Patchwork [13/38] KVM: PPC: Book3S HV: Fix incorrect branch in H_CEDE code

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Submitter Alexander Graf
Date Aug. 14, 2012, 11:04 p.m.
Message ID <1344985483-7440-14-git-send-email-agraf@suse.de>
Download mbox | patch
Permalink /patch/177502/
State New
Headers show

Comments

Alexander Graf - Aug. 14, 2012, 11:04 p.m.
From: Paul Mackerras <paulus@samba.org>

In handling the H_CEDE hypercall, if this vcpu has already been
prodded (with the H_PROD hypercall, which Linux guests don't in fact
use), we branch to a numeric label '1f'.  Unfortunately there is
another '1:' label before the one that we want to jump to.  This fixes
the problem by using a textual label, 'kvm_cede_prodded'.  It also
changes the label for another longish branch from '2:' to
'kvm_cede_exit' to avoid a possible future problem if code modifications
add another numeric '2:' label in between.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
 arch/powerpc/kvm/book3s_hv_rmhandlers.S |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)

Patch

diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 5a84c8d..44b72fe 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1421,13 +1421,13 @@  _GLOBAL(kvmppc_h_cede)
 	sync			/* order setting ceded vs. testing prodded */
 	lbz	r5,VCPU_PRODDED(r3)
 	cmpwi	r5,0
-	bne	1f
+	bne	kvm_cede_prodded
 	li	r0,0		/* set trap to 0 to say hcall is handled */
 	stw	r0,VCPU_TRAP(r3)
 	li	r0,H_SUCCESS
 	std	r0,VCPU_GPR(R3)(r3)
 BEGIN_FTR_SECTION
-	b	2f		/* just send it up to host on 970 */
+	b	kvm_cede_exit	/* just send it up to host on 970 */
 END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_206)
 
 	/*
@@ -1446,7 +1446,7 @@  END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_206)
 	or	r4,r4,r0
 	PPC_POPCNTW(R7,R4)
 	cmpw	r7,r8
-	bge	2f
+	bge	kvm_cede_exit
 	stwcx.	r4,0,r6
 	bne	31b
 	li	r0,1
@@ -1555,7 +1555,8 @@  kvm_end_cede:
 	b	hcall_real_fallback
 
 	/* cede when already previously prodded case */
-1:	li	r0,0
+kvm_cede_prodded:
+	li	r0,0
 	stb	r0,VCPU_PRODDED(r3)
 	sync			/* order testing prodded vs. clearing ceded */
 	stb	r0,VCPU_CEDED(r3)
@@ -1563,7 +1564,8 @@  kvm_end_cede:
 	blr
 
 	/* we've ceded but we want to give control to the host */
-2:	li	r3,H_TOO_HARD
+kvm_cede_exit:
+	li	r3,H_TOO_HARD
 	blr
 
 secondary_too_late: