KVM: PPC: Read out syscall instruction on trap

We have a few traps where we cache the instruction that cause the trap
for analysis later on. Since we now need to be able to distinguish
between SC 0 and SC 1 system calls and the only way to find out which
is which is by looking at the instruction, we also read out the instruction
causing the system call.

Signed-off-by: Alexander Graf <agraf@suse.de>

diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S
index aed32e5..678b6be 100644 (file)
--- a/arch/powerpc/kvm/book3s_segment.S
+++ b/arch/powerpc/kvm/book3s_segment.S
@@ -213,11 +213,16 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
        beq     ld_last_inst
        cmpwi   r12, BOOK3S_INTERRUPT_PROGRAM
        beq     ld_last_inst
+       cmpwi   r12, BOOK3S_INTERRUPT_SYSCALL
+       beq     ld_last_prev_inst
        cmpwi   r12, BOOK3S_INTERRUPT_ALIGNMENT
        beq-    ld_last_inst
 
        b       no_ld_last_inst
 
+ld_last_prev_inst:
+       addi    r3, r3, -4
+
 ld_last_inst:
        /* Save off the guest instruction we're at */