Bug 233960
| Summary: | Add Volume Management Device (VMD) stub driver | ||||||
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| Product: | Base System | Reporter: | David Fugate <dave.fugate> | ||||
| Component: | kern | Assignee: | Doug Ambrisko <ambrisko> | ||||
| Status: | Closed FIXED | ||||||
| Severity: | Affects Many People | CC: | ambrisko, cem, emaste, imp | ||||
| Priority: | --- | Keywords: | patch | ||||
| Version: | CURRENT | ||||||
| Hardware: | amd64 | ||||||
| OS: | Any | ||||||
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BTW, this patch was tested in a system with VMD enabled: root@midnight-freebsd:/usr/src # dmesg | grep vmd vmd0: Unsupported Volume Management Device (VMD) controller enabled. Hi David, I have a hacked up VMD driver limping along. I'd like to co-ordinate work on this. It's not full feature but I can do I/Os to SSD's in VMD mode and with VROC enabled. GRAID should be taught how to read the EFI variable from VROC and get RAID 5 write support etc. Checked in driver r353380. |
Created attachment 200058 [details] VMD Driver Patch At a high-level, "Intel® VMD enables hot swap replacement of NVMe* SSDs from the PCIe* bus without shutting down the system while standardized LED management helps provide quick identification of SSD status." This is realized through the addition of a VMD controller on the PCIe bus of high-end systems (e.g., Xeon) which "hides" 1 to N PCIe ports underneath it. As you might imagine, this implies the need for a VMD driver which either delegates incoming NVMe requests to the appropriate drivers (e.g., NVMe, hot-plug, etc.) or a VMD driver which incorporates the NVMe, hot-plug, etc. functionality all on its own. FreeBSD is missing either such type of VMD driver today, and consequently end-users like Netflix are getting the mistaken impression FreeBSD doesn't have a driver for their invisible NVMe devices or the NVMe devices are broken... Attached to this bug report is a patch adding a VMD stub driver informing the end-user they should disable the VMD feature in their BIOS. This stub driver is a stop-gap measure to eventually be replaced with a full-fledged VMD driver (I work for the NVMe/VMD OSS driver team at Intel).