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Commit 6f597c6b authored by Simon Guo's avatar Simon Guo Committed by Paul Mackerras
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KVM: PPC: Book3S PR: Add guest MSR parameter for kvmppc_save_tm()/kvmppc_restore_tm() 



HV KVM and PR KVM need different MSR source to indicate whether
treclaim. or trecheckpoint. is necessary.

This patch add new parameter (guest MSR) for these kvmppc_save_tm/
kvmppc_restore_tm() APIs:
- For HV KVM, it is VCPU_MSR
- For PR KVM, it is current host MSR or VCPU_SHADOW_SRR1

This enhancement enables these 2 APIs to be reused by PR KVM later.
And the patch keeps HV KVM logic unchanged.

This patch also reworks kvmppc_save_tm()/kvmppc_restore_tm() to
have a clean ABI: r3 for vcpu and r4 for guest_msr.

During kvmppc_save_tm/kvmppc_restore_tm(), the R1 need to be saved
or restored. Currently the R1 is saved into HSTATE_HOST_R1. In PR
KVM, we are going to add a C function wrapper for
kvmppc_save_tm/kvmppc_restore_tm() where the R1 will be incremented
with added stackframe and save into HSTATE_HOST_R1. There are several
places in HV KVM to load HSTATE_HOST_R1 as R1, and we don't want to
bring risk or confusion by TM code.

This patch will use HSTATE_SCRATCH2 to save/restore R1 in
kvmppc_save_tm/kvmppc_restore_tm() to avoid future confusion, since
the r1 is actually a temporary/scratch value to be saved/stored.

[paulus@ozlabs.org - rebased on top of 7b0e827c ("KVM: PPC: Book3S HV:
 Factor fake-suspend handling out of kvmppc_save/restore_tm", 2018-05-30)]

Signed-off-by: default avatarSimon Guo <wei.guo.simon@gmail.com>
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
parent 009c872a

arch/powerpc/kvm/book3s_hv_rmhandlers.S

+21 −12
Original line number Diff line number Diff line
@@ -793,7 +793,10 @@ END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0) 
	/*

	 * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR

	 */

	mr      r3, r4

	ld      r4, VCPU_MSR(r3)

	bl	kvmppc_restore_tm_hv

	ld	r4, HSTATE_KVM_VCPU(r13)

91:

#endif
@@ -1777,7 +1780,10 @@ END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0) 
	/*

	 * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR

	 */

	mr      r3, r9

	ld      r4, VCPU_MSR(r3)

	bl	kvmppc_save_tm_hv

	ld	r9, HSTATE_KVM_VCPU(r13)

91:

#endif
@@ -2680,7 +2686,8 @@ END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0) 
	/*

	 * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR

	 */

	ld	r9, HSTATE_KVM_VCPU(r13)

	ld	r3, HSTATE_KVM_VCPU(r13)

	ld      r4, VCPU_MSR(r3)

	bl	kvmppc_save_tm_hv

91:

#endif
@@ -2799,7 +2806,10 @@ END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0) 
	/*

	 * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR

	 */

	mr      r3, r4

	ld      r4, VCPU_MSR(r3)

	bl	kvmppc_restore_tm_hv

	ld	r4, HSTATE_KVM_VCPU(r13)

91:

#endif
@@ -3120,9 +3130,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) 
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM

/*

 * Save transactional state and TM-related registers.

 * Called with r9 pointing to the vcpu struct.

 * Called with r3 pointing to the vcpu struct and r4 containing

 * the guest MSR value.

 * This can modify all checkpointed registers, but

 * restores r1, r2 and r9 (vcpu pointer) before exit.

 * restores r1 and r2 before exit.

 */

kvmppc_save_tm_hv:

	/* See if we need to handle fake suspend mode */
@@ -3205,9 +3216,10 @@ END_FTR_SECTION_NESTED(CPU_FTR_P9_TM_XER_SO_BUG, CPU_FTR_P9_TM_XER_SO_BUG, 96) 


/*

 * Restore transactional state and TM-related registers.

 * Called with r4 pointing to the vcpu struct.

 * Called with r3 pointing to the vcpu struct

 * and r4 containing the guest MSR value.

 * This potentially modifies all checkpointed registers.

 * It restores r1, r2, r4 from the PACA.

