On Tue, Dec 10, 2024 at 09:24:03PM +0000, Marc Zyngier wrote:
> > +static int a6xx_switch_secure_mode(struct msm_gpu *gpu)
> > +{
> > + int ret;
> > +
> > +#ifdef CONFIG_ARM64
> > + /*
> > + * We can access SECVID_TRUST_CNTL register when kernel is booted in EL2 mode. So, use it
> > + * to switch the secure mode to avoid the dependency on zap shader.
> > + */
> > + if (is_kernel_in_hyp_mode())
> > + goto direct_switch;
>
> No, please. To check whether you are *booted* at EL2, you need to
> check for is_hyp_available(). Whether the kernel runs at EL1 or EL2 is
> none of the driver's business, really. This is still absolutely
> disgusting from an abstraction perspective, but I guess we don't have
> much choice here.
>
Thanks Marc. Any suggestions on how we can make is_hyp_mode_available()
available for modules? Do you prefer exporting
kvm_protected_mode_initialized and __boot_cpu_mode symbols directly or
try something like [1]?
[1]
https://lore.kernel.org/lkml/1443649252-10702-1-git-send-email-ralf@xxxxxxxxxxxxxxxxxxxxxx/#t
Thanks,
Pavan
