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Commit 04f995a5 authored by Paul Mackerras's avatar Paul Mackerras Committed by Alexander Graf
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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: default avatarPaul Mackerras <paulus@samba.org>
Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
parent 439793d4

arch/powerpc/kvm/book3s_hv_rmhandlers.S

+7 −5
Original line number Diff line number Diff line
@@ -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: