[vfio-users] Hyperthreading and kvm

Wed Aug 19 20:23:43 UTC 2015

The need of Q35 is overrated. Usually you need it for booting from sata
controllers or something.
For our use 440fx works better.
I've used windows 7 on my machine. All you need to do is to follow the OVMF
whitepaper:
http://www.linux-kvm.org/downloads/lersek/ovmf-whitepaper-c770f8c.txt

2015-08-19 20:35 GMT+03:00 José Ramón Muñoz <koalinux at gmail.com>:

>         Hi,
>
>         Sorry for not replying to all, I wrote from the phone and sometimes
> happens.
>
>         About the ovmf stuff, I would give it a try just in case I didn't
> read the
> Alex Williamson post that explained that I need windows > win7 to be able
> to
> use it. I'm still not planning to upgrade it to windows 10.
>
>         How about q35? I tried to launch it but it seems to yield a
> beautiful
> BSOD because of the ati drivers not being expanded. Do anyone uses it
> regularly?
>
>         BR.
>
>         José.
>
> On Wednesday 19 August 2015 20:12:23 Blank Field wrote:
> > Please, use the reply-all button. Include "vfio-users at redhat.com"
> address
> > in the "to:" field.
> >
> > >    So, I got it right that using OVMF my setup can work reliably? I was
> >
> > considering to build it but it seems to be not so straight forward in
> > Gentoo.
> >
> > I haven't tried doing this on gentoo, but you can try using "alien" to
> use
> > RPMs from kraxel.org
> > https://www.kraxel.org/repos/
> > Also, i recall there was just plain binary files builds from jenkins,
> lurk
> > around and see if you can make yourself an ebuild with an overlay.
> > Also, there's a xen-tools package which has OVMF USE-flag, try
> researching
> > this.
> > And i think i saw an user-created portage overlay with the OVMF package
> in
> > there.
> >
> > I think plain libvirt and virt-manager should already be in the main
> > portage tree.
> >
> > 2015-08-19 6:16 GMT+03:00 José Ramón Muñoz Pekkarinen <
> koalinux at gmail.com>:
> > >      Hi,
> > >
> > >     So, I got it right that using OVMF my setup can work reliably? I
> was
> > >
> > > considering to build it but it seems to be not so straight forward in
> > > Gentoo.
> > >
> > >     BR.
> > >
> > >     José
> > >
> > > On Aug 19, 2015 3:09 AM, "Blank Field" <ihatethisfield at gmail.com>
> wrote:
> > >> Well, that sounds like the first time i've got it working.
> > >> Sooo, i've managed to make it work back then with just x-vga and qemu.
> > >> It worked. Sometimes.
> > >> Sometimes it crashed the host.
> > >> Sometimes it froze the VM and messed up the GPU.
> > >> I did a foolish research with no results whatsoever, but i've made one
> > >> observation - if the firefox is started and it eats a ton of memory, i
> > >> have
> > >> better chances to run the VM right.
> > >> However, i've dropped that way and went the OVMF way, avoiding the
> VGA.
> > >> Check the dmesg, maybe you're more lucky than me with the motherboard
> and
> > >> it's just the GPU that freezes. Also, i'd check the temperatures.
> > >>
> > >> 2015-08-19 0:25 GMT+03:00 José Ramón Muñoz <koalinux at gmail.com>:
> > >>>         Hi,
> > >>>
> > >>>         I'm using and APU a8-7650k, and apart that from time to time
> the
> > >>>
> > >>> win7
> > >>> guest decides to freeze, so many times during boot time, and
> > >>> ocassionally
> > >>> during gaming, I'm fairly happy with the performance. The passed
> through
> > >>> gpu
> > >>> is a HD5670 and I managed to play games like MGS Ground Zeroes,
> Blades
> > >>> of
> > >>> times, and currently DAO: Origins.
> > >>>
> > >>>         Best regards.
> > >>>
> > >>>         José.
> > >>>
> > >>> On Wednesday 19 August 2015 00:09:09 Blank Field wrote:
> > >>> > Use "Reply All" button. Include the mailing list in the "to:"
> field.
> > >>> >
