On Mon, Feb 19, 2018 at 03:50:20PM +0000, Julien Grall wrote: > Hi Christoffer, > > On 15/02/18 21:02, Christoffer Dall wrote: > >We already have the percpu area for the host cpu state, which points to > >the VCPU, so there's no need to store the VCPU pointer on the stack on > >every context switch. We can be a little more clever and just use > >tpidr_el2 for the percpu offset and load the VCPU pointer from the host > >context. > > > >This does require us to calculate the percpu offset without including > >the offset from the kernel mapping of the percpu array to the linear > >mapping of the array (which is what we store in tpidr_el1), because a > >PC-relative generated address in EL2 is already giving us the hyp alias > >of the linear mapping of a kernel address. We do this in > >__cpu_init_hyp_mode() by using kvm_ksym_ref(). > > > >This change also requires us to have a scratch register, so we take the > >chance to rearrange some of the el1_sync code to only look at the > >vttbr_el2 to determine if this is a trap from the guest or an HVC from > >the host. We do add an extra check to call the panic code if the kernel > >is configured with debugging enabled and we saw a trap from the host > >which wasn't an HVC, indicating that we left some EL2 trap configured by > >mistake. > > You might want to remove this paragraph as you don't seem to have rework > that part of the code in this version. > Yes, will do. Thanks, -Christoffer
