This is a note to let you know that I've just added the patch titled drm/radeon: fix asic initialization for virtualized environments to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-radeon-fix-asic-initialization-for-virtualized-environments.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 05082b8bbd1a0ffc74235449c4b8930a8c240f85 Mon Sep 17 00:00:00 2001 From: Alex Deucher <alexander.deucher@xxxxxxx> Date: Mon, 13 Jun 2016 15:37:34 -0400 Subject: drm/radeon: fix asic initialization for virtualized environments From: Alex Deucher <alexander.deucher@xxxxxxx> commit 05082b8bbd1a0ffc74235449c4b8930a8c240f85 upstream. When executing in a PCI passthrough based virtuzliation environment, the hypervisor will usually attempt to send a PCIe bus reset signal to the ASIC when the VM reboots. In this scenario, the card is not correctly initialized, but we still consider it to be posted. Therefore, in a passthrough based environemnt we should always post the card to guarantee it is in a good state for driver initialization. Ported from amdgpu commit: amdgpu: fix asic initialization for virtualized environments Cc: Andres Rodriguez <andres.rodriguez@xxxxxxx> Cc: Alex Williamson <alex.williamson@xxxxxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/radeon/radeon_device.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) --- a/drivers/gpu/drm/radeon/radeon_device.c +++ b/drivers/gpu/drm/radeon/radeon_device.c @@ -548,6 +548,23 @@ void radeon_gtt_location(struct radeon_d /* * GPU helpers function. */ + +/** + * radeon_device_is_virtual - check if we are running is a virtual environment + * + * Check if the asic has been passed through to a VM (all asics). + * Used at driver startup. + * Returns true if virtual or false if not. + */ +static bool radeon_device_is_virtual(void) +{ +#ifdef CONFIG_X86 + return boot_cpu_has(X86_FEATURE_HYPERVISOR); +#else + return false; +#endif +} + /** * radeon_card_posted - check if the hw has already been initialized * @@ -561,6 +578,10 @@ bool radeon_card_posted(struct radeon_de { uint32_t reg; + /* for pass through, always force asic_init */ + if (radeon_device_is_virtual()) + return false; + /* required for EFI mode on macbook2,1 which uses an r5xx asic */ if (efi_enabled(EFI_BOOT) && (rdev->pdev->subsystem_vendor == PCI_VENDOR_ID_APPLE) && Patches currently in stable-queue which might be from alexander.deucher@xxxxxxx are queue-3.14/drm-radeon-fix-asic-initialization-for-virtualized-environments.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html