[v6,3/5] KVM: PPC: clean up redundant kvm_run parameters in assembly
diff mbox series

Message ID 20200623131418.31473-4-tianjia.zhang@linux.alibaba.com
State Not Applicable
Headers show
Series
  • clean up redundant 'kvm_run' parameters
Related show

Commit Message

Tianjia Zhang June 23, 2020, 1:14 p.m. UTC
In the current kvm version, 'kvm_run' has been included in the 'kvm_vcpu'
structure. For historical reasons, many kvm-related function parameters
retain the 'kvm_run' and 'kvm_vcpu' parameters at the same time. This
patch does a unified cleanup of these remaining redundant parameters.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
---
 arch/powerpc/include/asm/kvm_ppc.h    |  2 +-
 arch/powerpc/kvm/book3s_interrupts.S  | 22 ++++++++++------------
 arch/powerpc/kvm/book3s_pr.c          |  9 ++++-----
 arch/powerpc/kvm/booke.c              |  9 ++++-----
 arch/powerpc/kvm/booke_interrupts.S   |  9 ++++-----
 arch/powerpc/kvm/bookehv_interrupts.S | 10 +++++-----
 6 files changed, 28 insertions(+), 33 deletions(-)

Comments

Paolo Bonzini July 10, 2020, 7:57 a.m. UTC | #1
On 23/06/20 15:14, Tianjia Zhang wrote:
>  
>  	/* Load non-volatile guest state from the vcpu */
> -	VCPU_LOAD_NVGPRS(r4)
> +	VCPU_LOAD_NVGPRS(r3)
>  
>  kvm_start_lightweight:
>  	/* Copy registers into shadow vcpu so we can access them in real mode */
> -	mr	r3, r4
>  	bl	FUNC(kvmppc_copy_to_svcpu)
>  	nop
> -	REST_GPR(4, r1)
> +	REST_GPR(3, r1)
>  
>  #ifdef CONFIG_PPC_BOOK3S_64
>  	/* Get the dcbz32 flag */
> @@ -146,7 +144,7 @@ after_sprg3_load:

Below, there are a bunch of references to r3 and r4 left

        rldicl  r3, r3, 0, 63           /* r3 &= 1 */
        stb     r3, HSTATE_RESTORE_HID5(r13)

        /* Load up guest SPRG3 value, since it's user readable */
        lwz     r3, VCPU_SHAREDBE(r4)				  <<<
        cmpwi   r3, 0
        ld      r5, VCPU_SHARED(r4)				  <<<

where r3 is also destroyed.  So I'd rather have three patches:

- one that is as small as possible, changing the prototypes and adding

	mr r4, r3

- one that entirely swaps out r3 and r4.  This would be the hard one to
review!

- one that cleans up the prologue and epilogue

But overall I think it's simplest to just leave out this patch.

Paolo
Paul Mackerras July 23, 2020, 6:19 a.m. UTC | #2
On Tue, Jun 23, 2020 at 09:14:16PM +0800, Tianjia Zhang wrote:
> In the current kvm version, 'kvm_run' has been included in the 'kvm_vcpu'
> structure. For historical reasons, many kvm-related function parameters
> retain the 'kvm_run' and 'kvm_vcpu' parameters at the same time. This
> patch does a unified cleanup of these remaining redundant parameters.

Thanks, patch applied to my kvm-ppc-next branch, with fixes.

Paul.

Patch
diff mbox series

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index ccf66b3a4c1d..0a056c64c317 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -59,7 +59,7 @@  enum xlate_readwrite {
 };
 
 extern int kvmppc_vcpu_run(struct kvm_vcpu *vcpu);
-extern int __kvmppc_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu);
+extern int __kvmppc_vcpu_run(struct kvm_vcpu *vcpu);
 extern void kvmppc_handler_highmem(void);
 
 extern void kvmppc_dump_vcpu(struct kvm_vcpu *vcpu);
diff --git a/arch/powerpc/kvm/book3s_interrupts.S b/arch/powerpc/kvm/book3s_interrupts.S
index f7ad99d972ce..a3674f6b8d3d 100644
--- a/arch/powerpc/kvm/book3s_interrupts.S
+++ b/arch/powerpc/kvm/book3s_interrupts.S
@@ -55,8 +55,7 @@ 
  ****************************************************************************/
 
