Re: [PATCH 8/8] hw/arm/virt: Disable highmem when on hypervisor.framework

[Eduardo Habkost]

On Fri, Nov 27, 2020 at 06:16:27PM +0000, Peter Maydell wrote:
> On Fri, 27 Nov 2020 at 17:18, Eduardo Habkost <ehabkost@redhat.com> wrote:
> > Thanks!  Is the data returned by kvm_arm_get_host_cpu_features()
> > supposed to eventually affect the value of id_aa64mmfr0?  I don't
> > see how that could happen.
> 
> kvm_arm_get_host_cpu_features() does:
>         err |= read_sys_reg64(fdarray[2], &ahcf->isar.id_aa64mmfr0,
>                               ARM64_SYS_REG(3, 0, 0, 7, 0));
> 
> which is filling in data in the ARMHostCPUFeatures* that it is
> passed as an argument. The caller is kvm_arm_set_cpu_features_from_host(),
> which does
>  kvm_arm_get_host_cpu_features(&arm_host_cpu_features)
> (assuming it hasn't already done it once and cached the results;
> arm_host_cpu_features is a global) and then
>  cpu->isar = arm_host_cpu_features.isar;
> thus copying the ID values into the "struct ARMISARegisters isar"
> that is part of the ARMCPU struct. (It also copies across the
> 'features' word which gets set up with ARM_FEATURE_* flags
> for the benefit of the parts of the target code which key off
> those rather than ID register fields.)

Thanks!  For some reason I missed the line above when grepping
for id_aa64mmfr0.

-- 
Eduardo