This adds a parameter to __kvmppc_save_tm and __kvmppc_restore_tm
which allows the caller to indicate whether it wants the nonvolatile
register state to be preserved across the call, as required by the C
calling conventions. This parameter being non-zero also causes the
MSR bits that enable TM, FP, VMX and VSX to be preserved. The
condition register and DSCR are now always preserved.
With this, kvmppc_save_tm_hv and kvmppc_restore_tm_hv can be called
from C code provided the 3rd parameter is non-zero. So that these
functions can be called from modules, they now include code to set
the TOC pointer (r2) on entry, as they can call other built-in C
functions which will assume the TOC to have been set.
Also, the fake suspend code in kvmppc_save_tm_hv is modified here to
assume that treclaim in fake-suspend state does not modify any registers,
which is the case on POWER9. This enables the code to be simplified
quite a bit.
_kvmppc_save_tm_pr and _kvmppc_restore_tm_pr become much simpler with
this change, since they now only need to save and restore TAR and pass
1 for the 3rd argument to __kvmppc_{save,restore}_tm.
Signed-off-by: Paul Mackerras <paulus@xxxxxxxxxx>
---
arch/powerpc/include/asm/asm-prototypes.h | 10 ++
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 49 +++---
arch/powerpc/kvm/tm.S | 250 ++++++++++++++++--------------
3 files changed, 169 insertions(+), 140 deletions(-)
diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
index 024e8fc..0c1a2b0 100644
--- a/arch/powerpc/include/asm/asm-prototypes.h
+++ b/arch/powerpc/include/asm/asm-prototypes.h
@@ -150,6 +150,16 @@ extern s32 patch__memset_nocache, patch__memcpy_nocache;
extern long flush_count_cache;
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+void kvmppc_save_tm_hv(struct kvm_vcpu *vcpu, u64 msr, bool preserve_nv);
+void kvmppc_restore_tm_hv(struct kvm_vcpu *vcpu, u64 msr, bool preserve_nv);
+#else
+static inline void kvmppc_save_tm_hv(struct kvm_vcpu *vcpu, u64 msr,
+ bool preserve_nv) { }
+static inline void kvmppc_restore_tm_hv(struct kvm_vcpu *vcpu, u64 msr,
+ bool preserve_nv) { }
+#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+
void kvmhv_save_host_pmu(void);
void kvmhv_load_host_pmu(void);
void kvmhv_save_guest_pmu(struct kvm_vcpu *vcpu, bool pmu_in_use);
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 772740d..67a847f 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -759,11 +759,13 @@ BEGIN_FTR_SECTION
b 91f
END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
/*
- * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR
+ * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS (but not CR)
*/
mr r3, r4
ld r4, VCPU_MSR(r3)
+ li r5, 0 /* don't preserve non-vol regs */
bl kvmppc_restore_tm_hv
+ nop
ld r4, HSTATE_KVM_VCPU(r13)
91:
#endif
@@ -1603,11 +1605,13 @@ BEGIN_FTR_SECTION
b 91f
END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
/*
- * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR
+ * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS (but not CR)
*/
mr r3, r9
ld r4, VCPU_MSR(r3)
+ li r5, 0 /* don't preserve non-vol regs */
bl kvmppc_save_tm_hv
+ nop
ld r9, HSTATE_KVM_VCPU(r13)
91:
#endif
@@ -2486,11 +2490,13 @@ BEGIN_FTR_SECTION
b 91f
END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
/*
- * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR
+ * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS (but not CR)
*/
ld r3, HSTATE_KVM_VCPU(r13)
ld r4, VCPU_MSR(r3)
+ li r5, 0 /* don't preserve non-vol regs */
bl kvmppc_save_tm_hv
+ nop
91:
#endif
@@ -2606,11 +2612,13 @@ BEGIN_FTR_SECTION
b 91f
END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
/*
- * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS INCLUDING CR
+ * NOTE THAT THIS TRASHES ALL NON-VOLATILE REGISTERS (but not CR)
*/
mr r3, r4
ld r4, VCPU_MSR(r3)
+ li r5, 0 /* don't preserve non-vol regs */
bl kvmppc_restore_tm_hv
+ nop
ld r4, HSTATE_KVM_VCPU(r13)
91:
#endif
@@ -2943,10 +2951,12 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
* Save transactional state and TM-related registers.
* Called with r3 pointing to the vcpu struct and r4 containing
* the guest MSR value.
