[Qemu-devel] issues about igd-passthrough using vfio-pci

[杨福来]

Hello，
    I have realized the IGD passthrough with Intel(R) Core(TM) i7-4770 CPU，but 
when I change the platform with the Intel Core i3-6100U，it doesn’t have any VGA 
output and windows7 refuses to boot with black screen. This problem has been 
bothering me for a long time,someone can help me?


dmesg:
Sep 12 14:04:39 ruijie-pc kernel: [254939.809585] DMAR: DRHD: handling fault 
status reg 2
Sep 12 14:04:39 ruijie-pc kernel: [254939.809592] DMAR: DMAR:[DMA Write] 
Request device [00:02.0] fault addr 0
Sep 12 14:04:39 ruijie-pc kernel: [254939.809592] DMAR:[fault reason 02] 
Present bit in context entry is clear
Sep 12 14:10:11 ruijie-pc kernel: [255272.523271] vfio-pci 0000:00:02.0: 
enabling device (0400 -> 0403)
Sep 12 14:10:11 ruijie-pc kernel: [255272.627404] vfio_ecap_init: 0000:00:02.0 
hiding ecap address@hidden
Sep 12 14:10:19 ruijie-pc kernel: [255280.602875] kvm: zapping shadow pages for 
mmio generation wraparound


My environment :
Intel Core i3-6100U @ 2.30GHz
Intel Corporation Sky Lake Integrated Graphics 
Ubuntu 16.04 LTS
Host kernel 4.6.6 x86_64 GNU/Linux
qemu 2.7.0