 /* Registers:
- *  r3: kvm_run pointer
- *  r4: vcpu pointer
+ *  r3: vcpu pointer
  */
 _GLOBAL(__kvmppc_vcpu_run)
 
@@ -68,8 +67,8 @@  kvm_start_entry:
 	/* Save host state to the stack */
 	PPC_STLU r1, -SWITCH_FRAME_SIZE(r1)
 
-	/* Save r3 (kvm_run) and r4 (vcpu) */
-	SAVE_2GPRS(3, r1)
+	/* Save r3 (vcpu) */
+	SAVE_GPR(3, r1)
 
 	/* Save non-volatile registers (r14 - r31) */
 	SAVE_NVGPRS(r1)
@@ -82,14 +81,13 @@  kvm_start_entry:
 	PPC_STL	r0, _LINK(r1)
 
 	/* Load non-volatile guest state from the vcpu */
-	VCPU_LOAD_NVGPRS(r4)
+	VCPU_LOAD_NVGPRS(r3)
 
 kvm_start_lightweight:
 	/* Copy registers into shadow vcpu so we can access them in real mode */
-	mr	r3, r4
 	bl	FUNC(kvmppc_copy_to_svcpu)
 	nop
-	REST_GPR(4, r1)
+	REST_GPR(3, r1)
 
 #ifdef CONFIG_PPC_BOOK3S_64
 	/* Get the dcbz32 flag */
@@ -146,7 +144,7 @@  after_sprg3_load:
 	 *
 	 */
 
-	PPC_LL	r3, GPR4(r1)		/* vcpu pointer */
+	PPC_LL	r3, GPR3(r1)		/* vcpu pointer */
 
 	/*
 	 * kvmppc_copy_from_svcpu can clobber volatile registers, save
@@ -190,11 +188,11 @@  after_sprg3_load:
 	PPC_STL	r30, VCPU_GPR(R30)(r7)
 	PPC_STL	r31, VCPU_GPR(R31)(r7)
 
-	/* Pass the exit number as 3rd argument to kvmppc_handle_exit */
-	lwz	r5, VCPU_TRAP(r7)
+	/* Pass the exit number as 2nd argument to kvmppc_handle_exit */
+	lwz	r4, VCPU_TRAP(r7)
 
-	/* Restore r3 (kvm_run) and r4 (vcpu) */
-	REST_2GPRS(3, r1)
+	/* Restore r3 (vcpu) */
+	REST_GPR(3, r1)
 	bl	FUNC(kvmppc_handle_exit_pr)
 
 	/* If RESUME_GUEST, get back in the loop */
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index ef54f917bdaf..01c8fe5abe0d 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -1151,9 +1151,9 @@  static int kvmppc_exit_pr_progint(struct kvm_vcpu *vcpu, unsigned int exit_nr)
 	return r;
 }
 
-int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu,
-			  unsigned int exit_nr)
+int kvmppc_handle_exit_pr(struct kvm_vcpu *vcpu, unsigned int exit_nr)
 {
+	struct kvm_run *run = vcpu->run;
 	int r = RESUME_HOST;
 	int s;
 
@@ -1826,7 +1826,6 @@  static void kvmppc_core_vcpu_free_pr(struct kvm_vcpu *vcpu)
 
 static int kvmppc_vcpu_run_pr(struct kvm_vcpu *vcpu)
 {
-	struct kvm_run *run = vcpu->run;
 	int ret;
 #ifdef CONFIG_ALTIVEC
 	unsigned long uninitialized_var(vrsave);
@@ -1834,7 +1833,7 @@  static int kvmppc_vcpu_run_pr(struct kvm_vcpu *vcpu)
 
 	/* Check if we can run the vcpu at all */
 	if (!vcpu->arch.sane) {
-		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 		ret = -EINVAL;
 		goto out;
 	}
@@ -1861,7 +1860,7 @@  static int kvmppc_vcpu_run_pr(struct kvm_vcpu *vcpu)
 
 	kvmppc_fix_ee_before_entry();
 
-	ret = __kvmppc_vcpu_run(run, vcpu);
+	ret = __kvmppc_vcpu_run(vcpu);
 
 	kvmppc_clear_debug(vcpu);
 
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index c0d62a917e20..3e1c9f08e302 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -731,12 +731,11 @@  int kvmppc_core_check_requests(struct kvm_vcpu *vcpu)
 
 int kvmppc_vcpu_run(struct kvm_vcpu *vcpu)
 {
-	struct kvm_run *run = vcpu->run;
 	int ret, s;
 	struct debug_reg debug;
 
 	if (!vcpu->arch.sane) {
-		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 		return -EINVAL;
 	}
 