- * This can modify all checkpointed registers, but
+ * r5 is non-zero iff non-volatile register state needs to be maintained.
+ * If r5 == 0, this can modify all checkpointed registers, but
* restores r1 and r2 before exit.
*/
-kvmppc_save_tm_hv:
+_GLOBAL_TOC(kvmppc_save_tm_hv)
+EXPORT_SYMBOL_GPL(kvmppc_save_tm_hv)
/* See if we need to handle fake suspend mode */
BEGIN_FTR_SECTION
b __kvmppc_save_tm
@@ -2974,12 +2984,6 @@ BEGIN_FTR_SECTION
END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_XER_SO_BUG)
nop
- std r1, HSTATE_HOST_R1(r13)
-
- /* Clear the MSR RI since r1, r13 may be foobar. */
- li r5, 0
- mtmsrd r5, 1
-
/* We have to treclaim here because that's the only way to do S->N */
li r3, TM_CAUSE_KVM_RESCHED
TRECLAIM(R3)
@@ -2988,22 +2992,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_XER_SO_BUG)
* We were in fake suspend, so we are not going to save the
* register state as the guest checkpointed state (since
* we already have it), therefore we can now use any volatile GPR.
+ * In fact treclaim in fake suspend state doesn't modify
+ * any registers.
*/
- /* Reload PACA pointer, stack pointer and TOC. */
- GET_PACA(r13)
- ld r1, HSTATE_HOST_R1(r13)
- ld r2, PACATOC(r13)
- /* Set MSR RI now we have r1 and r13 back. */
- li r5, MSR_RI
- mtmsrd r5, 1
-
- HMT_MEDIUM
- ld r6, HSTATE_DSCR(r13)
- mtspr SPRN_DSCR, r6
-BEGIN_FTR_SECTION_NESTED(96)
+BEGIN_FTR_SECTION
bl pnv_power9_force_smt4_release
-END_FTR_SECTION_NESTED(CPU_FTR_P9_TM_XER_SO_BUG, CPU_FTR_P9_TM_XER_SO_BUG, 96)
+END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_XER_SO_BUG)
nop
4:
@@ -3029,10 +3024,12 @@ 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 r3 pointing to the vcpu struct
* and r4 containing the guest MSR value.
+ * r5 is non-zero iff non-volatile register state needs to be maintained.
* This potentially modifies all checkpointed registers.
* It restores r1 and r2 from the PACA.
*/
-kvmppc_restore_tm_hv:
+_GLOBAL_TOC(kvmppc_restore_tm_hv)
+EXPORT_SYMBOL_GPL(kvmppc_restore_tm_hv)
/*
* If we are doing TM emulation for the guest on a POWER9 DD2,
* then we don't actually do a trechkpt -- we either set up
diff --git a/arch/powerpc/kvm/tm.S b/arch/powerpc/kvm/tm.S
index 90e330f..0531a14 100644
--- a/arch/powerpc/kvm/tm.S
+++ b/arch/powerpc/kvm/tm.S
@@ -28,17 +28,25 @@
* Save transactional state and TM-related registers.
* Called with:
* - r3 pointing to the vcpu struct
- * - r4 points to the MSR with current TS bits:
+ * - r4 containing 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 before exit.
+ * - r5 containing a flag indicating that non-volatile registers
+ * must be preserved.
+ * If r5 == 0, this can modify all checkpointed registers, but
+ * restores r1, r2 before exit. If r5 != 0, this restores the
+ * MSR TM/FP/VEC/VSX bits to their state on entry.
*/
_GLOBAL(__kvmppc_save_tm)
mflr r0
std r0, PPC_LR_STKOFF(r1)
+ stdu r1, -SWITCH_FRAME_SIZE(r1)
+
+ mr r9, r3
+ cmpdi cr7, r5, 0
/* Turn on TM. */
mfmsr r8
+ mr r10, r8
li r0, 1
rldimi r8, r0, MSR_TM_LG, 63-MSR_TM_LG
ori r8, r8, MSR_FP
@@ -51,6 +59,27 @@ _GLOBAL(__kvmppc_save_tm)
std r1, HSTATE_SCRATCH2(r13)
std r3, HSTATE_SCRATCH1(r13)
+ /* Save CR on the stack - even if r5 == 0 we need to get cr7 back. */
+ mfcr r6
+ SAVE_GPR(6, r1)
+
+ /* Save DSCR so we can restore it to avoid running with user value */
+ mfspr r7, SPRN_DSCR
+ SAVE_GPR(7, r1)
+
+ /*
+ * We are going to do treclaim., which will modify all checkpointed
+ * registers. Save the non-volatile registers on the stack if
+ * preservation of non-volatile state has been requested.
