[PATCH 0/4] Improve CFAR handling

[PATCH 0/4] Improve CFAR handling

[Paul Mackerras]

The CFAR (Come From Address Register) is useful for debugging; it
records the address of the most recent taken branch or rfid
instructions.  At present, KVM doesn't even try to context switch it,
and the first-level interrupt handlers for some interrupts have a
branch before it gets saved, which will corrupt it.

This series fixes the interrupt handlers to not corrupt the CFAR, and
makes KVM context-switch it.  The series is against Ben H.'s
next branch.  The last patch in the series corrects a compile error
for 32-bit PR KVM configs which was introduced by an earlier commit in
Ben's next branch.

I suggest this series should go via Ben's tree rather than the KVM
tree, since most of the changes are to core powerpc interrupt handling
code.  Alex, if you could ack patch 3/4 that would be helpful.

Paul.

[PATCH 1/4] powerpc: Remove Cell-specific relocation-on interrupt vector code

[Paul Mackerras]

The Cell processor doesn't support relocation-on interrupts, so we
don't need relocation-on versions of the interrupt vectors that are
purely Cell-specific.  This removes them.

Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/kernel/exceptions-64s.S |   10 ----------
 1 file changed, 10 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 7a1c87c..dc64165 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -817,26 +817,16 @@ vsx_unavailable_relon_pSeries_1:
 	. = 0x4f40
 	b	vsx_unavailable_relon_pSeries
 
-#ifdef CONFIG_CBE_RAS
-	STD_RELON_EXCEPTION_HV(0x5200, 0x1202, cbe_system_error)
-#endif /* CONFIG_CBE_RAS */
 	STD_RELON_EXCEPTION_PSERIES(0x5300, 0x1300, instruction_breakpoint)
 #ifdef CONFIG_PPC_DENORMALISATION
 	. = 0x5500
 	b	denorm_exception_hv
 #endif
-#ifdef CONFIG_CBE_RAS
-	STD_RELON_EXCEPTION_HV(0x5600, 0x1602, cbe_maintenance)
-#else
 #ifdef CONFIG_HVC_SCOM
 	STD_RELON_EXCEPTION_HV(0x5600, 0x1600, maintence_interrupt)
 	KVM_HANDLER_SKIP(PACA_EXGEN, EXC_HV, 0x1600)
 #endif /* CONFIG_HVC_SCOM */
-#endif /* CONFIG_CBE_RAS */
 	STD_RELON_EXCEPTION_PSERIES(0x5700, 0x1700, altivec_assist)
-#ifdef CONFIG_CBE_RAS
-	STD_RELON_EXCEPTION_HV(0x5800, 0x1802, cbe_thermal)
-#endif /* CONFIG_CBE_RAS */
 
 	/* Other future vectors */
 	.align	7
-- 
1.7.10.4

[PATCH 2/4] powerpc: Save CFAR before branching in interrupt entry paths

[Paul Mackerras]

Some of the interrupt vectors on 64-bit POWER server processors are
only 32 bytes long, which is not enough for the full first-level
interrupt handler.  For these we currently just have a branch to an
out-of-line handler.  However, this means that we corrupt the CFAR
(come-from address register) on POWER7 and later processors.

To fix this, we split the EXCEPTION_PROLOG_1 macro into two pieces:
EXCEPTION_PROLOG_0 contains the part up to the point where the CFAR
is saved in the PACA, and EXCEPTION_PROLOG_1 contains the rest.  We
then put EXCEPTION_PROLOG_0 in the short interrupt vectors before
we branch to the out-of-line handler, which contains the rest of the
first-level interrupt handler.  To facilitate this, we define new
_OOL (out of line) variants of STD_EXCEPTION_PSERIES, etc.

In order to get EXCEPTION_PROLOG_0 to be short enough, i.e., no more
than 6 instructions, it was necessary to move the stores that move
the PPR and CFAR values into the PACA into __EXCEPTION_PROLOG_1 and
to get rid of one of the two HMT_MEDIUM instructions.  Previously
there was a HMT_MEDIUM_PPR_DISCARD before the prolog, which was
nop'd out on processors with the PPR (POWER7 and later), and then
another HMT_MEDIUM inside the HMT_MEDIUM_PPR_SAVE macro call inside
__EXCEPTION_PROLOG_1, which was nop'd out on processors without PPR.
Now the HMT_MEDIUM inside EXCEPTION_PROLOG_0 is there unconditionally
and the HMT_MEDIUM_PPR_DISCARD is not strictly necessary, although
this leaves it in for the interrupt vectors where there is room for
it.

