KVM: Consolidate guest fpu activation and deactivation

Easier to keep track of where the fpu is this way.

Signed-off-by: Avi Kivity <avi@qumranet.com>

2 files changed, 32 insertions, 20 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index bb32383ddfff..472408743d70 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -42,7 +42,7 @@
         (CR0_PG_MASK | CR0_PE_MASK | CR0_WP_MASK | CR0_NE_MASK \
          | CR0_NW_MASK | CR0_CD_MASK)
 #define KVM_VM_CR0_ALWAYS_ON \
-        (CR0_PG_MASK | CR0_PE_MASK | CR0_WP_MASK | CR0_NE_MASK)
+        (CR0_PG_MASK | CR0_PE_MASK | CR0_WP_MASK | CR0_NE_MASK | CR0_TS_MASK)
 #define KVM_GUEST_CR4_MASK \
         (CR4_PSE_MASK | CR4_PAE_MASK | CR4_PGE_MASK | CR4_VMXE_MASK | CR4_VME_MASK)
 #define KVM_PMODE_VM_CR4_ALWAYS_ON (CR4_VMXE_MASK | CR4_PAE_MASK)
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 2190020e055b..096cb6a1e899 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -396,6 +396,26 @@ static void vmx_vcpu_put(struct kvm_vcpu *vcpu)
         put_cpu();
 }
 
+static void vmx_fpu_activate(struct kvm_vcpu *vcpu)
+{
+        if (vcpu->fpu_active)
+                return;
+        vcpu->fpu_active = 1;
+        vmcs_clear_bits(GUEST_CR0, CR0_TS_MASK);
+        if (vcpu->cr0 & CR0_TS_MASK)
+                vmcs_set_bits(GUEST_CR0, CR0_TS_MASK);
+        update_exception_bitmap(vcpu);
+}
+
+static void vmx_fpu_deactivate(struct kvm_vcpu *vcpu)
+{
+        if (!vcpu->fpu_active)
+                return;
+        vcpu->fpu_active = 0;
+        vmcs_set_bits(GUEST_CR0, CR0_TS_MASK);
+        update_exception_bitmap(vcpu);
+}
+
 static void vmx_vcpu_decache(struct kvm_vcpu *vcpu)
 {
         vcpu_clear(vcpu);
@@ -925,6 +945,8 @@ static void vmx_decache_cr4_guest_bits(struct kvm_vcpu *vcpu)
 
 static void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
 {
+        vmx_fpu_deactivate(vcpu);
+
         if (vcpu->rmode.active && (cr0 & CR0_PE_MASK))
                 enter_pmode(vcpu);
 
@@ -940,26 +962,20 @@ static void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
         }
 #endif
 
-        if (!(cr0 & CR0_TS_MASK)) {
-                vcpu->fpu_active = 1;
-                update_exception_bitmap(vcpu);
-        }
-
         vmcs_writel(CR0_READ_SHADOW, cr0);
         vmcs_writel(GUEST_CR0,
                     (cr0 & ~KVM_GUEST_CR0_MASK) | KVM_VM_CR0_ALWAYS_ON);
         vcpu->cr0 = cr0;
+
+        if (!(cr0 & CR0_TS_MASK) || !(cr0 & CR0_PE_MASK))
+                vmx_fpu_activate(vcpu);
 }
 
 static void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
 {
         vmcs_writel(GUEST_CR3, cr3);
-
-        if (!(vcpu->cr0 & CR0_TS_MASK)) {
-                vcpu->fpu_active = 0;
-                vmcs_set_bits(GUEST_CR0, CR0_TS_MASK);
-                update_exception_bitmap(vcpu);
-        }
+        if (vcpu->cr0 & CR0_PE_MASK)
+                vmx_fpu_deactivate(vcpu);
 }
 
 static void vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
@@ -1328,6 +1344,7 @@ static int vmx_vcpu_setup(struct kvm_vcpu *vcpu)
 #ifdef CONFIG_X86_64
         vmx_set_efer(vcpu, 0);
 #endif
+        vmx_fpu_activate(vcpu);
         update_exception_bitmap(vcpu);
 
         return 0;
@@ -1488,10 +1505,7 @@ static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
         }
 
         if (is_no_device(intr_info)) {
-                vcpu->fpu_active = 1;
-                update_exception_bitmap(vcpu);
-                if (!(vcpu->cr0 & CR0_TS_MASK))
-                        vmcs_clear_bits(GUEST_CR0, CR0_TS_MASK);
+                vmx_fpu_activate(vcpu);
                 return 1;
         }
 
@@ -1683,11 +1697,10 @@ static int handle_cr(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
                 break;
         case 2: /* clts */
                 vcpu_load_rsp_rip(vcpu);
-                vcpu->fpu_active = 1;
-                update_exception_bitmap(vcpu);
-                vmcs_clear_bits(GUEST_CR0, CR0_TS_MASK);
+                vmx_fpu_deactivate(vcpu);
                 vcpu->cr0 &= ~CR0_TS_MASK;
                 vmcs_writel(CR0_READ_SHADOW, vcpu->cr0);
+                vmx_fpu_activate(vcpu);
                 skip_emulated_instruction(vcpu);
                 return 1;
         case 1: /*mov from cr*/
@@ -2158,7 +2171,6 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu)
         vmcs_clear(vmcs);
         vcpu->vmcs = vmcs;
         vcpu->launched = 0;
-        vcpu->fpu_active = 1;
 
         return 0;