+ */
+ beq cr7, 3f
+ SAVE_NVGPRS(r1)
+
+ /* MSR[TS] will be 0 (non-transactional) once we do treclaim. */
+ li r0, 0
+ rldimi r10, r0, MSR_TS_S_LG, 63 - MSR_TS_T_LG
+ SAVE_GPR(10, r1) /* final MSR value */
+3:
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
BEGIN_FTR_SECTION
/* Emulation of the treclaim instruction needs TEXASR before treclaim */
@@ -74,22 +103,25 @@ END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST)
std r9, PACATMSCRATCH(r13)
ld r9, HSTATE_SCRATCH1(r13)
- /* Get a few more GPRs free. */
- std r29, VCPU_GPRS_TM(29)(r9)
- std r30, VCPU_GPRS_TM(30)(r9)
- std r31, VCPU_GPRS_TM(31)(r9)
-
- /* Save away PPR and DSCR soon so don't run with user values. */
- mfspr r31, SPRN_PPR
+ /* Save away PPR soon so we don't run with user value. */
+ std r0, VCPU_GPRS_TM(0)(r9)
+ mfspr r0, SPRN_PPR
HMT_MEDIUM
- mfspr r30, SPRN_DSCR
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
- ld r29, HSTATE_DSCR(r13)
- mtspr SPRN_DSCR, r29
-#endif
- /* Save all but r9, r13 & r29-r31 */
- reg = 0
+ /* Reload stack pointer. */
+ std r1, VCPU_GPRS_TM(1)(r9)
+ ld r1, HSTATE_SCRATCH2(r13)
+
+ /* Set MSR RI now we have r1 and r13 back. */
+ std r2, VCPU_GPRS_TM(2)(r9)
+ li r2, MSR_RI
+ mtmsrd r2, 1
+
+ /* Reload TOC pointer. */
+ ld r2, PACATOC(r13)
+
+ /* Save all but r0-r2, r9 & r13 */
+ reg = 3
.rept 29
.if (reg != 9) && (reg != 13)
std reg, VCPU_GPRS_TM(reg)(r9)
@@ -103,33 +135,29 @@ END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST)
ld r4, PACATMSCRATCH(r13)
std r4, VCPU_GPRS_TM(9)(r9)
- /* Reload stack pointer and TOC. */
- ld r1, HSTATE_SCRATCH2(r13)
- ld r2, PACATOC(r13)
-
- /* Set MSR RI now we have r1 and r13 back. */
- li r5, MSR_RI
- mtmsrd r5, 1
+ /* Restore host DSCR and CR values, after saving guest values */
+ mfcr r6
+ mfspr r7, SPRN_DSCR
+ stw r6, VCPU_CR_TM(r9)
+ std r7, VCPU_DSCR_TM(r9)
+ REST_GPR(6, r1)
+ REST_GPR(7, r1)
+ mtcr r6
+ mtspr SPRN_DSCR, r7
- /* Save away checkpinted SPRs. */
- std r31, VCPU_PPR_TM(r9)
- std r30, VCPU_DSCR_TM(r9)
+ /* Save away checkpointed SPRs. */
+ std r0, VCPU_PPR_TM(r9)
mflr r5
- mfcr r6
mfctr r7
mfspr r8, SPRN_AMR
mfspr r10, SPRN_TAR
mfxer r11
std r5, VCPU_LR_TM(r9)
- stw r6, VCPU_CR_TM(r9)
std r7, VCPU_CTR_TM(r9)
std r8, VCPU_AMR_TM(r9)
std r10, VCPU_TAR_TM(r9)
std r11, VCPU_XER_TM(r9)
- /* Restore r12 as trap number. */
- lwz r12, VCPU_TRAP(r9)
-
/* Save FP/VSX. */
addi r3, r9, VCPU_FPRS_TM
bl store_fp_state
@@ -137,6 +165,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST)
bl store_vr_state
mfspr r6, SPRN_VRSAVE
stw r6, VCPU_VRSAVE_TM(r9)
+
+ /* Restore non-volatile registers if requested to */
+ beq cr7, 1f
+ REST_NVGPRS(r1)
+ REST_GPR(10, r1)
1:
/*
* We need to save these SPRs after the treclaim so that the software
@@ -146,12 +179,16 @@ END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST)
*/
mfspr r7, SPRN_TEXASR
std r7, VCPU_TEXASR(r9)
-11:
mfspr r5, SPRN_TFHAR
mfspr r6, SPRN_TFIAR
std r5, VCPU_TFHAR(r9)
std r6, VCPU_TFIAR(r9)
+ /* Restore MSR state if requested */
+ beq cr7, 2f
+ mtmsrd r10, 0
+2:
+ addi r1, r1, SWITCH_FRAME_SIZE
ld r0, PPC_LR_STKOFF(r1)
mtlr r0
blr
@@ -161,49 +198,22 @@ END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST)
* be invoked from C function by PR KVM only.
