Hi Zenghui, On 11/17/20 9:49 AM, Marc Zyngier wrote: > Hi Zenghui, > > On 2020-11-16 14:57, Zenghui Yu wrote: >> Hi Marc, >> >> On 2020/11/16 22:10, Marc Zyngier wrote: >>>> My take is that only if the "[Re]Distributor base address" is specified >>>> in the system memory map, will the user-provided kvm_device_attr.offset >>>> make sense. And we can then handle the access to the register which is >>>> defined by "base address + offset". >>> >>> I'd tend to agree, but it is just that this is a large change at -rc4. >>> I'd rather have a quick fix for 5.10, and a more invasive change for >>> 5.11, >>> spanning all the possible vgic devices. >> >> So you prefer fixing it by "return a value that doesn't have the Last >> bit set" for v5.10? I'm ok with it and can send v2 for it. > > Cool. Thanks for that. > >> Btw, looking again at the way we handle the user-reading of GICR_TYPER >> >> vgic_mmio_read_v3r_typer(vcpu, addr, len) >> >> it seems that @addr is actually the *offset* of GICR_TYPER (0x0008) and >> @addr is unlikely to be equal to last_rdist_typer, which is the *GPA* of >> the last RD. Looks like the user-reading of GICR_TYPER.Last is always >> broken? > > I think you are right. Somehow, we don't seem to track the index of > the RD in the region, so we can never compute the address of the RD > even if the base address is set. > > Let's drop the reporting of Last for userspace for now, as it never > worked. If you post a patch addressing that quickly, I'll get it to > Paolo by the end of the week (there's another fix that needs merging). > > Eric: do we have any test covering the userspace API? No, there are no KVM selftests for that yet. Thanks Eric > > Thanks, > > M. _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
