Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752009AbbFAJLs (ORCPT ); Mon, 1 Jun 2015 05:11:48 -0400 Received: from mail-wg0-f43.google.com ([74.125.82.43]:35217 "EHLO mail-wg0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751239AbbFAJLi (ORCPT ); Mon, 1 Jun 2015 05:11:38 -0400 Message-ID: <556C21BF.3090003@redhat.com> Date: Mon, 01 Jun 2015 11:11:27 +0200 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Xiao Guangrong CC: gleb@kernel.org, mtosatti@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 05/15] KVM: MTRR: clean up mtrr default type References: <1432983566-15773-1-git-send-email-guangrong.xiao@linux.intel.com> <1432983566-15773-6-git-send-email-guangrong.xiao@linux.intel.com> In-Reply-To: <1432983566-15773-6-git-send-email-guangrong.xiao@linux.intel.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4066 Lines: 118 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 > --- > 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) { > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/