Previously we had a handler for hypervisor maintenance interrupts at
0xe50, which doesn't leave enough room for the vector for hypervisor
emulation assist interrupts at 0xe40, since we need 8 instructions.
The 0xe50 vector was only used on POWER6, as the HMI vector was moved
to 0xe60 on POWER7.  Since we don't support running in hypervisor mode
on POWER6, we just remove the handler at 0xe50.

This also changes denorm_exception_hv to use EXCEPTION_PROLOG_0
instead of open-coding it, and removes the HMT_MEDIUM_PPR_DISCARD
from the relocation-on vectors (since any CPU that supports
relocation-on interrupts also has the PPR).

Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/include/asm/exception-64s.h |   84 +++++++++++++++++++++-----
 arch/powerpc/kernel/exceptions-64s.S     |   95 ++++++++++++++++++++----------
 2 files changed, 133 insertions(+), 46 deletions(-)

diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 370298a..4dfc515 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -50,7 +50,7 @@
 #define EX_PPR		88	/* SMT thread status register (priority) */
 
 #ifdef CONFIG_RELOCATABLE
-#define EXCEPTION_RELON_PROLOG_PSERIES_1(label, h)			\
+#define __EXCEPTION_RELON_PROLOG_PSERIES_1(label, h)			\
 	ld	r12,PACAKBASE(r13);	/* get high part of &label */	\
 	mfspr	r11,SPRN_##h##SRR0;	/* save SRR0 */			\
 	LOAD_HANDLER(r12,label);					\
@@ -61,13 +61,15 @@
 	blr;
 #else
 /* If not relocatable, we can jump directly -- and save messing with LR */
-#define EXCEPTION_RELON_PROLOG_PSERIES_1(label, h)			\
+#define __EXCEPTION_RELON_PROLOG_PSERIES_1(label, h)			\
 	mfspr	r11,SPRN_##h##SRR0;	/* save SRR0 */			\
 	mfspr	r12,SPRN_##h##SRR1;	/* and SRR1 */			\
 	li	r10,MSR_RI;						\
 	mtmsrd 	r10,1;			/* Set RI (EE=0) */		\
 	b	label;
 #endif
+#define EXCEPTION_RELON_PROLOG_PSERIES_1(label, h)			\
+	__EXCEPTION_RELON_PROLOG_PSERIES_1(label, h)			\
 
 /*
  * As EXCEPTION_PROLOG_PSERIES(), except we've already got relocation on
@@ -75,6 +77,7 @@
  * case EXCEPTION_RELON_PROLOG_PSERIES_1 will be using lr.
  */
 #define EXCEPTION_RELON_PROLOG_PSERIES(area, label, h, extra, vec)	\
+	EXCEPTION_PROLOG_0(area);					\
 	EXCEPTION_PROLOG_1(area, extra, vec);				\
 	EXCEPTION_RELON_PROLOG_PSERIES_1(label, h)
 
@@ -135,25 +138,32 @@ BEGIN_FTR_SECTION_NESTED(942)						\
 END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,0,942)  /*non P7*/		
 
 /*
- * Save PPR in paca whenever some register is available to use.
- * Then increase the priority.
+ * Get an SPR into a register if the CPU has the given feature
  */
-#define HMT_MEDIUM_PPR_SAVE(area, ra)					\
+#define OPT_GET_SPR(ra, spr, ftr)					\
 BEGIN_FTR_SECTION_NESTED(943)						\
-	mfspr	ra,SPRN_PPR;						\
-	std	ra,area+EX_PPR(r13);					\
-	HMT_MEDIUM;							\
-END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,943) 
+	mfspr	ra,spr;							\
+END_FTR_SECTION_NESTED(ftr,ftr,943)
 
