SOLVED: RE: Garbled audio - Windows 7 64 bit guest on Debian

SOLVED: RE: Garbled audio - Windows 7 64 bit guest on Debian

[Jimmy Crossley]

> -----Original Message-----
> From: kvm-owner@vger.kernel.org [mailto:kvm-owner@vger.kernel.org] On Behalf Of Jimmy Crossley
> Sent: Friday, June 08, 2012 17:29
> To: kvm@vger.kernel.org
> Subject: Garbled audio - Windows 7 64 bit guest on Debian
> 
> I am experiencing garbled sound on a Windows 7 64 bit guest running under 64 bit Debian.  I have
> searched many discussion groups, etc. on the net and could find nothing useful, so I thought I would
> post this here, hoping someone with a deeper understanding could help out.
> 
> I am running 64 bit Debian GNU/Linux "testing" on a Lenovo Thinkpad T420s, 8GB RAM, Crucial m4 512GB
> disk.  Using ALSA, the sound works perfectly when playing all kinds of files.  I am running
> everything from the standard Debian repositories.  This is using kernel version 3.0.0-1.  kvm --
> version says:
> 
>   QEMU emulator version 1.0 (qemu-kvm-1.0+dfsg-11, Debian), Copyright (c) 2003-2008 Fabrice Bellard
> 
> I am running Windows 7 Enterprise service pack 1 as a virtual machine.  The machine is started with
> the following command:
> 
>   /usr/bin/kvm \
>   -M pc \
>   -m 2048 \
>   -drive file="csilt033-6.qcow",if=virtio \
>   -soundhw hda \
>   -display sdl &
> 
> I believe I must use "-soundhw hda" because that is the only sound device that kvm emulates which
> has Windows 7 64 bit drivers.  Windows 7 automatically detects a "High Definition Audio Device" and
> uses the driver HDAudio.sys.  But the sounds it makes sound like they are very highly compressed, or
> a lot of bits are being lost or something.  Any application used to play sound has the same problem.
> Speech is barely recognizable.  Using the built in speakers or external speakers through the audio
> jack give the same result.
> 
> I have tried several QEMU_AUDIO* settings, but it seems like these make no difference.
> 
> If I connect to the machine using remote desktop (mstsc.exe, rdesktop, xfreerdp), the sound gets
> redirected to the local machine and sounds perfect.  The sound is only garbled when using SDL.  The
> same audio problems exist if I start up the machine and connect to it with vnc.
> 
> 
> I want to use SDL because I need to use Microsoft Lync, which requires me to log in on the console.
> Using voice with Lync is not supported in a remote desktop environment.
> 
> Here is lspci on the audio device on the host machine.
> 
> $ sudo lspci -vvv -s 00:1b.0
> 00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio
> Controller (rev 04)
>         Subsystem: Lenovo Device 21d2
>         Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
> DisINTx+
>         Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR-
> <PERR- INTx-
>         Latency: 0, Cache Line Size: 64 bytes
>         Interrupt: pin A routed to IRQ 51
>         Region 0: Memory at f1620000 (64-bit, non-prefetchable) [size=16K]
>         Capabilities: [50] Power Management version 2
>                 Flags: PMEClk- DSI- D1- D2- AuxCurrent=55mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
>                 Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
>         Capabilities: [60] MSI: Enable+ Count=1/1 Maskable- 64bit+
>                 Address: 00000000fee004b8  Data: 0000
>         Capabilities: [70] Express (v1) Root Complex Integrated Endpoint, MSI 00
>                 DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us
>                         ExtTag- RBE- FLReset+
>                 DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
>                         RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop-
>                         MaxPayload 128 bytes, MaxReadReq 128 bytes
>                 DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend-
>                 LnkCap: Port #0, Speed unknown, Width x0, ASPM unknown, Latency L0 <64ns, L1 <1us
>                         ClockPM- Surprise- LLActRep- BwNot-
>                 LnkCtl: ASPM Disabled; Disabled- Retrain- CommClk-
>                         ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
>                 LnkSta: Speed unknown, Width x0, TrErr- Train- SlotClk- DLActive- BWMgmt- ABWMgmt-
>         Capabilities: [100 v1] Virtual Channel
>                 Caps:   LPEVC=0 RefClk=100ns PATEntryBits=1
>                 Arb:    Fixed- WRR32- WRR64- WRR128-
>                 Ctrl:   ArbSelect=Fixed
>                 Status: InProgress-
>                 VC0:    Caps:   PATOffset=00 MaxTimeSlots=1 RejSnoopTrans-
>                         Arb:    Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256-
>                         Ctrl:   Enable+ ID=0 ArbSelect=Fixed TC/VC=01
>                         Status: NegoPending- InProgress-
>                 VC1:    Caps:   PATOffset=00 MaxTimeSlots=1 RejSnoopTrans-
>                         Arb:    Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256-
>                         Ctrl:   Enable+ ID=1 ArbSelect=Fixed TC/VC=22
>                         Status: NegoPending- InProgress-
>         Capabilities: [130 v1] Root Complex Link
>                 Desc:   PortNumber=0f ComponentID=00 EltType=Config
>                 Link0:  Desc:   TargetPort=00 TargetComponent=00 AssocRCRB- LinkType=MemMapped
> LinkValid+
>                         Addr:   00000000fed1c000
>         Kernel driver in use: HDA Intel
> 
> Any ideas on how to get this to work would be appreciated.
> 
> 
> 
> -----------------------------
> Jimmy Crossley
> CoNetrix
> Sentry Plaza III
> 5214 68th Street, Suite 200
> Lubbock, TX  79424
> jcrossley@CoNetrix.com
> https://www.CoNetrix.com
> Telephone: 806-687-8600
> Toll Free: 800-356-6568
> Fax: 806-687-8511
> This e-mail message (and attachments) may contain confidential CoNetrix information. If you are not
> the intended recipient, you cannot use, distribute or copy the message or attachments. In such a
> case, please notify the sender by return e-mail immediately and erase all copies of the message and
> attachments. Opinions, conclusions and other information in this message and attachments that do not
> relate to official business are neither given nor endorsed by CoNetrix.
> 
> 
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I have mostly solved this issue.  The sound works much, much, better, but is still not as good as on my host machine.

