Ross S. W. Walker
2008-Apr-28 17:52 UTC
RE: [Xen-users] Advantages of HVM vs. paravirtualization in aLinux-only enviroment?
Jamie J. Begin wrote:> > Newbie here... My hardware supports HVM (full virtualization), > but I only need to run Linux on it. I initially tried to > create a HVM domU, but couldn''t get pciback to work with a > telephony card I need for use with Asterisk. However > everything seems to be working fine under a paravirtualized > guest as long as I use permissive mode on the card. (Knock on > wood-I''ve had some weird instability issues prior enabling > permissive mode).You can always look into the logs at the io port violations and add them to the pci-quirks for that card until you''ve covered them all. It''s a little trial-and-error until you get them all covered, but it''s more secure then just setting pci permissive globally.> Is there any real advantage to using HVM if I don''t need to > virtualize Windows? And if there is, how do I go about > passing through PCI cards to the HVM guest? I''m trying to > figure out if it''s worth me continuing to hack on this problem.No, if your OS can do para-virtualized that is the preferred way to go. The only reason for HVM is if the OS cannot be para-virtualized. -Ross ______________________________________________________________________ This e-mail, and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution or copying of this e-mail, and any attachments thereto, is strictly prohibited. If you have received this e-mail in error, please immediately notify the sender and permanently delete the original and any copy or printout thereof. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Jamie J. Begin
2008-Apr-28 23:43 UTC
RE: [Xen-users] Advantages of HVM vs. paravirtualization in aLinux-only enviroment?
>-----Original Message----- >From: Ross S. W. Walker [mailto:rwalker@medallion.com] >Sent: Monday, April 28, 2008 1:53 PM >To: Jamie J. Begin; xen-users@lists.xensource.com >Subject: RE: [Xen-users] Advantages of HVM vs. paravirtualization in >aLinux-only enviroment? > >Jamie J. Begin wrote: >> >> Newbie here... My hardware supports HVM (full virtualization), >> but I only need to run Linux on it. I initially tried to >> create a HVM domU, but couldn''t get pciback to work with a >> telephony card I need for use with Asterisk. However >> everything seems to be working fine under a paravirtualized >> guest as long as I use permissive mode on the card. (Knock on >> wood-I''ve had some weird instability issues prior enabling >> permissive mode). > >You can always look into the logs at the io port violations >and add them to the pci-quirks for that card until you''ve >covered them all. It''s a little trial-and-error until you >get them all covered, but it''s more secure then just >setting pci permissive globally. > >> Is there any real advantage to using HVM if I don''t need to >> virtualize Windows? And if there is, how do I go about >> passing through PCI cards to the HVM guest? I''m trying to >> figure out if it''s worth me continuing to hack on this problem. > >No, if your OS can do para-virtualized that is the preferred >way to go. The only reason for HVM is if the OS cannot be >para-virtualized. > >-RossThanks for the reply; at least I know I''m on the right track. However, it doesn''t look like permissive mode actually solved my problem. When I try to reboot dom0, it switches to runlevel 6 and the xen init.d script attempts to pause the Asterisk domU. It''s at that point I get an "hda: interrupt lost" on the physical console. SSH become inaccessible and eventually the system pukes up a bunch of ext3 and RAID controller related errors and freezes. I have to physically power cycle the box to get it back up. Any suggestions? This is a new Dell PowerEdge 1950 with a PERC SATA RAID 1 array, running CentOS 5.1 (2.6.18-53.1.14.el5xen) in both the dom0 and domU. The PCI device that''s being passed-through to the domU is a Digium AEX800 (which is actually a PCIe version of Digium''s PCI-based TDM800P). lspci output is: 0b:08.0 Ethernet controller: Digium, Inc. Unknown device 8002 (rev 11) Subsystem: Digium, Inc. Unknown device 8002 Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- Interrupt: pin A routed to IRQ 16 Region 0: I/O ports at dc00 [disabled] [size=256] Region 1: Memory at fc7dfc00 (32-bit, non-prefetchable) [disabled] [size=1K] Expansion ROM at fc7e0000 [disabled] [size=128K] Capabilities: [c0] Power Management version 2 Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=0mA PME(D0+,D1+,D2+,D3hot+,D3cold-) Status: D0 PME-Enable- DSel=0 DScale=0 PME- _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users