 * It restores r1 and r2 from the PACA.

 */

kvmppc_restore_tm_hv:

	/*
@@ -3234,15 +3246,14 @@ END_FTR_SECTION_IFCLR(CPU_FTR_P9_TM_HV_ASSIST) 
	 * The user may change these outside of a transaction, so they must

	 * always be context switched.

	 */

	ld	r5, VCPU_TFHAR(r4)

	ld	r6, VCPU_TFIAR(r4)

	ld	r7, VCPU_TEXASR(r4)

	ld	r5, VCPU_TFHAR(r3)

	ld	r6, VCPU_TFIAR(r3)

	ld	r7, VCPU_TEXASR(r3)

	mtspr	SPRN_TFHAR, r5

	mtspr	SPRN_TFIAR, r6

	mtspr	SPRN_TEXASR, r7



	ld	r5, VCPU_MSR(r4)

	rldicl. r5, r5, 64 - MSR_TS_S_LG, 62

	rldicl. r5, r4, 64 - MSR_TS_S_LG, 62

	beqlr		/* TM not active in guest */



	/* Make sure the failure summary is set */
@@ -3255,10 +3266,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_P9_TM_HV_ASSIST) 
	b	9f		/* and return */

10:	stdu	r1, -PPC_MIN_STKFRM(r1)

	/* guest is in transactional state, so simulate rollback */

	mr	r3, r4

	bl	kvmhv_emulate_tm_rollback

	nop

	ld      r4, HSTATE_KVM_VCPU(r13) /* our vcpu pointer has been trashed */

	addi	r1, r1, PPC_MIN_STKFRM

9:	ld	r0, PPC_LR_STKOFF(r1)

	mtlr	r0

arch/powerpc/kvm/tm.S

+36 −35
Original line number Diff line number Diff line
@@ -26,9 +26,12 @@ 


/*

 * Save transactional state and TM-related registers.

 * Called with r9 pointing to the vcpu struct.

 * Called with:

 * - r3 pointing to the vcpu struct

 * - r4 points to the MSR with current TS bits:

 * 	(For HV KVM, it is VCPU_MSR ; For PR KVM, it is host MSR).

 * This can modify all checkpointed registers, but

 * restores r1, r2 and r9 (vcpu pointer) before exit.

 * restores r1, r2 before exit.

 */

_GLOBAL(kvmppc_save_tm)

	mflr	r0
@@ -40,20 +43,17 @@ _GLOBAL(kvmppc_save_tm) 
	rldimi	r8, r0, MSR_TM_LG, 63-MSR_TM_LG

	mtmsrd	r8



#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE

	ld	r5, VCPU_MSR(r9)

	rldicl. r5, r5, 64 - MSR_TS_S_LG, 62

	rldicl. r4, r4, 64 - MSR_TS_S_LG, 62

	beq	1f	/* TM not active in guest. */

#endif



	std	r1, HSTATE_HOST_R1(r13)

	li	r3, TM_CAUSE_KVM_RESCHED

	std	r1, HSTATE_SCRATCH2(r13)

	std	r3, HSTATE_SCRATCH1(r13)



#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE

BEGIN_FTR_SECTION

	/* Emulation of the treclaim instruction needs TEXASR before treclaim */

	mfspr	r6, SPRN_TEXASR

	std	r6, VCPU_ORIG_TEXASR(r9)

	std	r6, VCPU_ORIG_TEXASR(r3)

END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST)

#endif
@@ -61,6 +61,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST) 
	li	r5, 0

	mtmsrd	r5, 1



	li	r3, TM_CAUSE_KVM_RESCHED



	/* All GPRs are volatile at this point. */

	TRECLAIM(R3)
@@ -68,9 +70,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST) 
	SET_SCRATCH0(r13)

	GET_PACA(r13)

	std	r9, PACATMSCRATCH(r13)

#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE

	ld	r9, HSTATE_KVM_VCPU(r13)

#endif

	ld	r9, HSTATE_SCRATCH1(r13)



	/* Get a few more GPRs free. */

	std	r29, VCPU_GPRS_TM(29)(r9)
@@ -102,7 +102,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST) 
	std	r4, VCPU_GPRS_TM(9)(r9)



	/* Reload stack pointer and TOC. */

	ld	r1, HSTATE_HOST_R1(r13)

	ld	r1, HSTATE_SCRATCH2(r13)

	ld	r2, PACATOC(r13)



	/* Set MSR RI now we have r1 and r13 back. */
@@ -156,9 +156,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST) 


/*

 * Restore transactional state and TM-related registers.

