KVM: PPC: Book3S: Add infrastructure to implement kernel-side RTAS calls

For pseries machine emulation, in order to move the interrupt
controller code to the kernel, we need to intercept some RTAS
calls in the kernel itself.  This adds an infrastructure to allow
in-kernel handlers to be registered for RTAS services by name.
A new ioctl, KVM_PPC_RTAS_DEFINE_TOKEN, then allows userspace to
associate token values with those service names.  Then, when the
guest requests an RTAS service with one of those token values, it
will be handled by the relevant in-kernel handler rather than being
passed up to userspace as at present.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
[agraf: fix warning]
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 8 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index d8e81e6c1afe..d4fd443ae7bd 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -341,6 +341,7 @@ int kvm_dev_ioctl_check_extension(long ext)
 #ifdef CONFIG_PPC_BOOK3S_64
         case KVM_CAP_SPAPR_TCE:
         case KVM_CAP_PPC_ALLOC_HTAB:
+        case KVM_CAP_PPC_RTAS:
                 r = 1;
                 break;
 #endif /* CONFIG_PPC_BOOK3S_64 */
@@ -986,6 +987,7 @@ long kvm_arch_vm_ioctl(struct file *filp,
 #ifdef CONFIG_KVM_BOOK3S_64_HV
         case KVM_ALLOCATE_RMA: {
                 struct kvm_allocate_rma rma;
+                struct kvm *kvm = filp->private_data;
 
                 r = kvm_vm_ioctl_allocate_rma(kvm, &rma);
                 if (r >= 0 && copy_to_user(argp, &rma, sizeof(rma)))
@@ -1030,6 +1032,12 @@ long kvm_arch_vm_ioctl(struct file *filp,
                         r = -EFAULT;
                 break;
         }
+        case KVM_PPC_RTAS_DEFINE_TOKEN: {
+                struct kvm *kvm = filp->private_data;
+
+                r = kvm_vm_ioctl_rtas_define_token(kvm, argp);
+                break;
+        }
 #endif /* CONFIG_PPC_BOOK3S_64 */
         default:
                 r = -ENOTTY;