Discussion:
qemu - some confusions
(too old to reply)
Kamil Jońca
2020-09-11 17:20:01 UTC
Permalink
I try to migrate some my ancient virutal machines from virtualbox to
qemu, and some things are unclear for me.
1. scsi devices:

--8<---------------cut here---------------start------------->8---
%qemu-system-x86_64 -device help|grep lsi
name "lsi53c810", bus PCI
name "lsi53c895a", bus PCI, alias "lsi"
--8<---------------cut here---------------end--------------->8---

but in /usr/share/libvirt/schemas/domaincommon.rng
we have:

--8<---------------cut here---------------start------------->8---
<attribute name="model">
<choice>
<value>auto</value>
<value>buslogic</value>
<value>lsilogic</value>
<value>lsisas1068</value>
<value>vmpvscsi</value>
<value>ibmvscsi</value>
<value>virtio-scsi</value>
<value>lsisas1078</value>
<value>virtio-transitional</value>
<value>virtio-non-transitional</value>
</choice>
</attribute>
--8<---------------cut here---------------end--------------->8---
what is relation between them?

I tried to edit machine via virsh and set "lsilogic" value. Machine
started and in command line I can see:
"[...] -device lsi,id=scsi0,bus=pci.4,addr=0x0 [..]"
so it is seem to be translated "lsilogic -> lsi".
Any hints about that? Point to proper doc?

Another (OT) question: does anybody knows about places from I can take drivers
for these ( lsi53c810 , lsi53c895a) controllers for windows NT 4 and
windows 2000?

KJ
--
http://stopstopnop.pl/stop_stopnop.pl_o_nas.html
Dan Ritter
2020-09-11 18:40:02 UTC
Permalink
Post by Kamil Jońca
I try to migrate some my ancient virutal machines from virtualbox to
qemu, and some things are unclear for me.
--8<---------------cut here---------------start------------->8---
%qemu-system-x86_64 -device help|grep lsi
name "lsi53c810", bus PCI
name "lsi53c895a", bus PCI, alias "lsi"
--8<---------------cut here---------------end--------------->8---
but in /usr/share/libvirt/schemas/domaincommon.rng
--8<---------------cut here---------------start------------->8---
<attribute name="model">
<choice>
<value>auto</value>
<value>buslogic</value>
<value>lsilogic</value>
<value>lsisas1068</value>
<value>vmpvscsi</value>
<value>ibmvscsi</value>
<value>virtio-scsi</value>
<value>lsisas1078</value>
<value>virtio-transitional</value>
<value>virtio-non-transitional</value>
</choice>
</attribute>
--8<---------------cut here---------------end--------------->8---
what is relation between them?
In your top cut, you have a specific SCSI adapter being selected
for emulation.

In the bottom, you have 9 different choices, of which you will
pick one.

The specific LSI 53c810 / 53c895a are not supported in qemu, but
it's possibly that the lsilogic emulator will work.

-dsr-
Post by Kamil Jońca
I tried to edit machine via virsh and set "lsilogic" value. Machine
"[...] -device lsi,id=scsi0,bus=pci.4,addr=0x0 [..]"
so it is seem to be translated "lsilogic -> lsi".
Any hints about that? Point to proper doc?
Another (OT) question: does anybody knows about places from I can take drivers
for these ( lsi53c810 , lsi53c895a) controllers for windows NT 4 and
windows 2000?
KJ
--
http://stopstopnop.pl/stop_stopnop.pl_o_nas.html
--
https://randomstring.org/~dsr/eula.html is hereby incorporated by reference.
there is no justice, there is just us.
Reco
2020-09-11 18:50:01 UTC
Permalink
Hi.
Post by Kamil Jońca
I try to migrate some my ancient virutal machines from virtualbox to
qemu, and some things are unclear for me.
--8<---------------cut here---------------start------------->8---
%qemu-system-x86_64 -device help|grep lsi
name "lsi53c810", bus PCI
name "lsi53c895a", bus PCI, alias "lsi"
--8<---------------cut here---------------end--------------->8---
but in /usr/share/libvirt/schemas/domaincommon.rng
--8<---------------cut here---------------start------------->8---
<attribute name="model">
<choice>
<value>auto</value>
<value>buslogic</value>
<value>lsilogic</value>
<value>lsisas1068</value>
<value>vmpvscsi</value>
<value>ibmvscsi</value>
<value>virtio-scsi</value>
<value>lsisas1078</value>
<value>virtio-transitional</value>
<value>virtio-non-transitional</value>
</choice>
</attribute>
--8<---------------cut here---------------end--------------->8---
what is relation between them?
As usual, libvirt provides you only the subset of qemu true
possibilities. Discrepancies such as this are to be expected.
Post by Kamil Jońca
I tried to edit machine via virsh and set "lsilogic" value. Machine
"[...] -device lsi,id=scsi0,bus=pci.4,addr=0x0 [..]"
so it is seem to be translated "lsilogic -> lsi".
Any hints about that? Point to proper doc?
In this particular case, qemu defines both lsi53c810 and lsi53c895a in a
single hw/scsi/lsi53c895a.c, and short of couple switches there is no
discernable difference between them.
As for the doc, qemu's documentation could definitely use some
improvement, and it's been like this for at least 10 years or so, so I
use [1].
Post by Kamil Jońca
Another (OT) question: does anybody knows about places from I can take drivers
for these ( lsi53c810 , lsi53c895a) controllers for windows NT 4 and
windows 2000?
Ask this guy - [2], seriously. He's *the* digital archeologist and a
Windows enthusiast at the same time.