-#define __EXCEPTION_PROLOG_1(area, extra, vec)				\
+/*
+ * Save a register to the PACA if the CPU has the given feature
+ */
+#define OPT_SAVE_REG_TO_PACA(offset, ra, ftr)				\
+BEGIN_FTR_SECTION_NESTED(943)						\
+	std	ra,offset(r13);						\
+END_FTR_SECTION_NESTED(ftr,ftr,943)
+
+#define EXCEPTION_PROLOG_0(area)					\
 	GET_PACA(r13);							\
 	std	r9,area+EX_R9(r13);	/* save r9 */			\
-	HMT_MEDIUM_PPR_SAVE(area, r9);					\
+	OPT_GET_SPR(r9, SPRN_PPR, CPU_FTR_HAS_PPR);			\
+	HMT_MEDIUM;							\
 	std	r10,area+EX_R10(r13);	/* save r10 - r12 */		\
-	BEGIN_FTR_SECTION_NESTED(66);					\
-	mfspr	r10,SPRN_CFAR;						\
-	std	r10,area+EX_CFAR(r13);					\
-	END_FTR_SECTION_NESTED(CPU_FTR_CFAR, CPU_FTR_CFAR, 66);		\
+	OPT_GET_SPR(r10, SPRN_CFAR, CPU_FTR_CFAR)
+
+#define __EXCEPTION_PROLOG_1(area, extra, vec)				\
+	OPT_SAVE_REG_TO_PACA(area+EX_PPR, r9, CPU_FTR_HAS_PPR);		\
+	OPT_SAVE_REG_TO_PACA(area+EX_CFAR, r10, CPU_FTR_CFAR);		\
 	SAVE_LR(r10, area);						\
 	mfcr	r9;							\
 	extra(vec);							\
@@ -178,6 +188,7 @@ END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,943)
 	__EXCEPTION_PROLOG_PSERIES_1(label, h)
 
 #define EXCEPTION_PROLOG_PSERIES(area, label, h, extra, vec)		\
+	EXCEPTION_PROLOG_0(area);					\
 	EXCEPTION_PROLOG_1(area, extra, vec);				\
 	EXCEPTION_PROLOG_PSERIES_1(label, h);
 
@@ -312,6 +323,13 @@ label##_pSeries:					\
 	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common,	\
 				 EXC_STD, KVMTEST_PR, vec)
 
+/* Version of above for when we have to branch out-of-line */
+#define STD_EXCEPTION_PSERIES_OOL(vec, label)			\
+	.globl label##_pSeries;					\
+label##_pSeries:						\
+	EXCEPTION_PROLOG_1(PACA_EXGEN, KVMTEST_PR, vec);	\
+	EXCEPTION_PROLOG_PSERIES_1(label##_common, EXC_STD)
+
 #define STD_EXCEPTION_HV(loc, vec, label)		\
 	. = loc;					\
 	.globl label##_hv;				\
@@ -321,6 +339,13 @@ label##_hv:						\
 	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common,	\
 				 EXC_HV, KVMTEST, vec)
 
+/* Version of above for when we have to branch out-of-line */
+#define STD_EXCEPTION_HV_OOL(vec, label)		\
+	.globl label##_hv;				\
+label##_hv:						\
+	EXCEPTION_PROLOG_1(PACA_EXGEN, KVMTEST, vec);	\
+	EXCEPTION_PROLOG_PSERIES_1(label##_common, EXC_HV)
+
 #define STD_RELON_EXCEPTION_PSERIES(loc, vec, label)	\
 	. = loc;					\
 	.globl label##_relon_pSeries;			\
@@ -331,6 +356,12 @@ label##_relon_pSeries:					\
 	EXCEPTION_RELON_PROLOG_PSERIES(PACA_EXGEN, label##_common, \
 				       EXC_STD, KVMTEST_PR, vec)
 
+#define STD_RELON_EXCEPTION_PSERIES_OOL(vec, label)		\
+	.globl label##_relon_pSeries;				\
+label##_relon_pSeries:						\
+	EXCEPTION_PROLOG_1(PACA_EXGEN, KVMTEST_PR, vec);	\
+	EXCEPTION_RELON_PROLOG_PSERIES_1(label##_common, EXC_STD)
+
 #define STD_RELON_EXCEPTION_HV(loc, vec, label)		\
 	. = loc;					\
 	.globl label##_relon_hv;			\
@@ -341,6 +372,12 @@ label##_relon_hv:					\
 	EXCEPTION_RELON_PROLOG_PSERIES(PACA_EXGEN, label##_common, \
 				       EXC_HV, KVMTEST, vec)
 