*/
_GLOBAL(_kvmppc_save_tm_pr)
- mflr r5
- std r5, PPC_LR_STKOFF(r1)
- stdu r1, -SWITCH_FRAME_SIZE(r1)
- SAVE_NVGPRS(r1)
-
- /* save MSR since TM/math bits might be impacted
- * by __kvmppc_save_tm().
- */
- mfmsr r5
- SAVE_GPR(5, r1)
-
- /* also save DSCR/CR/TAR so that it can be recovered later */
- mfspr r6, SPRN_DSCR
- SAVE_GPR(6, r1)
-
- mfcr r7
- stw r7, _CCR(r1)
+ mflr r0
+ std r0, PPC_LR_STKOFF(r1)
+ stdu r1, -PPC_MIN_STKFRM(r1)
mfspr r8, SPRN_TAR
- SAVE_GPR(8, r1)
+ std r8, PPC_MIN_STKFRM-8(r1)
+ li r5, 1 /* preserve non-volatile registers */
bl __kvmppc_save_tm
- REST_GPR(8, r1)
+ ld r8, PPC_MIN_STKFRM-8(r1)
mtspr SPRN_TAR, r8
- ld r7, _CCR(r1)
- mtcr r7
-
- REST_GPR(6, r1)
- mtspr SPRN_DSCR, r6
-
- /* need preserve current MSR's MSR_TS bits */
- REST_GPR(5, r1)
- mfmsr r6
- rldicl r6, r6, 64 - MSR_TS_S_LG, 62
- rldimi r5, r6, MSR_TS_S_LG, 63 - MSR_TS_T_LG
- mtmsrd r5
-
- REST_NVGPRS(r1)
- addi r1, r1, SWITCH_FRAME_SIZE
- ld r5, PPC_LR_STKOFF(r1)
- mtlr r5
+ addi r1, r1, PPC_MIN_STKFRM
+ ld r0, PPC_LR_STKOFF(r1)
+ mtlr r0
blr
EXPORT_SYMBOL_GPL(_kvmppc_save_tm_pr);
@@ -215,15 +225,21 @@ EXPORT_SYMBOL_GPL(_kvmppc_save_tm_pr);
* - 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 from the PACA.
+ * - r5 containing a flag indicating that non-volatile registers
+ * must be preserved.
+ * If r5 == 0, this potentially modifies all checkpointed registers, but
+ * restores r1, r2 from the PACA before exit.
+ * If r5 != 0, this restores the MSR TM/FP/VEC/VSX bits to their state on entry.
*/
_GLOBAL(__kvmppc_restore_tm)
mflr r0
std r0, PPC_LR_STKOFF(r1)
+ cmpdi cr7, r5, 0
+
/* Turn on TM/FP/VSX/VMX so we can restore them. */
mfmsr r5
+ mr r10, r5
li r6, MSR_TM >> 32
sldi r6, r6, 32
or r5, r5, r6
@@ -244,8 +260,7 @@ _GLOBAL(__kvmppc_restore_tm)
mr r5, r4
rldicl. r5, r5, 64 - MSR_TS_S_LG, 62
- beqlr /* TM not active in guest */
- std r1, HSTATE_SCRATCH2(r13)
+ beq 9f /* TM not active in guest */
/* 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
@@ -256,6 +271,26 @@ _GLOBAL(__kvmppc_restore_tm)
mtspr SPRN_TEXASR, r7
/*
+ * Make a stack frame and save non-volatile registers if requested.