I installed PulseAudio and used it instead of ALSA.  In order to get kvm to use it, I set the environment variable QEMU_AUDIO_DRV=pa.  I had been using sudo to start the VM, and that kept this environment variable from being used.  I did a "sudo setcap cap_net_admin+ep /usr/bin/kvm" in order to be able to run kvm under a normal user account.  Now the sound works quite well.

Re: SOLVED: RE: Garbled audio - Windows 7 64 bit guest on Debian

[Avi Kivity]

On 06/18/2012 10:32 PM, Jimmy Crossley wrote:
> 
> I have mostly solved this issue.  The sound works much, much, better, but is still not as good as on my host machine.
> 
> I installed PulseAudio and used it instead of ALSA.  In order to get kvm to use it, I set the environment variable QEMU_AUDIO_DRV=pa.  I had been using sudo to start the VM, and that kept this environment variable from being used.  I did a "sudo setcap cap_net_admin+ep /usr/bin/kvm" in order to be able to run kvm under a normal user account.  Now the sound works quite well.
> 

That is good to hear.  But you are giving up on a lot of security if
you're running kvm as root (or with CAP_NET_ADMIN).  qemu supports
setting up the network externally and running with no special privileges.

Of course, it may not matter for your use case.

-- 
error compiling committee.c: too many arguments to function

RE: SOLVED: RE: Garbled audio - Windows 7 64 bit guest on Debian

[Jimmy Crossley]

Thanks for that reminder, Avi.  You are right - it would be best to not be running kvm as root or with any special capabilities.  I mainly wanted to report back that I got the sound working by switching to PulseAudio.  I made the other changes so I would not have to run kvm as root and it would see the environment variable.  When I run without that capability, it seems that kvm cannot create the tun device.  I will do more research and if I can't find the information I need, I'll start a new thread.

>

-----------------------------
Jimmy Crossley
CoNetrix
Sentry Plaza III
5214 68th Street, Suite 200
Lubbock, TX  79424
jcrossley@CoNetrix.com
https://www.CoNetrix.com
Telephone: 806-687-8600
Toll Free: 800-356-6568
Fax: 806-687-8511
This e-mail message (and attachments) may contain confidential CoNetrix information. If you are not the intended recipient, you cannot use, distribute or copy the message or attachments. In such a case, please notify the sender by return e-mail immediately and erase all copies of the message and attachments. Opinions, conclusions and other information in this message and attachments that do not relate to official business are neither given nor endorsed by CoNetrix.


