* [PATCH 2/3] KVM: PPC: book3s_pr: Simplify transitions between virtual and real mode
From: Paul Mackerras @ 2011-07-23 7:41 UTC (permalink / raw)
To: linuxppc-dev, kvm-ppc, Alexander Graf
In-Reply-To: <20110723074111.GA17927@bloggs.ozlabs.ibm.com>
This simplifies the way that the book3s_pr makes the transition to
real mode when entering the guest. We now call kvmppc_entry_trampoline
(renamed from kvmppc_rmcall) in the base kernel using a normal function
call instead of doing an indirect call through a pointer in the vcpu.
If kvm is a module, the module loader takes care of generating a
trampoline as it does for other calls to functions outside the module.
kvmppc_entry_trampoline then disables interrupts and jumps to
kvmppc_handler_trampoline_enter in real mode using an rfi[d].
That then uses the link register as the address to return to
(potentially in module space) when the guest exits.
This also simplifies the way that we call the Linux interrupt handler
when we exit the guest due to an external, decrementer or performance
monitor interrupt. Instead of turning on the MMU, then deciding that
we need to call the Linux handler and turning the MMU back off again,
we now go straight to the handler at the point where we would turn the
MMU on. The handler will then return to the virtual-mode code
(potentially in the module).
Along the way, this moves the setting and clearing of the HID5 DCBZ32
bit into real-mode interrupts-off code, and also makes sure that
we clear the MSR[RI] bit before loading values into SRR0/1.
The net result is that we no longer need any code addresses to be
stored in vcpu->arch.
Signed-off-by: Paul Mackerras <paulus@samba.org>
---
arch/powerpc/include/asm/kvm_book3s.h | 4 +-
arch/powerpc/include/asm/kvm_book3s_asm.h | 1 +
arch/powerpc/include/asm/kvm_host.h | 8 --
arch/powerpc/kernel/asm-offsets.c | 7 +--
arch/powerpc/kvm/book3s_32_sr.S | 2 +-
arch/powerpc/kvm/book3s_64_slb.S | 2 +-
arch/powerpc/kvm/book3s_exports.c | 4 +-
arch/powerpc/kvm/book3s_interrupts.S | 129 +---------------------------
arch/powerpc/kvm/book3s_pr.c | 12 ---
arch/powerpc/kvm/book3s_rmhandlers.S | 51 ++++--------
arch/powerpc/kvm/book3s_segment.S | 112 ++++++++++++++++++++-----
11 files changed, 120 insertions(+), 212 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index 98da010..a70c0e6 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -139,9 +139,7 @@ extern void kvmppc_giveup_ext(struct kvm_vcpu *vcpu, ulong msr);
extern int kvmppc_emulate_paired_single(struct kvm_run *run, struct kvm_vcpu *vcpu);
extern pfn_t kvmppc_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn);
-extern void kvmppc_handler_lowmem_trampoline(void);
-extern void kvmppc_handler_trampoline_enter(void);
-extern void kvmppc_rmcall(ulong srr0, ulong srr1);
+extern void kvmppc_entry_trampoline(void);
extern void kvmppc_hv_entry_trampoline(void);
extern void kvmppc_load_up_fpu(void);
extern void kvmppc_load_up_altivec(void);
diff --git a/arch/powerpc/include/asm/kvm_book3s_asm.h b/arch/powerpc/include/asm/kvm_book3s_asm.h
index ef7b368..af73469 100644
--- a/arch/powerpc/include/asm/kvm_book3s_asm.h
+++ b/arch/powerpc/include/asm/kvm_book3s_asm.h
@@ -75,6 +75,7 @@ struct kvmppc_host_state {
ulong scratch0;
ulong scratch1;
u8 in_guest;
+ u8 restore_hid5;
#ifdef CONFIG_KVM_BOOK3S_64_HV
struct kvm_vcpu *kvm_vcpu;
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index cc22b28..db15384 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -258,14 +258,6 @@ struct kvm_vcpu_arch {
ulong host_stack;
u32 host_pid;
#ifdef CONFIG_PPC_BOOK3S
- ulong host_msr;
- ulong host_r2;
- void *host_retip;
- ulong trampoline_lowmem;
- ulong trampoline_enter;
- ulong highmem_handler;
- ulong rmcall;
- ulong host_paca_phys;
struct kvmppc_slb slb[64];
int slb_max; /* 1 + index of last valid entry in slb[] */
int slb_nr; /* total number of entries in SLB */
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 54b935f..d34cd32 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -446,8 +446,6 @@ int main(void)
#ifdef CONFIG_PPC_BOOK3S
DEFINE(VCPU_KVM, offsetof(struct kvm_vcpu, kvm));
DEFINE(VCPU_VCPUID, offsetof(struct kvm_vcpu, vcpu_id));
- DEFINE(VCPU_HOST_RETIP, offsetof(struct kvm_vcpu, arch.host_retip));
- DEFINE(VCPU_HOST_MSR, offsetof(struct kvm_vcpu, arch.host_msr));
DEFINE(VCPU_PURR, offsetof(struct kvm_vcpu, arch.purr));
DEFINE(VCPU_SPURR, offsetof(struct kvm_vcpu, arch.spurr));
DEFINE(VCPU_DSCR, offsetof(struct kvm_vcpu, arch.dscr));
@@ -455,10 +453,6 @@ int main(void)
DEFINE(VCPU_UAMOR, offsetof(struct kvm_vcpu, arch.uamor));
DEFINE(VCPU_CTRL, offsetof(struct kvm_vcpu, arch.ctrl));
DEFINE(VCPU_DABR, offsetof(struct kvm_vcpu, arch.dabr));
- DEFINE(VCPU_TRAMPOLINE_LOWMEM, offsetof(struct kvm_vcpu, arch.trampoline_lowmem));
- DEFINE(VCPU_TRAMPOLINE_ENTER, offsetof(struct kvm_vcpu, arch.trampoline_enter));
- DEFINE(VCPU_HIGHMEM_HANDLER, offsetof(struct kvm_vcpu, arch.highmem_handler));
- DEFINE(VCPU_RMCALL, offsetof(struct kvm_vcpu, arch.rmcall));
DEFINE(VCPU_HFLAGS, offsetof(struct kvm_vcpu, arch.hflags));
DEFINE(VCPU_DEC, offsetof(struct kvm_vcpu, arch.dec));
DEFINE(VCPU_DEC_EXPIRES, offsetof(struct kvm_vcpu, arch.dec_expires));
@@ -534,6 +528,7 @@ int main(void)
HSTATE_FIELD(HSTATE_SCRATCH0, scratch0);
HSTATE_FIELD(HSTATE_SCRATCH1, scratch1);
HSTATE_FIELD(HSTATE_IN_GUEST, in_guest);
+ HSTATE_FIELD(HSTATE_RESTORE_HID5, restore_hid5);
#ifdef CONFIG_KVM_BOOK3S_64_HV
HSTATE_FIELD(HSTATE_KVM_VCPU, kvm_vcpu);
diff --git a/arch/powerpc/kvm/book3s_32_sr.S b/arch/powerpc/kvm/book3s_32_sr.S
index 3608471..7e06a6f 100644
--- a/arch/powerpc/kvm/book3s_32_sr.S
+++ b/arch/powerpc/kvm/book3s_32_sr.S
@@ -31,7 +31,7 @@
* R1 = host R1
* R2 = host R2
* R3 = shadow vcpu
- * all other volatile GPRS = free
+ * all other volatile GPRS = free except R4, R6
* SVCPU[CR] = guest CR
* SVCPU[XER] = guest XER
* SVCPU[CTR] = guest CTR
diff --git a/arch/powerpc/kvm/book3s_64_slb.S b/arch/powerpc/kvm/book3s_64_slb.S
index 04e7d3b..f2e6e48 100644
--- a/arch/powerpc/kvm/book3s_64_slb.S
+++ b/arch/powerpc/kvm/book3s_64_slb.S
@@ -53,7 +53,7 @@ slb_exit_skip_ ## num:
* R1 = host R1
* R2 = host R2
* R3 = shadow vcpu
- * all other volatile GPRS = free
+ * all other volatile GPRS = free except R4, R6
* SVCPU[CR] = guest CR
* SVCPU[XER] = guest XER
* SVCPU[CTR] = guest CTR
diff --git a/arch/powerpc/kvm/book3s_exports.c b/arch/powerpc/kvm/book3s_exports.c
index 88c8f26..f7f63a0 100644
--- a/arch/powerpc/kvm/book3s_exports.c
+++ b/arch/powerpc/kvm/book3s_exports.c
@@ -23,9 +23,7 @@
#ifdef CONFIG_KVM_BOOK3S_64_HV
EXPORT_SYMBOL_GPL(kvmppc_hv_entry_trampoline);
#else
-EXPORT_SYMBOL_GPL(kvmppc_handler_trampoline_enter);
-EXPORT_SYMBOL_GPL(kvmppc_handler_lowmem_trampoline);
-EXPORT_SYMBOL_GPL(kvmppc_rmcall);
+EXPORT_SYMBOL_GPL(kvmppc_entry_trampoline);
EXPORT_SYMBOL_GPL(kvmppc_load_up_fpu);
#ifdef CONFIG_ALTIVEC
EXPORT_SYMBOL_GPL(kvmppc_load_up_altivec);
diff --git a/arch/powerpc/kvm/book3s_interrupts.S b/arch/powerpc/kvm/book3s_interrupts.S
index c54b0e3..0a8515a 100644
--- a/arch/powerpc/kvm/book3s_interrupts.S
+++ b/arch/powerpc/kvm/book3s_interrupts.S
@@ -29,27 +29,11 @@
#define ULONG_SIZE 8
#define FUNC(name) GLUE(.,name)
-#define GET_SHADOW_VCPU_R13
-
-#define DISABLE_INTERRUPTS \
- mfmsr r0; \
- rldicl r0,r0,48,1; \
- rotldi r0,r0,16; \
- mtmsrd r0,1; \
-
#elif defined(CONFIG_PPC_BOOK3S_32)
#define ULONG_SIZE 4
#define FUNC(name) name
-#define GET_SHADOW_VCPU_R13 \
- lwz r13, (THREAD + THREAD_KVM_SVCPU)(r2)
-
-#define DISABLE_INTERRUPTS \
- mfmsr r0; \
- rlwinm r0,r0,0,17,15; \
- mtmsr r0; \
-
#endif /* CONFIG_PPC_BOOK3S_XX */
@@ -108,44 +92,17 @@ kvm_start_entry:
kvm_start_lightweight:
- GET_SHADOW_VCPU_R13
- PPC_LL r3, VCPU_HIGHMEM_HANDLER(r4)
- PPC_STL r3, HSTATE_VMHANDLER(r13)
-
- PPC_LL r10, VCPU_SHADOW_MSR(r4) /* r10 = vcpu->arch.shadow_msr */
-
- DISABLE_INTERRUPTS
-
#ifdef CONFIG_PPC_BOOK3S_64
- /* Some guests may need to have dcbz set to 32 byte length.
- *
- * Usually we ensure that by patching the guest's instructions
- * to trap on dcbz and emulate it in the hypervisor.
- *
- * If we can, we should tell the CPU to use 32 byte dcbz though,
- * because that's a lot faster.
- */
-
PPC_LL r3, VCPU_HFLAGS(r4)
- rldicl. r3, r3, 0, 63 /* CR = ((r3 & 1) == 0) */
- beq no_dcbz32_on
-
- mfspr r3,SPRN_HID5
- ori r3, r3, 0x80 /* XXX HID5_dcbz32 = 0x80 */
- mtspr SPRN_HID5,r3
-
-no_dcbz32_on:
-
+ rldicl r3, r3, 0, 63 /* r3 &= 1 */
+ stb r3, HSTATE_RESTORE_HID5(r13)
#endif /* CONFIG_PPC_BOOK3S_64 */
- PPC_LL r6, VCPU_RMCALL(r4)
- mtctr r6
-
- PPC_LL r3, VCPU_TRAMPOLINE_ENTER(r4)
- LOAD_REG_IMMEDIATE(r4, MSR_KERNEL & ~(MSR_IR | MSR_DR))
+ PPC_LL r4, VCPU_SHADOW_MSR(r4) /* get shadow_msr */
/* Jump to segment patching handler and into our guest */
- bctr
+ bl FUNC(kvmppc_entry_trampoline)
+ nop
/*
* This is the handler in module memory. It gets jumped at from the
@@ -170,21 +127,6 @@ kvmppc_handler_highmem:
/* R7 = vcpu */
PPC_LL r7, GPR4(r1)
-#ifdef CONFIG_PPC_BOOK3S_64
-
- PPC_LL r5, VCPU_HFLAGS(r7)
- rldicl. r5, r5, 0, 63 /* CR = ((r5 & 1) == 0) */
- beq no_dcbz32_off
-
- li r4, 0
- mfspr r5,SPRN_HID5
- rldimi r5,r4,6,56
- mtspr SPRN_HID5,r5
-
-no_dcbz32_off:
-
-#endif /* CONFIG_PPC_BOOK3S_64 */
-
PPC_STL r14, VCPU_GPR(r14)(r7)
PPC_STL r15, VCPU_GPR(r15)(r7)
PPC_STL r16, VCPU_GPR(r16)(r7)
@@ -204,67 +146,6 @@ no_dcbz32_off:
PPC_STL r30, VCPU_GPR(r30)(r7)
PPC_STL r31, VCPU_GPR(r31)(r7)
- /* Restore host msr -> SRR1 */
- PPC_LL r6, VCPU_HOST_MSR(r7)
-
- /*
- * For some interrupts, we need to call the real Linux
- * handler, so it can do work for us. This has to happen
- * as if the interrupt arrived from the kernel though,
- * so let's fake it here where most state is restored.
- *
- * Call Linux for hardware interrupts/decrementer
- * r3 = address of interrupt handler (exit reason)
- */
-
- cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL
- beq call_linux_handler
- cmpwi r12, BOOK3S_INTERRUPT_DECREMENTER
- beq call_linux_handler
- cmpwi r12, BOOK3S_INTERRUPT_PERFMON
- beq call_linux_handler
-
- /* Back to EE=1 */
- mtmsr r6
- sync
- b kvm_return_point
-
-call_linux_handler:
-
- /*
- * If we land here we need to jump back to the handler we
- * came from.
- *
- * We have a page that we can access from real mode, so let's
- * jump back to that and use it as a trampoline to get back into the
- * interrupt handler!
- *
- * R3 still contains the exit code,
- * R5 VCPU_HOST_RETIP and
- * R6 VCPU_HOST_MSR
- */
-
- /* Restore host IP -> SRR0 */
- PPC_LL r5, VCPU_HOST_RETIP(r7)
-
- /* XXX Better move to a safe function?
- * What if we get an HTAB flush in between mtsrr0 and mtsrr1? */
-
- mtlr r12
-
- PPC_LL r4, VCPU_TRAMPOLINE_LOWMEM(r7)
- mtsrr0 r4
- LOAD_REG_IMMEDIATE(r3, MSR_KERNEL & ~(MSR_IR | MSR_DR))
- mtsrr1 r3
-
- RFI
-
-.global kvm_return_point
-kvm_return_point:
-
- /* Jump back to lightweight entry if we're supposed to */
- /* go back into the guest */
-
/* Pass the exit number as 3rd argument to kvmppc_handle_exit */
mr r5, r12
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 0c0d3f2..d7ab552 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -841,8 +841,6 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
if (!p)
goto uninit_vcpu;
- vcpu->arch.host_retip = kvm_return_point;
- vcpu->arch.host_msr = mfmsr();
#ifdef CONFIG_PPC_BOOK3S_64
/* default to book3s_64 (970fx) */
vcpu->arch.pvr = 0x3C0301;
@@ -853,16 +851,6 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
kvmppc_set_pvr(vcpu, vcpu->arch.pvr);
vcpu->arch.slb_nr = 64;
- /* remember where some real-mode handlers are */
- vcpu->arch.trampoline_lowmem = __pa(kvmppc_handler_lowmem_trampoline);
- vcpu->arch.trampoline_enter = __pa(kvmppc_handler_trampoline_enter);
- vcpu->arch.highmem_handler = (ulong)kvmppc_handler_highmem;
-#ifdef CONFIG_PPC_BOOK3S_64
- vcpu->arch.rmcall = *(ulong*)kvmppc_rmcall;
-#else
- vcpu->arch.rmcall = (ulong)kvmppc_rmcall;
-#endif
-
vcpu->arch.shadow_msr = MSR_USER64;
err = kvmppc_mmu_init(vcpu);
diff --git a/arch/powerpc/kvm/book3s_rmhandlers.S b/arch/powerpc/kvm/book3s_rmhandlers.S
index 5ee66ed..3418758 100644
--- a/arch/powerpc/kvm/book3s_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_rmhandlers.S
@@ -36,9 +36,8 @@
#if defined(CONFIG_PPC_BOOK3S_64)
-#define LOAD_SHADOW_VCPU(reg) GET_PACA(reg)
-#define MSR_NOIRQ MSR_KERNEL & ~(MSR_IR | MSR_DR)
#define FUNC(name) GLUE(.,name)
+#define MTMSR_EERI(reg) mtmsrd (reg),1
.globl kvmppc_skip_interrupt
kvmppc_skip_interrupt:
@@ -68,8 +67,8 @@ kvmppc_skip_Hinterrupt:
#elif defined(CONFIG_PPC_BOOK3S_32)
-#define MSR_NOIRQ MSR_KERNEL
#define FUNC(name) name
+#define MTMSR_EERI(reg) mtmsr (reg)
.macro INTERRUPT_TRAMPOLINE intno
@@ -170,40 +169,24 @@ kvmppc_handler_skip_ins:
#endif
/*
- * This trampoline brings us back to a real mode handler
- *
- * Input Registers:
- *
- * R5 = SRR0
- * R6 = SRR1
- * LR = real-mode IP
+ * Call kvmppc_handler_trampoline_enter in real mode
*
+ * On entry, r4 contains the guest shadow MSR
*/
-.global kvmppc_handler_lowmem_trampoline
-kvmppc_handler_lowmem_trampoline:
-
- mtsrr0 r5
+_GLOBAL(kvmppc_entry_trampoline)
+ mfmsr r5
+ LOAD_REG_ADDR(r7, kvmppc_handler_trampoline_enter)
+ toreal(r7)
+
+ li r9, MSR_RI
+ ori r9, r9, MSR_EE
+ andc r9, r5, r9 /* Clear EE and RI in MSR value */
+ li r6, MSR_IR | MSR_DR
+ ori r6, r6, MSR_EE
+ andc r6, r5, r6 /* Clear EE, DR and IR in MSR value */
+ MTMSR_EERI(r9) /* Clear EE and RI in MSR */
+ mtsrr0 r7 /* before we set srr0/1 */
mtsrr1 r6
- blr
-kvmppc_handler_lowmem_trampoline_end:
-
-/*
- * Call a function in real mode
- *
- * Input Registers:
- *
- * R3 = function
- * R4 = MSR
- * R5 = scratch register
- *
- */
-_GLOBAL(kvmppc_rmcall)
- LOAD_REG_IMMEDIATE(r5, MSR_NOIRQ)
- mtmsr r5 /* Disable relocation and interrupts, so mtsrr
- doesn't get interrupted */
- sync
- mtsrr0 r3
- mtsrr1 r4
RFI
#if defined(CONFIG_PPC_BOOK3S_32)
diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S
index aed32e5..3663564 100644
--- a/arch/powerpc/kvm/book3s_segment.S
+++ b/arch/powerpc/kvm/book3s_segment.S
@@ -23,6 +23,7 @@
#define GET_SHADOW_VCPU(reg) \
mr reg, r13
+#define MTMSR_EERI(reg) mtmsrd (reg),1
#elif defined(CONFIG_PPC_BOOK3S_32)
@@ -30,6 +31,7 @@
tophys(reg, r2); \
lwz reg, (THREAD + THREAD_KVM_SVCPU)(reg); \
tophys(reg, reg)
+#define MTMSR_EERI(reg) mtmsr (reg)
#endif
@@ -57,10 +59,12 @@ kvmppc_handler_trampoline_enter:
/* Required state:
*
* MSR = ~IR|DR
- * R13 = PACA
* R1 = host R1
* R2 = host R2
- * R10 = guest MSR
+ * R4 = guest shadow MSR
+ * R5 = normal host MSR
+ * R6 = current host MSR (EE, IR, DR off)
+ * LR = highmem guest exit code
* all other volatile GPRS = free
* SVCPU[CR] = guest CR
* SVCPU[XER] = guest XER
@@ -71,15 +75,15 @@ kvmppc_handler_trampoline_enter:
/* r3 = shadow vcpu */
GET_SHADOW_VCPU(r3)
+ /* Save guest exit handler address and MSR */
+ mflr r0
+ PPC_STL r0, HSTATE_VMHANDLER(r3)
+ PPC_STL r5, HSTATE_HOST_MSR(r3)
+
/* Save R1/R2 in the PACA (64-bit) or shadow_vcpu (32-bit) */
PPC_STL r1, HSTATE_HOST_R1(r3)
PPC_STL r2, HSTATE_HOST_R2(r3)
- /* Move SRR0 and SRR1 into the respective regs */
- PPC_LL r9, SVCPU_PC(r3)
- mtsrr0 r9
- mtsrr1 r10
-
/* Activate guest mode, so faults get handled by KVM */
li r11, KVM_GUEST_MODE_GUEST
stb r11, HSTATE_IN_GUEST(r3)
@@ -87,17 +91,46 @@ kvmppc_handler_trampoline_enter:
/* Switch to guest segment. This is subarch specific. */
LOAD_GUEST_SEGMENTS
+#ifdef CONFIG_PPC_BOOK3S_64
+ /* Some guests may need to have dcbz set to 32 byte length.
