On 30/05/2015 12:59, Xiao Guangrong wrote:
> Use union definition to avoid the decode/code workload and drop all the
> hard code
>
> Signed-off-by: Xiao Guangrong <[email protected]>
> ---
> 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)
I know Linus doesn't like bitfields too much. Can you change these to
inline functions, and only leave an "u64 deftype" in the struct?
Paolo
> 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) {
>
--
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