+#define STD_RELON_EXCEPTION_HV_OOL(vec, label)			\
+	.globl label##_relon_hv;				\
+label##_relon_hv:						\
+	EXCEPTION_PROLOG_1(PACA_EXGEN, KVMTEST, vec);		\
+	EXCEPTION_RELON_PROLOG_PSERIES_1(label##_common, EXC_HV)
+
 /* This associate vector numbers with bits in paca->irq_happened */
 #define SOFTEN_VALUE_0x500	PACA_IRQ_EE
 #define SOFTEN_VALUE_0x502	PACA_IRQ_EE
@@ -375,8 +412,10 @@ label##_relon_hv:					\
 #define __MASKABLE_EXCEPTION_PSERIES(vec, label, h, extra)		\
 	HMT_MEDIUM_PPR_DISCARD;						\
 	SET_SCRATCH0(r13);    /* save r13 */				\
-	__EXCEPTION_PROLOG_1(PACA_EXGEN, extra, vec);		\
+	EXCEPTION_PROLOG_0(PACA_EXGEN);					\
+	__EXCEPTION_PROLOG_1(PACA_EXGEN, extra, vec);			\
 	EXCEPTION_PROLOG_PSERIES_1(label##_common, h);
+
 #define _MASKABLE_EXCEPTION_PSERIES(vec, label, h, extra)		\
 	__MASKABLE_EXCEPTION_PSERIES(vec, label, h, extra)
 
@@ -394,9 +433,16 @@ label##_hv:								\
 	_MASKABLE_EXCEPTION_PSERIES(vec, label,				\
 				    EXC_HV, SOFTEN_TEST_HV)
 
+#define MASKABLE_EXCEPTION_HV_OOL(vec, label)				\
+	.globl label##_hv;						\
+label##_hv:								\
+	EXCEPTION_PROLOG_1(PACA_EXGEN, SOFTEN_TEST_HV, vec);		\
+	EXCEPTION_PROLOG_PSERIES_1(label##_common, EXC_HV);
+
 #define __MASKABLE_RELON_EXCEPTION_PSERIES(vec, label, h, extra)	\
 	HMT_MEDIUM_PPR_DISCARD;						\
 	SET_SCRATCH0(r13);    /* save r13 */				\
+	EXCEPTION_PROLOG_0(PACA_EXGEN);					\
 	__EXCEPTION_PROLOG_1(PACA_EXGEN, extra, vec);		\
 	EXCEPTION_RELON_PROLOG_PSERIES_1(label##_common, h);
 #define _MASKABLE_RELON_EXCEPTION_PSERIES(vec, label, h, extra)	\
@@ -416,6 +462,12 @@ label##_relon_hv:							\
 	_MASKABLE_RELON_EXCEPTION_PSERIES(vec, label,			\
 					  EXC_HV, SOFTEN_NOTEST_HV)
 
+#define MASKABLE_RELON_EXCEPTION_HV_OOL(vec, label)			\
+	.globl label##_relon_hv;					\
+label##_relon_hv:							\
+	EXCEPTION_PROLOG_1(PACA_EXGEN, SOFTEN_NOTEST_HV, vec);		\
+	EXCEPTION_PROLOG_PSERIES_1(label##_common, EXC_HV);
+
 /*
  * Our exception common code can be passed various "additions"
  * to specify the behaviour of interrupts, whether to kick the
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index dc64165..b9bcf21 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -153,7 +153,10 @@ machine_check_pSeries_1:
 	 * some code path might still want to branch into the original
 	 * vector
 	 */
-	b	machine_check_pSeries
+	HMT_MEDIUM_PPR_DISCARD
+	SET_SCRATCH0(r13)		/* save r13 */
+	EXCEPTION_PROLOG_0(PACA_EXMC)
+	b	machine_check_pSeries_0
 