+ *
+ * Usually we ensure that by patching the guest's instructions
+ * to trap on dcbz and emulate it in the hypervisor.
+ *
+ * If we can, we should tell the CPU to use 32 byte dcbz though,
+ * because that's a lot faster.
+ */
+ lbz r0, HSTATE_RESTORE_HID5(r3)
+ cmpwi r0, 0
+ beq no_dcbz32_on
+
+ mfspr r0,SPRN_HID5
+ ori r0, r0, 0x80 /* XXX HID5_dcbz32 = 0x80 */
+ mtspr SPRN_HID5,r0
+no_dcbz32_on:
+
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
/* Enter guest */
- PPC_LL r4, SVCPU_CTR(r3)
- PPC_LL r5, SVCPU_LR(r3)
- lwz r6, SVCPU_CR(r3)
- lwz r7, SVCPU_XER(r3)
+ PPC_LL r8, SVCPU_CTR(r3)
+ PPC_LL r9, SVCPU_LR(r3)
+ lwz r10, SVCPU_CR(r3)
+ lwz r11, SVCPU_XER(r3)
+
+ mtctr r8
+ mtlr r9
+ mtcr r10
+ mtxer r11
- mtctr r4
- mtlr r5
- mtcr r6
- mtxer r7
+ /* Move SRR0 and SRR1 into the respective regs */
+ PPC_LL r9, SVCPU_PC(r3)
+ /* First clear RI in our current MSR value */
+ li r0, MSR_RI
+ andc r6, r6, r0
+ MTMSR_EERI(r6)
+ mtsrr0 r9
+ mtsrr1 r4
PPC_LL r0, SVCPU_R0(r3)
PPC_LL r1, SVCPU_R1(r3)
@@ -254,6 +287,43 @@ no_ld_last_inst:
/* Switch back to host MMU */
LOAD_HOST_SEGMENTS
+#ifdef CONFIG_PPC_BOOK3S_64
+
+ lbz r5, HSTATE_RESTORE_HID5(r13)
+ cmpwi r5, 0
+ beq no_dcbz32_off
+
+ li r4, 0
+ mfspr r5,SPRN_HID5
+ rldimi r5,r4,6,56
+ mtspr SPRN_HID5,r5
+
+no_dcbz32_off:
+
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+ /*
+ * For some interrupts, we need to call the real Linux
+ * handler, so it can do work for us. This has to happen
+ * as if the interrupt arrived from the kernel though,
+ * so let's fake it here where most state is restored.
+ *
+ * Having set up SRR0/1 with the address where we want
+ * to continue with relocation on (potentially in module
+ * space), we either just go straight there with rfi[d],
+ * or we jump to an interrupt handler with bctr if there
+ * is an interrupt to be handled first. In the latter
+ * case, the rfi[d] at the end of the interrupt handler
+ * will get us back to where we want to continue.
+ */
+
+ cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL
+ beq 1f
+ cmpwi r12, BOOK3S_INTERRUPT_DECREMENTER
+ beq 1f
+ cmpwi r12, BOOK3S_INTERRUPT_PERFMON
+1: mtctr r12
+
/* Register usage at this point:
*
* R1 = host R1
@@ -264,13 +334,15 @@ no_ld_last_inst:
*
*/
- /* RFI into the highmem handler */
- mfmsr r7
- ori r7, r7, MSR_IR|MSR_DR|MSR_RI|MSR_ME /* Enable paging */
- mtsrr1 r7
- /* Load highmem handler address */
+ PPC_LL r6, HSTATE_HOST_MSR(r13)
PPC_LL r8, HSTATE_VMHANDLER(r13)
+
+ /* Restore host msr -> SRR1 */
+ mtsrr1 r6
+ /* Load highmem handler address */
mtsrr0 r8
+ /* RFI into the highmem handler, or jump to interrupt handler */
+ beqctr
RFI
kvmppc_handler_trampoline_exit_end:
--
1.7.5.4
^ permalink raw reply related
* [PATCH 3/3] KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code
From: Paul Mackerras @ 2011-07-23 7:42 UTC (permalink / raw)
To: linuxppc-dev, kvm-ppc, Alexander Graf
In-Reply-To: <20110723074111.GA17927@bloggs.ozlabs.ibm.com>
With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per
core), whenever a CPU goes idle, we have to pull all the other
hardware threads in the core out of the guest, because the H_CEDE
hcall is handled in the kernel. This is inefficient.
This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall
in real mode. When a guest vcpu does an H_CEDE hcall, we now only
exit to the kernel if all the other vcpus in the same core are also
idle. Otherwise we mark this vcpu as napping, save state that could
be lost in nap mode (mainly GPRs and FPRs), and execute the nap
instruction. When the thread wakes up, because of a decrementer or
external interrupt, we come back in at kvm_start_guest (from the
system reset interrupt vector), find the `napping' flag set in the
paca, and go to the resume path.
This has some other ramifications. First, when starting a core, we
now start all the threads, both those that are immediately runnable and
those that are idle. This is so that we don't have to pull all the
threads out of the guest when an idle thread gets a decrementer interrupt
and wants to start running. In fact the idle threads will all start
with the H_CEDE hcall returning; being idle they will just do another
H_CEDE immediately and go to nap mode.
This required some changes to kvmppc_run_core() and kvmppc_run_vcpu().
These functions have been restructured to make them simpler and clearer.
We introduce a level of indirection in the wait queue that gets woken
when external and decrementer interrupts get generated for a vcpu, so
that we can have the 4 vcpus in a vcore using the same wait queue.
We need this because the 4 vcpus are being handled by one thread.
Secondly, when we need to exit from the guest to the kernel, we now
have to generate an IPI for any napping threads, because an HDEC
interrupt doesn't wake up a napping thread.
Thirdly, we now need to be able to handle virtual external interrupts
and decrementer interrupts becoming pending while a thread is napping,
and deliver those interrupts to the guest when the thread wakes.
This is done in kvmppc_cede_reentry, just before fast_guest_return.
Finally, since we are not using the generic kvm_vcpu_block for book3s_hv,
and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef
from kvm_arch_vcpu_runnable.
Signed-off-by: Paul Mackerras <paulus@samba.org>
---
arch/powerpc/include/asm/kvm_book3s_asm.h | 1 +
arch/powerpc/include/asm/kvm_host.h | 19 ++-
arch/powerpc/kernel/asm-offsets.c | 6 +
arch/powerpc/kvm/book3s_hv.c | 335 ++++++++++++++++-------------
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 297 ++++++++++++++++++++++---
arch/powerpc/kvm/powerpc.c | 21 +-
6 files changed, 483 insertions(+), 196 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s_asm.h b/arch/powerpc/include/asm/kvm_book3s_asm.h
index af73469..1f2f5b6 100644
--- a/arch/powerpc/include/asm/kvm_book3s_asm.h
+++ b/arch/powerpc/include/asm/kvm_book3s_asm.h
@@ -76,6 +76,7 @@ struct kvmppc_host_state {
ulong scratch1;
u8 in_guest;
u8 restore_hid5;
+ u8 napping;
#ifdef CONFIG_KVM_BOOK3S_64_HV
struct kvm_vcpu *kvm_vcpu;
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index db15384..652b05f 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -198,21 +198,29 @@ struct kvm_arch {
*/
struct kvmppc_vcore {
int n_runnable;
- int n_blocked;
+ int n_busy;
int num_threads;
int entry_exit_count;
int n_woken;
int nap_count;
+ int napping_threads;
u16 pcpu;
- u8 vcore_running;
+ u8 vcore_state;
u8 in_guest;
struct list_head runnable_threads;
spinlock_t lock;
+ wait_queue_head_t wq;
};
#define VCORE_ENTRY_COUNT(vc) ((vc)->entry_exit_count & 0xff)
#define VCORE_EXIT_COUNT(vc) ((vc)->entry_exit_count >> 8)
+/* Values for vcore_state */
+#define VCORE_INACTIVE 0
+#define VCORE_RUNNING 1
+#define VCORE_EXITING 2
+#define VCORE_SLEEPING 3
+
struct kvmppc_pte {
ulong eaddr;
u64 vpage;
@@ -400,11 +408,13 @@ struct kvm_vcpu_arch {
struct dtl *dtl;
struct dtl *dtl_end;
+ wait_queue_head_t *wqp;
struct kvmppc_vcore *vcore;
int ret;
int trap;
int state;
int ptid;
+ bool timer_running;
wait_queue_head_t cpu_run;
struct kvm_vcpu_arch_shared *shared;
@@ -420,8 +430,9 @@ struct kvm_vcpu_arch {
#endif
};
-#define KVMPPC_VCPU_BUSY_IN_HOST 0
-#define KVMPPC_VCPU_BLOCKED 1
+/* Values for vcpu->arch.state */
+#define KVMPPC_VCPU_STOPPED 0
+#define KVMPPC_VCPU_BUSY_IN_HOST 1
#define KVMPPC_VCPU_RUNNABLE 2
#endif /* __POWERPC_KVM_HOST_H__ */
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index d34cd32..833021c 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -44,6 +44,7 @@
#include <asm/compat.h>
#include <asm/mmu.h>
#include <asm/hvcall.h>
+#include <asm/xics.h>
#endif
#ifdef CONFIG_PPC_ISERIES
#include <asm/iseries/alpaca.h>
@@ -457,6 +458,8 @@ int main(void)
DEFINE(VCPU_DEC, offsetof(struct kvm_vcpu, arch.dec));
DEFINE(VCPU_DEC_EXPIRES, offsetof(struct kvm_vcpu, arch.dec_expires));
DEFINE(VCPU_PENDING_EXC, offsetof(struct kvm_vcpu, arch.pending_exceptions));
+ DEFINE(VCPU_CEDED, offsetof(struct kvm_vcpu, arch.ceded));
+ DEFINE(VCPU_PRODDED, offsetof(struct kvm_vcpu, arch.prodded));
DEFINE(VCPU_VPA, offsetof(struct kvm_vcpu, arch.vpa));
DEFINE(VCPU_MMCR, offsetof(struct kvm_vcpu, arch.mmcr));
DEFINE(VCPU_PMC, offsetof(struct kvm_vcpu, arch.pmc));
@@ -472,6 +475,7 @@ int main(void)
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));
+ DEFINE(VCORE_NAPPING_THREADS, offsetof(struct kvmppc_vcore, napping_threads));
DEFINE(VCPU_SVCPU, offsetof(struct kvmppc_vcpu_book3s, shadow_vcpu) -
offsetof(struct kvmppc_vcpu_book3s, vcpu));
DEFINE(VCPU_SLB_E, offsetof(struct kvmppc_slb, orige));
@@ -529,6 +533,7 @@ int main(void)
HSTATE_FIELD(HSTATE_SCRATCH1, scratch1);
HSTATE_FIELD(HSTATE_IN_GUEST, in_guest);
HSTATE_FIELD(HSTATE_RESTORE_HID5, restore_hid5);
+ HSTATE_FIELD(HSTATE_NAPPING, napping);
#ifdef CONFIG_KVM_BOOK3S_64_HV
HSTATE_FIELD(HSTATE_KVM_VCPU, kvm_vcpu);
@@ -541,6 +546,7 @@ int main(void)
HSTATE_FIELD(HSTATE_DSCR, host_dscr);
HSTATE_FIELD(HSTATE_DABR, dabr);
HSTATE_FIELD(HSTATE_DECEXP, dec_expires);
+ DEFINE(IPI_PRIORITY, IPI_PRIORITY);
#endif /* CONFIG_KVM_BOOK3S_64_HV */
#else /* CONFIG_PPC_BOOK3S */
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index cc0d7f1..81c384d 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -62,6 +62,8 @@
/* #define EXIT_DEBUG_SIMPLE */
/* #define EXIT_DEBUG_INT */
+static void kvmppc_end_cede(struct kvm_vcpu *vcpu);
+
void kvmppc_core_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
local_paca->kvm_hstate.kvm_vcpu = vcpu;
@@ -72,40 +74,10 @@ void kvmppc_core_vcpu_put(struct kvm_vcpu *vcpu)
{
}
-static void kvmppc_vcpu_blocked(struct kvm_vcpu *vcpu);
-static void kvmppc_vcpu_unblocked(struct kvm_vcpu *vcpu);
-
-void kvmppc_vcpu_block(struct kvm_vcpu *vcpu)
-{
- u64 now;
- unsigned long dec_nsec;
-
- now = get_tb();
- if (now >= vcpu->arch.dec_expires && !kvmppc_core_pending_dec(vcpu))
- kvmppc_core_queue_dec(vcpu);
- if (vcpu->arch.pending_exceptions)
- return;
- if (vcpu->arch.dec_expires != ~(u64)0) {
- dec_nsec = (vcpu->arch.dec_expires - now) * NSEC_PER_SEC /
- tb_ticks_per_sec;
- hrtimer_start(&vcpu->arch.dec_timer, ktime_set(0, dec_nsec),
- HRTIMER_MODE_REL);
- }
-
- kvmppc_vcpu_blocked(vcpu);
-
- kvm_vcpu_block(vcpu);
- vcpu->stat.halt_wakeup++;
-
- if (vcpu->arch.dec_expires != ~(u64)0)
- hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
-
- kvmppc_vcpu_unblocked(vcpu);
-}
-
void kvmppc_set_msr(struct kvm_vcpu *vcpu, u64 msr)
{
vcpu->arch.shregs.msr = msr;
+ kvmppc_end_cede(vcpu);
}
void kvmppc_set_pvr(struct kvm_vcpu *vcpu, u32 pvr)
@@ -257,15 +229,6 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
switch (req) {
case H_CEDE:
- vcpu->arch.shregs.msr |= MSR_EE;
- vcpu->arch.ceded = 1;
- smp_mb();
- if (!vcpu->arch.prodded)
- kvmppc_vcpu_block(vcpu);
- else
- vcpu->arch.prodded = 0;
- smp_mb();
- vcpu->arch.ceded = 0;
break;
case H_PROD:
target = kvmppc_get_gpr(vcpu, 4);
@@ -388,20 +351,6 @@ static int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
break;
}
-
- if (!(r & RESUME_HOST)) {
- /* To avoid clobbering exit_reason, only check for signals if
- * we aren't already exiting to userspace for some other
- * reason. */
- if (signal_pending(tsk)) {
- vcpu->stat.signal_exits++;
- run->exit_reason = KVM_EXIT_INTR;
- r = -EINTR;
- } else {
- kvmppc_core_deliver_interrupts(vcpu);
- }
- }
-
return r;
}
@@ -479,13 +428,9 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
kvmppc_mmu_book3s_hv_init(vcpu);
/*
- * Some vcpus may start out in stopped state. If we initialize
- * them to busy-in-host state they will stop other vcpus in the
- * vcore from running. Instead we initialize them to blocked
- * state, effectively considering them to be stopped until we
- * see the first run ioctl for them.
+ * We consider the vcpu stopped until we see the first run ioctl for it.
