KVM: Allow userspace to process hypercalls which have no kernel handler
This is useful for paravirtualized graphics devices, for example.
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 39cf8fd..de93117 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1203,7 +1203,16 @@
}
switch (nr) {
default:
- ;
+ run->hypercall.args[0] = a0;
+ run->hypercall.args[1] = a1;
+ run->hypercall.args[2] = a2;
+ run->hypercall.args[3] = a3;
+ run->hypercall.args[4] = a4;
+ run->hypercall.args[5] = a5;
+ run->hypercall.ret = ret;
+ run->hypercall.longmode = is_long_mode(vcpu);
+ kvm_arch_ops->decache_regs(vcpu);
+ return 0;
}
vcpu->regs[VCPU_REGS_RAX] = ret;
kvm_arch_ops->decache_regs(vcpu);
@@ -1599,6 +1608,13 @@
vcpu->mmio_needed = 0;
+ if (kvm_run->exit_type == KVM_EXIT_TYPE_VM_EXIT
+ && kvm_run->exit_reason == KVM_EXIT_HYPERCALL) {
+ kvm_arch_ops->cache_regs(vcpu);
+ vcpu->regs[VCPU_REGS_RAX] = kvm_run->hypercall.ret;
+ kvm_arch_ops->decache_regs(vcpu);
+ }
+
r = kvm_arch_ops->run(vcpu, kvm_run);
vcpu_put(vcpu);