[PATCH v6 45/48] KVM: PPC: Book3S HV P9: Reflect userspace hcalls to hash guests to support PR KVM

[Nicholas Piggin <npiggin@gmail.com>]

The reflection of sc 1 interrupts from guest PR=1 to the guest kernel is
required to support a hash guest running PR KVM where its guest is
making hcalls with sc 1.

In preparation for hash guest support, add this hcall reflection to the
P9 path. The P7/8 path does this in its realmode hcall handler
(sc_1_fast_return).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index d8e36f1ea66d..7cd97e6757e5 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1455,13 +1455,23 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
 			 * Guest userspace executed sc 1. This can only be
 			 * reached by the P9 path because the old path
 			 * handles this case in realmode hcall handlers.
-			 *
-			 * Radix guests can not run PR KVM or nested HV hash
-			 * guests which might run PR KVM, so this is always
-			 * a privilege fault. Send a program check to guest
-			 * kernel.
 			 */
-			kvmppc_core_queue_program(vcpu, SRR1_PROGPRIV);
+			if (!kvmhv_vcpu_is_radix(vcpu)) {
+				/*
+				 * A guest could be running PR KVM, so this
+				 * may be a PR KVM hcall. It must be reflected
+				 * to the guest kernel as a sc interrupt.
+				 */
+				kvmppc_core_queue_syscall(vcpu);
+			} else {
+				/*
+				 * Radix guests can not run PR KVM or nested HV
+				 * hash guests which might run PR KVM, so this
+				 * is always a privilege fault. Send a program
+				 * check to guest kernel.
+				 */
+				kvmppc_core_queue_program(vcpu, SRR1_PROGPRIV);
+			}
 			r = RESUME_GUEST;
 			break;
 		}
-- 
2.23.0