On 16/07/18 14:06, Christoffer Dall wrote: > This series addresses a peculiarity of the current VGIC > implementation, namely that we don't support interrupt grouping. > > KVM either implements a GICv2 without support for the security > extensions, or a GICv3 with DS=1. For GICv2, on systems without the > security extensions, group 0 interrupts can be configured to be either > signalled as FIQs or as IRQs by the VM, whereas group 1 interrupts are > always IRQs. For GICv3, with DS=1, group 1 interrupts are always IRQs > and group 0 interrupts are always FIQs, and there is no concept of > secure vs. non-secure group 1 interrupts when DS=1. > > We were treating all interrupts on GICv2 as group 0, but yet telling the > guest that they were group 1. The first patch changes this behavior, > which seems to have no effect on no known guests, but still. > > The remaining patches introduce proper interrupt grouping support, along > with MMIO accessors for the VM and userspace to retrieve and set the > which group SGIs, PPIs, and SPIs belong to. LPIs are always group 1 > interrupts as per the architecture, and there is no way to modify this > configuration (no IGROUPR registers for LPIs or equivalent ITS > commands). > > Tested on Seattle, TX1, and the foundation model. I've run a > GICv2 guest on a GICv3 host on the foundation model. I've tested > migration on Seattle, and migration from an old kernel to a newer kernel > with an unmodified QEMU binary continues to work. I also tested a > modified userspace that sets some interrupts to group 1, and that is > reflected in the vgic debug output. Applied to kvmarm/next Thanks, M. -- Jazz is not dead. It just smells funny...
