On Wed, Feb 29, 2012 at 12:00:41PM +0200, Avi Kivity wrote: > On 02/29/2012 11:55 AM, Gleb Natapov wrote: > > > > > > > > > > How about using a virtio-serial channel for this? You can transfer any > > > amount of information (including the dump itself). > > > > > Isn't it unreliable after the guest panicked? > > So is calling hypercalls, or dumping, or writing to the screen. Of > course calling a hypercall is simpler and so is more reliable. > Yes, crash can be so severe that it is not even detected by a kernel itself, so not OOPS message even printed. But in most cases if kernel is functional enough to print OOPS it is functional enough to call single hypercall instruction. > > Having special kdump > > kernel that transfers dump to a host via virtio-serial channel though > > sounds interesting. May be that's what you mean. > > Yes. The "panic, starting dump" signal should be initiated by the > panicking kernel though, in case the dump fails. > Then panic hypercall sounds like a reasonable solution. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
