Re: [PATCH v2 6/6] KVM: arm64: initialise SCTLR2_EL1 at __kvm_host_psci_cpu_entry()
From: Marc Zyngier
Date: Tue Aug 12 2025 - 06:11:25 EST
On Mon, 11 Aug 2025 20:43:00 +0100,
Yeoreum Yun <yeoreum.yun@xxxxxxx> wrote:
>
> Hi Marc,
>
> > > initialise SCTLR2_EL1 at __kvm_host_psci_cpu_entry().
> >
> > Same comment, I don't think this is an acceptable commit message.
> > Please ask for help if you don't feel confident writing it (I'm sure
> > some of your colleagues will be happy to help).
>
> Okay. I'll rewrite the commit message
>
> > > @@ -219,6 +220,8 @@ asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on)
> > > release_boot_args(boot_args);
> > >
> > > write_sysreg_el1(INIT_SCTLR_EL1_MMU_OFF, SYS_SCTLR);
> > > + if (alternative_has_cap_unlikely(ARM64_HAS_SCTLR2))
> > > + write_sysreg_el1(INIT_SCTLR2_EL1, SYS_SCTLR2);
> > > write_sysreg(INIT_PSTATE_EL1, SPSR_EL2);
> > >
> > > __host_enter(host_ctxt);
> >
> > This needs to be folded into patch #1.
> >
> > Otherwise, there is a window of patches where the kernel will not
> > survive CPU hotplug when booted in protected mode.
>
> Do you mean fold this patch into patch #2 where initialise
> SCTLR2_ELx?
Yes, sorry, I got it mixed with HCRX_EL2. Patch #2 is where it should
land indeed.
M.
--
Without deviation from the norm, progress is not possible.