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KVM: PPC: Book3S PR: Fix ABIv2 issues

PATCH Applied Anton Blanchard 2 participants 6 messages Jun 12, 2014 – Jun 17, 2014

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Anton Blanchard

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#0 lore raw

PATCH 1/4 KVM: PPC: Book3S PR: Fix ABIv2 issues

binutils knows that a branch to a function descriptor is actually a branch to the function text. By removing the explicit branch to dot symbols, we maintain both ABIv1 and ABIv2 compatibility.

Signed-off-by Anton Blanchard <[email protected]>

---

arch/powerpc/kvm/book3s_interrupts.S +4 -6
Index: b/arch/powerpc/kvm/book3s_interrupts.S
===================================================================
@@ -25,11 +25,9 @@
 #include <asm/exception-64s.h>
 
 #if defined(CONFIG_PPC_BOOK3S_64)
-#define FUNC(name) 		GLUE(.,name)
 #define GET_SHADOW_VCPU(reg)    addi	reg, r13, PACA_SVCPU
 
 #elif defined(CONFIG_PPC_BOOK3S_32)
-#define FUNC(name)		name
 #define GET_SHADOW_VCPU(reg)	lwz     reg, (THREAD + THREAD_KVM_SVCPU)(r2)
 
 #endif /* CONFIG_PPC_BOOK3S_XX */

@@ -93,7 +91,7 @@ kvm_start_entry:
 kvm_start_lightweight:
 	/* Copy registers into shadow vcpu so we can access them in real mode */
 	GET_SHADOW_VCPU(r3)
-	bl	FUNC(kvmppc_copy_to_svcpu)
+	bl	kvmppc_copy_to_svcpu
 	nop
 	REST_GPR(4, r1)
 

@@ -131,7 +129,7 @@ after_sprg3_load:
 	PPC_LL	r4, VCPU_SHADOW_MSR(r4)	/* get shadow_msr */
 
 	/* Jump to segment patching handler and into our guest */
-	bl	FUNC(kvmppc_entry_trampoline)
+	bl	kvmppc_entry_trampoline
 	nop
 
 /*

@@ -164,7 +162,7 @@ after_sprg3_load:
 	/* On 64-bit, interrupts are still off at this point */
 
 	GET_SHADOW_VCPU(r4)
-	bl	FUNC(kvmppc_copy_from_svcpu)
+	bl	kvmppc_copy_from_svcpu
 	nop
 
 #ifdef CONFIG_PPC_BOOK3S_64

@@ -203,7 +201,7 @@ after_sprg3_load:
 
 	/* Restore r3 (kvm_run) and r4 (vcpu) */
 	REST_2GPRS(3, r1)
-	bl	FUNC(kvmppc_handle_exit_pr)
+	bl	kvmppc_handle_exit_pr
 
 	/* If RESUME_GUEST, get back in the loop */
 	cmpwi	r3, RESUME_GUEST
arch/powerpc/kvm/book3s_rmhandlers.S +1 -7
Index: b/arch/powerpc/kvm/book3s_rmhandlers.S
===================================================================
@@ -34,13 +34,7 @@
  *                                                                           *
  ****************************************************************************/
 
-#if defined(CONFIG_PPC_BOOK3S_64)
-
-#define FUNC(name) 		GLUE(.,name)
-
-#elif defined(CONFIG_PPC_BOOK3S_32)
-
-#define FUNC(name)		name
+#ifdef CONFIG_PPC_BOOK3S_32
 
 .macro INTERRUPT_TRAMPOLINE intno
author
#1 lore raw

PATCH 2/4 KVM: PPC: Book3S HV: Fix ABIv2 issues

binutils knows that a branch to a function descriptor is actually a branch to the function text. By removing the explicit branch to dot symbols, we maintain both ABIv1 and ABIv2 compatibility.

Signed-off-by Anton Blanchard <[email protected]>

---

Index: b/arch/powerpc/kvm/book3s_hv_rmhandlers.S =================================--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -675,9 +675,9 @@ END_FTR_SECTION_IFCLR(CPU_FTR_TM)

mr r31, r4
addi r3, r31, VCPU_FPRS_TM
- bl .load_fp_state
+ bl load_fp_state
addi r3, r31, VCPU_VRS_TM
- bl .load_vr_state
+ bl load_vr_state
mr r4, r31
lwz r7, VCPU_VRSAVE_TM(r4)
mtspr SPRN_VRSAVE, r7
@@ -1421,9 +1421,9 @@ END_FTR_SECTION_IFCLR(CPU_FTR_TM)