@@ -778,7 +777,7 @@  int kvmppc_vcpu_run(struct kvm_vcpu *vcpu)
 	vcpu->arch.pgdir = vcpu->kvm->mm->pgd;
 	kvmppc_fix_ee_before_entry();
 
-	ret = __kvmppc_vcpu_run(run, vcpu);
+	ret = __kvmppc_vcpu_run(vcpu);
 
 	/* No need for guest_exit. It's done in handle_exit.
 	   We also get here with interrupts enabled. */
@@ -982,9 +981,9 @@  static int kvmppc_resume_inst_load(struct kvm_vcpu *vcpu,
  *
  * Return value is in the form (errcode<<2 | RESUME_FLAG_HOST | RESUME_FLAG_NV)
  */
-int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
-                       unsigned int exit_nr)
+int kvmppc_handle_exit(struct kvm_vcpu *vcpu, unsigned int exit_nr)
 {
+	struct kvm_run *run = vcpu->run;
 	int r = RESUME_HOST;
 	int s;
 	int idx;
diff --git a/arch/powerpc/kvm/booke_interrupts.S b/arch/powerpc/kvm/booke_interrupts.S
index 2e56ab5a5f55..6fa82efe833b 100644
--- a/arch/powerpc/kvm/booke_interrupts.S
+++ b/arch/powerpc/kvm/booke_interrupts.S
@@ -237,7 +237,7 @@  _GLOBAL(kvmppc_resume_host)
 	/* Switch to kernel stack and jump to handler. */
 	LOAD_REG_ADDR(r3, kvmppc_handle_exit)
 	mtctr	r3
-	lwz	r3, HOST_RUN(r1)
+	mr	r3, r4
 	lwz	r2, HOST_R2(r1)
 	mr	r14, r4 /* Save vcpu pointer. */
 
@@ -337,15 +337,14 @@  heavyweight_exit:
 
 
 /* Registers:
- *  r3: kvm_run pointer
- *  r4: vcpu pointer
+ *  r3: vcpu pointer
  */
 _GLOBAL(__kvmppc_vcpu_run)
 	stwu	r1, -HOST_STACK_SIZE(r1)
-	stw	r1, VCPU_HOST_STACK(r4)	/* Save stack pointer to vcpu. */
+	stw	r1, VCPU_HOST_STACK(r3)	/* Save stack pointer to vcpu. */
 
 	/* Save host state to stack. */
-	stw	r3, HOST_RUN(r1)
+	mr	r4, r3
 	mflr	r3
 	stw	r3, HOST_STACK_LR(r1)
 	mfcr	r5
diff --git a/arch/powerpc/kvm/bookehv_interrupts.S b/arch/powerpc/kvm/bookehv_interrupts.S
index c577ba4b3169..8262c14fc9e6 100644
--- a/arch/powerpc/kvm/bookehv_interrupts.S
+++ b/arch/powerpc/kvm/bookehv_interrupts.S
@@ -434,9 +434,10 @@  _GLOBAL(kvmppc_resume_host)
 #endif
 
 	/* Switch to kernel stack and jump to handler. */
-	PPC_LL	r3, HOST_RUN(r1)
+	mr	r3, r4
 	mr	r5, r14 /* intno */
 	mr	r14, r4 /* Save vcpu pointer. */
+	mr	r4, r5
 	bl	kvmppc_handle_exit
 
 	/* Restore vcpu pointer and the nonvolatiles we used. */
@@ -525,15 +526,14 @@  heavyweight_exit:
 	blr
 
 /* Registers:
- *  r3: kvm_run pointer
- *  r4: vcpu pointer
+ *  r3: vcpu pointer
  */
 _GLOBAL(__kvmppc_vcpu_run)
 	stwu	r1, -HOST_STACK_SIZE(r1)
-	PPC_STL	r1, VCPU_HOST_STACK(r4)	/* Save stack pointer to vcpu. */
+	PPC_STL	r1, VCPU_HOST_STACK(r3)	/* Save stack pointer to vcpu. */
 
 	/* Save host state to stack. */
-	PPC_STL	r3, HOST_RUN(r1)
+	mr	r4, r3
 	mflr	r3
 	mfcr	r5
 	PPC_STL	r3, HOST_STACK_LR(r1)