> > >>> > >I'm currently running an A10-5700 with a discrete Nvidia card, and
> > >>>
> > >>> I've
> > >>>
> > >>> > got a LMDE2 install in which I'm preparing to do an experimental
> W10
> > >>>
> > >>> VM.
> > >>>
> > >>> > So, according to your experience, I shouldn't expect much with this
> > >>> > processor, then?
> > >>> > http://pastebin.com/rEhebfQM
> > >>> > It will work. But it has taken a year for me to figure out how to
> make
> > >>>
> > >>> it
> > >>>
> > >>> > work.
> > >>> > The pastebin link is my currently working domain xml.
> > >>> > Two asus HD7750 on an asus F2A55+Athlon X4 750k (Trinity).
> > >>> > The kernel and module parameters are:
> > >>> > options kvm-amd npt=1 nested=0
> > >>> > options kvm ignore_msrs=0 allow_unsafe_assigned_interrupts=0
> > >>> > options vfio_iommu_type1 disable_hugepages=1
> allow_unsafe_interrupts=0
> > >>> > CMDLINE:
> > >>> > nofb pci-stub.ids=1022:780d,1002:683f,1002:aab0 enable_mtrr_cleanup
> > >>> > amd_iommu_dump=1 iommu=pt acpi_enforce_resources=lax
> > >>> >
> > >>> > Try doing it with nested=1
> > >>> >
> > >>> > If you will use libvirt, that should work 100%, as i have almost
> the
> > >>>
> > >>> same
> > >>>
> > >>> > CPU.
> > >>> >
> > >>> > 2015-08-18 23:57 GMT+03:00 ALG Bass <olorin12 at gmail.com>:
> > >>> > > Gotcha. So it would be better if I got the i7.
> > >>> > > I'm currently running an A10-5700 with a discrete Nvidia card,
> and
> > >>>
> > >>> I've
> > >>>
> > >>> > > got a LMDE2 install in which I'm preparing to do an experimental
> W10
> > >>>
> > >>> VM.
> > >>>
> > >>> > > So, according to your experience, I shouldn't expect much with
> this
> > >>> > > processor, then?
> > >>> > >
> > >>> > > On Tue, Aug 18, 2015 at 3:46 PM, Blank Field <
> > >>>
> > >>> ihatethisfield at gmail.com>
> > >>>
> > >>> > > wrote:
> > >>> > >> Hyperthreading on host means MORE cores which you can commit to
> the
> > >>>
> > >>> VM.
> > >>>
> > >>> > >> More cores = more performance.
> > >>> > >> It is good for you.
> > >>> > >> For the host it doesn't matter logical or physical. For the VM,
> > >>>
> > >>> you'd
> > >>>
> > >>> > >> want to pin "pairs" of cores, so there would be less CPU cache
> > >>>
> > >>> issues.
> > >>>
> > >>> > >> Like, assign a core and it's sibling instead of two separate
> cores.
> > >>> > >>
> > >>> > >> I use AMD Athlon X4 750k which is based off A10-5700, and it's
> > >>>
> > >>> working
> > >>>
> > >>> > >> very unstable.
> > >>> > >> The only way to get it working - use OVMF without VGA and do not
> > >>> > >> use
> > >>> > >> hugepages.
> > >>> > >> That's all.
> > >>> > >>
> > >>> > >> P.S.
> > >>> > >> Oh well, here we go again.
> > >>> > >>
> > >>> > >> 2015-08-18 22:26 GMT+03:00 ALG Bass <olorin12 at gmail.com>:
> > >>> > >>> Hi all, new to this list, kvm, and vfio. I've been researching
> > >>>
> > >>> this for
> > >>>
> > >>> > >>> about a week.
> > >>> > >>> I'm also going to be building a computer in the near future, so
> > >>>
> > >>> I've got
> > >>>
> > >>> > >>> a quick two part question:
> > >>> > >>> Does the hyperthreading on i7 series Intel processors make a
> > >>>
> > >>> significant
> > >>>
> > >>> > >>> difference in running Windows in a VM, such that it's a
> noticeable
> > >>> > >>> increase
> > >>> > >>> in performance over an i5? And, does anyone here run Windows
> in a
> > >>>
> > >>> VM
> > >>>
> > >>> > >>> using
> > >>> > >>> an AMD A-series APU like the 7700k, and how is the performance?
> > >>> > >>>
> > >>> > >>> Thank you!
> > >>> > >>>
> > >>> > >>> _______________________________________________
> > >>> > >>> vfio-users mailing list
> > >>> > >>> vfio-users at redhat.com
> > >>> > >>> https://www.redhat.com/mailman/listinfo/vfio-users
>
>
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