 	. = 0x300
 	.globl data_access_pSeries
@@ -172,6 +175,7 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_SLB)
 data_access_slb_pSeries:
 	HMT_MEDIUM_PPR_DISCARD
 	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXSLB)
 	EXCEPTION_PROLOG_1(PACA_EXSLB, KVMTEST, 0x380)
 	std	r3,PACA_EXSLB+EX_R3(r13)
 	mfspr	r3,SPRN_DAR
@@ -203,6 +207,7 @@ data_access_slb_pSeries:
 instruction_access_slb_pSeries:
 	HMT_MEDIUM_PPR_DISCARD
 	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXSLB)
 	EXCEPTION_PROLOG_1(PACA_EXSLB, KVMTEST_PR, 0x480)
 	std	r3,PACA_EXSLB+EX_R3(r13)
 	mfspr	r3,SPRN_SRR0		/* SRR0 is faulting address */
@@ -284,16 +289,28 @@ system_call_pSeries:
 	 */
 	. = 0xe00
 hv_exception_trampoline:
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	b	h_data_storage_hv
+
 	. = 0xe20
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	b	h_instr_storage_hv
+
 	. = 0xe40
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	b	emulation_assist_hv
-	. = 0xe50
-	b	hmi_exception_hv
+
 	. = 0xe60
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	b	hmi_exception_hv
+
 	. = 0xe80
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	b	h_doorbell_hv
 
 	/* We need to deal with the Altivec unavailable exception
@@ -303,14 +320,20 @@ hv_exception_trampoline:
 	 */
 performance_monitor_pSeries_1:
 	. = 0xf00
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	b	performance_monitor_pSeries
 
 altivec_unavailable_pSeries_1:
 	. = 0xf20
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	b	altivec_unavailable_pSeries
 
 vsx_unavailable_pSeries_1:
 	. = 0xf40
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	b	vsx_unavailable_pSeries
 
 #ifdef CONFIG_CBE_RAS
@@ -326,10 +349,7 @@ vsx_unavailable_pSeries_1:
 denorm_exception_hv:
 	HMT_MEDIUM_PPR_DISCARD
 	mtspr	SPRN_SPRG_HSCRATCH0,r13
-	mfspr	r13,SPRN_SPRG_HPACA
-	std	r9,PACA_EXGEN+EX_R9(r13)
-	HMT_MEDIUM_PPR_SAVE(PACA_EXGEN, r9)
-	std	r10,PACA_EXGEN+EX_R10(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	std	r11,PACA_EXGEN+EX_R11(r13)
 	std	r12,PACA_EXGEN+EX_R12(r13)
 	mfspr	r9,SPRN_SPRG_HSCRATCH0
@@ -372,8 +392,10 @@ machine_check_pSeries:
 machine_check_fwnmi:
 	HMT_MEDIUM_PPR_DISCARD
 	SET_SCRATCH0(r13)		/* save r13 */
-	EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common,
-				 EXC_STD, KVMTEST, 0x200)
+	EXCEPTION_PROLOG_0(PACA_EXMC)
+machine_check_pSeries_0:
+	EXCEPTION_PROLOG_1(PACA_EXMC, KVMTEST, 0x200)
+	EXCEPTION_PROLOG_PSERIES_1(machine_check_common, EXC_STD)
 	KVM_HANDLER_SKIP(PACA_EXMC, EXC_STD, 0x200)
 
 	/* moved from 0x300 */
@@ -510,23 +532,23 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_206)
 
 	.align	7
 	/* moved from 0xe00 */
-	STD_EXCEPTION_HV(., 0xe02, h_data_storage)
+	STD_EXCEPTION_HV_OOL(0xe02, h_data_storage)
 	KVM_HANDLER_SKIP(PACA_EXGEN, EXC_HV, 0xe02)
-	STD_EXCEPTION_HV(., 0xe22, h_instr_storage)
+	STD_EXCEPTION_HV_OOL(0xe22, h_instr_storage)
 	KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe22)
-	STD_EXCEPTION_HV(., 0xe42, emulation_assist)
+	STD_EXCEPTION_HV_OOL(0xe42, emulation_assist)
 	KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe42)
-	STD_EXCEPTION_HV(., 0xe62, hmi_exception) /* need to flush cache ? */
+	STD_EXCEPTION_HV_OOL(0xe62, hmi_exception) /* need to flush cache ? */
 	KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe62)
-	MASKABLE_EXCEPTION_HV(., 0xe82, h_doorbell)
+	MASKABLE_EXCEPTION_HV_OOL(0xe82, h_doorbell)
 	KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe82)
 
