Tian, Kevin wrote: >> >> If the guest fails to disable interrupts on a device that shares an >> interrupt line with the host, the host will experience an interrupt >> flood. Eventually the host will disable the host device as well. >> >> > > This issue also exists on host side, that one misbehaved driver > can hurt all other drivers sharing same irq line.
There is no issue on the host, since all drivers operate on the same trust level. A misbehaving driver on the host will take down the entire system even without shared interrupts, by corrupting memory, not releasing a lock, etc. But if you move a driver to the guest, you expect it will be isolated from the rest of the system, and if there are shared interrupts, it isn't. > But it seems no > good way to avoid it. Since not all devices support MSI, we still > need support irq sharing possibly with above caveats given. > > Existing approach at least works with a sane guest driver, with > some performance penality there. > > How can we recommend it to users? We tell them, your guests are isolated and secure as long as they don't misbehave? > Or do you have better alternative? > No. Maybe the Neocleus polarity trick (which also reduces performance). -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
