| Message ID | 1453737235-16522-17-git-send-email-marc.zyngier@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Jan 25, 2016 at 03:53:50PM +0000, Marc Zyngier wrote: > Despite the fact that a VHE enabled kernel runs at EL2, it uses > CPACR_EL1 to trap FPSIMD access. Add the required alternative > code to re-enable guest FPSIMD access when it has trapped to > EL2. > > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> > --- > arch/arm64/kvm/hyp/entry.S | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S > index fd0fbe9..759a0ec 100644 > --- a/arch/arm64/kvm/hyp/entry.S > +++ b/arch/arm64/kvm/hyp/entry.S > @@ -130,9 +130,15 @@ ENDPROC(__guest_exit) > ENTRY(__fpsimd_guest_restore) > stp x4, lr, [sp, #-16]! > > +alternative_if_not ARM64_HAS_VIRT_HOST_EXTN > mrs x2, cptr_el2 > bic x2, x2, #CPTR_EL2_TFP > msr cptr_el2, x2 > +alternative_else > + mrs x2, cpacr_el1 > + orr x2, x2, #(3 << 20) nit: bitfield definition again > + msr cpacr_el1, x2 > +alternative_endif > isb > > mrs x3, tpidr_el2 > -- > 2.1.4 > Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S index fd0fbe9..759a0ec 100644 --- a/arch/arm64/kvm/hyp/entry.S +++ b/arch/arm64/kvm/hyp/entry.S @@ -130,9 +130,15 @@ ENDPROC(__guest_exit) ENTRY(__fpsimd_guest_restore) stp x4, lr, [sp, #-16]! +alternative_if_not ARM64_HAS_VIRT_HOST_EXTN mrs x2, cptr_el2 bic x2, x2, #CPTR_EL2_TFP msr cptr_el2, x2 +alternative_else + mrs x2, cpacr_el1 + orr x2, x2, #(3 << 20) + msr cpacr_el1, x2 +alternative_endif isb mrs x3, tpidr_el2
Despite the fact that a VHE enabled kernel runs at EL2, it uses CPACR_EL1 to trap FPSIMD access. Add the required alternative code to re-enable guest FPSIMD access when it has trapped to EL2. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> --- arch/arm64/kvm/hyp/entry.S | 6 ++++++ 1 file changed, 6 insertions(+)