KVM: PPC: Book3S HV: trace_tlbie must not be called in realmode

This crashes with a "Bad real address for load" attempting to load
from the vmalloc region in realmode (faulting address is in DAR).

  Oops: Bad interrupt in KVM entry/exit code, sig: 6 [#1]
  LE SMP NR_CPUS=2048 NUMA PowerNV
  CPU: 53 PID: 6582 Comm: qemu-system-ppc Not tainted 4.16.0-01530-g43d1859f0994
  NIP:  c0000000000155ac LR: c0000000000c2430 CTR: c000000000015580
  REGS: c000000fff76dd80 TRAP: 0200   Not tainted  (4.16.0-01530-g43d1859f0994)
  MSR:  9000000000201003 <SF,HV,ME,RI,LE>  CR: 48082222  XER: 00000000
  CFAR: 0000000102900ef0 DAR: d00017fffd941a28 DSISR: 00000040 SOFTE: 3
  NIP [c0000000000155ac] perf_trace_tlbie+0x2c/0x1a0
  LR [c0000000000c2430] do_tlbies+0x230/0x2f0

I suspect the reason is the per-cpu data is not in the linear chunk.
This could be restored if that was able to be fixed, but for now,
just remove the tracepoints.

Fixes: 0428491cba92 ("powerpc/mm: Trace tlbie(l) instructions")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index e1c083fbe43480d0b0990ce25f9cd6f52dce2bac..78e6a392330f78b8407f8f7102762944c39c7d1f 100644 (file)
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -470,8 +470,6 @@ static void do_tlbies(struct kvm *kvm, unsigned long *rbvalues,
                for (i = 0; i < npages; ++i) {
                        asm volatile(PPC_TLBIE_5(%0,%1,0,0,0) : :
                                     "r" (rbvalues[i]), "r" (kvm->arch.lpid));
-                       trace_tlbie(kvm->arch.lpid, 0, rbvalues[i],
-                               kvm->arch.lpid, 0, 0, 0);
                }
 
                if (cpu_has_feature(CPU_FTR_P9_TLBIE_BUG)) {
@@ -492,8 +490,6 @@ static void do_tlbies(struct kvm *kvm, unsigned long *rbvalues,
                for (i = 0; i < npages; ++i) {
                        asm volatile(PPC_TLBIEL(%0,%1,0,0,0) : :
                                     "r" (rbvalues[i]), "r" (0));
-                       trace_tlbie(kvm->arch.lpid, 1, rbvalues[i],
-                               0, 0, 0, 0);
                }
                asm volatile("ptesync" : : : "memory");
        }