Bug 769745

Summary:	Released usb stick after passthrough fails to be reused on host
Product:	Red Hat Enterprise Linux 6	Reporter:	Shaolong Hu <shu>
Component:	qemu-kvm	Assignee:	Gerd Hoffmann <kraxel>
Status:	CLOSED ERRATA	QA Contact:	Virtualization Bugs <virt-bugs>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	6.3	CC:	acathrow, bsarathy, juzhang, michen, minovotn, mkenneth, qzhang, qzhou, rhod, tburke, virt-maint
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	qemu-kvm-0.12.1.2-2.222.el6	Doc Type:	Bug Fix
Doc Text:	Cause: USB release function was not called in the exit notifier Consequence: Host was unable to reuse USB device after it has been removed from the guest. Fix: Call release function in the exit notifier too. Result: Host still can reuse the USB device after removal from the guest.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2012-06-20 11:38:05 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Shaolong Hu 2011-12-22 03:23:09 UTC

Description of problem:
------------------------
Released usb stick after passthrough fails to be reused on host, according to test plan, this is not correct:

[passthrough] Release the physical USB stick/webcam from guest, check if it works well on host
Remove USB stick/webcam from guest.
Verify USB stick/webcam works correctly on host, no errors found in console of host, dmesg output of host. 

Version-Release number of selected component (if applicable):
--------------------------------------------------------------
qemu-kvm-0.12.1.2-2.213.el6.x86_64

How reproducible:
-------------------
100%

Steps to Reproduce:
--------------------
1.boot guest with "-readconfig ich9-ehci-uhci.cfg"
2.in qemu monitor, passthrough host usb stick to guest
3.in qemu monitor, delete the usb stick
  
Actual results:
-----------------
After step 3, on host:
1. lsusb can show the usb stick
2. fdisk -l fails to show the usb stick
3. ls /dev/sd* fails to show the stick

Expected results:
------------------
The best: Usb stick can be used on host automatically.
Workaround: Some manual configuration, like pci device passthrough, and if this is feasible, better qemu-kvm does it automatically.
Currently: Re-plug the stick.

Comment 1 Gerd Hoffmann 2012-01-04 11:54:13 UTC

What monitor commands do you issue for steps (2) + (3) ?

Comment 2 Shaolong Hu 2012-01-05 02:31:54 UTC

(In reply to comment #1)
> What monitor commands do you issue for steps (2) + (3) ?

2.(qemu)device_add usb-host,hostbus=X,hostaddr=X,id=hostusb1
3.(qemu)device_del hostusb1

Comment 4 Shaolong Hu 2012-02-09 02:58:02 UTC

Verified on qemu-kvm-0.12.1.2-2.223.el6.x86_64:

With steps in Description:

After step 3, on host:
1. lsusb shows the usb stick
2. fdisk -l shows the usb stick
3. ls /dev/sd* shows the usb stick
4. mount /dev/sdb1 /mnt, the usb stick can be used correctly

Verified.

Comment 6 Michal Novotny 2012-05-04 09:37:35 UTC

    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
Cause:
USB release function was not called in the exit notifier

Consequence:
Host was unable to reuse USB device after it has been removed from the guest.

Fix:
Call release function in the exit notifier too.

Result:
Host still can reuse the USB device after removal from the guest.

Comment 7 errata-xmlrpc 2012-06-20 11:38:05 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2012-0746.html