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[PATCH 4.4 12/30] KVM: PPC: Book3S PR: Fix illegal opcode emulation

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4.4-stable review patch.  If anyone has any objections, please let me know.

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

From: Thomas Huth <thuth@redhat.com>

commit 708e75a3ee750dce1072134e630d66c4e6eaf63c upstream.

If kvmppc_handle_exit_pr() calls kvmppc_emulate_instruction() to emulate
one instruction (in the BOOK3S_INTERRUPT_H_EMUL_ASSIST case), it calls
kvmppc_core_queue_program() afterwards if kvmppc_emulate_instruction()
returned EMULATE_FAIL, so the guest gets an program interrupt for the
illegal opcode.
However, the kvmppc_emulate_instruction() also tried to inject a
program exception for this already, so the program interrupt gets
injected twice and the return address in srr0 gets destroyed.
All other callers of kvmppc_emulate_instruction() are also injecting
a program interrupt, and since the callers have the right knowledge
about the srr1 flags that should be used, it is the function
kvmppc_emulate_instruction() that should _not_ inject program
interrupts, so remove the kvmppc_core_queue_program() here.

This fixes the issue discovered by Laurent Vivier with kvm-unit-tests
where the logs are filled with these messages when the test tries
to execute an illegal instruction:

     Couldn't emulate instruction 0x00000000 (op 0 xop 0)
     kvmppc_handle_exit_pr: emulation at 700 failed (00000000)

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Tested-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/powerpc/kvm/emulate.c |    1 -
 1 file changed, 1 deletion(-)

--- a/arch/powerpc/kvm/emulate.c
+++ b/arch/powerpc/kvm/emulate.c
@@ -302,7 +302,6 @@ int kvmppc_emulate_instruction(struct kv
 			advance = 0;
 			printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
 			       "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
-			kvmppc_core_queue_program(vcpu, 0);
 		}
 	}
 

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[PATCH 4.4 00/30] 4.4.57-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-24 19:10 +0100
  [PATCH 4.4 16/30] hv_netvsc: use skb_get_hash() instead of a homegrown implementation Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-24 19:20 +0100
  [PATCH 4.4 23/30] target/pscsi: Fix TYPE_TAPE + TYPE_MEDIMUM_CHANGER export Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-24 19:20 +0100
  [PATCH 4.4 21/30] powerpc/boot: Fix zImage TOC alignment Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-24 19:20 +0100
  [PATCH 4.4 12/30] KVM: PPC: Book3S PR: Fix illegal opcode emulation Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-24 19:20 +0100
  [PATCH 4.4 17/30] kernek/fork.c: allocate idle task for a CPU always on its local node Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-24 19:20 +0100
  [PATCH 4.4 19/30] perf/core: Fix event inheritance on fork() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-24 19:20 +0100
  [PATCH 4.4 01/30] usb: core: hub: hub_port_init lock controller instead of bus Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-24 19:20 +0100
  [PATCH 4.4 22/30] md/raid1/10: fix potential deadlock Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-24 19:20 +0100
  [PATCH 4.4 02/30] USB: dont free bandwidth_mutex too early Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-24 19:20 +0100
  [PATCH 4.4 13/30] s390/pci: fix use after free in dma_init Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-24 19:20 +0100
  [PATCH 4.4 15/30] tpm_tis: Use devm_free_irq not free_irq Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-24 19:20 +0100
  [PATCH 4.4 24/30] scsi: lpfc: Add shutdown method for kexec Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-24 19:20 +0100
  [PATCH 4.4 20/30] cpufreq: Fix and clean up show_cpuinfo_cur_freq() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-03-24 19:20 +0100
  Re: [PATCH 4.4 00/30] 4.4.57-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2017-03-25 01:10 +0100
  Re: [PATCH 4.4 00/30] 4.4.57-stable review Guenter Roeck <linux@roeck-us.net> - 2017-03-25 05:20 +0100
  Re: [PATCH 4.4 00/30] 4.4.57-stable review Guenter Roeck <linux@roeck-us.net> - 2017-03-25 05:20 +0100
    Re: [PATCH 4.4 00/30] 4.4.57-stable review Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2017-03-25 12:30 +0100
      Re: [PATCH 4.4 00/30] 4.4.57-stable review Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2017-03-25 12:40 +0100

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