| Message ID | 20191204002442.186018-1-jmattson@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] kvm: vmx: Stop wasting a page for guest_msrs | expand |
On 04/12/19 01:24, Jim Mattson wrote: > We will never need more guest_msrs than there are indices in > vmx_msr_index. Thus, at present, the guest_msrs array will not exceed > 168 bytes. > > Signed-off-by: Jim Mattson <jmattson@google.com> > Reviewed-by: Liran Alon <liran.alon@oracle.com> > --- > v1 -> v2: > Changed NR_GUEST_MSRS to NR_SHARED_MSRS. > Added BUILD_BUG_ON(ARRAY_SIZE(vmx_msr_index) != NR_SHARED_MSRS). > > arch/x86/kvm/vmx/vmx.c | 12 ++---------- > arch/x86/kvm/vmx/vmx.h | 8 +++++++- > 2 files changed, 9 insertions(+), 11 deletions(-) > > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index 1b9ab4166397d..e3394c839dea6 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -6666,7 +6666,6 @@ static void vmx_free_vcpu(struct kvm_vcpu *vcpu) > free_vpid(vmx->vpid); > nested_vmx_free_vcpu(vcpu); > free_loaded_vmcs(vmx->loaded_vmcs); > - kfree(vmx->guest_msrs); > kvm_vcpu_uninit(vcpu); > kmem_cache_free(x86_fpu_cache, vmx->vcpu.arch.user_fpu); > kmem_cache_free(x86_fpu_cache, vmx->vcpu.arch.guest_fpu); > @@ -6723,12 +6722,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) > goto uninit_vcpu; > } > > - vmx->guest_msrs = kmalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT); > - BUILD_BUG_ON(ARRAY_SIZE(vmx_msr_index) * sizeof(vmx->guest_msrs[0]) > - > PAGE_SIZE); > - > - if (!vmx->guest_msrs) > - goto free_pml; > + BUILD_BUG_ON(ARRAY_SIZE(vmx_msr_index) != NR_SHARED_MSRS); > > for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i) { > u32 index = vmx_msr_index[i]; > @@ -6760,7 +6754,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) > > err = alloc_loaded_vmcs(&vmx->vmcs01); > if (err < 0) > - goto free_msrs; > + goto free_pml; > > msr_bitmap = vmx->vmcs01.msr_bitmap; > vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_TSC, MSR_TYPE_R); > @@ -6822,8 +6816,6 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) > > free_vmcs: > free_loaded_vmcs(vmx->loaded_vmcs); > -free_msrs: > - kfree(vmx->guest_msrs); > free_pml: > vmx_destroy_pml_buffer(vmx); > uninit_vcpu: > diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h > index 7c1b978b2df44..a4f7f737c5d44 100644 > --- a/arch/x86/kvm/vmx/vmx.h > +++ b/arch/x86/kvm/vmx/vmx.h > @@ -22,6 +22,12 @@ extern u32 get_umwait_control_msr(void); > > #define X2APIC_MSR(r) (APIC_BASE_MSR + ((r) >> 4)) > > +#ifdef CONFIG_X86_64 > +#define NR_SHARED_MSRS 7 > +#else > +#define NR_SHARED_MSRS 4 > +#endif > + > #define NR_LOADSTORE_MSRS 8 > > struct vmx_msrs { > @@ -206,7 +212,7 @@ struct vcpu_vmx { > u32 idt_vectoring_info; > ulong rflags; > > - struct shared_msr_entry *guest_msrs; > + struct shared_msr_entry guest_msrs[NR_SHARED_MSRS]; > int nmsrs; > int save_nmsrs; > bool guest_msrs_ready; > Queued, thanks. Paolo
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 1b9ab4166397d..e3394c839dea6 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6666,7 +6666,6 @@ static void vmx_free_vcpu(struct kvm_vcpu *vcpu) free_vpid(vmx->vpid); nested_vmx_free_vcpu(vcpu); free_loaded_vmcs(vmx->loaded_vmcs); - kfree(vmx->guest_msrs); kvm_vcpu_uninit(vcpu); kmem_cache_free(x86_fpu_cache, vmx->vcpu.arch.user_fpu); kmem_cache_free(x86_fpu_cache, vmx->vcpu.arch.guest_fpu); @@ -6723,12 +6722,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) goto uninit_vcpu; } - vmx->guest_msrs = kmalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT); - BUILD_BUG_ON(ARRAY_SIZE(vmx_msr_index) * sizeof(vmx->guest_msrs[0]) - > PAGE_SIZE); - - if (!vmx->guest_msrs) - goto free_pml; + BUILD_BUG_ON(ARRAY_SIZE(vmx_msr_index) != NR_SHARED_MSRS); for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i) { u32 index = vmx_msr_index[i]; @@ -6760,7 +6754,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) err = alloc_loaded_vmcs(&vmx->vmcs01); if (err < 0) - goto free_msrs; + goto free_pml; msr_bitmap = vmx->vmcs01.msr_bitmap; vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_TSC, MSR_TYPE_R); @@ -6822,8 +6816,6 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) free_vmcs: free_loaded_vmcs(vmx->loaded_vmcs); -free_msrs: - kfree(vmx->guest_msrs); free_pml: vmx_destroy_pml_buffer(vmx); uninit_vcpu: diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 7c1b978b2df44..a4f7f737c5d44 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -22,6 +22,12 @@ extern u32 get_umwait_control_msr(void); #define X2APIC_MSR(r) (APIC_BASE_MSR + ((r) >> 4)) +#ifdef CONFIG_X86_64 +#define NR_SHARED_MSRS 7 +#else +#define NR_SHARED_MSRS 4 +#endif + #define NR_LOADSTORE_MSRS 8 struct vmx_msrs { @@ -206,7 +212,7 @@ struct vcpu_vmx { u32 idt_vectoring_info; ulong rflags; - struct shared_msr_entry *guest_msrs; + struct shared_msr_entry guest_msrs[NR_SHARED_MSRS]; int nmsrs; int save_nmsrs; bool guest_msrs_ready;