[20/39] KVM: Lazify fpu activation and deactivation

Message ID	1266048119-14325-21-git-send-email-avi@redhat.com (mailing list archive)
State	New, archived
Headers	show Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.3) with ESMTP id o1D87dJQ027716 for <patchwork-kvm@patchwork.kernel.org>; Sat, 13 Feb 2010 08:07:40 GMT From: Avi Kivity <avi@redhat.com> To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH 20/39] KVM: Lazify fpu activation and deactivation Date: Sat, 13 Feb 2010 10:01:40 +0200 Message-Id: <1266048119-14325-21-git-send-email-avi@redhat.com> In-Reply-To: <1266048119-14325-1-git-send-email-avi@redhat.com> References: <1266048119-14325-1-git-send-email-avi@redhat.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 693046a..93bee7a 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -506,6 +506,7 @@ struct kvm_x86_ops { void (*cache_reg)(struct kvm_vcpu *vcpu, enum kvm_reg reg); unsigned long (*get_rflags)(struct kvm_vcpu *vcpu); void (*set_rflags)(struct kvm_vcpu *vcpu, unsigned long rflags); + void (*fpu_deactivate)(struct kvm_vcpu *vcpu); void (*tlb_flush)(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 3899c2d..5b336a8 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -984,17 +984,11 @@ static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) if (npt_enabled) goto set; - if (kvm_read_cr0_bits(vcpu, X86_CR0_TS) && !(cr0 & X86_CR0_TS)) { - svm->vmcb->control.intercept_exceptions &= ~(1 << NM_VECTOR); - vcpu->fpu_active = 1; - } - vcpu->arch.cr0 = cr0; cr0 |= X86_CR0_PG | X86_CR0_WP; - if (!vcpu->fpu_active) { - svm->vmcb->control.intercept_exceptions |= (1 << NM_VECTOR); + + if (!vcpu->fpu_active) cr0 |= X86_CR0_TS; - } set: /* * re-enable caching here because the QEMU bios @@ -1250,6 +1244,8 @@ static int nm_interception(struct vcpu_svm *svm) svm->vmcb->control.intercept_exceptions &= ~(1 << NM_VECTOR); if (!kvm_read_cr0_bits(&svm->vcpu, X86_CR0_TS)) svm->vmcb->save.cr0 &= ~X86_CR0_TS; + else + svm->vmcb->save.cr0 |= X86_CR0_TS; svm->vcpu.fpu_active = 1; return 1; @@ -2586,6 +2582,8 @@ static void svm_flush_tlb(struct kvm_vcpu *vcpu) static void svm_prepare_guest_switch(struct kvm_vcpu *vcpu) { + if (npt_enabled) + vcpu->fpu_active = 1; } static inline void sync_cr8_to_lapic(struct kvm_vcpu *vcpu) @@ -2805,12 +2803,6 @@ static void svm_set_cr3(struct kvm_vcpu *vcpu, unsigned long root) svm->vmcb->save.cr3 = root; force_new_asid(vcpu); - - if (vcpu->fpu_active) { - svm->vmcb->control.intercept_exceptions |= (1 << NM_VECTOR); - svm->vmcb->save.cr0 |= X86_CR0_TS; - vcpu->fpu_active = 0; - } } static int is_disabled(void) @@ -2926,6 +2918,20 @@ static bool svm_rdtscp_supported(void) return false; } +static void svm_fpu_deactivate(struct kvm_vcpu *vcpu) +{ + struct vcpu_svm *svm = to_svm(vcpu); + + if (npt_enabled) { + /* hack: npt requires active fpu at this time */ + vcpu->fpu_active = 1; + return; + } + + svm->vmcb->control.intercept_exceptions |= 1 << NM_VECTOR; + svm->vmcb->save.cr0 |= X86_CR0_TS; +} + static struct kvm_x86_ops svm_x86_ops = { .cpu_has_kvm_support = has_svm, .disabled_by_bios = is_disabled, @@ -2967,6 +2973,7 @@ static struct kvm_x86_ops svm_x86_ops = { .cache_reg = svm_cache_reg, .get_rflags = svm_get_rflags, .set_rflags = svm_set_rflags, + .fpu_deactivate = svm_fpu_deactivate, .tlb_flush = svm_flush_tlb, diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index dbcdb55..d11be3f 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -66,7 +66,7 @@ module_param(emulate_invalid_guest_state, bool, S_IRUGO); #define KVM_GUEST_CR0_MASK \ (KVM_GUEST_CR0_MASK_UNRESTRICTED_GUEST | X86_CR0_PG | X86_CR0_PE) #define KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST \ - (X86_CR0_WP | X86_CR0_NE | X86_CR0_TS | X86_CR0_MP) + (X86_CR0_WP | X86_CR0_NE | X86_CR0_MP) #define KVM_VM_CR0_ALWAYS_ON \ (KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST | X86_CR0_PG | X86_CR0_PE) #define KVM_CR4_GUEST_OWNED_BITS \ @@ -579,9 +579,8 @@ static void update_exception_bitmap(struct kvm_vcpu *vcpu) { u32 eb; - eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR); - if (!vcpu->fpu_active) - eb |= 1u << NM_VECTOR; + eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR) + | (1u << NM_VECTOR); /* * Unconditionally intercept #DB so we can maintain dr6 without * reading it every exit. @@ -595,6 +594,8 @@ static void update_exception_bitmap(struct kvm_vcpu *vcpu) eb = ~0; if (enable_ept) eb &= ~(1u << PF_VECTOR); /* bypass_guest_pf = 0 */ + if (vcpu->fpu_active) + eb &= ~(1u << NM_VECTOR); vmcs_write32(EXCEPTION_BITMAP, eb); } @@ -806,9 +807,6 @@ static void vmx_fpu_activate(struct kvm_vcpu *vcpu) static void vmx_fpu_deactivate(struct kvm_vcpu *vcpu) { - if (!vcpu->fpu_active) - return; - vcpu->fpu_active = 0; vmcs_set_bits(GUEST_CR0, X86_CR0_TS); update_exception_bitmap(vcpu); } @@ -1737,8 +1735,6 @@ static void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) else hw_cr0 = (cr0 & ~KVM_GUEST_CR0_MASK) | KVM_VM_CR0_ALWAYS_ON; - vmx_fpu_deactivate(vcpu); - if (vmx->rmode.vm86_active && (cr0 & X86_CR0_PE)) enter_pmode(vcpu); @@ -1757,12 +1753,12 @@ static void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) if (enable_ept) ept_update_paging_mode_cr0(&hw_cr0, cr0, vcpu); + if (!vcpu->fpu_active) + hw_cr0 |= X86_CR0_TS; + vmcs_writel(CR0_READ_SHADOW, cr0); vmcs_writel(GUEST_CR0, hw_cr0); vcpu->arch.cr0 = cr0; - - if (!(cr0 & X86_CR0_TS) || !(cr0 & X86_CR0_PE)) - vmx_fpu_activate(vcpu); } static u64 construct_eptp(unsigned long root_hpa) @@ -1793,8 +1789,6 @@ static void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) vmx_flush_tlb(vcpu); vmcs_writel(GUEST_CR3, guest_cr3); - if (kvm_read_cr0_bits(vcpu, X86_CR0_PE)) - vmx_fpu_deactivate(vcpu); } static void vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) @@ -3002,11 +2996,9 @@ static int handle_cr(struct kvm_vcpu *vcpu) }; break; case 2: /* clts */ - vmx_fpu_deactivate(vcpu); vcpu->arch.cr0 &= ~X86_CR0_TS; vmcs_writel(CR0_READ_SHADOW, kvm_read_cr0(vcpu)); trace_kvm_cr_write(0, kvm_read_cr0(vcpu)); - vmx_fpu_activate(vcpu); skip_emulated_instruction(vcpu); return 1; case 1: /*mov from cr*/ @@ -4127,6 +4119,7 @@ static struct kvm_x86_ops vmx_x86_ops = { .cache_reg = vmx_cache_reg, .get_rflags = vmx_get_rflags, .set_rflags = vmx_set_rflags, + .fpu_deactivate = vmx_fpu_deactivate, .tlb_flush = vmx_flush_tlb, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 748b15d..1de2ad7 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1509,8 +1509,8 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { - kvm_x86_ops->vcpu_put(vcpu); kvm_put_guest_fpu(vcpu); + kvm_x86_ops->vcpu_put(vcpu); } static int is_efer_nx(void) @@ -4006,6 +4006,10 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) r = 0; goto out; } + if (test_and_clear_bit(KVM_REQ_DEACTIVATE_FPU, &vcpu->requests)) { + vcpu->fpu_active = 0; + kvm_x86_ops->fpu_deactivate(vcpu); + } } preempt_disable(); @@ -5075,6 +5079,7 @@ void kvm_put_guest_fpu(struct kvm_vcpu *vcpu) kvm_fx_save(&vcpu->arch.guest_fx_image); kvm_fx_restore(&vcpu->arch.host_fx_image); ++vcpu->stat.fpu_reload; + set_bit(KVM_REQ_DEACTIVATE_FPU, &vcpu->requests); } EXPORT_SYMBOL_GPL(kvm_put_guest_fpu); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index bb0314e..dfde04b 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -38,6 +38,7 @@ #define KVM_REQ_MMU_SYNC 7 #define KVM_REQ_KVMCLOCK_UPDATE 8 #define KVM_REQ_KICK 9 +#define KVM_REQ_DEACTIVATE_FPU 10 #define KVM_USERSPACE_IRQ_SOURCE_ID 0

[20/39] KVM: Lazify fpu activation and deactivation

Commit Message

Patch