USB redirection support in qemu is currently using synchronous ioctls, which might block the guest for too long (>100usec). The current host controller emulations allow only one pending transfer at a time, which might slow down the guest as well.
If you are using simple bulk device (disk on key, printer etc.), you can try the patch of USB 2.0 EHCI emulation, recently submitted to qemu-devel. It is at very preliminary stage, but still might be useful for you. Arnon -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Norbert Preining Sent: Sunday, January 06, 2008 6:42 PM To: kvm-devel@lists.sourceforge.net Subject: [kvm-devel] kvm with usb slow Hi all, (please Cc, thanks) I am running kernel 2.6.24-rc6 and kvm-56 (or was it 55) and as soon as I plug an usb device with usb enabled it is getting terrible slow. I have searched a bit and it seems to be related to async i/o not being implemented. Is this expected behaviour, and if yes, are there patches floating around for testing? Best wishes Norbert ------------------------------------------------------------------------ ------- Dr. Norbert Preining <[EMAIL PROTECTED]> Vienna University of Technology Debian Developer <[EMAIL PROTECTED]> Debian TeX Group gpg DSA: 0x09C5B094 fp: 14DF 2E6C 0307 BE6D AD76 A9C0 D2BF 4AA3 09C5 B094 ------------------------------------------------------------------------ ------- HASTINGS (pl.n.) Things said on the spur of the moment to explain to someone who comes into a room unexpectedly precisely what it is you are doing. --- Douglas Adams, The Meaning of Liff ------------------------------------------------------------------------ - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
