[PATCH] arch/powerpc/kvm: Avoid extra checks when emulating HFSCR bits

[Gautam Menghani]

When a KVM guest tries to use a feature disabled by HFSCR, it exits to
the host for emulation support, and the code checks for all bits which
are emulated. Avoid checking all the bits by using a switch case.

Signed-off-by: Gautam Menghani <gau...@linux.ibm.com>
---
 arch/powerpc/kvm/book3s_hv.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 99c7ce825..a72fd2543 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1922,14 +1922,22 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
 
                r = EMULATE_FAIL;
                if (cpu_has_feature(CPU_FTR_ARCH_300)) {
-                       if (cause == FSCR_MSGP_LG)
+                       switch (cause) {
+                       case FSCR_MSGP_LG:
                                r = kvmppc_emulate_doorbell_instr(vcpu);
-                       if (cause == FSCR_PM_LG)
+                               break;
+                       case FSCR_PM_LG:
                                r = kvmppc_pmu_unavailable(vcpu);
-                       if (cause == FSCR_EBB_LG)
+                               break;
+                       case FSCR_EBB_LG:
                                r = kvmppc_ebb_unavailable(vcpu);
-                       if (cause == FSCR_TM_LG)
+                               break;
+                       case FSCR_TM_LG:
                                r = kvmppc_tm_unavailable(vcpu);
+                               break;
+                       default:
+                               break;
+                       }
                }
                if (r == EMULATE_FAIL) {
                        kvmppc_core_queue_program(vcpu, SRR1_PROGILL |
-- 
2.45.2