[Bug 25332] When a VM is rebooted, assigned devices do not get RESET ...

[Bug 25332] When a VM is rebooted, assigned devices do not get RESET ...

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=25332


CJ <cyclonusj@gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |cyclonusj@gmail.com




--- Comment #1 from CJ <cyclonusj@gmail.com>  2011-08-12 08:55:31 ---
Is this for a VT-d case?

Thanks,
CJ

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are watching the assignee of the bug.

[Bug 25332] When a VM is rebooted, assigned devices do not get RESET ...

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=25332





--- Comment #2 from Casey Leedom <leedom@chelsio.com>  2011-08-15 15:51:25 ---
This is in reference to the ability to map a PCI Device into a Virtual Machine
— sometimes referred to as "PCI Pass Through."  For Intel architectures, VT-d
provides some of the critical underlaying architectural support for remapping
device DMA and interrupts.  Other architectures supply similar technology.

At issue here is that the KVM Support in the hypervisor kernel does not issue a
pci_reset_function() call against all such devices when a Virtual Machine
reboots.  This means that the Virtual Machine finds the device in a non-clean
condition on reboot.  It also means that any peer devices/services that the
device hardware may be attached to will continue to see the non-RESET state on
the other side of the device until a driver is loaded in the Virtual Machine to
manage the device.  Thus, for instance, if a network adapter had brought up a
link and then a reboot was done, the peer would continue to see a Link Up
condition until the Virtual Machine rebooted and a driver for the device was
loaded.

The above phenomenology doesn't match the way that a reboot would affect a real
machine.  For a real machine, part of the reboot cycle would involve all
devices and buses getting RESET.  We need the KVM Hipervisor support to do the
same thing.

-- 
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are watching the assignee of the bug.

[Bug 25332] When a VM is rebooted, assigned devices do not get RESET ...

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=25332

xerofoify@gmail.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |xerofoify@gmail.com

--- Comment #3 from xerofoify@gmail.com ---
Please test against a newer kernel to see if it's fixed.
Thanks Nick

-- 
You are receiving this mail because:
You are watching the assignee of the bug.

[Bug 25332] When a VM is rebooted, assigned devices do not get RESET ...

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=25332

Alan <alan@lxorguk.ukuu.org.uk> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |alan@lxorguk.ukuu.org.uk
     Kernel Version|                            |-
         Resolution|---                         |OBSOLETE

-- 
You are receiving this mail because:
You are watching the assignee of the bug.