 * Called with r4 pointing to the vcpu struct.

 * Called with:

 *  - r3 pointing to the vcpu struct.

 *  - r4 is the guest MSR with desired TS bits:

 * 	For HV KVM, it is VCPU_MSR

 * 	For PR KVM, it is provided by caller

 * This potentially modifies all checkpointed registers.

 * It restores r1, r2, r4 from the PACA.

 * It restores r1, r2 from the PACA.

 */

_GLOBAL(kvmppc_restore_tm)

	mflr	r0
@@ -177,19 +181,17 @@ _GLOBAL(kvmppc_restore_tm) 
	 * The user may change these outside of a transaction, so they must

	 * always be context switched.

	 */

	ld	r5, VCPU_TFHAR(r4)

	ld	r6, VCPU_TFIAR(r4)

	ld	r7, VCPU_TEXASR(r4)

	ld	r5, VCPU_TFHAR(r3)

	ld	r6, VCPU_TFIAR(r3)

	ld	r7, VCPU_TEXASR(r3)

	mtspr	SPRN_TFHAR, r5

	mtspr	SPRN_TFIAR, r6

	mtspr	SPRN_TEXASR, r7



#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE

	ld	r5, VCPU_MSR(r4)

	mr	r5, r4

	rldicl. r5, r5, 64 - MSR_TS_S_LG, 62

	beqlr		/* TM not active in guest */

#endif

	std	r1, HSTATE_HOST_R1(r13)

	std	r1, HSTATE_SCRATCH2(r13)



	/* Make sure the failure summary is set, otherwise we'll program check

	 * when we trechkpt.  It's possible that this might have been not set
@@ -205,21 +207,21 @@ _GLOBAL(kvmppc_restore_tm) 
	 * some SPRs.

	 */



	mr	r31, r4

	mr	r31, r3

	addi	r3, r31, VCPU_FPRS_TM

	bl	load_fp_state

	addi	r3, r31, VCPU_VRS_TM

	bl	load_vr_state

	mr	r4, r31

	lwz	r7, VCPU_VRSAVE_TM(r4)

	mr	r3, r31

	lwz	r7, VCPU_VRSAVE_TM(r3)

	mtspr	SPRN_VRSAVE, r7



	ld	r5, VCPU_LR_TM(r4)

	lwz	r6, VCPU_CR_TM(r4)

	ld	r7, VCPU_CTR_TM(r4)

	ld	r8, VCPU_AMR_TM(r4)

	ld	r9, VCPU_TAR_TM(r4)

	ld	r10, VCPU_XER_TM(r4)

	ld	r5, VCPU_LR_TM(r3)

	lwz	r6, VCPU_CR_TM(r3)

	ld	r7, VCPU_CTR_TM(r3)

	ld	r8, VCPU_AMR_TM(r3)

	ld	r9, VCPU_TAR_TM(r3)

	ld	r10, VCPU_XER_TM(r3)

	mtlr	r5

	mtcr	r6

	mtctr	r7
@@ -232,8 +234,8 @@ _GLOBAL(kvmppc_restore_tm) 
	 * till the last moment to avoid running with userspace PPR and DSCR for

	 * too long.

	 */

	ld	r29, VCPU_DSCR_TM(r4)

	ld	r30, VCPU_PPR_TM(r4)

	ld	r29, VCPU_DSCR_TM(r3)

	ld	r30, VCPU_PPR_TM(r3)



	std	r2, PACATMSCRATCH(r13) /* Save TOC */
@@ -265,9 +267,8 @@ _GLOBAL(kvmppc_restore_tm) 
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE

	ld	r29, HSTATE_DSCR(r13)

	mtspr	SPRN_DSCR, r29

	ld	r4, HSTATE_KVM_VCPU(r13)

#endif

	ld	r1, HSTATE_HOST_R1(r13)

	ld	r1, HSTATE_SCRATCH2(r13)

	ld	r2, PACATMSCRATCH(r13)



	/* Set the MSR RI since we have our registers back. */