Registers x0/x1 get repeateadly pushed and poped during a host HVC call. Instead, leave the registers on the stack, trading a store instruction on the fast path for an add on the slow path.
Reviewed-by: Alexandru Elisei <[email protected]> Signed-off-by: Marc Zyngier <[email protected]> --- arch/arm64/kvm/hyp/nvhe/host.S | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S index 4e207c1c5126..fe2740b224cf 100644 --- a/arch/arm64/kvm/hyp/nvhe/host.S +++ b/arch/arm64/kvm/hyp/nvhe/host.S @@ -13,8 +13,6 @@ .text SYM_FUNC_START(__host_exit) - stp x0, x1, [sp, #-16]! - get_host_ctxt x0, x1 /* Store the host regs x2 and x3 */ @@ -99,13 +97,15 @@ SYM_FUNC_END(__hyp_do_panic) mrs x0, esr_el2 lsr x0, x0, #ESR_ELx_EC_SHIFT cmp x0, #ESR_ELx_EC_HVC64 - ldp x0, x1, [sp], #16 b.ne __host_exit + ldp x0, x1, [sp] // Don't fixup the stack yet + /* Check for a stub HVC call */ cmp x0, #HVC_STUB_HCALL_NR b.hs __host_exit + add sp, sp, #16 /* * Compute the idmap address of __kvm_handle_stub_hvc and * jump there. Since we use kimage_voffset, do not use the -- 2.28.0 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
