Re: HVM virtualization?

[Chavdar Ivanov <ci4ic4%gmail.com@localhost>]

On Sat, 31 Oct 2020 at 19:14, Manuel Bouyer <bouyer%antioche.eu.org@localhost> wrote:
>
> On Sat, Oct 31, 2020 at 01:37:17PM -0500, Jeremy C. Reed wrote:
> > One of my hosting providers is converting VPSes from PV to HVM
> > virtualization due to security issue
> > https://xenbits.xen.org/xsa/advisory-286.html
> >
> > They say NetBSD does not work under HVM mode and can choose a different
> > BSD (or Linux).
> >
> > Can someone tell me about this? I did look briefly at
> > http://wiki.netbsd.org/ports/xen/howto/ but don't understand the context
> > of the wiki saying it is supported but the hosting provider saying it
> > does not work.
>
> plain HVM, with emulated devices, works without problems (and always has).
> If they only support PV devices, then it works only in HEAD (GENERIC supports
> it)

FWIW, on my XCP-NG server, a -current system shows:
..
➜  xci uname -a
NetBSD nbuild.lorien.lan 9.99.74 NetBSD 9.99.74 (WGUARD) #7: Thu Oct
29 21:18:53 GMT 2020
sysbuild@ymir:/home/sysbuild/src/sys/arch/amd64/compile/WGUARD amd64
➜  xci
➜  xci grep -i xen /var/run/dmesg.boot
Xen HVM domU (4.13)
Identified Guest XEN in HVM mode.
ACPI: RSDP 0x000000007F5FA014 000024 (v02 Xen   )
ACPI: XSDT 0x000000007F5F90E8 00004C (v01 Xen    HVM      00000000
 01000013)
ACPI: FACP 0x000000007F5F8000 0000F4 (v04 Xen    HVM      00000000
HVML 00000000)
ACPI: DSDT 0x000000007E50C000 0092A3 (v02 Xen    HVM      00000000
INTL 20160527)
ACPI: APIC 0x000000007F5F7000 000460 (v02 Xen    HVM      00000000
HVML 00000000)
ACPI: HPET 0x000000007F5F6000 000038 (v01 Xen    HVM      00000000
HVML 00000000)
ACPI: WAET 0x000000007F5F5000 000028 (v01 Xen    HVM      00000000
HVML 00000000)
hypervisor0 at mainbus0: Xen version 4.13
xenbus0 at hypervisor0: Xen Virtual Bus Interface
xencons0 at hypervisor0: Xen Virtual Console Driver
acpi0: X/RSDT: OemId <   Xen,     HVM,00000000>, AslId <    ,01000013>
XenSource, Inc. Xen Platform Device (SCSI mass storage, revision 0x01)
at pci0 dev 3 function 0 not configured
timecounter: Timecounter "xen_system_time" frequency 1000000000 Hz quality 10000
Xen cpu0 clock: using event channel 17
Xen cpu1 clock: using event channel 18
Xen cpu2 clock: using event channel 19
Xen cpu3 clock: using event channel 20
xenbus0: using event channel 5
xbd0 at xenbus0 id 768: Xen Virtual Block Device Interface
xbd1 at xenbus0 id 832: Xen Virtual Block Device Interface
xbd2 at xenbus0 id 5632: Xen Virtual Block Device Interface
xenbus0: ignoring device/vbd/5696 type cdrom
xbd3 at xenbus0 id 51776: Xen Virtual Block Device Interface
xbd4 at xenbus0 id 51792: Xen Virtual Block Device Interface
xennet0 at xenbus0 id 0: Xen Virtual Network Interface
xennet0: backend features 0x7<IPV6-CSUM,SG,RX-COPY>
xennet0: MAC address d6:3e:91:ab:da:ed
xennet0: using event channel 26
balloon at xenbus0 id 0 not configured
xenbus0: ignoring device/vbd/5696 type cdrom
xenbus0: ignoring device/vbd/5696 type cdrom
....

(WGUARD is GENERIC with wg).

The trickery to enable PV, with XEN3_DOMU kernel aside, no longer
works, perhaps since v.8.0.

>
> --
> Manuel Bouyer <bouyer%antioche.eu.org@localhost>
>      NetBSD: 26 ans d'experience feront toujours la difference
> --

Chavdar



--
----