[PATCH v4 02/28] arm64: KVM: Move lr save/restore to do_el2_call
From: Marc Zyngier <hidden>
Date: 2017-03-23 11:57:12
Also in:
kvm, kvmarm
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
On 21/03/17 19:20, Marc Zyngier wrote:
quoted hunk ↗ jump to hunk
At the moment, we only save/restore lr if on VHE, as we rely only the EL1 code to have preserved it in the non-VHE case. As we're about to get rid of the latter, let's move the save/restore code to the do_el2_call macro, unifying both code paths. Signed-off-by: Marc Zyngier <redacted> --- arch/arm64/kvm/hyp/hyp-entry.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S index 5e9052f087f2..d8ef788646c6 100644 --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S@@ -32,17 +32,17 @@ * Shuffle the parameters before calling the function * pointed to in x0. Assumes parameters in x[1,2,3]. */ + str lr, [sp, #-16]! mov lr, x0 mov x0, x1 mov x1, x2 mov x2, x3 blr lr + ldr lr, [sp], #16 .endm ENTRY(__vhe_hyp_call) - str lr, [sp, #-16]! do_el2_call - ldr lr, [sp], #16 /* * We used to rely on having an exception return to get * an implicit isb. In the E2H case, we don't have it anymore.
As a follow-up on this patch, here's a nit I missed where we were still saving lr in the EL2 entry code. Doesn't affect functionality, but might as well clean that one up (and kill an obscure comment):
diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
index 09391cf0c93c..952f6cb9cf72 100644
--- a/arch/arm64/kvm/hyp.S
+++ b/arch/arm64/kvm/hyp.S@@ -38,13 +38,10 @@ * A function pointer with a value less than 0xfff has a special meaning, * and is used to implement hyp stubs in the same way as in * arch/arm64/kernel/hyp_stub.S. - * HVC behaves as a 'bl' call and will clobber lr. */ ENTRY(__kvm_call_hyp) alternative_if_not ARM64_HAS_VIRT_HOST_EXTN - str lr, [sp, #-16]! hvc #0 - ldr lr, [sp], #16 ret alternative_else_nop_endif b __vhe_hyp_call
I'll squash it locally. Thanks, M. -- Jazz is not dead. It just smells funny...