Reco


[1] git://git.qemu.org/qemu.git
[2] https://virtuallyfun.com
Kamil Jońca
2020-09-11 19:30:01 UTC
Permalink
Post by Dan Ritter
Post by Kamil Jońca
I try to migrate some my ancient virutal machines from virtualbox to
qemu, and some things are unclear for me.
--8<---------------cut here---------------start------------->8---
%qemu-system-x86_64 -device help|grep lsi
name "lsi53c810", bus PCI
name "lsi53c895a", bus PCI, alias "lsi"
--8<---------------cut here---------------end--------------->8---
but in /usr/share/libvirt/schemas/domaincommon.rng
--8<---------------cut here---------------start------------->8---
<attribute name="model">
<choice>
<value>auto</value>
<value>buslogic</value>
<value>lsilogic</value>
<value>lsisas1068</value>
<value>vmpvscsi</value>
<value>ibmvscsi</value>
<value>virtio-scsi</value>
<value>lsisas1078</value>
<value>virtio-transitional</value>
<value>virtio-non-transitional</value>
</choice>
</attribute>
--8<---------------cut here---------------end--------------->8---
what is relation between them?
In your top cut, you have a specific SCSI adapter being selected
for emulation.
In the bottom, you have 9 different choices, of which you will
pick one.
The specific LSI 53c810 / 53c895a are not supported in qemu, but
it's possibly that the lsilogic emulator will work.
Sorry, I do not understand.
If LSI 53c810 / 53c895a is not supported, how output
"qemu-system-x86_64 -device help" should be interpreted?

KJ
--
http://stopstopnop.pl/stop_stopnop.pl_o_nas.html
After any salary raise, you will have less money at the end of the
month than you did before.
Dan Ritter
2020-09-11 19:30:01 UTC
Permalink
Post by Kamil Jońca
Sorry, I do not understand.
If LSI 53c810 / 53c895a is not supported, how output
"qemu-system-x86_64 -device help" should be interpreted?
KJ
Read Reco's message.

-dsr-
Kamil Jońca
2020-09-11 20:10:02 UTC
Permalink
Post by Dan Ritter
Post by Kamil Jońca
Sorry, I do not understand.
If LSI 53c810 / 53c895a is not supported, how output
"qemu-system-x86_64 -device help" should be interpreted?
KJ
Read Reco's message.
Sorry, still does not understand that: "LSI 53c810 / 53c895a is not
supported by qemu"

Sentence: "qemu handles more cases than virt-manager" (from Reco's message) is
understandable.

KJ
--
http://stopstopnop.pl/stop_stopnop.pl_o_nas.html
Giving money and power to governments is like giving whiskey and
car keys to teenage boys.
-- P. J. O'Rourke
Reco
2020-09-11 20:40:01 UTC
Permalink
Hi.
Post by Kamil Jońca
Post by Dan Ritter
Post by Kamil Jońca
Sorry, I do not understand.
If LSI 53c810 / 53c895a is not supported, how output
"qemu-system-x86_64 -device help" should be interpreted?
KJ
Read Reco's message.
Sorry, still does not understand that: "LSI 53c810 / 53c895a is not
supported by qemu"
Long story short.
There was (and still is) QEMU. It does many things (and most of them
aren't restricted to x86), and it's a truly community project. Many
projects say "anyone can contribute", but in the case of the QEMU it's
actually true. That was a bright side, but there is a dark side of QEMU
- it says it can do many things, but quality of doing them varies.

On the other hand, there's libvirt, which is a Red Hat-controlled
project. These days people see it as a glorified QEMU wrapper, but
actually it can do more (but again, the quality of doing so varies).
Contrary to the QEMU, libvirt does best what Red Hat needs it to do, no
more, no less.

It's hardly surprising that Red Hat cherry-picks certain QEMU
capabilities and declares them "supported" (i.e. - "worked for our
paying customers"), and deems everything else as "not supported" (i.e. -
"you're on your own").

What (probably) Dan meant is "you're trying to use QEMU feature that is
not approved by Red Hat". By itself it does not mean that the feature in
question is somehow bad, or incomplete, or will corrupt your data or
whatever. It means exactly what's stated above, no more and no less.

Here, at this list, people are rarely using QEMU directly, without the
kludges like libvirt. The reason being - one of the few mature programs
to deal with QEMU is called virt-manager, and it's built on top of
libvirt. So, unless specified otherwise, here QEMU = libvirt, and
restrictions of the latter apply to the former.

Reco
Kamil Jońca
2020-09-14 10:10:02 UTC
Permalink
Post by Reco
Hi.
Post by Kamil Jońca
Post by Dan Ritter
Post by Kamil Jońca
Sorry, I do not understand.
If LSI 53c810 / 53c895a is not supported, how output
"qemu-system-x86_64 -device help" should be interpreted?
KJ
Read Reco's message.
Sorry, still does not understand that: "LSI 53c810 / 53c895a is not
supported by qemu"
[...long and compehensive explanation ...]
Post by Reco
libvirt. So, unless specified otherwise, here QEMU = libvirt, and
Thank you.

KJ
--
http://wolnelektury.pl/wesprzyj/teraz/
In the dimestores and bus stations
People talk of situations
Read books repeat quotations
Draw conclusions on the wall.
-- Bob Dylan
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