KVM: add MSR based hypercall API
This adds a special MSR based hypercall API to KVM. This is to be
used by paravirtual kernels and virtual drivers.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index d1198e2..0198d40 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -1469,6 +1469,18 @@
return 0;
}
+static void
+vmx_patch_hypercall(struct kvm_vcpu *vcpu, unsigned char *hypercall)
+{
+ /*
+ * Patch in the VMCALL instruction:
+ */
+ hypercall[0] = 0x0f;
+ hypercall[1] = 0x01;
+ hypercall[2] = 0xc1;
+ hypercall[3] = 0xc3;
+}
+
static int handle_cr(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
u64 exit_qualification;
@@ -2064,6 +2076,7 @@
.run = vmx_vcpu_run,
.skip_emulated_instruction = skip_emulated_instruction,
.vcpu_setup = vmx_vcpu_setup,
+ .patch_hypercall = vmx_patch_hypercall,
};
static int __init vmx_init(void)