*/
- vcpu->arch.state = KVMPPC_VCPU_BLOCKED;
+ vcpu->arch.state = KVMPPC_VCPU_STOPPED;
init_waitqueue_head(&vcpu->arch.cpu_run);
@@ -496,6 +441,7 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
if (vcore) {
INIT_LIST_HEAD(&vcore->runnable_threads);
spin_lock_init(&vcore->lock);
+ init_waitqueue_head(&vcore->wq);
}
kvm->arch.vcores[core] = vcore;
}
@@ -506,7 +452,6 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
spin_lock(&vcore->lock);
++vcore->num_threads;
- ++vcore->n_blocked;
spin_unlock(&vcore->lock);
vcpu->arch.vcore = vcore;
@@ -524,30 +469,31 @@ void kvmppc_core_vcpu_free(struct kvm_vcpu *vcpu)
kfree(vcpu);
}
-static void kvmppc_vcpu_blocked(struct kvm_vcpu *vcpu)
+static void kvmppc_set_timer(struct kvm_vcpu *vcpu)
{
- struct kvmppc_vcore *vc = vcpu->arch.vcore;
+ unsigned long dec_nsec, now;
- spin_lock(&vc->lock);
- vcpu->arch.state = KVMPPC_VCPU_BLOCKED;
- ++vc->n_blocked;
- if (vc->n_runnable > 0 &&
- vc->n_runnable + vc->n_blocked == vc->num_threads) {
- vcpu = list_first_entry(&vc->runnable_threads, struct kvm_vcpu,
- arch.run_list);
- wake_up(&vcpu->arch.cpu_run);
+ now = get_tb();
+ if (now > vcpu->arch.dec_expires) {
+ /* decrementer has already gone negative */
+ kvmppc_core_queue_dec(vcpu);
+ kvmppc_core_deliver_interrupts(vcpu);
+ return;
}
- spin_unlock(&vc->lock);
+ dec_nsec = (vcpu->arch.dec_expires - now) * NSEC_PER_SEC
+ / tb_ticks_per_sec;
+ hrtimer_start(&vcpu->arch.dec_timer, ktime_set(0, dec_nsec),
+ HRTIMER_MODE_REL);
+ vcpu->arch.timer_running = 1;
}
-static void kvmppc_vcpu_unblocked(struct kvm_vcpu *vcpu)
+static void kvmppc_end_cede(struct kvm_vcpu *vcpu)
{
- struct kvmppc_vcore *vc = vcpu->arch.vcore;
-
- spin_lock(&vc->lock);
- vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
- --vc->n_blocked;
- spin_unlock(&vc->lock);
+ vcpu->arch.ceded = 0;
+ if (vcpu->arch.timer_running) {
+ hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
+ vcpu->arch.timer_running = 0;
+ }
}
extern int __kvmppc_vcore_entry(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu);
@@ -562,6 +508,7 @@ static void kvmppc_remove_runnable(struct kvmppc_vcore *vc,
return;
vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
--vc->n_runnable;
+ ++vc->n_busy;
/* decrement the physical thread id of each following vcpu */
v = vcpu;
list_for_each_entry_continue(v, &vc->runnable_threads, arch.run_list)
@@ -575,15 +522,20 @@ static void kvmppc_start_thread(struct kvm_vcpu *vcpu)
struct paca_struct *tpaca;
struct kvmppc_vcore *vc = vcpu->arch.vcore;
+ if (vcpu->arch.timer_running) {
+ hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
+ vcpu->arch.timer_running = 0;
+ }
cpu = vc->pcpu + vcpu->arch.ptid;
tpaca = &paca[cpu];
tpaca->kvm_hstate.kvm_vcpu = vcpu;
tpaca->kvm_hstate.kvm_vcore = vc;
+ tpaca->kvm_hstate.napping = 0;
+ vcpu->cpu = vc->pcpu;
smp_wmb();
#ifdef CONFIG_PPC_ICP_NATIVE
if (vcpu->arch.ptid) {
tpaca->cpu_start = 0x80;
- tpaca->kvm_hstate.in_guest = KVM_GUEST_MODE_GUEST;
wmb();
xics_wake_cpu(cpu);
++vc->n_woken;
@@ -631,9 +583,10 @@ static int on_primary_thread(void)
*/
static int kvmppc_run_core(struct kvmppc_vcore *vc)
{
- struct kvm_vcpu *vcpu, *vnext;
+ struct kvm_vcpu *vcpu, *vcpu0, *vnext;
long ret;
u64 now;
+ int ptid;
/* don't start if any threads have a signal pending */
list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
@@ -652,29 +605,50 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
goto out;
}
+ /*
+ * Assign physical thread IDs, first to non-ceded vcpus
+ * and then to ceded ones.
+ */
+ ptid = 0;
+ vcpu0 = NULL;
+ list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list) {
+ if (!vcpu->arch.ceded) {
+ if (!ptid)
+ vcpu0 = vcpu;
+ vcpu->arch.ptid = ptid++;
+ }
+ }
+ if (!vcpu0)
+ return 0; /* nothing to run */
+ list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
+ if (vcpu->arch.ceded)
+ vcpu->arch.ptid = ptid++;
+
vc->n_woken = 0;
vc->nap_count = 0;
vc->entry_exit_count = 0;
- vc->vcore_running = 1;
+ vc->vcore_state = VCORE_RUNNING;
vc->in_guest = 0;
vc->pcpu = smp_processor_id();
+ vc->napping_threads = 0;
list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
kvmppc_start_thread(vcpu);
- vcpu = list_first_entry(&vc->runnable_threads, struct kvm_vcpu,
- arch.run_list);
+ preempt_disable();
spin_unlock(&vc->lock);
- preempt_disable();
kvm_guest_enter();
- __kvmppc_vcore_entry(NULL, vcpu);
+ __kvmppc_vcore_entry(NULL, vcpu0);
- /* wait for secondary threads to finish writing their state to memory */
spin_lock(&vc->lock);
+ /* disable sending of IPIs on virtual external irqs */
+ list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
+ vcpu->cpu = -1;
+ /* wait for secondary threads to finish writing their state to memory */
if (vc->nap_count < vc->n_woken)
kvmppc_wait_for_nap(vc);
/* prevent other vcpu threads from doing kvmppc_start_thread() now */
- vc->vcore_running = 2;
+ vc->vcore_state = VCORE_EXITING;
spin_unlock(&vc->lock);
/* make sure updates to secondary vcpu structs are visible now */
@@ -690,22 +664,26 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
if (now < vcpu->arch.dec_expires &&
kvmppc_core_pending_dec(vcpu))
kvmppc_core_dequeue_dec(vcpu);
- if (!vcpu->arch.trap) {
- if (signal_pending(vcpu->arch.run_task)) {
- vcpu->arch.kvm_run->exit_reason = KVM_EXIT_INTR;
- vcpu->arch.ret = -EINTR;
- }
- continue; /* didn't get to run */
- }
- ret = kvmppc_handle_exit(vcpu->arch.kvm_run, vcpu,
- vcpu->arch.run_task);
+
+ ret = RESUME_GUEST;
+ if (vcpu->arch.trap)
+ ret = kvmppc_handle_exit(vcpu->arch.kvm_run, vcpu,
+ vcpu->arch.run_task);
+
vcpu->arch.ret = ret;
vcpu->arch.trap = 0;
+
+ if (vcpu->arch.ceded) {
+ if (ret != RESUME_GUEST)
+ kvmppc_end_cede(vcpu);
+ else
+ kvmppc_set_timer(vcpu);
+ }
}
spin_lock(&vc->lock);
out:
- vc->vcore_running = 0;
+ vc->vcore_state = VCORE_INACTIVE;
list_for_each_entry_safe(vcpu, vnext, &vc->runnable_threads,
arch.run_list) {
if (vcpu->arch.ret != RESUME_GUEST) {
@@ -717,82 +695,130 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
return 1;
}
-static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
+/*
+ * Wait for some other vcpu thread to execute us, and
+ * wake us up when we need to handle something in the host.
+ */
+static void kvmppc_wait_for_exec(struct kvm_vcpu *vcpu, int wait_state)
{
- int ptid;
- int wait_state;
- struct kvmppc_vcore *vc;
DEFINE_WAIT(wait);
- /* No need to go into the guest when all we do is going out */
- if (signal_pending(current)) {
- kvm_run->exit_reason = KVM_EXIT_INTR;
- return -EINTR;
+ prepare_to_wait(&vcpu->arch.cpu_run, &wait, wait_state);
+ if (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE)
+ schedule();
+ finish_wait(&vcpu->arch.cpu_run, &wait);
+}
+
+/*
+ * All the vcpus in this vcore are idle, so wait for a decrementer
+ * or external interrupt to one of the vcpus. vc->lock is held.
+ */
+static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
+{
+ DEFINE_WAIT(wait);
+ struct kvm_vcpu *v;
+ int all_idle = 1;
+
+ prepare_to_wait(&vc->wq, &wait, TASK_INTERRUPTIBLE);
+ vc->vcore_state = VCORE_SLEEPING;
+ spin_unlock(&vc->lock);
+ list_for_each_entry(v, &vc->runnable_threads, arch.run_list) {
+ if (!v->arch.ceded || v->arch.pending_exceptions) {
+ all_idle = 0;
+ break;
+ }
}
+ if (all_idle)
+ schedule();
+ finish_wait(&vc->wq, &wait);
+ spin_lock(&vc->lock);
+ vc->vcore_state = VCORE_INACTIVE;
+}
- /* On PPC970, check that we have an RMA region */
- if (!vcpu->kvm->arch.rma && cpu_has_feature(CPU_FTR_ARCH_201))
- return -EPERM;
+static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
+{
+ int n_ceded;
+ int prev_state;
+ struct kvmppc_vcore *vc;
+ struct kvm_vcpu *v, *vn;
kvm_run->exit_reason = 0;
vcpu->arch.ret = RESUME_GUEST;
vcpu->arch.trap = 0;
- flush_fp_to_thread(current);
- flush_altivec_to_thread(current);
- flush_vsx_to_thread(current);
-
/*
* Synchronize with other threads in this virtual core
*/
vc = vcpu->arch.vcore;
spin_lock(&vc->lock);
- /* This happens the first time this is called for a vcpu */
- if (vcpu->arch.state == KVMPPC_VCPU_BLOCKED)
- --vc->n_blocked;
- vcpu->arch.state = KVMPPC_VCPU_RUNNABLE;
- ptid = vc->n_runnable;
+ vcpu->arch.ceded = 0;
vcpu->arch.run_task = current;
vcpu->arch.kvm_run = kvm_run;
- vcpu->arch.ptid = ptid;
+ prev_state = vcpu->arch.state;
+ vcpu->arch.state = KVMPPC_VCPU_RUNNABLE;
list_add_tail(&vcpu->arch.run_list, &vc->runnable_threads);
++vc->n_runnable;
- wait_state = TASK_INTERRUPTIBLE;
- while (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE) {
- if (signal_pending(current)) {
- if (!vc->vcore_running) {
- kvm_run->exit_reason = KVM_EXIT_INTR;
- vcpu->arch.ret = -EINTR;
- break;
- }
- /* have to wait for vcore to stop executing guest */
- wait_state = TASK_UNINTERRUPTIBLE;
- smp_send_reschedule(vc->pcpu);
+ /*
+ * This happens the first time this is called for a vcpu.
+ * If the vcore is already running, we may be able to start
+ * this thread straight away and have it join in.
+ */
+ if (prev_state == KVMPPC_VCPU_STOPPED) {
+ if (vc->vcore_state == VCORE_RUNNING &&
+ VCORE_EXIT_COUNT(vc) == 0) {
+ vcpu->arch.ptid = vc->n_runnable - 1;
+ kvmppc_start_thread(vcpu);
}
- if (!vc->vcore_running &&
- vc->n_runnable + vc->n_blocked == vc->num_threads) {
- /* we can run now */
- if (kvmppc_run_core(vc))
- continue;
- }
+ } else if (prev_state == KVMPPC_VCPU_BUSY_IN_HOST)
+ --vc->n_busy;
- if (vc->vcore_running == 1 && VCORE_EXIT_COUNT(vc) == 0)
- kvmppc_start_thread(vcpu);
+ while (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE &&
+ !signal_pending(current)) {
+ if (vc->n_busy || vc->vcore_state != VCORE_INACTIVE) {
+ spin_unlock(&vc->lock);
+ kvmppc_wait_for_exec(vcpu, TASK_INTERRUPTIBLE);
+ spin_lock(&vc->lock);
+ continue;
+ }
+ n_ceded = 0;
+ list_for_each_entry(v, &vc->runnable_threads, arch.run_list)
+ n_ceded += v->arch.ceded;
+ if (n_ceded == vc->n_runnable)
+ kvmppc_vcore_blocked(vc);
+ else
+ kvmppc_run_core(vc);
+
+ list_for_each_entry_safe(v, vn, &vc->runnable_threads,
+ arch.run_list) {
+ kvmppc_core_deliver_interrupts(v);
+ if (signal_pending(v->arch.run_task)) {
+ kvmppc_remove_runnable(vc, v);
+ v->stat.signal_exits++;
+ v->arch.kvm_run->exit_reason = KVM_EXIT_INTR;
+ v->arch.ret = -EINTR;
+ wake_up(&v->arch.cpu_run);
+ }
+ }
+ }
- /* wait for other threads to come in, or wait for vcore */
- prepare_to_wait(&vcpu->arch.cpu_run, &wait, wait_state);
- spin_unlock(&vc->lock);
- schedule();
- finish_wait(&vcpu->arch.cpu_run, &wait);
- spin_lock(&vc->lock);
+ if (signal_pending(current)) {
+ if (vc->vcore_state == VCORE_RUNNING ||
+ vc->vcore_state == VCORE_EXITING) {
+ spin_unlock(&vc->lock);
+ kvmppc_wait_for_exec(vcpu, TASK_UNINTERRUPTIBLE);
+ spin_lock(&vc->lock);
+ }
+ if (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE) {
+ kvmppc_remove_runnable(vc, vcpu);
+ vcpu->stat.signal_exits++;
+ kvm_run->exit_reason = KVM_EXIT_INTR;
+ vcpu->arch.ret = -EINTR;
+ }
}
- if (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE)
- kvmppc_remove_runnable(vc, vcpu);
spin_unlock(&vc->lock);
-
return vcpu->arch.ret;
}
@@ -800,6 +826,21 @@ int kvmppc_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu)
{
int r;
+ /* No need to go into the guest when all we'll do is come back out */
+ if (signal_pending(current)) {
+ run->exit_reason = KVM_EXIT_INTR;
+ return -EINTR;
+ }
+
+ /* On PPC970, check that we have an RMA region */
+ if (!vcpu->kvm->arch.rma && cpu_has_feature(CPU_FTR_ARCH_201))
+ return -EPERM;
+
+ flush_fp_to_thread(current);
+ flush_altivec_to_thread(current);
+ flush_vsx_to_thread(current);
+ vcpu->arch.wqp = &vcpu->arch.vcore->wq;
+
do {
r = kvmppc_run_vcpu(run, vcpu);
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 543ee50..0e2ea04 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -52,7 +52,7 @@ kvmppc_skip_Hinterrupt:
b .
/*
- * Call kvmppc_handler_trampoline_enter in real mode.
+ * Call kvmppc_hv_entry in real mode.
* Must be called with interrupts hard-disabled.
*
* Input Registers:
@@ -92,6 +92,12 @@ _GLOBAL(kvmppc_hv_entry_trampoline)
kvm_start_guest:
ld r1,PACAEMERGSP(r13)
subi r1,r1,STACK_FRAME_OVERHEAD
+ ld r2,PACATOC(r13)
+
+ /* were we napping due to cede? */
+ lbz r0,HSTATE_NAPPING(r13)
+ cmpwi r0,0
+ bne kvm_end_cede
/* get vcpu pointer */
ld r4, HSTATE_KVM_VCPU(r13)
@@ -279,15 +285,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
cmpwi r0,0
beq 20b
- /* Set LPCR. Set the MER bit if there is a pending external irq. */
+ /* Set LPCR and RMOR. */
10: ld r8,KVM_LPCR(r9)
- ld r0,VCPU_PENDING_EXC(r4)
- li r7,(1 << BOOK3S_IRQPRIO_EXTERNAL)
- oris r7,r7,(1 << BOOK3S_IRQPRIO_EXTERNAL_LEVEL)@h
- and. r0,r0,r7
- beq 11f
- ori r8,r8,LPCR_MER
-11: mtspr SPRN_LPCR,r8
+ mtspr SPRN_LPCR,r8
ld r8,KVM_RMOR(r9)
mtspr SPRN_RMOR,r8
isync
@@ -451,19 +451,50 @@ toc_tlbie_lock:
mtctr r6
mtxer r7
- /* Move SRR0 and SRR1 into the respective regs */
+kvmppc_cede_reentry: /* r4 = vcpu, r13 = paca */
ld r6, VCPU_SRR0(r4)
ld r7, VCPU_SRR1(r4)
- mtspr SPRN_SRR0, r6
- mtspr SPRN_SRR1, r7
-
ld r10, VCPU_PC(r4)
+ ld r11, VCPU_MSR(r4) /* r11 = vcpu->arch.msr & ~MSR_HV */
- ld r11, VCPU_MSR(r4) /* r10 = vcpu->arch.msr & ~MSR_HV */
rldicl r11, r11, 63 - MSR_HV_LG, 1
rotldi r11, r11, 1 + MSR_HV_LG
ori r11, r11, MSR_ME
+ /* Check if we can deliver an external or decrementer interrupt now */
+ ld r0,VCPU_PENDING_EXC(r4)
+ li r8,(1 << BOOK3S_IRQPRIO_EXTERNAL)
+ oris r8,r8,(1 << BOOK3S_IRQPRIO_EXTERNAL_LEVEL)@h
+ and r0,r0,r8
+ cmpdi cr1,r0,0
+ andi. r0,r11,MSR_EE
+ beq cr1,11f
+BEGIN_FTR_SECTION
+ mfspr r8,SPRN_LPCR
+ ori r8,r8,LPCR_MER
+ mtspr SPRN_LPCR,r8
+ isync
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
+ beq 5f
+ li r0,BOOK3S_INTERRUPT_EXTERNAL
+12: mr r6,r10
+ mr r10,r0
+ mr r7,r11
+ li r11,(MSR_ME << 1) | 1 /* synthesize MSR_SF | MSR_ME */
+ rotldi r11,r11,63
+ b 5f
+11: beq 5f
+ mfspr r0,SPRN_DEC
+ cmpwi r0,0
+ li r0,BOOK3S_INTERRUPT_DECREMENTER
+ blt 12b
+
+ /* Move SRR0 and SRR1 into the respective regs */
+5: mtspr SPRN_SRR0, r6
+ mtspr SPRN_SRR1, r7
+ li r0,0
+ stb r0,VCPU_CEDED(r4) /* cancel cede */
+
fast_guest_return:
mtspr SPRN_HSRR0,r10
mtspr SPRN_HSRR1,r11
@@ -577,21 +608,20 @@ kvmppc_interrupt:
/* See if this is something we can handle in real mode */
cmpwi r12,BOOK3S_INTERRUPT_SYSCALL
beq hcall_try_real_mode
-hcall_real_cont:
/* Check for mediated interrupts (could be done earlier really ...) */
BEGIN_FTR_SECTION
cmpwi r12,BOOK3S_INTERRUPT_EXTERNAL
bne+ 1f
- ld r5,VCPU_KVM(r9)
- ld r5,KVM_LPCR(r5)
andi. r0,r11,MSR_EE
beq 1f
+ mfspr r5,SPRN_LPCR
andi. r0,r5,LPCR_MER
bne bounce_ext_interrupt
1:
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
+hcall_real_cont: /* r9 = vcpu, r12 = trap, r13 = paca */
/* Save DEC */
mfspr r5,SPRN_DEC
mftb r6
@@ -685,7 +715,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_201)
slbia
ptesync
-hdec_soon:
+hdec_soon: /* r9 = vcpu, r12 = trap, r13 = paca */
BEGIN_FTR_SECTION
b 32f
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
@@ -703,6 +733,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
addi r0,r3,0x100
stwcx. r0,0,r6
bne 41b
+ lwsync
/*
* At this point we have an interrupt that we have to pass
@@ -716,18 +747,39 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
* interrupt, since the other threads will already be on their
* way here in that case.
*/
+ cmpwi r3,0x100 /* Are we the first here? */
+ bge 43f
+ cmpwi r3,1 /* Are any other threads in the guest? */
+ ble 43f
cmpwi r12,BOOK3S_INTERRUPT_HV_DECREMENTER
beq 40f
- cmpwi r3,0x100 /* Are we the first here? */
- bge 40f
- cmpwi r3,1
- ble 40f
li r0,0
mtspr SPRN_HDEC,r0
40:
+ /*
+ * Send an IPI to any napping threads, since an HDEC interrupt
+ * doesn't wake CPUs up from nap.
