On Tue, Mar 21, 2017 at 07:20:35PM +0000, Marc Zyngier wrote: > In order to restore HYP mode to its original condition, KVM currently > implements __kvm_hyp_reset(). As we're moving towards a hyp-stub > defined API, it becomes necessary to implement HVC_RESET_VECTORS. > > This patch adds the HVC_RESET_VECTORS hypercall to the KVM init > code, which so far lacked any form of hypercall support. > > Reviewed-by: James Morse <james.morse@xxxxxxx> > Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> > --- > arch/arm64/kvm/hyp-init.S | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S > index 6b29d3d9e1f2..6cf98ccd10f2 100644 > --- a/arch/arm64/kvm/hyp-init.S > +++ b/arch/arm64/kvm/hyp-init.S > @@ -22,6 +22,7 @@ > #include <asm/kvm_mmu.h> > #include <asm/pgtable-hwdef.h> > #include <asm/sysreg.h> > +#include <asm/virt.h> > > .text > .pushsection .hyp.idmap.text, "ax" > @@ -58,6 +59,9 @@ __invalid: > * x2: HYP vectors > */ > __do_hyp_init: > + /* Check for a stub HVC call */ > + cmp x0, #HVC_STUB_HCALL_NR > + b.lo __kvm_handle_stub_hvc > > msr ttbr0_el2, x0 > > @@ -119,6 +123,9 @@ __do_hyp_init: > eret > ENDPROC(__kvm_hyp_init) > > +ENTRY(__kvm_handle_stub_hvc) > + cmp x0, #HVC_RESET_VECTORS > + b.ne 1f > /* > * Reset kvm back to the hyp stub. > */ > @@ -133,9 +140,14 @@ ENTRY(__kvm_hyp_reset) > /* Install stub vectors */ > adr_l x0, __hyp_stub_vectors > msr vbar_el2, x0 > + b exit > > +1: mov x0, #-1 nit: do we have the -1 return value documented somewhere and should we define it as HVC_SUB_ERR_RETURN or something like that? > + > +exit: > eret > ENDPROC(__kvm_hyp_reset) > +ENDPROC(__kvm_handle_stub_hvc) > > .ltorg > > -- > 2.11.0 > Thanks, -Christoffer
