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KVM: PPC: Book3S HV: Fix incorrect branch in H_CEDE code 

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>
This commit is contained in:
Paul Mackerras 2012-08-06 00:03:28 +00:00 committed by Alexander Graf
parent 439793d4b3
commit 04f995a544
1 changed files with 7 additions and 5 deletions
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12
arch/powerpc/kvm/book3s_hv_rmhandlers.S
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@ -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: