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    Subject[PATCH 4.15 20/53] KVM: PPC: Book3S HV: trace_tlbie must not be called in realmode
    Date
    4.15-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Nicholas Piggin <npiggin@gmail.com>

    commit 19ce7909ed11c49f7eddf59e7f49cd3062bf83d5 upstream.

    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>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    arch/powerpc/kvm/book3s_hv_rm_mmu.c | 4 ----
    1 file changed, 4 deletions(-)

    --- 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, u
    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);
    }
    asm volatile("eieio; tlbsync; ptesync" : : : "memory");
    kvm->arch.tlbie_lock = 0;
    @@ -481,8 +479,6 @@ static void do_tlbies(struct kvm *kvm, u
    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");
    }

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