+ */
+ lwz r3,VCORE_NAPPING_THREADS(r5)
+ lwz r4,VCPU_PTID(r9)
+ li r0,1
+ sldi r0,r0,r4
+ andc. r3,r3,r0 /* no sense IPI'ing ourselves */
+ beq 43f
+ mulli r4,r4,PACA_SIZE /* get paca for thread 0 */
+ subf r6,r4,r13
+42: andi. r0,r3,1
+ beq 44f
+ ld r8,HSTATE_XICS_PHYS(r6) /* get thread's XICS reg addr */
+ li r0,IPI_PRIORITY
+ li r7,XICS_QIRR
+ stbcix r0,r7,r8 /* trigger the IPI */
+44: srdi. r3,r3,1
+ addi r6,r6,PACA_SIZE
+ bne 42b
/* Secondary threads wait for primary to do partition switch */
- ld r4,VCPU_KVM(r9) /* pointer to struct kvm */
+43: ld r4,VCPU_KVM(r9) /* pointer to struct kvm */
ld r5,HSTATE_KVM_VCORE(r13)
lwz r3,VCPU_PTID(r9)
cmpwi r3,0
@@ -1080,7 +1132,6 @@ hcall_try_real_mode:
hcall_real_fallback:
li r12,BOOK3S_INTERRUPT_SYSCALL
ld r9, HSTATE_KVM_VCPU(r13)
- ld r11, VCPU_MSR(r9)
b hcall_real_cont
@@ -1142,7 +1193,7 @@ hcall_real_table:
.long 0 /* 0xd4 */
.long 0 /* 0xd8 */
.long 0 /* 0xdc */
- .long 0 /* 0xe0 */
+ .long .kvmppc_h_cede - hcall_real_table
.long 0 /* 0xe4 */
.long 0 /* 0xe8 */
.long 0 /* 0xec */
@@ -1171,7 +1222,8 @@ bounce_ext_interrupt:
mtspr SPRN_SRR0,r10
mtspr SPRN_SRR1,r11
li r10,BOOK3S_INTERRUPT_EXTERNAL
- LOAD_REG_IMMEDIATE(r11,MSR_SF | MSR_ME);
+ li r11,(MSR_ME << 1) | 1 /* synthesize MSR_SF | MSR_ME */
+ rotldi r11,r11,63
b fast_guest_return
_GLOBAL(kvmppc_h_set_dabr)
@@ -1180,6 +1232,178 @@ _GLOBAL(kvmppc_h_set_dabr)
li r3,0
blr
+_GLOBAL(kvmppc_h_cede)
+ ori r11,r11,MSR_EE
+ std r11,VCPU_MSR(r3)
+ li r0,1
+ stb r0,VCPU_CEDED(r3)
+ sync /* order setting ceded vs. testing prodded */
+ lbz r5,VCPU_PRODDED(r3)
+ cmpwi r5,0
+ bne 1f
+ 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 */
+END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_206)
+
+ /*
+ * Set our bit in the bitmask of napping threads unless all the
+ * other threads are already napping, in which case we send this
+ * up to the host.
+ */
+ ld r5,HSTATE_KVM_VCORE(r13)
+ lwz r6,VCPU_PTID(r3)
+ lwz r8,VCORE_ENTRY_EXIT(r5)
+ clrldi r8,r8,56
+ li r0,1
+ sld r0,r0,r6
+ addi r6,r5,VCORE_NAPPING_THREADS
+31: lwarx r4,0,r6
+ or r4,r4,r0
+ popcntw r7,r4
+ cmpw r7,r8
+ bge 2f
+ stwcx. r4,0,r6
+ bne 31b
+ li r0,1
+ stb r0,HSTATE_NAPPING(r13)
+ /* order napping_threads update vs testing entry_exit_count */
+ lwsync
+ mr r4,r3
+ lwz r7,VCORE_ENTRY_EXIT(r5)
+ cmpwi r7,0x100
+ bge 33f /* another thread already exiting */
+
+/*
+ * Although not specifically required by the architecture, POWER7
+ * preserves the following registers in nap mode, even if an SMT mode
+ * switch occurs: SLB entries, PURR, SPURR, AMOR, UAMOR, AMR, SPRG0-3,
+ * DAR, DSISR, DABR, DABRX, DSCR, PMCx, MMCRx, SIAR, SDAR.
+ */
+ /* Save non-volatile GPRs */
+ std r14, VCPU_GPR(r14)(r3)
+ std r15, VCPU_GPR(r15)(r3)
+ std r16, VCPU_GPR(r16)(r3)
+ std r17, VCPU_GPR(r17)(r3)
+ std r18, VCPU_GPR(r18)(r3)
+ std r19, VCPU_GPR(r19)(r3)
+ std r20, VCPU_GPR(r20)(r3)
+ std r21, VCPU_GPR(r21)(r3)
+ std r22, VCPU_GPR(r22)(r3)
+ std r23, VCPU_GPR(r23)(r3)
+ std r24, VCPU_GPR(r24)(r3)
+ std r25, VCPU_GPR(r25)(r3)
+ std r26, VCPU_GPR(r26)(r3)
+ std r27, VCPU_GPR(r27)(r3)
+ std r28, VCPU_GPR(r28)(r3)
+ std r29, VCPU_GPR(r29)(r3)
+ std r30, VCPU_GPR(r30)(r3)
+ std r31, VCPU_GPR(r31)(r3)
+
+ /* save FP state */
+ bl .kvmppc_save_fp
+
+ /*
+ * Take a nap until a decrementer or external interrupt occurs,
+ * with PECE1 (wake on decr) and PECE0 (wake on external) set in LPCR
+ */
+ li r0,0x80
+ stb r0,PACAPROCSTART(r13)
+ mfspr r5,SPRN_LPCR
+ ori r5,r5,LPCR_PECE0 | LPCR_PECE1
+ mtspr SPRN_LPCR,r5
+ isync
+ li r0, 0
+ std r0, HSTATE_SCRATCH0(r13)
+ ptesync
+ ld r0, HSTATE_SCRATCH0(r13)
+1: cmpd r0, r0
+ bne 1b
+ nap
+ b .
+
+kvm_end_cede:
+ /* Woken by external or decrementer interrupt */
+ ld r1, HSTATE_HOST_R1(r13)
+ ld r2, PACATOC(r13)
+
+ /* If we're a secondary thread and we got here by an IPI, ack it */
+ ld r4,HSTATE_KVM_VCPU(r13)
+ lwz r3,VCPU_PTID(r4)
+ cmpwi r3,0
+ beq 27f
+ mfspr r3,SPRN_SRR1
+ rlwinm r3,r3,44-31,0x7 /* extract wake reason field */
+ cmpwi r3,4 /* was it an external interrupt? */
+ bne 27f
+ ld r5, HSTATE_XICS_PHYS(r13)
+ li r0,0xff
+ li r6,XICS_QIRR
+ li r7,XICS_XIRR
+ lwzcix r8,r5,r7 /* ack the interrupt */
+ sync
+ stbcix r0,r5,r6 /* clear it */
+ stwcix r8,r5,r7 /* EOI it */
+27:
+ /* load up FP state */
+ bl kvmppc_load_fp
+
+ /* Load NV GPRS */
+ ld r14, VCPU_GPR(r14)(r4)
+ ld r15, VCPU_GPR(r15)(r4)
+ ld r16, VCPU_GPR(r16)(r4)
+ ld r17, VCPU_GPR(r17)(r4)
+ ld r18, VCPU_GPR(r18)(r4)
+ ld r19, VCPU_GPR(r19)(r4)
+ ld r20, VCPU_GPR(r20)(r4)
+ ld r21, VCPU_GPR(r21)(r4)
+ ld r22, VCPU_GPR(r22)(r4)
+ ld r23, VCPU_GPR(r23)(r4)
+ ld r24, VCPU_GPR(r24)(r4)
+ ld r25, VCPU_GPR(r25)(r4)
+ ld r26, VCPU_GPR(r26)(r4)
+ ld r27, VCPU_GPR(r27)(r4)
+ ld r28, VCPU_GPR(r28)(r4)
+ ld r29, VCPU_GPR(r29)(r4)
+ ld r30, VCPU_GPR(r30)(r4)
+ ld r31, VCPU_GPR(r31)(r4)
+
+ /* clear our bit in vcore->napping_threads */
+33: ld r5,HSTATE_KVM_VCORE(r13)
+ lwz r3,VCPU_PTID(r4)
+ li r0,1
+ sld r0,r0,r3
+ addi r6,r5,VCORE_NAPPING_THREADS
+32: lwarx r7,0,r6
+ andc r7,r7,r0
+ stwcx. r7,0,r6
+ bne 32b
+ li r0,0
+ stb r0,HSTATE_NAPPING(r13)
+
+ /* see if any other thread is already exiting */
+ lwz r0,VCORE_ENTRY_EXIT(r5)
+ cmpwi r0,0x100
+ blt kvmppc_cede_reentry /* if not go back to guest */
+
+ /* some threads are exiting, so go to the guest exit path */
+ b hcall_real_fallback
+
+ /* cede when already previously prodded case */
+1: li r0,0
+ stb r0,VCPU_PRODDED(r3)
+ sync /* order testing prodded vs. clearing ceded */
+ stb r0,VCPU_CEDED(r3)
+ li r3,H_SUCCESS
+ blr
+
+ /* we've ceded but we want to give control to the host */
+2: li r3,H_TOO_HARD
+ blr
+
secondary_too_late:
ld r5,HSTATE_KVM_VCORE(r13)
HMT_LOW
@@ -1197,14 +1421,20 @@ secondary_too_late:
slbmte r6,r5
1: addi r11,r11,16
.endr
- b 50f
secondary_nap:
- /* Clear any pending IPI */
-50: ld r5, HSTATE_XICS_PHYS(r13)
+ /* Clear any pending IPI - assume we're a secondary thread */
+ ld r5, HSTATE_XICS_PHYS(r13)
+ li r7, XICS_XIRR
+ lwzcix r3, r5, r7 /* ack any pending interrupt */
+ rlwinm. r0, r3, 0, 0xffffff /* any pending? */
+ beq 37f
+ sync
li r0, 0xff
li r6, XICS_QIRR
- stbcix r0, r5, r6
+ stbcix r0, r5, r6 /* clear the IPI */
+ stwcix r3, r5, r7 /* EOI it */
+37: sync
/* increment the nap count and then go to nap mode */
ld r4, HSTATE_KVM_VCORE(r13)
@@ -1214,13 +1444,12 @@ secondary_nap:
addi r3, r3, 1
stwcx. r3, 0, r4
bne 51b
- isync
+ li r3, LPCR_PECE0
mfspr r4, SPRN_LPCR
- li r0, LPCR_PECE
- andc r4, r4, r0
- ori r4, r4, LPCR_PECE0 /* exit nap on interrupt */
+ rlwimi r4, r3, 0, LPCR_PECE0 | LPCR_PECE1
mtspr SPRN_LPCR, r4
+ isync
li r0, 0
std r0, HSTATE_SCRATCH0(r13)
ptesync
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index a107c9b..cd0e3e5 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -39,12 +39,8 @@
int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
{
-#ifndef CONFIG_KVM_BOOK3S_64_HV
return !(v->arch.shared->msr & MSR_WE) ||
!!(v->arch.pending_exceptions);
-#else
- return !(v->arch.ceded) || !!(v->arch.pending_exceptions);
-#endif
}
int kvmppc_kvm_pv(struct kvm_vcpu *vcpu)
@@ -258,6 +254,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
{
struct kvm_vcpu *vcpu;
vcpu = kvmppc_core_vcpu_create(kvm, id);
+ vcpu->arch.wqp = &vcpu->wq;
if (!IS_ERR(vcpu))
kvmppc_create_vcpu_debugfs(vcpu, id);
return vcpu;
@@ -289,8 +286,8 @@ static void kvmppc_decrementer_func(unsigned long data)
kvmppc_core_queue_dec(vcpu);
- if (waitqueue_active(&vcpu->wq)) {
- wake_up_interruptible(&vcpu->wq);
+ if (waitqueue_active(vcpu->arch.wqp)) {
+ wake_up_interruptible(vcpu->arch.wqp);
vcpu->stat.halt_wakeup++;
}
}
@@ -543,13 +540,15 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
{
- if (irq->irq == KVM_INTERRUPT_UNSET)
+ if (irq->irq == KVM_INTERRUPT_UNSET) {
kvmppc_core_dequeue_external(vcpu, irq);
- else
- kvmppc_core_queue_external(vcpu, irq);
+ return 0;
+ }
+
+ kvmppc_core_queue_external(vcpu, irq);
- if (waitqueue_active(&vcpu->wq)) {
- wake_up_interruptible(&vcpu->wq);
+ if (waitqueue_active(vcpu->arch.wqp)) {
+ wake_up_interruptible(vcpu->arch.wqp);
vcpu->stat.halt_wakeup++;
} else if (vcpu->cpu != -1) {
smp_send_reschedule(vcpu->cpu);
--
1.7.5.4
^ permalink raw reply related
* [PATCH v3 1/6] fault-injection: notifier error injection
From: Akinobu Mita @ 2011-07-23 8:50 UTC (permalink / raw)
To: linux-kernel, akpm
Cc: Greg KH, Akinobu Mita, Rafael J. Wysocki, linux-mm,
Paul Mackerras, Pavel Machek, linux-pm, linuxppc-dev
In-Reply-To: <1311411060-30124-1-git-send-email-akinobu.mita@gmail.com>
The notifier error injection provides the ability to inject artifical
errors to specified notifier chain callbacks. It is useful to test the
error handling of notifier call chain failures.
This adds common basic functions to define which type of events can be
fail and to initialize the debugfs interface to control what error code
should be returned and which event should be failed.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: linux-pm@lists.linux-foundation.org
Cc: Greg KH <greg@kroah.com>
Cc: linux-mm@kvack.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
---
* v3
- export err_inject_notifier_block_{init,cleanup} for modules
include/linux/notifier.h | 25 ++++++++++++++
kernel/notifier.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++
lib/Kconfig.debug | 11 ++++++
3 files changed, 119 insertions(+), 0 deletions(-)
diff --git a/include/linux/notifier.h b/include/linux/notifier.h
index c0688b0..51882d6 100644
--- a/include/linux/notifier.h
+++ b/include/linux/notifier.h
@@ -278,5 +278,30 @@ extern struct blocking_notifier_head reboot_notifier_list;
#define VT_UPDATE 0x0004 /* A bigger update occurred */
#define VT_PREWRITE 0x0005 /* A char is about to be written to the console */
+#ifdef CONFIG_NOTIFIER_ERROR_INJECTION
+
+struct err_inject_notifier_action {
+ unsigned long val;
+ int error;
+ const char *name;
+};
+
+#define ERR_INJECT_NOTIFIER_ACTION(action) \
+ .name = #action, .val = (action),
+
+struct err_inject_notifier_block {
+ struct notifier_block nb;
+ struct dentry *dir;
+ struct err_inject_notifier_action actions[];
+ /* The last slot must be terminated with zero sentinel */
+};
+
+extern int err_inject_notifier_block_init(struct err_inject_notifier_block *enb,
+ const char *name, int priority);
+extern void err_inject_notifier_block_cleanup(
+ struct err_inject_notifier_block *enb);
+
+#endif /* CONFIG_NOTIFIER_ERROR_INJECTION */
+
#endif /* __KERNEL__ */
#endif /* _LINUX_NOTIFIER_H */
diff --git a/kernel/notifier.c b/kernel/notifier.c
index 2488ba7..8dcb2cc 100644
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -5,6 +5,7 @@
#include <linux/rcupdate.h>
#include <linux/vmalloc.h>
#include <linux/reboot.h>
+#include <linux/debugfs.h>
/*
* Notifier list for kernel code which wants to be called
@@ -584,3 +585,85 @@ int unregister_die_notifier(struct notifier_block *nb)
return atomic_notifier_chain_unregister(&die_chain, nb);
}
EXPORT_SYMBOL_GPL(unregister_die_notifier);
+
+#ifdef CONFIG_NOTIFIER_ERROR_INJECTION
+
+static int debugfs_errno_set(void *data, u64 val)
+{
+ *(int *)data = clamp_t(int, val, -MAX_ERRNO, 0);
+ return 0;
+}
+
+static int debugfs_errno_get(void *data, u64 *val)
+{
+ *val = *(int *)data;
+ return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(fops_errno, debugfs_errno_get, debugfs_errno_set,
+ "%lld\n");
+
+static struct dentry *debugfs_create_errno(const char *name, mode_t mode,
+ struct dentry *parent, int *value)
+{
+ return debugfs_create_file(name, mode, parent, value, &fops_errno);
+}
+
+static int err_inject_notifier_callback(struct notifier_block *nb,
+ unsigned long val, void *p)
+{
+ int err = 0;
+ struct err_inject_notifier_block *enb =
+ container_of(nb, struct err_inject_notifier_block, nb);
+ struct err_inject_notifier_action *action;
+
+ for (action = enb->actions; action->name; action++) {
+ if (action->val == val) {
+ err = action->error;
+ break;
+ }
+ }
+ if (err) {
+ printk(KERN_INFO "Injecting error (%d) to %s\n",
+ err, action->name);
+ }
+
+ return notifier_from_errno(err);
+}
+
+int err_inject_notifier_block_init(struct err_inject_notifier_block *enb,
+ const char *name, int priority)
+{
+ struct err_inject_notifier_action *action;
+ mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
+
+ enb->nb.notifier_call = err_inject_notifier_callback;
+ enb->nb.priority = priority;
+
+ enb->dir = debugfs_create_dir(name, NULL);
+ if (!enb->dir)
+ return -ENOMEM;
+
+ for (action = enb->actions; action->name; action++) {
+ /*
+ * Create debugfs r/w file containing action->error. If
+ * notifier call chain is called with action->val, it will
+ * fail with the error code
+ */
+ if (!debugfs_create_errno(action->name, mode, enb->dir,
+ &action->error)) {
+ debugfs_remove_recursive(enb->dir);
+ return -ENOMEM;
+ }
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(err_inject_notifier_block_init);
+
+void err_inject_notifier_block_cleanup(struct err_inject_notifier_block *enb)
+{
+ debugfs_remove_recursive(enb->dir);
+}
+EXPORT_SYMBOL_GPL(err_inject_notifier_block_cleanup);
+
+#endif /* CONFIG_NOTIFIER_ERROR_INJECTION */
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index c0cb9c4..2a62c5a 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1021,6 +1021,17 @@ config LKDTM
Documentation on how to use the module can be found in
Documentation/fault-injection/provoke-crashes.txt
+config NOTIFIER_ERROR_INJECTION
+ bool "Notifier error injection"
+ depends on DEBUG_KERNEL
+ select DEBUG_FS
+ help
+ This option provides the ability to inject artifical errors to
+ specified notifier chain callbacks. It is useful to test the error
+ handling of notifier call chain failures.
+
+ Say N if unsure.
+
config CPU_NOTIFIER_ERROR_INJECT
tristate "CPU notifier error injection module"
depends on HOTPLUG_CPU && DEBUG_KERNEL
--
1.7.4.4
^ permalink raw reply related
* [PATCH v3 5/6] powerpc: pSeries reconfig notifier error injection module
From: Akinobu Mita @ 2011-07-23 8:50 UTC (permalink / raw)
To: linux-kernel, akpm; +Cc: linuxppc-dev, Paul Mackerras, Akinobu Mita
In-Reply-To: <1311411060-30124-1-git-send-email-akinobu.mita@gmail.com>
This provides the ability to inject artifical errors to pSeries reconfig
notifier chain callbacks. It is controlled through debugfs interface
under /sys/kernel/debug/pSeries-reconfig-notifier-error-inject/
Each of the files in the directory represents an event which can be failed
and contains the error code. If the notifier call chain should be failed
with some events notified, write the error code to the files.