 	/* moved from 0xf00 */
-	STD_EXCEPTION_PSERIES(., 0xf00, performance_monitor)
+	STD_EXCEPTION_PSERIES_OOL(0xf00, performance_monitor)
 	KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0xf00)
-	STD_EXCEPTION_PSERIES(., 0xf20, altivec_unavailable)
+	STD_EXCEPTION_PSERIES_OOL(0xf20, altivec_unavailable)
 	KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0xf20)
-	STD_EXCEPTION_PSERIES(., 0xf40, vsx_unavailable)
+	STD_EXCEPTION_PSERIES_OOL(0xf40, vsx_unavailable)
 	KVM_HANDLER_PR(PACA_EXGEN, EXC_STD, 0xf40)
 
 /*
@@ -718,8 +740,8 @@ machine_check_common:
 	. = 0x4380
 	.globl data_access_slb_relon_pSeries
 data_access_slb_relon_pSeries:
-	HMT_MEDIUM_PPR_DISCARD
 	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXSLB)
 	EXCEPTION_PROLOG_1(PACA_EXSLB, NOTEST, 0x380)
 	std	r3,PACA_EXSLB+EX_R3(r13)
 	mfspr	r3,SPRN_DAR
@@ -743,8 +765,8 @@ data_access_slb_relon_pSeries:
 	. = 0x4480
 	.globl instruction_access_slb_relon_pSeries
 instruction_access_slb_relon_pSeries:
-	HMT_MEDIUM_PPR_DISCARD
 	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXSLB)
 	EXCEPTION_PROLOG_1(PACA_EXSLB, NOTEST, 0x480)
 	std	r3,PACA_EXSLB+EX_R3(r13)
 	mfspr	r3,SPRN_SRR0		/* SRR0 is faulting address */
@@ -788,33 +810,46 @@ system_call_relon_pSeries:
 	STD_RELON_EXCEPTION_PSERIES(0x4d00, 0xd00, single_step)
 
 	. = 0x4e00
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	b	h_data_storage_relon_hv
 
 	. = 0x4e20
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	b	h_instr_storage_relon_hv
 
 	. = 0x4e40
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	b	emulation_assist_relon_hv
 
-	. = 0x4e50
-	b	hmi_exception_relon_hv
-
 	. = 0x4e60
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	b	hmi_exception_relon_hv
 
 	. = 0x4e80
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	b	h_doorbell_relon_hv
 
 performance_monitor_relon_pSeries_1:
 	. = 0x4f00
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	b	performance_monitor_relon_pSeries
 
 altivec_unavailable_relon_pSeries_1:
 	. = 0x4f20
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	b	altivec_unavailable_relon_pSeries
 
 vsx_unavailable_relon_pSeries_1:
 	. = 0x4f40
+	SET_SCRATCH0(r13)
+	EXCEPTION_PROLOG_0(PACA_EXGEN)
 	b	vsx_unavailable_relon_pSeries
 
 	STD_RELON_EXCEPTION_PSERIES(0x5300, 0x1300, instruction_breakpoint)
@@ -1171,20 +1206,20 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
 __end_handlers:
 
 	/* Equivalents to the above handlers for relocation-on interrupt vectors */
-	STD_RELON_EXCEPTION_HV(., 0xe00, h_data_storage)
+	STD_RELON_EXCEPTION_HV_OOL(0xe00, h_data_storage)
 	KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe00)
-	STD_RELON_EXCEPTION_HV(., 0xe20, h_instr_storage)
+	STD_RELON_EXCEPTION_HV_OOL(0xe20, h_instr_storage)
 	KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe20)
-	STD_RELON_EXCEPTION_HV(., 0xe40, emulation_assist)
+	STD_RELON_EXCEPTION_HV_OOL(0xe40, emulation_assist)
 	KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe40)
-	STD_RELON_EXCEPTION_HV(., 0xe60, hmi_exception)
+	STD_RELON_EXCEPTION_HV_OOL(0xe60, hmi_exception)
 	KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe60)
-	MASKABLE_RELON_EXCEPTION_HV(., 0xe80, h_doorbell)
+	MASKABLE_RELON_EXCEPTION_HV_OOL(0xe80, h_doorbell)
 	KVM_HANDLER(PACA_EXGEN, EXC_HV, 0xe80)
 
