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

From: Xiao Guangrong
Date: Sat May 30 2015 - 06:59:59 EST


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

Signed-off-by: Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
---
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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