Messages in this thread | | | From | Haiyang Zhang <> | Subject | RE: [PATCH v2] PCI: hv: Detect and fix Hyper-V PCI domain number collision | Date | Mon, 12 Aug 2019 13:50:34 +0000 |
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> -----Original Message----- > From: LKML haiyangz <lkmlhyz@microsoft.com> On Behalf Of Haiyang > Zhang > Sent: Tuesday, August 6, 2019 7:52 PM > To: sashal@kernel.org; bhelgaas@google.com; lorenzo.pieralisi@arm.com; > linux-hyperv@vger.kernel.org; linux-pci@vger.kernel.org > Cc: Haiyang Zhang <haiyangz@microsoft.com>; KY Srinivasan > <kys@microsoft.com>; Stephen Hemminger <sthemmin@microsoft.com>; > olaf@aepfle.de; vkuznets <vkuznets@redhat.com>; linux- > kernel@vger.kernel.org > Subject: [PATCH v2] PCI: hv: Detect and fix Hyper-V PCI domain number > collision > > Currently in Azure cloud, for passthrough devices including GPU, the > host sets the device instance ID's bytes 8 - 15 to a value derived from > the host HWID, which is the same on all devices in a VM. So, the device > instance ID's bytes 8 and 9 provided by the host are no longer unique. > > This can cause device passthrough to VMs to fail because the bytes 8 and > 9 is used as PCI domain number. So, as recommended by Azure host team, > we now use the bytes 4 and 5 which usually contain unique numbers as PCI > domain. The chance of collision is greatly reduced. In the rare cases of > collision, we will detect and find another number that is not in use. > > Thanks to Michael Kelley <mikelley@microsoft.com> for proposing this idea. > > Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> > Acked-by: Sasha Levin <sashal@kernel.org> > --- > drivers/pci/controller/pci-hyperv.c | 92
Hi Lorenzo,
This patch has been updated based on Bjorn's comments. Do you have any further comments? Could you take it from your tree?
Thanks, - Haiyang
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