linux-kernel - [PATCH] KVM: x86: merge handle_mmio_page_fault and handle_mmio_page_fault

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Date:	Wed,  4 Nov 2015 13:45:32 +0100
From:	Paolo Bonzini <pbonzini@...hat.com>
To:	linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:	rkrcmar@...hat.com
Subject: [PATCH] KVM: x86: merge handle_mmio_page_fault and handle_mmio_page_fault_common

They are exactly the same, except that handle_mmio_page_fault
has an unused argument and a call to WARN_ON.  Remove the unused
argument from the callers, and move the warning to (the former)
handle_mmio_page_fault_common.
---
 arch/x86/kvm/mmu.c         | 20 +++++---------------
 arch/x86/kvm/mmu.h         |  6 +++---
 arch/x86/kvm/paging_tmpl.h |  3 +--
 arch/x86/kvm/vmx.c         |  2 +-
 4 files changed, 10 insertions(+), 21 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 7d85bcae3332..e7c2c1428a69 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3359,7 +3359,7 @@ exit:
 	return reserved;
 }
 
-int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct)
+int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct)
 {
 	u64 spte;
 	bool reserved;
@@ -3368,7 +3368,7 @@ int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct)
 		return RET_MMIO_PF_EMULATE;
 
 	reserved = walk_shadow_page_get_mmio_spte(vcpu, addr, &spte);
-	if (unlikely(reserved))
+	if (WARN_ON(reserved))
 		return RET_MMIO_PF_BUG;
 
 	if (is_mmio_spte(spte)) {
@@ -3392,17 +3392,7 @@ int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct)
 	 */
 	return RET_MMIO_PF_RETRY;
 }
-EXPORT_SYMBOL_GPL(handle_mmio_page_fault_common);
-
-static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr,
-				  u32 error_code, bool direct)
-{
-	int ret;
-
-	ret = handle_mmio_page_fault_common(vcpu, addr, direct);
-	WARN_ON(ret == RET_MMIO_PF_BUG);
-	return ret;
-}
+EXPORT_SYMBOL_GPL(handle_mmio_page_fault);
 
 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
 				u32 error_code, bool prefault)
@@ -3413,7 +3403,7 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
 	pgprintk("%s: gva %lx error %x\n", __func__, gva, error_code);
 
 	if (unlikely(error_code & PFERR_RSVD_MASK)) {
-		r = handle_mmio_page_fault(vcpu, gva, error_code, true);
+		r = handle_mmio_page_fault(vcpu, gva, true);
 
 		if (likely(r != RET_MMIO_PF_INVALID))
 			return r;
@@ -3503,7 +3493,7 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code,
 	MMU_WARN_ON(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
 
 	if (unlikely(error_code & PFERR_RSVD_MASK)) {
-		r = handle_mmio_page_fault(vcpu, gpa, error_code, true);
+		r = handle_mmio_page_fault(vcpu, gpa, true);
 
 		if (likely(r != RET_MMIO_PF_INVALID))
 			return r;
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index e4202e41d535..55ffb7b0f95e 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -56,13 +56,13 @@ void
 reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context);
 
 /*
- * Return values of handle_mmio_page_fault_common:
+ * Return values of handle_mmio_page_fault:
  * RET_MMIO_PF_EMULATE: it is a real mmio page fault, emulate the instruction
  *			directly.
  * RET_MMIO_PF_INVALID: invalid spte is detected then let the real page
  *			fault path update the mmio spte.
  * RET_MMIO_PF_RETRY: let CPU fault again on the address.
- * RET_MMIO_PF_BUG: bug is detected.
+ * RET_MMIO_PF_BUG: a bug was detected (and a WARN was printed).
  */
 enum {
 	RET_MMIO_PF_EMULATE = 1,
@@ -71,7 +71,7 @@ enum {
 	RET_MMIO_PF_BUG = -1
 };
 
-int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct);
+int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct);
 void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu);
 void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly);
 
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index b41faa91a6f9..3058a22a658d 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -705,8 +705,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
 	pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code);
 
 	if (unlikely(error_code & PFERR_RSVD_MASK)) {
-		r = handle_mmio_page_fault(vcpu, addr, error_code,
-					      mmu_is_nested(vcpu));
+		r = handle_mmio_page_fault(vcpu, addr, mmu_is_nested(vcpu));
 		if (likely(r != RET_MMIO_PF_INVALID))
 			return r;
 
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 89f4fa25b06d..04007a032004 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5908,7 +5908,7 @@ static int handle_ept_misconfig(struct kvm_vcpu *vcpu)
 		return 1;
 	}
 
-	ret = handle_mmio_page_fault_common(vcpu, gpa, true);
+	ret = handle_mmio_page_fault(vcpu, gpa, true);
 	if (likely(ret == RET_MMIO_PF_EMULATE))
 		return x86_emulate_instruction(vcpu, gpa, 0, NULL, 0) ==
 					      EMULATE_DONE;
-- 
1.8.3.1

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