Similar to the arm64 version, add the code that deals with VFP traps, re-enabling VFP, save/restoring the registers and resuming the guest.
Reviewed-by: Christoffer Dall <[email protected]> Signed-off-by: Marc Zyngier <[email protected]> --- arch/arm/kvm/hyp/entry.S | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/arch/arm/kvm/hyp/entry.S b/arch/arm/kvm/hyp/entry.S index 32f79b0..21c2388 100644 --- a/arch/arm/kvm/hyp/entry.S +++ b/arch/arm/kvm/hyp/entry.S @@ -66,5 +66,36 @@ ENTRY(__guest_exit) bx lr ENDPROC(__guest_exit) +/* + * If VFPv3 support is not available, then we will not switch the VFP + * registers; however cp10 and cp11 accesses will still trap and fallback + * to the regular coprocessor emulation code, which currently will + * inject an undefined exception to the guest. + */ +#ifdef CONFIG_VFPv3 +ENTRY(__vfp_guest_restore) + push {r3, r4, lr} + + @ NEON/VFP used. Turn on VFP access. + mrc p15, 4, r1, c1, c1, 2 @ HCPTR + bic r1, r1, #(HCPTR_TCP(10) | HCPTR_TCP(11)) + mcr p15, 4, r1, c1, c1, 2 @ HCPTR + isb + + @ Switch VFP/NEON hardware state to the guest's + mov r4, r0 + ldr r0, [r0, #VCPU_HOST_CTXT] + add r0, r0, #CPU_CTXT_VFP + bl __vfp_save_state + add r0, r4, #(VCPU_GUEST_CTXT + CPU_CTXT_VFP) + bl __vfp_restore_state + + pop {r3, r4, lr} + pop {r0, r1, r2} + clrex + eret +ENDPROC(__vfp_guest_restore) +#endif + .popsection -- 2.1.4 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
