KVM: PPC: Book3s: Remove kvmppc_read_inst() function

In the context of replacing kvmppc_ld() function calls with a version of
kvmppc_get_last_inst() which allow to fail, Alex Graf suggested this:

"If we get EMULATE_AGAIN, we just have to make sure we go back into the guest.
No need to inject an ISI into  the guest - it'll do that all by itself.
With an error returning kvmppc_get_last_inst we can just use completely
get rid of kvmppc_read_inst() and only use kvmppc_get_last_inst() instead."

As a intermediate step get rid of kvmppc_read_inst() and only use kvmppc_ld()
instead.

Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index e40765f8cbad4edc8cd9c3b2930f5ae03aa34e6c..e76aec38ec216283fbd73b520c695c6c3e4b3277 100644 (file)
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -710,42 +710,6 @@ static void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac)
 #endif
 }
 
-static int kvmppc_read_inst(struct kvm_vcpu *vcpu)
-{
-       ulong srr0 = kvmppc_get_pc(vcpu);
-       u32 last_inst = kvmppc_get_last_inst(vcpu);
-       int ret;
-
-       ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false);
-       if (ret == -ENOENT) {
-               ulong msr = kvmppc_get_msr(vcpu);
-
-               msr = kvmppc_set_field(msr, 33, 33, 1);
-               msr = kvmppc_set_field(msr, 34, 36, 0);
-               msr = kvmppc_set_field(msr, 42, 47, 0);
-               kvmppc_set_msr_fast(vcpu, msr);
-               kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_INST_STORAGE);
-               return EMULATE_AGAIN;
-       }
-
-       return EMULATE_DONE;
-}
-
-static int kvmppc_check_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr)
-{
-
-       /* Need to do paired single emulation? */
-       if (!(vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE))
-               return EMULATE_DONE;
-
-       /* Read out the instruction */
-       if (kvmppc_read_inst(vcpu) == EMULATE_DONE)
-               /* Need to emulate */
-               return EMULATE_FAIL;
-
-       return EMULATE_AGAIN;
-}
-
 /* Handle external providers (FPU, Altivec, VSX) */
 static int kvmppc_handle_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr,
                             ulong msr)
@@ -1149,31 +1113,49 @@ program_interrupt:
        case BOOK3S_INTERRUPT_VSX:
        {
                int ext_msr = 0;
+               int emul;
+               ulong pc;
+               u32 last_inst;
+
+               if (vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE) {
+                       /* Do paired single instruction emulation */
+                       pc = kvmppc_get_pc(vcpu);
+                       last_inst = kvmppc_get_last_inst(vcpu);
+                       emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst,
+                                        false);
+                       if (emul == EMULATE_DONE)
+                               goto program_interrupt;
+                       else
+                               r = RESUME_GUEST;
 
-               switch (exit_nr) {
-               case BOOK3S_INTERRUPT_FP_UNAVAIL: ext_msr = MSR_FP;  break;
-               case BOOK3S_INTERRUPT_ALTIVEC:    ext_msr = MSR_VEC; break;
-               case BOOK3S_INTERRUPT_VSX:        ext_msr = MSR_VSX; break;
+                       break;
                }
 
-               switch (kvmppc_check_ext(vcpu, exit_nr)) {
-               case EMULATE_DONE:
-                       /* everything ok - let's enable the ext */
-                       r = kvmppc_handle_ext(vcpu, exit_nr, ext_msr);
+               /* Enable external provider */
+               switch (exit_nr) {
+               case BOOK3S_INTERRUPT_FP_UNAVAIL:
+                       ext_msr = MSR_FP;
                        break;
-               case EMULATE_FAIL:
-                       /* we need to emulate this instruction */
-                       goto program_interrupt;
+
+               case BOOK3S_INTERRUPT_ALTIVEC:
+                       ext_msr = MSR_VEC;
                        break;
-               default:
-                       /* nothing to worry about - go again */
+
+               case BOOK3S_INTERRUPT_VSX:
+                       ext_msr = MSR_VSX;
                        break;
                }
+
+               r = kvmppc_handle_ext(vcpu, exit_nr, ext_msr);
                break;
        }
        case BOOK3S_INTERRUPT_ALIGNMENT:
-               if (kvmppc_read_inst(vcpu) == EMULATE_DONE) {
-                       u32 last_inst = kvmppc_get_last_inst(vcpu);
+       {
+               ulong pc = kvmppc_get_pc(vcpu);
+               u32 last_inst = kvmppc_get_last_inst(vcpu);
+               int emul = kvmppc_ld(vcpu, &pc, sizeof(u32), &last_inst, false);
+
+               if (emul == EMULATE_DONE) {
                        u32 dsisr;
                        u64 dar;
 
@@ -1187,6 +1169,7 @@ program_interrupt:
                }
                r = RESUME_GUEST;
                break;
+       }
 #ifdef CONFIG_PPC_BOOK3S_64
        case BOOK3S_INTERRUPT_FAC_UNAVAIL:
                kvmppc_handle_fac(vcpu, vcpu->arch.shadow_fscr >> 56);