4 files changed, 37 insertions, 31 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 693046a7a12d..93bee7abb71c 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 3899c2d19830..5b336a80f31e 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 dbcdb55094f7..d11be3fb7c80 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 748b15d8e46d..1de2ad7a004d 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);