Changes since v2: - Add Michael's R-b tags to PATCHes1-3 and Bjorn's A-b tag to PATCH1. - Commit messages tweaks [Michael]. Passed through PCI device sometimes misbehave on Gen1 VMs when Hyper-V DRM driver is also loaded. Looking at IOMEM assignment, we can see e.g. $ cat /proc/iomem ... f8000000-fffbffff : PCI Bus 0000:00 f8000000-fbffffff : 0000:00:08.0 f8000000-f8001fff : bb8c4f33-2ba2-4808-9f7f-02f3b4da22fe ... fe0000000-fffffffff : PCI Bus 0000:00 fe0000000-fe07fffff : bb8c4f33-2ba2-4808-9f7f-02f3b4da22fe fe0000000-fe07fffff : 2ba2:00:02.0 fe0000000-fe07fffff : mlx4_core the interesting part is the 'f8000000' region as it is actually the VM's framebuffer: $ lspci -v ... 0000:00:08.0 VGA compatible controller: Microsoft Corporation Hyper-V virtual VGA (prog-if 00 [VGA controller]) Flags: bus master, fast devsel, latency 0, IRQ 11 Memory at f8000000 (32-bit, non-prefetchable) [size=64M] ... Recently merged commit a0ab5abced55 ("drm/hyperv : Removing the restruction of VRAM allocation with PCI bar size") improved the situation as resources, reserved through vmbus_allocate_mmio() can't be allocated twice: ... f8000000-fffbffff : PCI Bus 0000:00 f8000000-fbffffff : 0000:00:08.0 f8000000-f8001fff : bb8c4f33-2ba2-4808-9f7f-02f3b4da22fe f8100000-f88fffff : 5620e0c7-8062-4dce-aeb7-520c7ef76171 ... Always reserve FB region on Gen1 VMs (PATCH2) and make sure we never allocate anything besides framebuffer from there (PATCH3). Vitaly Kuznetsov (3): PCI: Move PCI_VENDOR_ID_MICROSOFT/PCI_DEVICE_ID_HYPERV_VIDEO definitions to pci_ids.h Drivers: hv: Always reserve framebuffer region for Gen1 VMs Drivers: hv: Never allocate anything besides framebuffer from framebuffer memory region drivers/gpu/drm/hyperv/hyperv_drm_drv.c | 3 - drivers/hv/vmbus_drv.c | 56 ++++++++++++++----- .../net/ethernet/microsoft/mana/gdma_main.c | 4 -- drivers/video/fbdev/hyperv_fb.c | 4 -- include/linux/pci_ids.h | 3 + 5 files changed, 44 insertions(+), 26 deletions(-) -- 2.37.1