x86/cpu: Detect FreeBSD Bhyve hypervisor

Detect the Bhyve hypervisor and enable 15-bit MSI support if available.

Detecting Bhyve used to be a purely cosmetic issue of the kernel printing
'Hypervisor detected: Bhyve' at boot time.

But FreeBSD 15.0 will support¹ the 15-bit MSI enlightenment to support
more than 255 vCPUs (http://david.woodhou.se/ExtDestId.pdf) which means
there's now actually some functional reason to do so.

  ¹ 313a68ea20

  [ bp: Massage, move tail comment ontop. ]

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Ahmed S. Darwish <darwi@linutronix.de>
Link: https://lore.kernel.org/03802f6f7f5b5cf8c5e8adfe123c397ca8e21093.camel@infradead.org
This commit is contained in:
David Woodhouse 2025-08-16 11:06:32 +01:00 • committed by Borislav Petkov (AMD)
commit fa1d117162
5 changed files with 81 additions and 0 deletions