This module needs pSeries_reconfig_notifier_{,un}register symbols to be
exported.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
---
* v3
- rewrite to be kernel modules instead of initializing at late_initcall()s
- export pSeries_reconfig_notifier_{,un}register symbols for this module
- notifier priority can be specified as a module parameter
arch/powerpc/platforms/pseries/reconfig.c | 2 +
lib/Kconfig.debug | 14 +++++++
lib/Makefile | 2 +
lib/pSeries-reconfig-notifier-error-inject.c | 48 ++++++++++++++++++++++++++
4 files changed, 66 insertions(+), 0 deletions(-)
create mode 100644 lib/pSeries-reconfig-notifier-error-inject.c
diff --git a/arch/powerpc/platforms/pseries/reconfig.c b/arch/powerpc/platforms/pseries/reconfig.c
index 168651a..b9808e9 100644
--- a/arch/powerpc/platforms/pseries/reconfig.c
+++ b/arch/powerpc/platforms/pseries/reconfig.c
@@ -103,11 +103,13 @@ int pSeries_reconfig_notifier_register(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&pSeries_reconfig_chain, nb);
}
+EXPORT_SYMBOL_GPL(pSeries_reconfig_notifier_register);
void pSeries_reconfig_notifier_unregister(struct notifier_block *nb)
{
blocking_notifier_chain_unregister(&pSeries_reconfig_chain, nb);
}
+EXPORT_SYMBOL_GPL(pSeries_reconfig_notifier_unregister);
int pSeries_reconfig_notify(unsigned long action, void *p)
{
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index a2b0856..46298d7 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1099,6 +1099,20 @@ config MEMORY_NOTIFIER_ERROR_INJECT
If unsure, say N.
+config PSERIES_RECONFIG_NOTIFIER_ERROR_INJECT
+ tristate "pSeries reconfig notifier error injection module"
+ depends on PPC_PSERIES && NOTIFIER_ERROR_INJECTION
+ help
+ This option provides the ability to inject artifical errors to
+ pSeries reconfig notifier chain callbacks. It is controlled
+ through debugfs interface under
+ /sys/kernel/debug/pSeries-reconfig-notifier-error-inject/
+
+ To compile this code as a module, choose M here: the module will
+ be called memory-notifier-error-inject.
+
+ If unsure, say N.
+
config FAULT_INJECTION
bool "Fault-injection framework"
depends on DEBUG_KERNEL
diff --git a/lib/Makefile b/lib/Makefile
index f28914b..e68cea7 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -92,6 +92,8 @@ obj-$(CONFIG_FAULT_INJECTION) += fault-inject.o
obj-$(CONFIG_CPU_NOTIFIER_ERROR_INJECT) += cpu-notifier-error-inject.o
obj-$(CONFIG_PM_NOTIFIER_ERROR_INJECT) += pm-notifier-error-inject.o
obj-$(CONFIG_MEMORY_NOTIFIER_ERROR_INJECT) += memory-notifier-error-inject.o
+obj-$(CONFIG_PSERIES_RECONFIG_NOTIFIER_ERROR_INJECT) += \
+ pSeries-reconfig-notifier-error-inject.o
lib-$(CONFIG_GENERIC_BUG) += bug.o
diff --git a/lib/pSeries-reconfig-notifier-error-inject.c b/lib/pSeries-reconfig-notifier-error-inject.c
new file mode 100644
index 0000000..f4ed2b3
--- /dev/null
+++ b/lib/pSeries-reconfig-notifier-error-inject.c
@@ -0,0 +1,48 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+
+#include <asm/pSeries_reconfig.h>
+
+static int priority;
+module_param(priority, int, 0);
+MODULE_PARM_DESC(priority, "specify pSeries reconfig notifier priority");
+
+static struct err_inject_notifier_block err_inject_reconfig_nb = {
+ .actions = {
+ { ERR_INJECT_NOTIFIER_ACTION(PSERIES_RECONFIG_ADD) },
+ { ERR_INJECT_NOTIFIER_ACTION(PSERIES_RECONFIG_REMOVE) },
+ { ERR_INJECT_NOTIFIER_ACTION(PSERIES_DRCONF_MEM_ADD) },
+ { ERR_INJECT_NOTIFIER_ACTION(PSERIES_DRCONF_MEM_REMOVE) },
+ {}
+ }
+};
+
+static int err_inject_init(void)
+{
+ int err;
+
+ err = err_inject_notifier_block_init(&err_inject_reconfig_nb,
+ "pSeries-reconfig-notifier-error-inject", priority);
+ if (err)
+ return err;
+
+ err = pSeries_reconfig_notifier_register(&err_inject_reconfig_nb.nb);
+ if (err)
+ err_inject_notifier_block_cleanup(&err_inject_reconfig_nb);
+
+ return err;
+}
+
+static void err_inject_exit(void)
+{
+ pSeries_reconfig_notifier_unregister(&err_inject_reconfig_nb.nb);
+ err_inject_notifier_block_cleanup(&err_inject_reconfig_nb);
+}
+
+module_init(err_inject_init);
+module_exit(err_inject_exit);
+
+MODULE_DESCRIPTION("pSeries reconfig notifier error injection module");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
--
1.7.4.4
^ permalink raw reply related
* [PATCH v3 6/6] fault-injection: add notifier error injection testing scripts
From: Akinobu Mita @ 2011-07-23 8:51 UTC (permalink / raw)
To: linux-kernel, akpm
Cc: Greg KH, Akinobu Mita, Rafael J. Wysocki, linux-mm,
Paul Mackerras, Pavel Machek, Américo Wang, linux-pm,
linuxppc-dev
In-Reply-To: <1311411060-30124-1-git-send-email-akinobu.mita@gmail.com>
* tools/testing/fault-injection/cpu-notifier.sh is testing script for
CPU notifier error handling by using cpu-notifier-error-inject.ko.
1. Offline all hot-pluggable CPUs in preparation for testing
2. Test CPU hot-add error handling by injecting notifier errors
3. Online all hot-pluggable CPUs in preparation for testing
4. Test CPU hot-remove error handling by injecting notifier errors
* tools/testing/fault-injection/memory-notifier.sh is doing the same thing
for memory hotplug notifier.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: linux-pm@lists.linux-foundation.org
Cc: Greg KH <greg@kroah.com>
Cc: linux-mm@kvack.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Américo Wang <xiyou.wangcong@gmail.com>
---
* v3
- new patch
tools/testing/fault-injection/cpu-notifier.sh | 162 +++++++++++++++++++++
tools/testing/fault-injection/memory-notifier.sh | 163 ++++++++++++++++++++++
2 files changed, 325 insertions(+), 0 deletions(-)
create mode 100755 tools/testing/fault-injection/cpu-notifier.sh
create mode 100755 tools/testing/fault-injection/memory-notifier.sh
diff --git a/tools/testing/fault-injection/cpu-notifier.sh b/tools/testing/fault-injection/cpu-notifier.sh
new file mode 100755
index 0000000..be02a85
--- /dev/null
+++ b/tools/testing/fault-injection/cpu-notifier.sh
@@ -0,0 +1,162 @@
+#!/bin/bash
+
+#
+# list all hot-pluggable CPUs
+#
+hotpluggable_cpus()
+{
+ local state=${1:-.\*}
+
+ for cpu in /sys/devices/system/cpu/cpu*; do
+ if [ -f $cpu/online ] && grep -q $state $cpu/online; then
+ echo ${cpu##/*/cpu}
+ fi
+ done
+}
+
+hotplaggable_offline_cpus()
+{
+ hotpluggable_cpus 0
+}
+
+hotpluggable_online_cpus()
+{
+ hotpluggable_cpus 1
+}
+
+cpu_is_online()
+{
+ grep -q 1 /sys/devices/system/cpu/cpu$1/online
+}
+
+cpu_is_offline()
+{
+ grep -q 0 /sys/devices/system/cpu/cpu$1/online
+}
+
+add_cpu()
+{
+ echo 1 > /sys/devices/system/cpu/cpu$1/online
+}
+
+remove_cpu()
+{
+ echo 0 > /sys/devices/system/cpu/cpu$1/online
+}
+
+add_cpu_expect_success()
+{
+ local cpu=$1
+
+ if ! add_cpu $cpu; then
+ echo $FUNCNAME $cpu: unexpected fail >&2
+ elif ! cpu_is_online $cpu; then
+ echo $FUNCNAME $cpu: unexpected offline >&2
+ fi
+}
+
+add_cpu_expect_fail()
+{
+ local cpu=$1
+
+ if add_cpu $cpu 2> /dev/null; then
+ echo $FUNCNAME $cpu: unexpected success >&2
+ elif ! cpu_is_offline $cpu; then
+ echo $FUNCNAME $cpu: unexpected online >&2
+ fi
+}
+
+remove_cpu_expect_success()
+{
+ local cpu=$1
+
+ if ! remove_cpu $cpu; then
+ echo $FUNCNAME $cpu: unexpected fail >&2
+ elif ! cpu_is_offline $cpu; then
+ echo $FUNCNAME $cpu: unexpected offline >&2
+ fi
+}
+
+remove_cpu_expect_fail()
+{
+ local cpu=$1
+
+ if remove_cpu $cpu 2> /dev/null; then
+ echo $FUNCNAME $cpu: unexpected success >&2
+ elif ! cpu_is_online $cpu; then
+ echo $FUNCNAME $cpu: unexpected offline >&2
+ fi
+}
+
+if [ $UID != 0 ]; then
+ echo must be run as root >&2
+ exit 1
+fi
+
+error=-12
+priority=0
+
+while getopts e:p: opt; do
+ case $opt in
+ e)
+ error=$OPTARG
+ ;;
+ p)
+ priority=$OPTARG
+ ;;
+ esac
+done
+
+if ! [ "$error" -ge -4095 -a "$error" -lt 0 ]; then
+ echo "error code must be -4095 <= errno < 0" >&2
+ exit 1
+fi
+
+DEBUGFS=`mount -t debugfs | head -1 | awk '{ print $3 }'`
+
+if [ ! -d "$DEBUGFS" ]; then
+ echo debugfs is not mounted >&2
+ exit 1
+fi
+
+/sbin/modprobe -r cpu-notifier-error-inject
+/sbin/modprobe -q cpu-notifier-error-inject priority=$priority
+
+if [ ! -d $DEBUGFS/cpu-notifier-error-inject ]; then
+ echo cpu-notifier-error-inject module is not available >&2
+ exit 1
+fi
+
+#
+# Offline all hot-pluggable CPUs
+#
+echo 0 > $DEBUGFS/cpu-notifier-error-inject/CPU_DOWN_PREPARE
+for cpu in `hotpluggable_online_cpus`; do
+ remove_cpu_expect_success $cpu
+done
+
+#
+# Test CPU hot-add error handling (offline => online)
+#
+echo $error > $DEBUGFS/cpu-notifier-error-inject/CPU_UP_PREPARE
+for cpu in `hotplaggable_offline_cpus`; do
+ add_cpu_expect_fail $cpu
+done
+
+#
+# Online all hot-pluggable CPUs
+#
+echo 0 > $DEBUGFS/cpu-notifier-error-inject/CPU_UP_PREPARE
+for cpu in `hotplaggable_offline_cpus`; do
+ add_cpu_expect_success $cpu
+done
+
+#
+# Test CPU hot-remove error handling (online => offline)
+#
+echo $error > $DEBUGFS/cpu-notifier-error-inject/CPU_DOWN_PREPARE
+for cpu in `hotpluggable_online_cpus`; do
+ remove_cpu_expect_fail $cpu
+done
+
+/sbin/modprobe -r cpu-notifier-error-inject
diff --git a/tools/testing/fault-injection/memory-notifier.sh b/tools/testing/fault-injection/memory-notifier.sh
new file mode 100755
index 0000000..b7e7fa5
--- /dev/null
+++ b/tools/testing/fault-injection/memory-notifier.sh
@@ -0,0 +1,163 @@
+#!/bin/bash
+
+#
+# list all hot-pluggable memory
+#
+hotpluggable_memory()
+{
+ local state=${1:-.\*}
+
+ for memory in /sys/devices/system/memory/memory*; do
+ if grep -q 1 $memory/removable &&
+ grep -q $state $memory/state; then
+ echo ${memory##/*/memory}
+ fi
+ done
+}
+
+hotplaggable_offline_memory()
+{
+ hotpluggable_memory offline
+}
+
+hotpluggable_online_memory()
+{
+ hotpluggable_memory online
+}
+
+memory_is_online()
+{
+ grep -q online /sys/devices/system/memory/memory$1/state
+}
+
+memory_is_offline()
+{
+ grep -q offline /sys/devices/system/memory/memory$1/state
+}
+
+add_memory()
+{
+ echo online > /sys/devices/system/memory/memory$1/state
+}
+
+remove_memory()
+{
+ echo offline > /sys/devices/system/memory/memory$1/state
+}
+
+add_memory_expect_success()
+{
+ local memory=$1
+
+ if ! add_memory $memory; then
+ echo $FUNCNAME $memory: unexpected fail >&2
+ elif ! memory_is_online $memory; then
+ echo $FUNCNAME $memory: unexpected offline >&2
+ fi
+}
+
+add_memory_expect_fail()
+{
+ local memory=$1
+
+ if add_memory $memory 2> /dev/null; then
+ echo $FUNCNAME $memory: unexpected success >&2
+ elif ! memory_is_offline $memory; then
+ echo $FUNCNAME $memory: unexpected online >&2
+ fi
+}
+
+remove_memory_expect_success()
+{
+ local memory=$1
+
+ if ! remove_memory $memory; then
+ echo $FUNCNAME $memory: unexpected fail >&2
+ elif ! memory_is_offline $memory; then
+ echo $FUNCNAME $memory: unexpected offline >&2
+ fi
+}
+
+remove_memory_expect_fail()
+{
+ local memory=$1
+
+ if remove_memory $memory 2> /dev/null; then
+ echo $FUNCNAME $memory: unexpected success >&2
+ elif ! memory_is_online $memory; then
+ echo $FUNCNAME $memory: unexpected offline >&2
+ fi
+}
+
+if [ $UID != 0 ]; then
+ echo must be run as root >&2
+ exit 1
+fi
+
+error=-12
+priority=0
+
+while getopts e:p: opt; do
+ case $opt in
+ e)
+ error=$OPTARG
+ ;;
+ p)
+ priority=$OPTARG
+ ;;
+ esac
+done
+
+if ! [ "$error" -ge -4095 -a "$error" -lt 0 ]; then
+ echo "error code must be -4095 <= errno < 0" >&2
+ exit 1
+fi
+
+DEBUGFS=`mount -t debugfs | head -1 | awk '{ print $3 }'`
+
+if [ ! -d "$DEBUGFS" ]; then
+ echo debugfs is not mounted >&2
+ exit 1
+fi
+
+/sbin/modprobe -r memory-notifier-error-inject
+/sbin/modprobe -q memory-notifier-error-inject priority=$priority
+
+if [ ! -d $DEBUGFS/memory-notifier-error-inject ]; then
+ echo memory-notifier-error-inject module is not available >&2
+ exit 1
+fi
+
+#
+# Offline all hot-pluggable memory
+#
+echo 0 > $DEBUGFS/memory-notifier-error-inject/MEM_GOING_OFFLINE
+for memory in `hotpluggable_online_memory`; do
+ remove_memory_expect_success $memory
+done
+
+#
+# Test memory hot-add error handling (offline => online)
+#
+echo $error > $DEBUGFS/memory-notifier-error-inject/MEM_GOING_ONLINE
+for memory in `hotplaggable_offline_memory`; do
+ add_memory_expect_fail $memory
+done
+
+#
+# Online all hot-pluggable memory
+#
+echo 0 > $DEBUGFS/memory-notifier-error-inject/MEM_GOING_ONLINE
+for memory in `hotplaggable_offline_memory`; do
+ add_memory_expect_success $memory
+done
+
+#
+# Test memory hot-remove error handling (online => offline)
+#
+echo $error > $DEBUGFS/memory-notifier-error-inject/MEM_GOING_OFFLINE
+for memory in `hotpluggable_online_memory`; do
+ remove_memory_expect_fail $memory
+done
+
+/sbin/modprobe -r memory-notifier-error-inject
--
1.7.4.4
^ permalink raw reply related
* [PATCH tip:x86/memblock RFC] powerpc: Use HAVE_MEMBLOCK_NODE_MAP
From: Tejun Heo @ 2011-07-23 13:32 UTC (permalink / raw)
To: Benjamin Herrenschmidt, H. Peter Anvin, Paul Mackerras
Cc: linuxppc-dev, linux-kernel
powerpc doesn't access early_node_map[] directly and enabling
HAVE_MEMBLOCK_NODE_MAP is trivial - replacing add_active_range() calls
with memblock_set_node() and selecting HAVE_MEMBLOCK_NODE_MAP is
enough.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
benh, the proposed memblock changes are now in tip:x86/memblock, which
is probably scheduled for the next merge window. This patch converts
powerpc to drop early_node_map[] and put NUMA information in memblock.
I'm planning on converting all early_node_map[] users and dropping the
code. I don't have access to ppc NUMA machine so the patch is tested
only on a non-NUMA SMP machine. It builds fine for all valid
combinations of of 32/64 [!]SMP [!]NUMA.
If this change is okay, how should this patch be routed? ppc tree
pulls from x86/memblock and puts this patch on top of it?
Thanks.
arch/powerpc/Kconfig | 1 +
arch/powerpc/mm/mem.c | 2 +-
arch/powerpc/mm/numa.c | 10 ++++------
3 files changed, 6 insertions(+), 7 deletions(-)
Index: work/arch/powerpc/Kconfig
===================================================================
--- work.orig/arch/powerpc/Kconfig
+++ work/arch/powerpc/Kconfig
@@ -117,6 +117,7 @@ config PPC
select HAVE_KRETPROBES
select HAVE_ARCH_TRACEHOOK
select HAVE_MEMBLOCK
+ select HAVE_MEMBLOCK_NODE_MAP
select HAVE_DMA_ATTRS
select HAVE_DMA_API_DEBUG
select USE_GENERIC_SMP_HELPERS if SMP
Index: work/arch/powerpc/mm/mem.c
===================================================================
--- work.orig/arch/powerpc/mm/mem.c
+++ work/arch/powerpc/mm/mem.c
@@ -197,7 +197,7 @@ void __init do_init_bootmem(void)
unsigned long start_pfn, end_pfn;
start_pfn = memblock_region_memory_base_pfn(reg);
end_pfn = memblock_region_memory_end_pfn(reg);
- add_active_range(0, start_pfn, end_pfn);
+ memblock_set_node(0, (phys_addr_t)ULLONG_MAX, 0);
}
/* Add all physical memory to the bootmem map, mark each area
Index: work/arch/powerpc/mm/numa.c
===================================================================
--- work.orig/arch/powerpc/mm/numa.c
+++ work/arch/powerpc/mm/numa.c
@@ -680,9 +680,7 @@ static void __init parse_drconf_memory(s
node_set_online(nid);
sz = numa_enforce_memory_limit(base, size);
if (sz)
- add_active_range(nid, base >> PAGE_SHIFT,
- (base >> PAGE_SHIFT)
- + (sz >> PAGE_SHIFT));
+ memblock_set_node(base, sz, nid);
} while (--ranges);
}
}
@@ -772,8 +770,7 @@ new_range:
continue;
}
- add_active_range(nid, start >> PAGE_SHIFT,
- (start >> PAGE_SHIFT) + (size >> PAGE_SHIFT));
+ memblock_set_node(start, size, nid);
if (--ranges)
goto new_range;
@@ -808,7 +805,8 @@ static void __init setup_nonnuma(void)
end_pfn = memblock_region_memory_end_pfn(reg);
fake_numa_create_new_node(end_pfn, &nid);
- add_active_range(nid, start_pfn, end_pfn);
+ memblock_set_node(PFN_PHYS(start_pfn),
+ PFN_PHYS(end_pfn - start_pfn), nid);
node_set_online(nid);
}
}
^ permalink raw reply
* Linux 3.0 boot failure on the Powerbook G4
From: Michael Büsch @ 2011-07-23 20:20 UTC (permalink / raw)
To: linuxppc-dev
Linux 3.0 fails to boot _very_ early on my Powerbook G4. See the
yaboot/OF screenshot:
http://bues.ch/misc/linux-3.0-pbook.jpg
Linux 2.6.39.2 boots fine.
