KVM: x86 emulator: define callbacks for using the guest fpu within the emulator
Needed for emulating fpu instructions.
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index c00aed1..4c0e682 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -158,6 +158,8 @@
int (*set_dr)(int dr, unsigned long value, struct kvm_vcpu *vcpu);
int (*set_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 data);
int (*get_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata);
+ void (*get_fpu)(struct x86_emulate_ctxt *ctxt); /* disables preempt */
+ void (*put_fpu)(struct x86_emulate_ctxt *ctxt); /* reenables preempt */
};
/* Type, address-of, and value of an instruction's operand. */
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 11d692c..5af6651 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4281,6 +4281,22 @@
kvm_set_segment(vcpu, &kvm_seg, seg);
}
+static void emulator_get_fpu(struct x86_emulate_ctxt *ctxt)
+{
+ preempt_disable();
+ kvm_load_guest_fpu(ctxt->vcpu);
+ /*
+ * CR0.TS may reference the host fpu state, not the guest fpu state,
+ * so it may be clear at this point.
+ */
+ clts();
+}
+
+static void emulator_put_fpu(struct x86_emulate_ctxt *ctxt)
+{
+ preempt_enable();
+}
+
static struct x86_emulate_ops emulate_ops = {
.read_std = kvm_read_guest_virt_system,
.write_std = kvm_write_guest_virt_system,
@@ -4304,6 +4320,8 @@
.set_dr = emulator_set_dr,
.set_msr = kvm_set_msr,
.get_msr = kvm_get_msr,
+ .get_fpu = emulator_get_fpu,
+ .put_fpu = emulator_put_fpu,
};
static void cache_all_regs(struct kvm_vcpu *vcpu)