Message-ID: <d5834c32f2ea0a619e848a9aef644161cfeab6b9.camel@linux.intel.com>
Subject: BCM43602 system freeze with PCI passthrough
From:   James Prestwood <james.prestwood@linux.intel.com>
To:     linux-wireless@vger.kernel.org
Date:   Thu, 31 Jan 2019 09:13:04 -0800
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Sender: linux-wireless-owner@vger.kernel.org
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Hi,

I posted about a month ago about an Ath9k card that was causing my host
machine to freeze/lock up when doing PCI passthrough into a VM. This
was resolved by adding:

DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0034,
quirk_no_bus_reset);

to drivers/pci/quirks.c and rebuilding the host kernel.

Original thread: 
https://marc.info/?l=linux-wireless&m=154689580213002&w=2

I am now trying to get this BCM43602 card working under the same
conditions but again I am seeing the host machine freeze when starting
the VM. I did try adding a similar line for this card, which actually
prevented the machine from freezing, but I am seeing this when starting
the VM:

qemu-system-x86_64: vfio: Cannot reset device 0000:0a:00.0, no
available reset mechanism.

And once inside the VM the device is UNCLAIMED and not usable:

$ lshw -C network

*-network:2 UNCLAIMED
       description: Network controller
       product: BCM43602 802.11ac Wireless LAN SoC
       vendor: Broadcom Limited
       physical id: 6
       bus info: pci@0000:00:06.0
       version: 01
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress cap_list
       configuration: latency=0
       resources: memory:fe890000-fe897fff memory:fe400000-fe7fffff

This change was really a shot in the dark as I only have a vague
understanding of what its actually doing. I see other entries in
quirks.c for the Broadcom vendor ID but would rather not go poking
around here without any direction.

Thanks,
James