Does somebody have an idea?
The config can be found here:
http://bues.ch/misc/linux-3.0-ppc-config
It's mostly equivalent to the working 2.6.39 config. I enabled
early OF console, but that didn't help to show better error messages.
The machine is a:
cpu : 7447A, altivec supported
clock : 1499.999000MHz
revision : 1.2 (pvr 8003 0102)
platform : PowerMac
motherboard : PowerBook5,6 MacRISC3 Power Macintosh
detected as : 287 (PowerBook G4 15")
pmac-generation : NewWorld
--
Greetings, Michael.
^ permalink raw reply
* Re: Linux 3.0 boot failure on the Powerbook G4
From: Andreas Schwab @ 2011-07-24 8:06 UTC (permalink / raw)
To: Michael Büsch; +Cc: linuxppc-dev
In-Reply-To: <20110723222034.6757604b__32574.6897528463$1311473425$gmane$org@maggie>
Michael Büsch <m@bues.ch> writes:
> Linux 3.0 fails to boot _very_ early on my Powerbook G4. See the
> yaboot/OF screenshot:
> http://bues.ch/misc/linux-3.0-pbook.jpg
>
> Linux 2.6.39.2 boots fine.
> Does somebody have an idea?
Perhaps your image is getting too large?
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."
^ permalink raw reply
* Re: Linux 3.0 boot failure on the Powerbook G4
From: Michael Büsch @ 2011-07-24 10:37 UTC (permalink / raw)
To: Andreas Schwab; +Cc: linuxppc-dev
In-Reply-To: <m2tyacdrx0.fsf@igel.home>
On Sun, 24 Jul 2011 10:06:03 +0200
Andreas Schwab <schwab@linux-m68k.org> wrote:
> Michael B=C3=BCsch <m@bues.ch> writes:
>=20
> > Linux 3.0 fails to boot _very_ early on my Powerbook G4. See the
> > yaboot/OF screenshot:
> > http://bues.ch/misc/linux-3.0-pbook.jpg
> >
> > Linux 2.6.39.2 boots fine.
> > Does somebody have an idea?
>=20
> Perhaps your image is getting too large?
I reduced the image size, so that it's way less than the
2.6.39 kernel size (old is 2.6.39. a is 3.0)
-rwxr-xr-x 1 root root 5.6M Jul 24 12:16 /boot/linux.a
-rwxr-xr-x 1 root root 6.3M Jul 23 20:50 /boot/linux.old
But that didn't help. :(
I'm currently trying to bisect it, but that turns out to be hard
due to various compile issues and stuff like that...
--=20
Greetings, Michael.
^ permalink raw reply
* Re: Linux 3.0 boot failure on the Powerbook G4
From: Benjamin Herrenschmidt @ 2011-07-24 12:07 UTC (permalink / raw)
To: Michael Büsch; +Cc: linuxppc-dev
In-Reply-To: <20110723222034.6757604b@maggie>
On Sat, 2011-07-23 at 22:20 +0200, Michael Büsch wrote:
> Linux 3.0 fails to boot _very_ early on my Powerbook G4. See the
> yaboot/OF screenshot:
> http://bues.ch/misc/linux-3.0-pbook.jpg
>
> Linux 2.6.39.2 boots fine.
> Does somebody have an idea?
Interesting, that's before it even kills OF. Are you booting a zImage or
a vmlinux ?
It might be also useful to compile yaboot with debug output enabled to
figure out where the kernel is loaded so we can try calculating where
exactly it dies if it's a vmlinux...
Cheers,
Ben.
> The config can be found here:
> http://bues.ch/misc/linux-3.0-ppc-config
> It's mostly equivalent to the working 2.6.39 config. I enabled
> early OF console, but that didn't help to show better error messages.
>
> The machine is a:
>
> cpu : 7447A, altivec supported
> clock : 1499.999000MHz
> revision : 1.2 (pvr 8003 0102)
> platform : PowerMac
> motherboard : PowerBook5,6 MacRISC3 Power Macintosh
> detected as : 287 (PowerBook G4 15")
> pmac-generation : NewWorld
>
^ permalink raw reply
* Re: Linux 3.0 boot failure on the Powerbook G4
From: Michael Büsch @ 2011-07-24 12:10 UTC (permalink / raw)
To: Benjamin Herrenschmidt; +Cc: linuxppc-dev
In-Reply-To: <1311509250.25044.583.camel@pasglop>
On Sun, 24 Jul 2011 22:07:30 +1000
Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
> On Sat, 2011-07-23 at 22:20 +0200, Michael B=C3=BCsch wrote:
> > Linux 3.0 fails to boot _very_ early on my Powerbook G4. See the
> > yaboot/OF screenshot:
> > http://bues.ch/misc/linux-3.0-pbook.jpg
> >=20
> > Linux 2.6.39.2 boots fine.
> > Does somebody have an idea?
>=20
> Interesting, that's before it even kills OF. Are you booting a zImage or
> a vmlinux ?
I'm booting zImage.pmac.
> It might be also useful to compile yaboot with debug output enabled to
> figure out where the kernel is loaded so we can try calculating where
> exactly it dies if it's a vmlinux...
Hm, I guess I could probably try that.
--=20
Greetings, Michael.
^ permalink raw reply
* Re: Linux 3.0 boot failure on the Powerbook G4
From: Benjamin Herrenschmidt @ 2011-07-24 12:13 UTC (permalink / raw)
To: Michael Büsch; +Cc: linuxppc-dev
In-Reply-To: <20110724141051.771d6492@maggie>
On Sun, 2011-07-24 at 14:10 +0200, Michael Büsch wrote:
> On Sun, 24 Jul 2011 22:07:30 +1000
> Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
>
> > On Sat, 2011-07-23 at 22:20 +0200, Michael Büsch wrote:
> > > Linux 3.0 fails to boot _very_ early on my Powerbook G4. See the
> > > yaboot/OF screenshot:
> > > http://bues.ch/misc/linux-3.0-pbook.jpg
> > >
> > > Linux 2.6.39.2 boots fine.
> > > Does somebody have an idea?
> >
> > Interesting, that's before it even kills OF. Are you booting a zImage or
> > a vmlinux ?
>
> I'm booting zImage.pmac.
Ah that might make it easier... I don't remember where it links, can you
show me the program headers out of readelf -a of the zImage ?
> > It might be also useful to compile yaboot with debug output enabled to
> > figure out where the kernel is loaded so we can try calculating where
> > exactly it dies if it's a vmlinux...
>
> Hm, I guess I could probably try that.
Cheers,
Ben.
^ permalink raw reply
* Re: Linux 3.0 boot failure on the Powerbook G4
From: Michael Büsch @ 2011-07-24 12:37 UTC (permalink / raw)
To: Benjamin Herrenschmidt; +Cc: linuxppc-dev
In-Reply-To: <1311509614.25044.585.camel@pasglop>
On Sun, 24 Jul 2011 22:13:34 +1000
Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
> > I'm booting zImage.pmac.
>
> Ah that might make it easier... I don't remember where it links, can you
> show me the program headers out of readelf -a of the zImage ?
As I recompiled stuff, here's the current failure log:
http://bues.ch/misc/linux-3.0-pbook-2.jpg
And this is the corresponding readelf output:
mb@maggie:~$ readelf -a /boot/linux.a
ELF Header:
Magic: 7f 45 4c 46 01 02 01 00 00 00 00 00 00 00 00 00
Class: ELF32
Data: 2's complement, big endian
Version: 1 (current)
OS/ABI: UNIX - System V
ABI Version: 0
Type: EXEC (Executable file)
Machine: PowerPC
Version: 0x1
Entry point address: 0x400230
Start of program headers: 52 (bytes into file)
Start of section headers: 5769716 (bytes into file)
Flags: 0x8000, relocatable-lib
Size of this header: 52 (bytes)
Size of program headers: 32 (bytes)
Number of program headers: 2
Size of section headers: 40 (bytes)
Number of section headers: 12
Section header string table index: 9
Section Headers:
[Nr] Name Type Addr Off Size ES Flg Lk Inf Al
[ 0] NULL 00000000 000000 000000 00 0 0 0
[ 1] .text PROGBITS 00400000 010000 0048b0 00 AX 0 0 4
[ 2] .data PROGBITS 00405000 015000 0012f8 00 WA 0 0 4
[ 3] .got PROGBITS 004062f8 0162f8 00000c 04 WA 0 0 4
[ 4] __builtin_cmdline PROGBITS 00406304 016304 000200 00 WA 0 0 4
[ 5] .kernel:vmlinux.s PROGBITS 00407000 017000 569952 00 A 0 0 1
[ 6] .bss NOBITS 00971000 580952 00bc70 00 WA 0 0 4
[ 7] .comment PROGBITS 00000000 580952 00001c 01 MS 0 0 1
[ 8] .gnu.attributes LOOS+ffffff5 00000000 58096e 000014 00 0 0 1
[ 9] .shstrtab STRTAB 00000000 580982 000072 00 0 0 1
[10] .symtab SYMTAB 00000000 580bd4 000780 10 11 55 4
[11] .strtab STRTAB 00000000 581354 0004f3 00 0 0 1
Key to Flags:
W (write), A (alloc), X (execute), M (merge), S (strings)
I (info), L (link order), G (group), x (unknown)
O (extra OS processing required) o (OS specific), p (processor specific)
There are no section groups in this file.
Program Headers:
Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
LOAD 0x010000 0x00400000 0x00400000 0x570952 0x57cc70 RWE 0x10000
GNU_STACK 0x000000 0x00000000 0x00000000 0x00000 0x00000 RWE 0x4
Section to Segment mapping:
Segment Sections...
00 .text .data .got __builtin_cmdline .kernel:vmlinux.strip .bss
01
There is no dynamic section in this file.
There are no relocations in this file.
There are no unwind sections in this file.
Symbol table '.symtab' contains 120 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 00000000 0 NOTYPE LOCAL DEFAULT UND
1: 00400000 0 SECTION LOCAL DEFAULT 1
2: 00405000 0 SECTION LOCAL DEFAULT 2
3: 004062f8 0 SECTION LOCAL DEFAULT 3
4: 00406304 0 SECTION LOCAL DEFAULT 4
5: 00407000 0 SECTION LOCAL DEFAULT 5
6: 00971000 0 SECTION LOCAL DEFAULT 6
7: 00000000 0 SECTION LOCAL DEFAULT 7
8: 00000000 0 SECTION LOCAL DEFAULT 8
9: 00000000 0 FILE LOCAL DEFAULT ABS of.c
10: 00400000 96 FUNC LOCAL DEFAULT 1 of_image_hdr
11: 00400130 220 FUNC LOCAL DEFAULT 1 of_try_claim
12: 00971000 4 OBJECT LOCAL DEFAULT 6 claim_base
13: 00000000 0 FILE LOCAL DEFAULT ABS empty.c
14: 0040021c 0 NOTYPE LOCAL DEFAULT 1 p_start
15: 00400220 0 NOTYPE LOCAL DEFAULT 1 p_etext
16: 00400224 0 NOTYPE LOCAL DEFAULT 1 p_bss_start
17: 00400228 0 NOTYPE LOCAL DEFAULT 1 p_end
18: 0040022c 0 NOTYPE LOCAL DEFAULT 1 p_pstack
19: 00400234 0 NOTYPE LOCAL DEFAULT 1 p_base
20: 00000007 0 NOTYPE LOCAL DEFAULT ABS RELA
21: 6ffffff9 0 NOTYPE LOCAL DEFAULT ABS RELACOUNT
22: 00000000 0 FILE LOCAL DEFAULT ABS main.c
23: 0040032c 536 FUNC LOCAL DEFAULT 1 prep_kernel
24: 00971004 46960 OBJECT LOCAL DEFAULT 6 gzstate
25: 00406304 512 OBJECT LOCAL DEFAULT 4 cmdline
26: 00000000 0 FILE LOCAL DEFAULT ABS gunzip_util.c
27: 0097c774 128 OBJECT LOCAL DEFAULT 6 discard_buf.1439
28: 00000000 0 FILE LOCAL DEFAULT ABS elf_util.c
29: 00000000 0 FILE LOCAL DEFAULT ABS inflate.c
30: 00400ed4 424 FUNC LOCAL DEFAULT 1 zlib_adler32
31: 004011c4 292 FUNC LOCAL DEFAULT 1 zlib_updatewindow
32: 00405484 2048 OBJECT LOCAL DEFAULT 2 lenfix.1147
33: 00405c84 128 OBJECT LOCAL DEFAULT 2 distfix.1148
34: 00405d04 38 OBJECT LOCAL DEFAULT 2 order.1216
35: 00000000 0 FILE LOCAL DEFAULT ABS inftrees.c
36: 00405e8e 62 OBJECT LOCAL DEFAULT 2 lext.1062
37: 00405ecc 62 OBJECT LOCAL DEFAULT 2 lbase.1061
38: 00405f0a 64 OBJECT LOCAL DEFAULT 2 dext.1064
39: 00405f4a 64 OBJECT LOCAL DEFAULT 2 dbase.1063
40: 00000000 0 FILE LOCAL DEFAULT ABS oflib.c
41: 00402a4c 432 FUNC LOCAL DEFAULT 1 of_call_prom_ret
42: 0040611c 4 OBJECT LOCAL DEFAULT 2 need_map
43: 0097c7f4 4 OBJECT LOCAL DEFAULT 6 prom
44: 0097c7f8 4 OBJECT LOCAL DEFAULT 6 chosen_mmu
45: 0097c7fc 4 OBJECT LOCAL DEFAULT 6 memory
46: 00000000 0 FILE LOCAL DEFAULT ABS ofconsole.c
47: 004032b0 104 FUNC LOCAL DEFAULT 1 of_console_open
48: 0040325c 84 FUNC LOCAL DEFAULT 1 of_console_write
49: 0097c800 4 OBJECT LOCAL DEFAULT 6 of_stdout_handle
50: 00000000 0 FILE LOCAL DEFAULT ABS stdio.c
51: 0040369c 848 FUNC LOCAL DEFAULT 1 number
52: 0097c804 1024 OBJECT LOCAL DEFAULT 6 sprint_buf
53: 00000000 0 FILE LOCAL DEFAULT ABS inffast.c
54: 004062f8 0 OBJECT LOCAL HIDDEN 3 _GLOBAL_OFFSET_TABLE_
55: 00400060 208 FUNC GLOBAL DEFAULT 1 platform_init
56: 00403318 0 NOTYPE GLOBAL DEFAULT 1 strcpy
57: 00000000 0 NOTYPE WEAK DEFAULT UND _platform_stack_top
58: 00400924 240 FUNC GLOBAL DEFAULT 1 gunzip_partial
59: 0040413c 188 FUNC GLOBAL DEFAULT 1 printf
60: 004039ec 1872 FUNC GLOBAL DEFAULT 1 vsprintf
61: 0040426c 0 NOTYPE GLOBAL DEFAULT 1 __div64_32
62: 00403468 0 NOTYPE GLOBAL DEFAULT 1 memmove
63: 00402a10 60 FUNC GLOBAL DEFAULT 1 of_init
64: 00406508 0 NOTYPE GLOBAL DEFAULT 4 _dtb_start
65: 0040020c 0 NOTYPE GLOBAL DEFAULT 1 _zimage_start_opd
66: 004048b0 0 NOTYPE GLOBAL DEFAULT 1 _etext
67: 00402e04 72 FUNC GLOBAL DEFAULT 1 of_finddevice
68: 00401088 132 FUNC GLOBAL DEFAULT 1 zlib_inflateReset
69: 00403470 0 NOTYPE GLOBAL DEFAULT 1 memcpy
70: 00403624 0 NOTYPE GLOBAL DEFAULT 1 flush_cache
71: 0040430c 1444 FUNC GLOBAL DEFAULT 1 inflate_fast
72: 00407000 0 NOTYPE GLOBAL DEFAULT 5 _vmlinux_start
73: 0040110c 152 FUNC GLOBAL DEFAULT 1 zlib_inflateInit2
74: 00402dac 88 FUNC GLOBAL DEFAULT 1 of_getprop
75: 00400b80 484 FUNC GLOBAL DEFAULT 1 gunzip_start
76: 0097cc04 20 OBJECT GLOBAL DEFAULT 6 loader_info
77: 0097cc18 28 OBJECT GLOBAL DEFAULT 6 platform_ops
78: 00403140 212 FUNC GLOBAL DEFAULT 1 of_vmlinux_alloc
79: 00400a7c 120 FUNC GLOBAL DEFAULT 1 gunzip_exactly
80: 004012e8 240 FUNC GLOBAL DEFAULT 1 zlib_inflateIncomp
81: 00400d64 200 FUNC GLOBAL DEFAULT 1 parse_elf64
82: 0097cc34 20 OBJECT GLOBAL DEFAULT 6 console_ops
83: 00403650 76 FUNC GLOBAL DEFAULT 1 strnlen
84: 00400a14 104 FUNC GLOBAL DEFAULT 1 gunzip_finish
85: 00402e90 688 FUNC GLOBAL DEFAULT 1 of_claim
86: 00402480 1424 FUNC GLOBAL DEFAULT 1 zlib_inflate_table
87: 00400af4 140 FUNC GLOBAL DEFAULT 1 gunzip_discard
88: 004013d8 4264 FUNC GLOBAL DEFAULT 1 zlib_inflate
89: 00400e2c 168 FUNC GLOBAL DEFAULT 1 parse_elf32
90: 0040335c 0 NOTYPE GLOBAL DEFAULT 1 strcat
91: 00402e4c 68 FUNC GLOBAL DEFAULT 1 of_exit
92: 004035cc 0 NOTYPE GLOBAL DEFAULT 1 memchr
93: 00400000 0 NOTYPE GLOBAL DEFAULT 1 _start
94: 004033cc 0 NOTYPE GLOBAL DEFAULT 1 strncmp
95: 00403214 72 FUNC GLOBAL DEFAULT 1 of_console_init
96: 0040107c 12 FUNC GLOBAL DEFAULT 1 zlib_inflate_workspacesiz
97: 00403334 0 NOTYPE GLOBAL DEFAULT 1 strncpy
98: 004035f4 0 NOTYPE GLOBAL DEFAULT 1 memcmp
99: 00971000 0 NOTYPE GLOBAL DEFAULT 5 _initrd_start
100: 00400230 0 NOTYPE WEAK DEFAULT 1 _zimage_start
101: 00403528 0 NOTYPE GLOBAL DEFAULT 1 backwards_memcpy
102: 00971000 0 NOTYPE GLOBAL DEFAULT 6 __bss_start
103: 0040340c 0 NOTYPE GLOBAL DEFAULT 1 memset
104: 00406508 0 NOTYPE GLOBAL DEFAULT 4 _dtb_end
105: 00971000 0 NOTYPE GLOBAL DEFAULT 5 _initrd_end
106: 0097cc48 40 OBJECT GLOBAL DEFAULT 6 dt_ops
107: 004033a8 0 NOTYPE GLOBAL DEFAULT 1 strcmp
108: 004041f8 116 FUNC GLOBAL DEFAULT 1 sprintf
109: 00971000 0 NOTYPE GLOBAL DEFAULT 6 _edata
110: 0097cc70 0 NOTYPE GLOBAL DEFAULT 6 _end
111: 00400544 992 FUNC GLOBAL DEFAULT 1 start
112: 00970952 0 NOTYPE GLOBAL DEFAULT 5 _vmlinux_end
113: 004033f4 0 NOTYPE GLOBAL DEFAULT 1 strlen
114: 00403388 0 NOTYPE GLOBAL DEFAULT 1 strchr
115: 00400230 0 NOTYPE GLOBAL DEFAULT 1 _zimage_start_lib
116: 00406504 0 NOTYPE GLOBAL DEFAULT 4 __dynamic_start
117: 004011a4 32 FUNC GLOBAL DEFAULT 1 zlib_inflateEnd
118: 00402d54 88 FUNC GLOBAL DEFAULT 1 of_setprop
119: 00402bfc 344 FUNC GLOBAL DEFAULT 1 of_call_prom
No version information found in this file.
