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authorThomas Huth <thuth@redhat.com>2016-05-18 22:01:20 +0300
committerPaul Mackerras <paulus@ozlabs.org>2016-06-20 07:11:25 +0300
commit708e75a3ee750dce1072134e630d66c4e6eaf63c (patch)
tree7827ed2ebc0d34d0421fb3e822fb82c080b920be /arch/powerpc/kvm/emulate.c
parent64672c95ea4c2f7096e519e826076867e8ef0938 (diff)
downloadlinux-708e75a3ee750dce1072134e630d66c4e6eaf63c.tar.xz
KVM: PPC: Book3S PR: Fix illegal opcode emulation
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>
Diffstat (limited to 'arch/powerpc/kvm/emulate.c')
-rw-r--r--arch/powerpc/kvm/emulate.c1
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c
index 5cc2e7af3a7b..b379146de55b 100644
--- a/arch/powerpc/kvm/emulate.c
+++ b/arch/powerpc/kvm/emulate.c
@@ -302,7 +302,6 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
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);
}
}