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Commit e1f8acf8 authored by Alexander Graf's avatar Alexander Graf Committed by Paul Mackerras
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KVM: PPC: Save/Restore CR over vcpu_run 



On PPC, CR2-CR4 are nonvolatile, thus have to be saved across function calls.
We didn't respect that for any architecture until Paul spotted it in his
patch for Book3S-HV. This patch saves/restores CR for all KVM capable PPC hosts.

Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent a5ddea0e

arch/powerpc/kvm/book3s_interrupts.S

+7 −0
Original line number Diff line number Diff line
@@ -84,6 +84,10 @@ kvm_start_entry: 
	/* Save non-volatile registers (r14 - r31) */

	SAVE_NVGPRS(r1)



	/* Save CR */

	mfcr	r14

	stw	r14, _CCR(r1)



	/* Save LR */

	PPC_STL	r0, _LINK(r1)
@@ -165,6 +169,9 @@ kvm_exit_loop: 
	PPC_LL	r4, _LINK(r1)

	mtlr	r4



	lwz	r14, _CCR(r1)

	mtcr	r14



	/* Restore non-volatile host registers (r14 - r31) */

	REST_NVGPRS(r1)

arch/powerpc/kvm/booke_interrupts.S

+6 −1
Original line number Diff line number Diff line
@@ -34,7 +34,8 @@ 
/* r2 is special: it holds 'current', and it made nonvolatile in the

 * kernel with the -ffixed-r2 gcc option. */

#define HOST_R2         12

#define HOST_NV_GPRS    16

#define HOST_CR         16

#define HOST_NV_GPRS    20

#define HOST_NV_GPR(n)  (HOST_NV_GPRS + ((n - 14) * 4))

#define HOST_MIN_STACK_SIZE (HOST_NV_GPR(31) + 4)

#define HOST_STACK_SIZE (((HOST_MIN_STACK_SIZE + 15) / 16) * 16) /* Align. */
@@ -296,8 +297,10 @@ heavyweight_exit: 


	/* Return to kvm_vcpu_run(). */

	lwz	r4, HOST_STACK_LR(r1)

	lwz	r5, HOST_CR(r1)

	addi	r1, r1, HOST_STACK_SIZE

	mtlr	r4

	mtcr	r5

	/* r3 still contains the return code from kvmppc_handle_exit(). */

	blr
@@ -314,6 +317,8 @@ _GLOBAL(__kvmppc_vcpu_run) 
	stw	r3, HOST_RUN(r1)

	mflr	r3

	stw	r3, HOST_STACK_LR(r1)

	mfcr	r5

	stw	r5, HOST_CR(r1)



	/* Save host non-volatile register state to stack. */

	stw	r14, HOST_NV_GPR(r14)(r1)