/* Save FP/VSX. */
addi r3, r9, VCPU_FPRS_TM
- bl .store_fp_state
+ bl store_fp_state
addi r3, r9, VCPU_VRS_TM
- bl .store_vr_state
+ bl store_vr_state
mfspr r6, SPRN_VRSAVE
stw r6, VCPU_VRSAVE_TM(r9)
1:
@@ -2421,11 +2421,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
mtmsrd r8
isync
addi r3,r3,VCPU_FPRS
- bl .store_fp_state
+ bl store_fp_state
#ifdef CONFIG_ALTIVEC
BEGIN_FTR_SECTION
addi r3,r31,VCPU_VRS
- bl .store_vr_state
+ bl store_vr_state
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif
mfspr r6,SPRN_VRSAVE
@@ -2457,11 +2457,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
mtmsrd r8
isync
addi r3,r4,VCPU_FPRS
- bl .load_fp_state
+ bl load_fp_state
#ifdef CONFIG_ALTIVEC
BEGIN_FTR_SECTION
addi r3,r31,VCPU_VRS
- bl .load_vr_state
+ bl load_vr_state
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif
lwz r7,VCPU_VRSAVE(r31)

author
#2 lore raw

PATCH 3/4 KVM: PPC: Book3S HV: Fix ABIv2 indirect branch issue

In reply to Anton Blanchard

To establish addressability quickly, ABIv2 requires the target address of the function being called to be in r12.

Signed-off-by Anton Blanchard <[email protected]>

---

Index: b/arch/powerpc/kvm/book3s_hv_rmhandlers.S =================================--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1920,8 +1920,8 @@ hcall_try_real_mode:
lwax r3,r3,r4
cmpwi r3,0
beq guest_exit_cont
- add r3,r3,r4
- mtctr r3
+ add r12,r3,r4
+ mtctr r12
mr r3,r9 /* get vcpu pointer */
ld r4,VCPU_GPR(R4)(r9)
bctrl

Applied
#3 lore raw

Re: [PATCH 3/4] KVM: PPC: Book3S HV: Fix ABIv2 indirect branch issue

Quoted 4 lines · Anton Blanchard

To establish addressability quickly, ABIv2 requires the target address of the function being called to be in r12.

Signed-off-by Anton Blanchard <[email protected]>

Thanks, applied to kvm-ppc-queue.

Alex

Quoted 17 lines

---

Index: b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
===================================================================

arch/powerpc/kvm/book3s_hv_rmhandlers.S +2 -2
@@ -1920,8 +1920,8 @@ hcall_try_real_mode:
  	lwax	r3,r3,r4
  	cmpwi	r3,0
  	beq	guest_exit_cont
-	add	r3,r3,r4
-	mtctr	r3
+	add	r12,r3,r4
+	mtctr	r12
  	mr	r3,r9		/* get vcpu pointer */
  	ld	r4,VCPU_GPR(R4)(r9)
  	bctrl
author
#4 lore raw

PATCH 4/4 KVM: PPC: Assembly functions exported to modules need _GLOBAL_TOC()

In reply to Anton Blanchard

Both kvmppc_hv_entry_trampoline and kvmppc_entry_trampoline are assembly functions that are exported to modules and also require a valid r2.

As such we need to use _GLOBAL_TOC so we provide a global entry point that establishes the TOC (r2).

Signed-off-by Anton Blanchard <[email protected]>

---

arch/powerpc/kvm/book3s_hv_rmhandlers.S +1 -1
Index: b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
===================================================================
@@ -51,7 +51,7 @@
  *
  * LR = return address to continue at after eventually re-enabling MMU
  */
-_GLOBAL(kvmppc_hv_entry_trampoline)
+_GLOBAL_TOC(kvmppc_hv_entry_trampoline)
 	mflr	r0
 	std	r0, PPC_LR_STKOFF(r1)
 	stdu	r1, -112(r1)
arch/powerpc/kvm/book3s_rmhandlers.S +1 -1
Index: b/arch/powerpc/kvm/book3s_rmhandlers.S
===================================================================
@@ -140,7 +140,7 @@ kvmppc_handler_skip_ins:
  * On entry, r4 contains the guest shadow MSR
  * MSR.EE has to be 0 when calling this function
  */
-_GLOBAL(kvmppc_entry_trampoline)
+_GLOBAL_TOC(kvmppc_entry_trampoline)
 	mfmsr	r5
 	LOAD_REG_ADDR(r7, kvmppc_handler_trampoline_enter)
 	toreal(r7)
Applied
#5 lore raw

Re: [PATCH 4/4] KVM: PPC: Assembly functions exported to modules need _GLOBAL_TOC()

Quoted 8 lines · Anton Blanchard

Both kvmppc_hv_entry_trampoline and kvmppc_entry_trampoline are assembly functions that are exported to modules and also require a valid r2.

As such we need to use _GLOBAL_TOC so we provide a global entry point that establishes the TOC (r2).

Signed-off-by Anton Blanchard <[email protected]>

Thanks, applied to kvm-ppc-queue.

I've not applied patches 1 and 2 for now, as they break BE module support.

Alex