Thread (4 messages) 4 messages, 3 authors, 2020-01-20

Re: [PATCH] arm64: kvm: Annotate guest entry/exit as a single function

From: Marc Zyngier <maz@kernel.org>
Date: 2020-01-20 16:59:15

On 2020-01-20 16:45, Will Deacon wrote:
[+Marc Z]
Thanks for the heads up!
On Mon, Jan 20, 2020 at 12:47:06PM +0000, Mark Brown wrote:
quoted
In an effort to clarify and simplify the annotations of assembly
functions in the kernel new macros have been introduced replacing 
ENTRY
and ENDPROC. There are separate annotations SYM_FUNC_ for normal C
functions and SYM_CODE_ for other code. Currently __guest_enter and
__guest_exit are annotated as standard functions but this is not
entirely correct as the former doesn't do a normal return and the 
latter
is not entered in a normal fashion. From the point of view of the
hypervisor the guest entry/exit may be viewed as a single
function which happens to have an eret in the middle of it so let's
annotate it as such.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 arch/arm64/kvm/hyp/entry.S | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S
index e5cc8d66bf53..5b76a89939b1 100644
--- a/arch/arm64/kvm/hyp/entry.S
+++ b/arch/arm64/kvm/hyp/entry.S
@@ -44,7 +44,7 @@
  * u64 __guest_enter(struct kvm_vcpu *vcpu,
  *		     struct kvm_cpu_context *host_ctxt);
  */
-ENTRY(__guest_enter)
+SYM_FUNC_START(__guest_enter)
 	// x0: vcpu
 	// x1: host context
 	// x2-x17: clobbered by macros
@@ -96,9 +96,8 @@ alternative_else_nop_endif
 	// Do not touch any register after this!
 	eret
 	sb
-ENDPROC(__guest_enter)

-ENTRY(__guest_exit)
+SYM_INNER_LABEL(__guest_exit, SYM_L_GLOBAL)
 	// x0: return code
 	// x1: vcpu
 	// x2-x29,lr: vcpu regs
@@ -192,4 +191,4 @@ abort_guest_exit_end:
 	msr	spsr_el2, x4
 	orr	x0, x0, x5
 1:	ret
-ENDPROC(__guest_exit)
+SYM_FUNC_END(__guest_enter)
I wondered what the INNER_LABEL thing was for! Looks good:

Acked-by: Will Deacon <will@kernel.org>

Assuming this is going via the kvm tree.
Yup, I've now picked it up.

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...

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