+ */
+ stdu r1, -SWITCH_FRAME_SIZE(r1)
+ std r1, HSTATE_SCRATCH2(r13)
+
+ mfcr r6
+ mfspr r7, SPRN_DSCR
+ SAVE_GPR(2, r1)
+ SAVE_GPR(6, r1)
+ SAVE_GPR(7, r1)
+
+ beq cr7, 4f
+ SAVE_NVGPRS(r1)
+
+ /* MSR[TS] will be 1 (suspended) once we do trechkpt */
+ li r0, 1
+ rldimi r10, r0, MSR_TS_S_LG, 63 - MSR_TS_T_LG
+ SAVE_GPR(10, r1) /* final MSR value */
+4:
+ /*
* We need to load up the checkpointed state for the guest.
* We need to do this early as it will blow away any GPRs, VSRs and
* some SPRs.
@@ -291,8 +326,6 @@ _GLOBAL(__kvmppc_restore_tm)
ld r29, VCPU_DSCR_TM(r3)
ld r30, VCPU_PPR_TM(r3)
- std r2, PACATMSCRATCH(r13) /* Save TOC */
-
/* Clear the MSR RI since r1, r13 are all going to be foobar. */
li r5, 0
mtmsrd r5, 1
@@ -318,18 +351,31 @@ _GLOBAL(__kvmppc_restore_tm)
/* Now let's get back the state we need. */
HMT_MEDIUM
GET_PACA(r13)
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
- ld r29, HSTATE_DSCR(r13)
- mtspr SPRN_DSCR, r29
-#endif
ld r1, HSTATE_SCRATCH2(r13)
- ld r2, PACATMSCRATCH(r13)
+ REST_GPR(7, r1)
+ mtspr SPRN_DSCR, r7
/* Set the MSR RI since we have our registers back. */
li r5, MSR_RI
mtmsrd r5, 1
+
+ /* Restore TOC pointer and CR */
+ REST_GPR(2, r1)
+ REST_GPR(6, r1)
+ mtcr r6
+
+ /* Restore non-volatile registers if requested to. */
+ beq cr7, 5f
+ REST_GPR(10, r1)
+ REST_NVGPRS(r1)
+
+5: addi r1, r1, SWITCH_FRAME_SIZE
ld r0, PPC_LR_STKOFF(r1)
mtlr r0
+
+9: /* Restore MSR bits if requested */
+ beqlr cr7
+ mtmsrd r10, 0
blr
/*
@@ -337,47 +383,23 @@ _GLOBAL(__kvmppc_restore_tm)
* can be invoked from C function by PR KVM only.
*/
_GLOBAL(_kvmppc_restore_tm_pr)
- mflr r5
- std r5, PPC_LR_STKOFF(r1)
- stdu r1, -SWITCH_FRAME_SIZE(r1)
- SAVE_NVGPRS(r1)
-
- /* save MSR to avoid TM/math bits change */
- mfmsr r5
- SAVE_GPR(5, r1)
-
- /* also save DSCR/CR/TAR so that it can be recovered later */
- mfspr r6, SPRN_DSCR
- SAVE_GPR(6, r1)
-
- mfcr r7
- stw r7, _CCR(r1)
+ mflr r0
+ std r0, PPC_LR_STKOFF(r1)
+ stdu r1, -PPC_MIN_STKFRM(r1)
+ /* save TAR so that it can be recovered later */
mfspr r8, SPRN_TAR
- SAVE_GPR(8, r1)
+ std r8, PPC_MIN_STKFRM-8(r1)
+ li r5, 1
bl __kvmppc_restore_tm
- REST_GPR(8, r1)
+ ld r8, PPC_MIN_STKFRM-8(r1)
mtspr SPRN_TAR, r8
- ld r7, _CCR(r1)
- mtcr r7
-
- REST_GPR(6, r1)
- mtspr SPRN_DSCR, r6
-
- /* need preserve current MSR's MSR_TS bits */
- REST_GPR(5, r1)
- mfmsr r6
- rldicl r6, r6, 64 - MSR_TS_S_LG, 62
- rldimi r5, r6, MSR_TS_S_LG, 63 - MSR_TS_T_LG
- mtmsrd r5
-
- REST_NVGPRS(r1)
- addi r1, r1, SWITCH_FRAME_SIZE
- ld r5, PPC_LR_STKOFF(r1)
- mtlr r5
+ addi r1, r1, PPC_MIN_STKFRM
+ ld r0, PPC_LR_STKOFF(r1)
+ mtlr r0
blr
EXPORT_SYMBOL_GPL(_kvmppc_restore_tm_pr);
--
2.7.4
