, + cur_region->size); + return -1; + } /* map physical memory */ pci_dev->v_addrs[i].e_physbase = cur_region->base_addr; -- To unsubscribe from this list: send the line "unsubscribe kvm-commits" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html