[PATCH 15/58] KVM: Consolidate guest fpu activation and deactivation

Avi Kivity
2007-06-17T09:43:56Z

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

Signed-off-by: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
---
drivers/kvm/kvm.h | 2 +-
drivers/kvm/vmx.c | 50 +++++++++++++++++++++++++++++++-------------------
2 files changed, 32 insertions(+), 20 deletions(-)

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index bb32383..4724087 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 2190020..096cb6a 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;