linux-kernel - [PATCH 05/15] KVM: MTRR: clean up mtrr default type

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Date:	Sat, 30 May 2015 18:59:16 +0800
From:	Xiao Guangrong <guangrong.xiao@...ux.intel.com>
To:	pbonzini@...hat.com
Cc:	gleb@...nel.org, mtosatti@...hat.com, kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Xiao Guangrong <guangrong.xiao@...ux.intel.com>
Subject: [PATCH 05/15] KVM: MTRR: clean up mtrr default type

Use union definition to avoid the decode/code workload and drop all the
hard code

Signed-off-by: Xiao Guangrong <guangrong.xiao@...ux.intel.com>
---
 arch/x86/include/asm/kvm_host.h | 12 ++++++++++--
 arch/x86/kvm/mtrr.c             | 19 ++++++++-----------
 2 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 2c3c52d..95ce2ff 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -347,8 +347,16 @@ enum {
 struct kvm_mtrr {
 	struct mtrr_var_range var_ranges[KVM_NR_VAR_MTRR];
 	mtrr_type fixed_ranges[KVM_NR_FIXED_MTRR_REGION];
-	unsigned char enabled;
-	mtrr_type def_type;
+
+	union {
+		u64 deftype;
+		struct {
+			unsigned def_type:8;
+			unsigned reserved:2;
+			unsigned fixed_mtrr_enabled:1;
+			unsigned mtrr_enabled:1;
+		};
+	};
 };
 
 struct kvm_vcpu_arch {
diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
index 562341b..6de49dd 100644
--- a/arch/x86/kvm/mtrr.c
+++ b/arch/x86/kvm/mtrr.c
@@ -105,7 +105,6 @@ EXPORT_SYMBOL_GPL(kvm_mtrr_valid);
 static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
 {
 	struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;
-	unsigned char mtrr_enabled = mtrr_state->enabled;
 	gfn_t start, end, mask;
 	int index;
 	bool is_fixed = true;
@@ -114,7 +113,7 @@ static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
 	      !kvm_arch_has_noncoherent_dma(vcpu->kvm))
 		return;
 
-	if (!(mtrr_enabled & 0x2) && msr != MSR_MTRRdefType)
+	if (!mtrr_state->mtrr_enabled && msr != MSR_MTRRdefType)
 		return;
 
 	switch (msr) {
@@ -153,7 +152,7 @@ static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr)
 		end = ((start & mask) | ~mask) + 1;
 	}
 
-	if (is_fixed && !(mtrr_enabled & 0x1))
+	if (is_fixed && !mtrr_state->fixed_mtrr_enabled)
 		return;
 
 	kvm_zap_gfn_range(vcpu->kvm, gpa_to_gfn(start), gpa_to_gfn(end));
@@ -166,10 +165,9 @@ int kvm_mtrr_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data)
 	if (!kvm_mtrr_valid(vcpu, msr, data))
 		return 1;
 
-	if (msr == MSR_MTRRdefType) {
-		vcpu->arch.mtrr_state.def_type = data;
-		vcpu->arch.mtrr_state.enabled = (data & 0xc00) >> 10;
-	} else if (msr == MSR_MTRRfix64K_00000)
+	if (msr == MSR_MTRRdefType)
+		vcpu->arch.mtrr_state.deftype = data;
+	else if (msr == MSR_MTRRfix64K_00000)
 		p[0] = data;
 	else if (msr == MSR_MTRRfix16K_80000 || msr == MSR_MTRRfix16K_A0000)
 		p[1 + msr - MSR_MTRRfix16K_80000] = data;
@@ -216,8 +214,7 @@ int kvm_mtrr_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
 		return 1;
 
 	if (msr == MSR_MTRRdefType)
-		*pdata = vcpu->arch.mtrr_state.def_type +
-			 (vcpu->arch.mtrr_state.enabled << 10);
+		*pdata = vcpu->arch.mtrr_state.deftype;
 	else if (msr == MSR_MTRRfix64K_00000)
 		*pdata = p[0];
 	else if (msr == MSR_MTRRfix16K_80000 || msr == MSR_MTRRfix16K_A0000)
@@ -256,14 +253,14 @@ static int get_mtrr_type(struct kvm_mtrr *mtrr_state,
 	int i, num_var_ranges = KVM_NR_VAR_MTRR;
 
 	/* MTRR is completely disabled, use UC for all of physical memory. */
-	if (!(mtrr_state->enabled & 0x2))
+	if (!mtrr_state->mtrr_enabled)
 		return MTRR_TYPE_UNCACHABLE;
 
 	/* Make end inclusive end, instead of exclusive */
 	end--;
 
 	/* Look in fixed ranges. Just return the type as per start */
-	if ((mtrr_state->enabled & 0x1) && (start < 0x100000)) {
+	if (mtrr_state->fixed_mtrr_enabled && (start < 0x100000)) {
 		int idx;
 
 		if (start < 0x80000) {
-- 
2.1.0

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