Other Can bhyve pass disk vendor, model and serial values to guests?

robroy · Jun 16, 2020

FreeBSD Friends,

This is on 12.1-RELEASE-p6.

Can bhyve pass disks to guests in a way that preserves the disk's actual vendor, model and serial number values (as viewed from inside of the guest)?

When I pass a disk with ahci-hd emulation, it looks like this in the guest:

Code:

linux_in_bhyve# lsblk --output vendor,model,serial /dev/sda
VENDOR   MODEL            SERIAL
ATA      BHYVE SATA DISK  BHYVE-FC87-ABA5-711B

Or, when using virtio-blk emulation:

Code:

linux_in_bhyve# lsblk -o vendor,model,serial /dev/vdb
VENDOR MODEL SERIAL
0x1af4

Meanwhile, a similar disk configured on ESXi 5.5 U3b as a "pass-through RDM" looks like this in the guest:

Code:

linux_in_esxi# lsblk -o vendor,model,serial /dev/sdb
VENDOR   MODEL            SERIAL
HITACHI  OPEN-V-CM        60060e801602a100000102a100000bba

Thank you!

Phishfry · Jun 16, 2020

As far as I know FreeBSD bhyve passthru is based on PCI address.
For instance a NVMe is a PCIe device and you can pass it thru. and it is recognized in the VM.
So for a SAS/SATA disk drive I would try and pass thru a HBA with the disk attached.
I think that is the best approach.
Perhaps you could pass through a motherboard interface depending on the SATA PCIe bus address arrangment.

robroy · Jun 16, 2020

Phishfry, thank you. I'd be tempted to try that, but the HBA's actually used by other things also (like ZFS on the host); I think bhyve would want the HBA all to itself if HBA pass-through were set.

Phishfry · Jun 16, 2020

Yes that would be the drawback. You would have to dedicate the whole device to the cause.

Here is the output for motherboard SATA on a SuperMicro X9 board.

Code:

ahci0@pci0:0:31:2:    class=0x010601 card=0x066915d9 chip=0x1d028086 rev=0x06 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'C600/X79 series chipset 6-Port SATA AHCI Controller'
    class      = mass storage
    subclass   = SATA

So you could pass thru this device to the VM.
I use NVMe to boot/host from so my SATA controller is unused and would be a prime candidate.

Phishfry · Jun 18, 2020

I tried passing thru the onboard SATA controller above with bad results.
From /var/log/messages:

Code:

 bhyve: passthru device 0/31/2 BAR 5: base 0xc7f00000 or size 0x800 not page aligned

That seems to be the same issue aragats was referencing here:

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Seems motherboard peripheries have some issues with BAR page length.

I will try another LSI controller in this test virt box to see how a passed thru disk works.

Phishfry · Jun 18, 2020

With a LSI SAS2308 controller using pass-thru I was able to see the raw devices.

aragats · Jun 18, 2020

Phishfry said:
That seems to be the same issue @aragats was referencing here

I thought the "page not aligned" problem was fixed: before I've seen it with many devices, but recently I set up pass-thru of USB and NVMe controllers in several boxes without any problem, including the devices I experienced that issue with before.