-	STD_RELON_EXCEPTION_PSERIES(., 0xf00, performance_monitor)
-	STD_RELON_EXCEPTION_PSERIES(., 0xf20, altivec_unavailable)
-	STD_RELON_EXCEPTION_PSERIES(., 0xf40, vsx_unavailable)
+	STD_RELON_EXCEPTION_PSERIES_OOL(0xf00, performance_monitor)
+	STD_RELON_EXCEPTION_PSERIES_OOL(0xf20, altivec_unavailable)
+	STD_RELON_EXCEPTION_PSERIES_OOL(0xf40, vsx_unavailable)
 
 #if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV)
 /*
-- 
1.7.10.4

[PATCH 3/4] KVM: PPC: Book3S HV: Preserve guest CFAR register value

[Paul Mackerras]

The CFAR (Come-From Address Register) is a useful debugging aid that
exists on POWER7 processors.  Currently HV KVM doesn't save or restore
the CFAR register for guest vcpus, making the CFAR of limited use in
guests.

This adds the necessary code to capture the CFAR value saved in the
early exception entry code (it has to be saved before any branch is
executed), save it in the vcpu.arch struct, and restore it on entry
to the guest.

Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/include/asm/exception-64s.h  |    8 ++++++--
 arch/powerpc/include/asm/kvm_book3s_asm.h |    3 +++
 arch/powerpc/include/asm/kvm_host.h       |    1 +
 arch/powerpc/kernel/asm-offsets.c         |    5 +++++
 arch/powerpc/kvm/book3s_hv_rmhandlers.S   |    9 +++++++++
 5 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 4dfc515..05e6d2e 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -199,10 +199,14 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)
 
 #define __KVM_HANDLER(area, h, n)					\
 do_kvm_##n:								\
+	BEGIN_FTR_SECTION_NESTED(947)					\
+	ld	r10,area+EX_CFAR(r13);					\
+	std	r10,HSTATE_CFAR(r13);					\
+	END_FTR_SECTION_NESTED(CPU_FTR_CFAR,CPU_FTR_CFAR,947);		\
 	ld	r10,area+EX_R10(r13);					\
-	stw	r9,HSTATE_SCRATCH1(r13);			\
+	stw	r9,HSTATE_SCRATCH1(r13);				\
 	ld	r9,area+EX_R9(r13);					\
-	std	r12,HSTATE_SCRATCH0(r13);			\
+	std	r12,HSTATE_SCRATCH0(r13);				\
 	li	r12,n;							\
 	b	kvmppc_interrupt
 
diff --git a/arch/powerpc/include/asm/kvm_book3s_asm.h b/arch/powerpc/include/asm/kvm_book3s_asm.h
index 88609b2..cdc3d27 100644
--- a/arch/powerpc/include/asm/kvm_book3s_asm.h
+++ b/arch/powerpc/include/asm/kvm_book3s_asm.h
@@ -93,6 +93,9 @@ struct kvmppc_host_state {
 	u64 host_dscr;
 	u64 dec_expires;
 #endif
+#ifdef CONFIG_PPC_BOOK3S_64
+	u64 cfar;
+#endif
 };
 
 struct kvmppc_book3s_shadow_vcpu {
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index ca9bf45..03d7bea 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -440,6 +440,7 @@ struct kvm_vcpu_arch {
 	ulong uamor;
 	u32 ctrl;
 	ulong dabr;
+	ulong cfar;
 #endif
 	u32 vrsave; /* also USPRG0 */
 	u32 mmucr;
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index e39ca55..9a73fb0 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -475,6 +475,7 @@ int main(void)
 	DEFINE(VCPU_LAST_INST, offsetof(struct kvm_vcpu, arch.last_inst));
 	DEFINE(VCPU_TRAP, offsetof(struct kvm_vcpu, arch.trap));
 	DEFINE(VCPU_PTID, offsetof(struct kvm_vcpu, arch.ptid));
+	DEFINE(VCPU_CFAR, offsetof(struct kvm_vcpu, arch.cfar));
 	DEFINE(VCORE_ENTRY_EXIT, offsetof(struct kvmppc_vcore, entry_exit_count));
 	DEFINE(VCORE_NAP_COUNT, offsetof(struct kvmppc_vcore, nap_count));
 	DEFINE(VCORE_IN_GUEST, offsetof(struct kvmppc_vcore, in_guest));
@@ -554,6 +555,10 @@ int main(void)
 	DEFINE(IPI_PRIORITY, IPI_PRIORITY);
 #endif /* CONFIG_KVM_BOOK3S_64_HV */
 