Attribute Section: gnu
File Attributes
Tag_GNU_Power_ABI_FP: Soft float
Tag_GNU_Power_ABI_Vector: Generic
Tag_GNU_Power_ABI_Struct_Return: Memory
--
Greetings, Michael.
^ permalink raw reply
* Re: [PATCH 2/5] hugetlb: add phys addr to struct huge_bootmem_page
From: Tabi Timur-B04825 @ 2011-07-24 16:48 UTC (permalink / raw)
To: Becky Bruce
Cc: linuxppc-dev@lists.ozlabs.org,
List linux-kernel@vger.kernel.org Mailing, David Gibson
In-Reply-To: <786B027A-4EC8-4175-A18D-9DA57E9549D6@kernel.crashing.org>
On Thu, Jun 30, 2011 at 1:50 PM, Becky Bruce <beckyb@kernel.crashing.org> w=
rote:
> Because there was no bootmem allocation in the normal case - the non-high=
mem
> version stores data structure in the huge page itself. =A0This is perfect=
ly fine as long
> as you have a mapping. =A0Since this isn't true for HIGHMEM pages, I allo=
cate
> bootmem to store the early data structure that stores information about t=
he
> hugepage (this happens in arch-specific code in alloc_bootmem_huge_page).
I would put this text in a comment in the code.
--=20
Timur Tabi
Linux kernel developer at Freescale=
^ permalink raw reply
* Re: perf PPC: kernel panic with callchains and context switch events
From: David Ahern @ 2011-07-24 17:18 UTC (permalink / raw)
To: Anton Blanchard, Paul Mackerras, linux-perf-users, LKML,
linuxppc-dev
In-Reply-To: <4E274F5F.7000604@gmail.com>
On 07/20/2011 03:57 PM, David Ahern wrote:
> I am hoping someone familiar with PPC can help understand a panic that
> is generated when capturing callchains with context switch events.
>
> Call trace is below. The short of it is that walking the callchain
> generates a page fault. To handle the page fault the mmap_sem is needed,
> but it is currently held by setup_arg_pages. setup_arg_pages calls
> shift_arg_pages with the mmap_sem held. shift_arg_pages then calls
> move_page_tables which has a cond_resched at the top of its for loop. If
> the cond_resched() is removed from move_page_tables everything works
> beautifully - no panics.
>
> So, the question: is it normal for walking the stack to trigger a page
> fault on PPC? The panic is not seen on x86 based systems.
Can anyone confirm whether page faults while walking the stack are
normal for PPC? We really want to use the context switch event with
callchains and need to understand whether this behavior is normal. Of
course if it is normal, a way to address the problem without a panic
will be needed.
Thanks,
David
>
> [<b0180e00>]rb_erase+0x1b4/0x3e8
> [<b00430f4>]__dequeue_entity+0x50/0xe8
> [<b0043304>]set_next_entity+0x178/0x1bc
> [<b0043440>]pick_next_task_fair+0xb0/0x118
> [<b02ada80>]schedule+0x500/0x614
> [<b02afaa8>]rwsem_down_failed_common+0xf0/0x264
> [<b02afca0>]rwsem_down_read_failed+0x34/0x54
> [<b02aed4c>]down_read+0x3c/0x54
> [<b0023b58>]do_page_fault+0x114/0x5e8
> [<b001e350>]handle_page_fault+0xc/0x80
> [<b0022dec>]perf_callchain+0x224/0x31c
> [<b009ba70>]perf_prepare_sample+0x240/0x2fc
> [<b009d760>]__perf_event_overflow+0x280/0x398
> [<b009d914>]perf_swevent_overflow+0x9c/0x10c
> [<b009db54>]perf_swevent_ctx_event+0x1d0/0x230
> [<b009dc38>]do_perf_sw_event+0x84/0xe4
> [<b009dde8>]perf_sw_event_context_switch+0x150/0x1b4
> [<b009de90>]perf_event_task_sched_out+0x44/0x2d4
> [<b02ad840>]schedule+0x2c0/0x614
> [<b0047dc0>]__cond_resched+0x34/0x90
> [<b02adcc8>]_cond_resched+0x4c/0x68
> [<b00bccf8>]move_page_tables+0xb0/0x418
> [<b00d7ee0>]setup_arg_pages+0x184/0x2a0
> [<b0110914>]load_elf_binary+0x394/0x1208
> [<b00d6e28>]search_binary_handler+0xe0/0x2c4
> [<b00d834c>]do_execve+0x1bc/0x268
> [<b0015394>]sys_execve+0x84/0xc8
> [<b001df10>]ret_from_syscall+0x0/0x3c
>
> Thanks,
> David
^ permalink raw reply
* Re: Linux 3.0 boot failure on the Powerbook G4
From: Benjamin Herrenschmidt @ 2011-07-24 23:23 UTC (permalink / raw)
To: Michael Büsch; +Cc: linuxppc-dev
In-Reply-To: <20110724143729.49c69ce8@maggie>
On Sun, 2011-07-24 at 14:37 +0200, Michael Büsch wrote:
> On Sun, 24 Jul 2011 22:13:34 +1000
> Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
> > > I'm booting zImage.pmac.
> >
> > Ah that might make it easier... I don't remember where it links, can you
> > show me the program headers out of readelf -a of the zImage ?
>
> As I recompiled stuff, here's the current failure log:
> http://bues.ch/misc/linux-3.0-pbook-2.jpg
>
> And this is the corresponding readelf output:
Hrm.. the faulting address is outside of the zImage. Odd.
Can you try loading a plain vmlinux instead ? (feel free to strip it).
yaboot 1.3.13 might not be the best one to load a real ELF ...
On my side I'll dig one of my old powerbooks and see if I can reproduce
(I generally tend to netboot the zImage directly, but it needs to be <
4M for that to work due to Apple OF limitations, or use yaboot with plan
vmlinux which exercises a different code path within yaboot).
Cheers,
Ben.
> mb@maggie:~$ readelf -a /boot/linux.a
> ELF Header:
> Magic: 7f 45 4c 46 01 02 01 00 00 00 00 00 00 00 00 00
> Class: ELF32
> Data: 2's complement, big endian
> Version: 1 (current)
> OS/ABI: UNIX - System V
> ABI Version: 0
> Type: EXEC (Executable file)
> Machine: PowerPC
> Version: 0x1
> Entry point address: 0x400230
> Start of program headers: 52 (bytes into file)
> Start of section headers: 5769716 (bytes into file)
> Flags: 0x8000, relocatable-lib
> Size of this header: 52 (bytes)
> Size of program headers: 32 (bytes)
> Number of program headers: 2
> Size of section headers: 40 (bytes)
> Number of section headers: 12
> Section header string table index: 9
>
> Section Headers:
> [Nr] Name Type Addr Off Size ES Flg Lk Inf Al
> [ 0] NULL 00000000 000000 000000 00 0 0 0
> [ 1] .text PROGBITS 00400000 010000 0048b0 00 AX 0 0 4
> [ 2] .data PROGBITS 00405000 015000 0012f8 00 WA 0 0 4
> [ 3] .got PROGBITS 004062f8 0162f8 00000c 04 WA 0 0 4
> [ 4] __builtin_cmdline PROGBITS 00406304 016304 000200 00 WA 0 0 4
> [ 5] .kernel:vmlinux.s PROGBITS 00407000 017000 569952 00 A 0 0 1
> [ 6] .bss NOBITS 00971000 580952 00bc70 00 WA 0 0 4
> [ 7] .comment PROGBITS 00000000 580952 00001c 01 MS 0 0 1
> [ 8] .gnu.attributes LOOS+ffffff5 00000000 58096e 000014 00 0 0 1
> [ 9] .shstrtab STRTAB 00000000 580982 000072 00 0 0 1
> [10] .symtab SYMTAB 00000000 580bd4 000780 10 11 55 4
> [11] .strtab STRTAB 00000000 581354 0004f3 00 0 0 1
> Key to Flags:
> W (write), A (alloc), X (execute), M (merge), S (strings)
> I (info), L (link order), G (group), x (unknown)
> O (extra OS processing required) o (OS specific), p (processor specific)
>
> There are no section groups in this file.
>
> Program Headers:
> Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
> LOAD 0x010000 0x00400000 0x00400000 0x570952 0x57cc70 RWE 0x10000
> GNU_STACK 0x000000 0x00000000 0x00000000 0x00000 0x00000 RWE 0x4
>
> Section to Segment mapping:
> Segment Sections...
> 00 .text .data .got __builtin_cmdline .kernel:vmlinux.strip .bss
> 01
>
> There is no dynamic section in this file.
>
> There are no relocations in this file.
>
> There are no unwind sections in this file.
>
> Symbol table '.symtab' contains 120 entries:
> Num: Value Size Type Bind Vis Ndx Name
> 0: 00000000 0 NOTYPE LOCAL DEFAULT UND
> 1: 00400000 0 SECTION LOCAL DEFAULT 1
> 2: 00405000 0 SECTION LOCAL DEFAULT 2
> 3: 004062f8 0 SECTION LOCAL DEFAULT 3
> 4: 00406304 0 SECTION LOCAL DEFAULT 4
> 5: 00407000 0 SECTION LOCAL DEFAULT 5
> 6: 00971000 0 SECTION LOCAL DEFAULT 6
> 7: 00000000 0 SECTION LOCAL DEFAULT 7
> 8: 00000000 0 SECTION LOCAL DEFAULT 8
> 9: 00000000 0 FILE LOCAL DEFAULT ABS of.c
> 10: 00400000 96 FUNC LOCAL DEFAULT 1 of_image_hdr
> 11: 00400130 220 FUNC LOCAL DEFAULT 1 of_try_claim
> 12: 00971000 4 OBJECT LOCAL DEFAULT 6 claim_base
> 13: 00000000 0 FILE LOCAL DEFAULT ABS empty.c
> 14: 0040021c 0 NOTYPE LOCAL DEFAULT 1 p_start
> 15: 00400220 0 NOTYPE LOCAL DEFAULT 1 p_etext
> 16: 00400224 0 NOTYPE LOCAL DEFAULT 1 p_bss_start
> 17: 00400228 0 NOTYPE LOCAL DEFAULT 1 p_end
> 18: 0040022c 0 NOTYPE LOCAL DEFAULT 1 p_pstack
> 19: 00400234 0 NOTYPE LOCAL DEFAULT 1 p_base
> 20: 00000007 0 NOTYPE LOCAL DEFAULT ABS RELA
> 21: 6ffffff9 0 NOTYPE LOCAL DEFAULT ABS RELACOUNT
> 22: 00000000 0 FILE LOCAL DEFAULT ABS main.c
> 23: 0040032c 536 FUNC LOCAL DEFAULT 1 prep_kernel
> 24: 00971004 46960 OBJECT LOCAL DEFAULT 6 gzstate
> 25: 00406304 512 OBJECT LOCAL DEFAULT 4 cmdline
> 26: 00000000 0 FILE LOCAL DEFAULT ABS gunzip_util.c
> 27: 0097c774 128 OBJECT LOCAL DEFAULT 6 discard_buf.1439
> 28: 00000000 0 FILE LOCAL DEFAULT ABS elf_util.c
> 29: 00000000 0 FILE LOCAL DEFAULT ABS inflate.c
> 30: 00400ed4 424 FUNC LOCAL DEFAULT 1 zlib_adler32
> 31: 004011c4 292 FUNC LOCAL DEFAULT 1 zlib_updatewindow
> 32: 00405484 2048 OBJECT LOCAL DEFAULT 2 lenfix.1147
> 33: 00405c84 128 OBJECT LOCAL DEFAULT 2 distfix.1148
> 34: 00405d04 38 OBJECT LOCAL DEFAULT 2 order.1216
> 35: 00000000 0 FILE LOCAL DEFAULT ABS inftrees.c
> 36: 00405e8e 62 OBJECT LOCAL DEFAULT 2 lext.1062
> 37: 00405ecc 62 OBJECT LOCAL DEFAULT 2 lbase.1061
> 38: 00405f0a 64 OBJECT LOCAL DEFAULT 2 dext.1064
> 39: 00405f4a 64 OBJECT LOCAL DEFAULT 2 dbase.1063
> 40: 00000000 0 FILE LOCAL DEFAULT ABS oflib.c
> 41: 00402a4c 432 FUNC LOCAL DEFAULT 1 of_call_prom_ret
> 42: 0040611c 4 OBJECT LOCAL DEFAULT 2 need_map
> 43: 0097c7f4 4 OBJECT LOCAL DEFAULT 6 prom
> 44: 0097c7f8 4 OBJECT LOCAL DEFAULT 6 chosen_mmu
> 45: 0097c7fc 4 OBJECT LOCAL DEFAULT 6 memory
> 46: 00000000 0 FILE LOCAL DEFAULT ABS ofconsole.c
> 47: 004032b0 104 FUNC LOCAL DEFAULT 1 of_console_open
> 48: 0040325c 84 FUNC LOCAL DEFAULT 1 of_console_write
> 49: 0097c800 4 OBJECT LOCAL DEFAULT 6 of_stdout_handle
> 50: 00000000 0 FILE LOCAL DEFAULT ABS stdio.c
> 51: 0040369c 848 FUNC LOCAL DEFAULT 1 number
> 52: 0097c804 1024 OBJECT LOCAL DEFAULT 6 sprint_buf
> 53: 00000000 0 FILE LOCAL DEFAULT ABS inffast.c
> 54: 004062f8 0 OBJECT LOCAL HIDDEN 3 _GLOBAL_OFFSET_TABLE_
> 55: 00400060 208 FUNC GLOBAL DEFAULT 1 platform_init
> 56: 00403318 0 NOTYPE GLOBAL DEFAULT 1 strcpy
> 57: 00000000 0 NOTYPE WEAK DEFAULT UND _platform_stack_top
> 58: 00400924 240 FUNC GLOBAL DEFAULT 1 gunzip_partial
> 59: 0040413c 188 FUNC GLOBAL DEFAULT 1 printf
> 60: 004039ec 1872 FUNC GLOBAL DEFAULT 1 vsprintf
> 61: 0040426c 0 NOTYPE GLOBAL DEFAULT 1 __div64_32
> 62: 00403468 0 NOTYPE GLOBAL DEFAULT 1 memmove
> 63: 00402a10 60 FUNC GLOBAL DEFAULT 1 of_init
> 64: 00406508 0 NOTYPE GLOBAL DEFAULT 4 _dtb_start
> 65: 0040020c 0 NOTYPE GLOBAL DEFAULT 1 _zimage_start_opd
> 66: 004048b0 0 NOTYPE GLOBAL DEFAULT 1 _etext
> 67: 00402e04 72 FUNC GLOBAL DEFAULT 1 of_finddevice
> 68: 00401088 132 FUNC GLOBAL DEFAULT 1 zlib_inflateReset
> 69: 00403470 0 NOTYPE GLOBAL DEFAULT 1 memcpy
> 70: 00403624 0 NOTYPE GLOBAL DEFAULT 1 flush_cache
> 71: 0040430c 1444 FUNC GLOBAL DEFAULT 1 inflate_fast
> 72: 00407000 0 NOTYPE GLOBAL DEFAULT 5 _vmlinux_start
> 73: 0040110c 152 FUNC GLOBAL DEFAULT 1 zlib_inflateInit2
> 74: 00402dac 88 FUNC GLOBAL DEFAULT 1 of_getprop
> 75: 00400b80 484 FUNC GLOBAL DEFAULT 1 gunzip_start
> 76: 0097cc04 20 OBJECT GLOBAL DEFAULT 6 loader_info
> 77: 0097cc18 28 OBJECT GLOBAL DEFAULT 6 platform_ops
> 78: 00403140 212 FUNC GLOBAL DEFAULT 1 of_vmlinux_alloc
> 79: 00400a7c 120 FUNC GLOBAL DEFAULT 1 gunzip_exactly
> 80: 004012e8 240 FUNC GLOBAL DEFAULT 1 zlib_inflateIncomp
> 81: 00400d64 200 FUNC GLOBAL DEFAULT 1 parse_elf64
> 82: 0097cc34 20 OBJECT GLOBAL DEFAULT 6 console_ops
> 83: 00403650 76 FUNC GLOBAL DEFAULT 1 strnlen
> 84: 00400a14 104 FUNC GLOBAL DEFAULT 1 gunzip_finish
> 85: 00402e90 688 FUNC GLOBAL DEFAULT 1 of_claim
> 86: 00402480 1424 FUNC GLOBAL DEFAULT 1 zlib_inflate_table
> 87: 00400af4 140 FUNC GLOBAL DEFAULT 1 gunzip_discard
> 88: 004013d8 4264 FUNC GLOBAL DEFAULT 1 zlib_inflate
> 89: 00400e2c 168 FUNC GLOBAL DEFAULT 1 parse_elf32
> 90: 0040335c 0 NOTYPE GLOBAL DEFAULT 1 strcat
> 91: 00402e4c 68 FUNC GLOBAL DEFAULT 1 of_exit
> 92: 004035cc 0 NOTYPE GLOBAL DEFAULT 1 memchr
> 93: 00400000 0 NOTYPE GLOBAL DEFAULT 1 _start
> 94: 004033cc 0 NOTYPE GLOBAL DEFAULT 1 strncmp
> 95: 00403214 72 FUNC GLOBAL DEFAULT 1 of_console_init
> 96: 0040107c 12 FUNC GLOBAL DEFAULT 1 zlib_inflate_workspacesiz
> 97: 00403334 0 NOTYPE GLOBAL DEFAULT 1 strncpy
> 98: 004035f4 0 NOTYPE GLOBAL DEFAULT 1 memcmp
> 99: 00971000 0 NOTYPE GLOBAL DEFAULT 5 _initrd_start
> 100: 00400230 0 NOTYPE WEAK DEFAULT 1 _zimage_start
> 101: 00403528 0 NOTYPE GLOBAL DEFAULT 1 backwards_memcpy
> 102: 00971000 0 NOTYPE GLOBAL DEFAULT 6 __bss_start
> 103: 0040340c 0 NOTYPE GLOBAL DEFAULT 1 memset
> 104: 00406508 0 NOTYPE GLOBAL DEFAULT 4 _dtb_end
> 105: 00971000 0 NOTYPE GLOBAL DEFAULT 5 _initrd_end
> 106: 0097cc48 40 OBJECT GLOBAL DEFAULT 6 dt_ops
> 107: 004033a8 0 NOTYPE GLOBAL DEFAULT 1 strcmp
> 108: 004041f8 116 FUNC GLOBAL DEFAULT 1 sprintf
> 109: 00971000 0 NOTYPE GLOBAL DEFAULT 6 _edata
> 110: 0097cc70 0 NOTYPE GLOBAL DEFAULT 6 _end
> 111: 00400544 992 FUNC GLOBAL DEFAULT 1 start
> 112: 00970952 0 NOTYPE GLOBAL DEFAULT 5 _vmlinux_end
> 113: 004033f4 0 NOTYPE GLOBAL DEFAULT 1 strlen
> 114: 00403388 0 NOTYPE GLOBAL DEFAULT 1 strchr
> 115: 00400230 0 NOTYPE GLOBAL DEFAULT 1 _zimage_start_lib
> 116: 00406504 0 NOTYPE GLOBAL DEFAULT 4 __dynamic_start
> 117: 004011a4 32 FUNC GLOBAL DEFAULT 1 zlib_inflateEnd
> 118: 00402d54 88 FUNC GLOBAL DEFAULT 1 of_setprop
> 119: 00402bfc 344 FUNC GLOBAL DEFAULT 1 of_call_prom
>
> No version information found in this file.
