On 08/09/16 10:44, Christoffer Dall wrote: > On Tue, Sep 06, 2016 at 02:01:58PM +0100, Marc Zyngier wrote: >> A little known "feature" of giving guest access to real memory mapped >> HW is that it could trigger asynchronous aborts (SError on ARMv8) if >> the guest accesses it in a non-conventional way (and depending on how >> HW and firmware have been integrated). So far, KVM lacks any support >> to handle this gracefully. >> >> This series introduces a set of mechanisms to catch such a fault and >> deliver a vSError (or Virtual Abort for 32bit) to the offending vcpu. >> >> These aborts can either trigger at EL1 (whilst the guest is running), >> or at EL2 (during the handling of an exit). The first case is pretty >> easy to handle (use the ad-hoc vectors on arm64, or decode the EA bit >> on arm), but the second one is a bit more fiddly, as we need to ensure >> that the exception is pending by the time we unmask it. This is >> achived by using some heavy DSBs on the hot path, with the following >> caveats: >> >> - I've only been able to trigger the EL2 handling on A57 (Seatle, >> Juno). >> - I've measured a 40/50 cycles hit on Juno (A57), but I haven't >> measured the impact on bigger systems >> >> The last patch of this series adds a missing feature to the >> GICV-proxying series, delivering a vSError to a guest that performed >> an illegal access to the GIC. >> >> Patches on top of current kvmarm/queue + the GICV przying series. > > przying? proxying? Or something in Polish perhaps? Proxying, with added fat fingers... ;-) > > For the series: > Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> Thanks! M. -- Jazz is not dead. It just smells funny... -- 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