+#ifdef CONFIG_PPC_BOOK3S_64
+	HSTATE_FIELD(HSTATE_CFAR, cfar);
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
 #else /* CONFIG_PPC_BOOK3S */
 	DEFINE(VCPU_CR, offsetof(struct kvm_vcpu, arch.cr));
 	DEFINE(VCPU_XER, offsetof(struct kvm_vcpu, arch.xer));
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 10b6c35..e33d11f 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -539,6 +539,11 @@ fast_guest_return:
 
 	/* Enter guest */
 
+BEGIN_FTR_SECTION
+	ld	r5, VCPU_CFAR(r4)
+	mtspr	SPRN_CFAR, r5
+END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
+
 	ld	r5, VCPU_LR(r4)
 	lwz	r6, VCPU_CR(r4)
 	mtlr	r5
@@ -604,6 +609,10 @@ kvmppc_interrupt:
 	lwz	r4, HSTATE_SCRATCH1(r13)
 	std	r3, VCPU_GPR(R12)(r9)
 	stw	r4, VCPU_CR(r9)
+BEGIN_FTR_SECTION
+	ld	r3, HSTATE_CFAR(r13)
+	std	r3, VCPU_CFAR(r9)
+END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
 
 	/* Restore R1/R2 so we can handle faults */
 	ld	r1, HSTATE_HOST_R1(r13)
-- 
1.7.10.4

[PATCH 4/4] KVM: PPC: Book3S PR: Fix compilation on 32-bit machines

[Paul Mackerras]

Commit a413f474a0 ("powerpc: Disable relocation on exceptions whenever
PR KVM is active") added calls to pSeries_disable_reloc_on_exc() and
pSeries_enable_reloc_on_exc() to book3s_pr.c, and added declarations
of those functions to <asm/hvcall.h>, but didn't add an include of
<asm/hvcall.h> to book3s_pr.c.  64-bit kernels seem to get hvcall.h
included via some other path, but 32-bit kernels fail to compile with:

arch/powerpc/kvm/book3s_pr.c: In function ‘kvmppc_core_init_vm’:
arch/powerpc/kvm/book3s_pr.c:1300:4: error: implicit declaration of function ‘pSeries_disable_reloc_on_exc’ [-Werror=implicit-function-declaration]
arch/powerpc/kvm/book3s_pr.c: In function ‘kvmppc_core_destroy_vm’:
arch/powerpc/kvm/book3s_pr.c:1316:4: error: implicit declaration of function ‘pSeries_enable_reloc_on_exc’ [-Werror=implicit-function-declaration]
cc1: all warnings being treated as errors
make[2]: *** [arch/powerpc/kvm/book3s_pr.o] Error 1
make[1]: *** [arch/powerpc/kvm] Error 2
make: *** [sub-make] Error 2

This fixes it by adding an include of hvcall.h.

Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/kvm/book3s_pr.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 67e4708..6702442 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -35,6 +35,7 @@
 #include <asm/mmu_context.h>
 #include <asm/switch_to.h>
 #include <asm/firmware.h>
+#include <asm/hvcall.h>
 #include <linux/gfp.h>
 #include <linux/sched.h>
 #include <linux/vmalloc.h>
-- 
1.7.10.4

Re: [PATCH 3/4] KVM: PPC: Book3S HV: Preserve guest CFAR register value

[Alexander Graf]

On 05.02.2013, at 05:10, Paul Mackerras wrote:

> The CFAR (Come-From Address Register) is a useful debugging aid that
> exists on POWER7 processors.  Currently HV KVM doesn't save or restore
> the CFAR register for guest vcpus, making the CFAR of limited use in
> guests.
> 
> This adds the necessary code to capture the CFAR value saved in the
> early exception entry code (it has to be saved before any branch is
> executed), save it in the vcpu.arch struct, and restore it on entry
> to the guest.
> 
> Signed-off-by: Paul Mackerras <paulus@samba.org>

Acked-by: Alexander Graf <agraf@suse.de>


Alex