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/svm.c b/drivers/kvm/svm.c
index 72cac04..f6e8652 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -1669,6 +1669,18 @@
return 0;
}
+static void
+svm_patch_hypercall(struct kvm_vcpu *vcpu, unsigned char *hypercall)
+{
+ /*
+ * Patch in the VMMCALL instruction:
+ */
+ hypercall[0] = 0x0f;
+ hypercall[1] = 0x01;
+ hypercall[2] = 0xd9;
+ hypercall[3] = 0xc3;
+}
+
static struct kvm_arch_ops svm_arch_ops = {
.cpu_has_kvm_support = has_svm,
.disabled_by_bios = is_disabled,
@@ -1717,6 +1729,7 @@
.run = svm_vcpu_run,
.skip_emulated_instruction = skip_emulated_instruction,
.vcpu_setup = svm_vcpu_setup,
+ .patch_hypercall = svm_patch_hypercall,
};
static int __init svm_init(void)