diff options
| author | Marc Zyngier <maz@kernel.org> | 2020-10-24 10:56:55 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2020-11-27 11:32:44 +0000 |
| commit | 83fa381f66ccb025f9e182d0b2ef9cd53c1f33ab (patch) | |
| tree | 207b2b322e52a2bac4d1d069a17e6c141f3116b0 /arch/arm64/kvm/hyp/nvhe/host.S | |
| parent | 29052f1b92f2bcb0419c544459f4c919bfb20898 (diff) | |
KVM: arm64: Avoid repetitive stack access on host EL1 to EL2 exception
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 <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe/host.S')
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/host.S | 6 |
1 files 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 |