-----Original Message-----
> From: Avi Kivity [mailto:avi@redhat.com]
> Sent: Tuesday, June 19, 2012 04:21
> To: Jimmy Crossley
> Cc: kvm@vger.kernel.org
> Subject: Re: SOLVED: RE: Garbled audio - Windows 7 64 bit guest on Debian
>
> On 06/18/2012 10:32 PM, Jimmy Crossley wrote:
> >
> > I have mostly solved this issue.  The sound works much, much, better, but is still not as good as
> on my host machine.
> >
> > I installed PulseAudio and used it instead of ALSA.  In order to get kvm to use it, I set the
> environment variable QEMU_AUDIO_DRV=pa.  I had been using sudo to start the VM, and that kept this
> environment variable from being used.  I did a "sudo setcap cap_net_admin+ep /usr/bin/kvm" in order
> to be able to run kvm under a normal user account.  Now the sound works quite well.
> >
>
> That is good to hear.  But you are giving up on a lot of security if
> you're running kvm as root (or with CAP_NET_ADMIN).  qemu supports
> setting up the network externally and running with no special privileges.
>
> Of course, it may not matter for your use case.
>
> --
> error compiling committee.c: too many arguments to function
>

Re: SOLVED: RE: Garbled audio - Windows 7 64 bit guest on Debian

[razamatan]

Jimmy Crossley <jcrossley <at> CoNetrix.com> writes:

> 
> > -----Original Message-----
> > From: kvm-owner <at> vger.kernel.org [mailto:kvm-owner <at> vger.kernel.org] 
On Behalf Of Jimmy Crossley
> > Sent: Friday, June 08, 2012 17:29
> > Subject: Garbled audio - Windows 7 64 bit guest on Debian
> > 
> > I am experiencing garbled sound on a Windows 7 64 bit guest running under 64 
bit Debian.  I have
> > searched many discussion groups, etc. on the net and could find nothing 
useful, so I thought I would
> > post this here, hoping someone with a deeper understanding could help out.

** <snip>

> > If I connect to the machine using remote desktop (mstsc.exe, rdesktop, 
xfreerdp), the sound gets
> > redirected to the local machine and sounds perfect.  The sound is only 
garbled when using SDL.  The
> > same audio problems exist if I start up the machine and connect to it with 
vnc.
> > 
> 
> I have mostly solved this issue.  The sound works much, much, better, but is 
still not as good as on my host machine.
> 
> I installed PulseAudio and used it instead of ALSA.  In order to get kvm to 
use it, I set the environment
> variable QEMU_AUDIO_DRV=pa.  I had been using sudo to start the VM, and that 
kept this environment
> variable from being used.  I did a "sudo setcap cap_net_admin+ep /usr/bin/kvm" 
in order to be able to run
> kvm under a normal user account.  Now the sound works quite well.
> 
> 


i've pretty much nearly duplicated this setup (gentoo host, qemu-kvm 1.2.1, 
pulseaudio, sdl, emulated hda audio, windows 7 64bit sp1 guest) due to the same 
reasons and the same result.  however, as jcrossley mentioned, it's not as crisp 
as the host; there's a lot of crackling and popping still.

based on jcrossley's investigation using rdp instead (and seeing no ill effects 
wrt sound), wouldn't the issue be pointed at the hda emulation?

how would one go about getting involved in terms of helping out w/ the hda 
emulator?

Re: SOLVED: RE: Garbled audio - Windows 7 64 bit guest on Debian

[Simon O'Riordan]

Sound works badly with hda.
There is a slight improvement with Pulseaudio in the host;
the solution, however, is to use ALSA with AC97.

Since qemu-kvm 1.1, ac97 emulation has been reworked
 and now works with Windows 7 x64.

The windows update mechanism will install the drivers
 automatically, but whatcan be seen is that the drivers
 are actually only the Realtek 6305-series OEM
drivers, so if you have an isolated Win 7 system, 
simply find the 6305 driver set(available as a zip, 
sorry no link at the moment, google '6305_Vista_Win7_PG537.zip'), 
run the setup programme and you should have perfect sound.
I know we do.

The same applies to Qemu-kvm 1.2.