> Attribute Section: gnu
> File Attributes
> Tag_GNU_Power_ABI_FP: Soft float
> Tag_GNU_Power_ABI_Vector: Generic
> Tag_GNU_Power_ABI_Struct_Return: Memory
>
>
^ permalink raw reply
* [PATCH] perf: powerpc: Disable pagefaults during callchain stack read
From: Anton Blanchard @ 2011-07-25 0:05 UTC (permalink / raw)
To: David Ahern; +Cc: linux-perf-users, linuxppc-dev, Paul Mackerras, LKML
In-Reply-To: <4E2C53E0.3020400@gmail.com>
Hi David,
> > I am hoping someone familiar with PPC can help understand a panic
> > that is generated when capturing callchains with context switch
> > events.
> >
> > Call trace is below. The short of it is that walking the callchain
> > generates a page fault. To handle the page fault the mmap_sem is
> > needed, but it is currently held by setup_arg_pages.
> > setup_arg_pages calls shift_arg_pages with the mmap_sem held.
> > shift_arg_pages then calls move_page_tables which has a
> > cond_resched at the top of its for loop. If the cond_resched() is
> > removed from move_page_tables everything works beautifully - no
> > panics.
> >
> > So, the question: is it normal for walking the stack to trigger a
> > page fault on PPC? The panic is not seen on x86 based systems.
>
> Can anyone confirm whether page faults while walking the stack are
> normal for PPC? We really want to use the context switch event with
> callchains and need to understand whether this behavior is normal. Of
> course if it is normal, a way to address the problem without a panic
> will be needed.
I talked to Ben about this last week and he pointed me at
pagefault_disable/enable. Untested patch below.
Anton
--
We need to disable pagefaults when reading the stack otherwise
we can lock up trying to take the mmap_sem when the code we are
profiling already has a write lock taken.
This will not happen for hardware events, but could for software
events.
Reported-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org>
---
Index: linux-powerpc/arch/powerpc/kernel/perf_callchain.c
===================================================================
--- linux-powerpc.orig/arch/powerpc/kernel/perf_callchain.c 2011-07-25 09:54:27.296757427 +1000
+++ linux-powerpc/arch/powerpc/kernel/perf_callchain.c 2011-07-25 09:56:08.828367882 +1000
@@ -154,8 +154,12 @@ static int read_user_stack_64(unsigned l
((unsigned long)ptr & 7))
return -EFAULT;
- if (!__get_user_inatomic(*ret, ptr))
+ pagefault_disable();
+ if (!__get_user_inatomic(*ret, ptr)) {
+ pagefault_enable();
return 0;
+ }
+ pagefault_enable();
return read_user_stack_slow(ptr, ret, 8);
}
@@ -166,8 +170,12 @@ static int read_user_stack_32(unsigned i
((unsigned long)ptr & 3))
return -EFAULT;
- if (!__get_user_inatomic(*ret, ptr))
+ pagefault_disable();
+ if (!__get_user_inatomic(*ret, ptr)) {
+ pagefault_enable();
return 0;
+ }
+ pagefault_enable();
return read_user_stack_slow(ptr, ret, 4);
}
^ permalink raw reply
* Re: perf PPC: kernel panic with callchains and context switch events
From: Benjamin Herrenschmidt @ 2011-07-25 1:55 UTC (permalink / raw)
To: David Ahern, Kumar Gala, Becky Bruce
Cc: linux-perf-users, linuxppc-dev, Paul Mackerras, Anton Blanchard,
LKML
In-Reply-To: <4E2C53E0.3020400@gmail.com>
On Sun, 2011-07-24 at 11:18 -0600, David Ahern wrote:
> On 07/20/2011 03:57 PM, David Ahern wrote:
> > I am hoping someone familiar with PPC can help understand a panic that
> > is generated when capturing callchains with context switch events.
> >
> > Call trace is below. The short of it is that walking the callchain
> > generates a page fault. To handle the page fault the mmap_sem is needed,
> > but it is currently held by setup_arg_pages. setup_arg_pages calls
> > shift_arg_pages with the mmap_sem held. shift_arg_pages then calls
> > move_page_tables which has a cond_resched at the top of its for loop. If
> > the cond_resched() is removed from move_page_tables everything works
> > beautifully - no panics.
> >
> > So, the question: is it normal for walking the stack to trigger a page
> > fault on PPC? The panic is not seen on x86 based systems.
>
> Can anyone confirm whether page faults while walking the stack are
> normal for PPC? We really want to use the context switch event with
> callchains and need to understand whether this behavior is normal. Of
> course if it is normal, a way to address the problem without a panic
> will be needed.
Now that leads to interesting discoveries :-) Becky, can you read all
the way and let me know what you think ?
So, trying to walk the user stack directly will potentially cause page
faults if it's done by direct access. So if you're going to do it in a
spot where you can't afford it, you need to pagefault_disable() I
suppose. I think the problem with our existing code is that it's missing
those around __get_user_inatomic().
In fact, arguably, we don't want the hash code from modifying the hash
either (or even hashing things in). Our 64-bit code handles it today in
perf_callchain.c in a way that involves pretty much duplicating the
functionality of __get_user_pages_fast() as used by x86 (see below), but
as a fallback from a direct access which misses the pagefault_disable()
as well.
I think it comes from an old assumption that this would always be called
from an nmi, and the explicit tracepoints broke that assumption.
In fact we probably want to bump the NMI count, not just the IRQ count
as pagefault_disable() does, to make sure we prevent hashing.
x86 does things differently, using __get_user_pages_fast() (a variant of
get_user_page_fast() that doesn't fallback to normal get_user_pages()).
Now, we could do the same (use __gup_fast too), but I can see a
potential issue with ppc 32-bit platforms that have 64-bit PTEs, since
we could end up GUP'ing in the middle of the two accesses.
Becky: I think gup_fast is generally broken on 32-bit with 64-bit PTE
because of that, the problem isn't specific to perf backtraces, I'll
propose a solution further down.
Now, on x86, there is a similar problem with PAE, which is handled by
- having gup disable IRQs
- rely on the fact that to change from a valid value to another valid
value, the PTE will first get invalidated, which requires an IPI
and thus will be blocked by our interrupts being off
We do the first part, but the second part will break if we use HW TLB
invalidation broadcast (yet another reason why those are bad, I think I
will write a blog entry about it one of these days).
I think we can work around this while keeping our broadcast TLB
invalidations by having the invalidation code also increment a global
generation count (using the existing lock used by the invalidation code,
all 32-bit platforms have such a lock).
>From there, gup_fast can be changed to, with proper ordering, check the
generation count around the loading of the PTE and loop if it has
changed, kind-of a seqlock.
We also need the NMI count bump if we are going to try to keep the
attempt at doing a direct access first for perfs.
Becky, do you feel like giving that a shot or should I find another
victim ? (Or even do it myself ... ) :-)
Cheers,
Ben.
> Thanks,
> David
>
> >
> > [<b0180e00>]rb_erase+0x1b4/0x3e8
> > [<b00430f4>]__dequeue_entity+0x50/0xe8
> > [<b0043304>]set_next_entity+0x178/0x1bc
> > [<b0043440>]pick_next_task_fair+0xb0/0x118
> > [<b02ada80>]schedule+0x500/0x614
> > [<b02afaa8>]rwsem_down_failed_common+0xf0/0x264
> > [<b02afca0>]rwsem_down_read_failed+0x34/0x54
> > [<b02aed4c>]down_read+0x3c/0x54
> > [<b0023b58>]do_page_fault+0x114/0x5e8
> > [<b001e350>]handle_page_fault+0xc/0x80
> > [<b0022dec>]perf_callchain+0x224/0x31c
> > [<b009ba70>]perf_prepare_sample+0x240/0x2fc
> > [<b009d760>]__perf_event_overflow+0x280/0x398
> > [<b009d914>]perf_swevent_overflow+0x9c/0x10c
> > [<b009db54>]perf_swevent_ctx_event+0x1d0/0x230
> > [<b009dc38>]do_perf_sw_event+0x84/0xe4
> > [<b009dde8>]perf_sw_event_context_switch+0x150/0x1b4
> > [<b009de90>]perf_event_task_sched_out+0x44/0x2d4
> > [<b02ad840>]schedule+0x2c0/0x614
> > [<b0047dc0>]__cond_resched+0x34/0x90
> > [<b02adcc8>]_cond_resched+0x4c/0x68
> > [<b00bccf8>]move_page_tables+0xb0/0x418
> > [<b00d7ee0>]setup_arg_pages+0x184/0x2a0
> > [<b0110914>]load_elf_binary+0x394/0x1208
> > [<b00d6e28>]search_binary_handler+0xe0/0x2c4
> > [<b00d834c>]do_execve+0x1bc/0x268
> > [<b0015394>]sys_execve+0x84/0xc8
> > [<b001df10>]ret_from_syscall+0x0/0x3c
> >
> > Thanks,
> > David
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev
^ permalink raw reply
* [PATCH 0/5] ppc64 scheduler fixes
From: Anton Blanchard @ 2011-07-25 2:33 UTC (permalink / raw)
To: mingo, peterz, benh; +Cc: linuxppc-dev, linux-kernel
Here are a set of ppc64 scheduler fixes that help with some
multi node performance issues.
^ permalink raw reply
* [PATCH 1/5] powerpc/numa: Enable SD_WAKE_AFFINE in node definition
From: Anton Blanchard @ 2011-07-25 2:33 UTC (permalink / raw)
To: mingo, peterz, benh
Cc: fenghua.yu, tony.luck, linux-kernel, ralf, lethal, cmetcalf,
linuxppc-dev, davem
In-Reply-To: <20110725023311.175792493@samba.org>
When chasing a performance issue on ppc64, I noticed tasks
communicating via a pipe would often end up on different nodes.
It turns out SD_WAKE_AFFINE is not set in our node defition. Commit
9fcd18c9e63e (sched: re-tune balancing) enabled SD_WAKE_AFFINE
in the node definition for x86 and we need a similar change for
ppc64.
I used lmbench lat_ctx and perf bench pipe to verify this fix. Each
benchmark was run 10 times and the average taken.
lmbench lat_ctx:
before: 66565 ops/sec
after: 204700 ops/sec
3.1x faster
perf bench pipe:
before: 5.6570 usecs
after: 1.3470 usecs
4.2x faster
Signed-off-by: Anton Blanchard <anton@samba.org>
---
Cc-ing arch maintainers who might need to look at their SD_NODE_INIT
definitions
Index: linux-2.6-work/arch/powerpc/include/asm/topology.h
===================================================================
--- linux-2.6-work.orig/arch/powerpc/include/asm/topology.h 2011-07-18 16:24:55.639949552 +1000
+++ linux-2.6-work/arch/powerpc/include/asm/topology.h 2011-07-18 16:25:02.630074557 +1000
@@ -73,7 +73,7 @@ static inline int pcibus_to_node(struct
| 1*SD_BALANCE_EXEC \
| 1*SD_BALANCE_FORK \
| 0*SD_BALANCE_WAKE \
- | 0*SD_WAKE_AFFINE \
+ | 1*SD_WAKE_AFFINE \
| 0*SD_PREFER_LOCAL \
| 0*SD_SHARE_CPUPOWER \
| 0*SD_POWERSAVINGS_BALANCE \
^ permalink raw reply
* [PATCH 2/5] sched: Allow SD_NODES_PER_DOMAIN to be overridden
From: Anton Blanchard @ 2011-07-25 2:33 UTC (permalink / raw)
To: mingo, peterz, benh; +Cc: linuxppc-dev, linux-kernel
In-Reply-To: <20110725023311.175792493@samba.org>
We want to override the default value of SD_NODES_PER_DOMAIN on ppc64,
so move it into linux/topology.h.
Signed-off-by: Anton Blanchard <anton@samba.org>
---
Index: linux-2.6-work/include/linux/topology.h
===================================================================
--- linux-2.6-work.orig/include/linux/topology.h 2011-07-25 11:20:02.588717796 +1000
+++ linux-2.6-work/include/linux/topology.h 2011-07-25 11:26:50.616468376 +1000
@@ -201,6 +201,10 @@ int arch_update_cpu_topology(void);
.balance_interval = 64, \
}
+#ifndef SD_NODES_PER_DOMAIN
+#define SD_NODES_PER_DOMAIN 16
+#endif
+
#ifdef CONFIG_SCHED_BOOK
#ifndef SD_BOOK_INIT
#error Please define an appropriate SD_BOOK_INIT in include/asm/topology.h!!!
Index: linux-2.6-work/kernel/sched.c
===================================================================
--- linux-2.6-work.orig/kernel/sched.c 2011-07-25 11:20:09.538850173 +1000
+++ linux-2.6-work/kernel/sched.c 2011-07-25 11:26:50.626468565 +1000
@@ -6938,8 +6938,6 @@ static int __init isolated_cpu_setup(cha
__setup("isolcpus=", isolated_cpu_setup);
-#define SD_NODES_PER_DOMAIN 16
-
#ifdef CONFIG_NUMA
/**
^ permalink raw reply
* [PATCH 3/5] powerpc/numa: Increase SD_NODES_PER_DOMAIN to 32.
From: Anton Blanchard @ 2011-07-25 2:33 UTC (permalink / raw)
To: mingo, peterz, benh; +Cc: linuxppc-dev, linux-kernel
In-Reply-To: <20110725023311.175792493@samba.org>
The largest POWER7 boxes have 32 nodes. SD_NODES_PER_DOMAIN groups
nodes into chunks of 16 and adds a global balancing domain
(SD_ALLNODES) above it.
If we bump SD_NODES_PER_DOMAIN to 32, then we avoid this extra
level of balancing on our largest boxes.
Signed-off-by: Anton Blanchard <anton@samba.org>
---
Index: linux-2.6-work/arch/powerpc/include/asm/topology.h
===================================================================
--- linux-2.6-work.orig/arch/powerpc/include/asm/topology.h 2011-07-25 11:43:24.954093179 +1000
+++ linux-2.6-work/arch/powerpc/include/asm/topology.h 2011-07-25 11:43:31.274205122 +1000
@@ -28,6 +28,12 @@ struct device_node;
*/
#define RECLAIM_DISTANCE 10
+/*
+ * Avoid creating an extra level of balancing (SD_ALLNODES) on the largest
+ * POWER7 boxes which have a maximum of 32 nodes.
+ */
+#define SD_NODES_PER_DOMAIN 32
+
#include <asm/mmzone.h>
static inline int cpu_to_node(int cpu)
^ permalink raw reply
* [PATCH 4/5] powerpc/numa: Disable NEWIDLE balancing at node level
From: Anton Blanchard @ 2011-07-25 2:33 UTC (permalink / raw)
To: mingo, peterz, benh; +Cc: linuxppc-dev, linux-kernel
In-Reply-To: <20110725023311.175792493@samba.org>
On big POWER7 boxes we see large amounts of CPU time in system
processes like workqueue and watchdog kernel threads.
We currently rebalance the entire machine each time a task goes
idle and this is very expensive on large machines. Disable newidle
balancing at the node level and rely on the scheduler tick to
rebalance across nodes.
Signed-off-by: Anton Blanchard <anton@samba.org>
---
Index: linux-2.6-work/arch/powerpc/include/asm/topology.h
===================================================================
--- linux-2.6-work.orig/arch/powerpc/include/asm/topology.h 2011-07-25 12:14:25.448671947 +1000
+++ linux-2.6-work/arch/powerpc/include/asm/topology.h 2011-07-25 12:14:26.568692651 +1000
@@ -75,7 +75,7 @@ static inline int pcibus_to_node(struct
.forkexec_idx = 0, \
\
.flags = 1*SD_LOAD_BALANCE \
- | 1*SD_BALANCE_NEWIDLE \
+ | 0*SD_BALANCE_NEWIDLE \
| 1*SD_BALANCE_EXEC \
| 1*SD_BALANCE_FORK \
| 0*SD_BALANCE_WAKE \
^ permalink raw reply
* [PATCH 5/5] powerpc/numa: Remove duplicate RECLAIM_DISTANCE definition
From: Anton Blanchard @ 2011-07-25 2:33 UTC (permalink / raw)
To: mingo, peterz, benh; +Cc: linuxppc-dev, linux-kernel
In-Reply-To: <20110725023311.175792493@samba.org>
We have two identical definitions of RECLAIM_DISTANCE, looks like
the patch got applied twice. Remove one.
Signed-off-by: Anton Blanchard <anton@samba.org>
---
Index: linux-2.6-work/arch/powerpc/include/asm/topology.h
===================================================================
--- linux-2.6-work.orig/arch/powerpc/include/asm/topology.h 2011-07-25 12:15:33.059921510 +1000
+++ linux-2.6-work/arch/powerpc/include/asm/topology.h 2011-07-25 12:15:46.750174446 +1000
@@ -19,16 +19,6 @@ struct device_node;
#define RECLAIM_DISTANCE 10
/*
- * Before going off node we want the VM to try and reclaim from the local
- * node. It does this if the remote distance is larger than RECLAIM_DISTANCE.
- * With the default REMOTE_DISTANCE of 20 and the default RECLAIM_DISTANCE of
- * 20, we never reclaim and go off node straight away.
- *
- * To fix this we choose a smaller value of RECLAIM_DISTANCE.
- */
-#define RECLAIM_DISTANCE 10
-
-/*
* Avoid creating an extra level of balancing (SD_ALLNODES) on the largest
* POWER7 boxes which have a maximum of 32 nodes.
*/
^ permalink raw reply
* [PATCH 0/3] pseries kexec fixes
From: Anton Blanchard @ 2011-07-25 11:46 UTC (permalink / raw)
To: benh, paulus; +Cc: linuxppc-dev
Here are a few pseries kexec fixes after testing on a recent version
version.
Anton
^ permalink raw reply
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