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| author | James Hogan <james.hogan@imgtec.com> | 2015-02-06 17:03:57 +0100 |
|---|---|---|
| committer | James Hogan <james.hogan@imgtec.com> | 2015-03-27 22:25:07 +0100 |
| commit | 0a5604272d80c985f87de959f0bb7e36fd53d3c7 (patch) | |
| tree | 391bbee989a6ab6ab22d7b4b32a0b7850602d5be /arch/mips/kvm/mips.c | |
| parent | MIPS: Clear [MSA]FPE CSR.Cause after notify_die() (diff) | |
| download | linux-0a5604272d80c985f87de959f0bb7e36fd53d3c7.tar.xz linux-0a5604272d80c985f87de959f0bb7e36fd53d3c7.zip | |
MIPS: KVM: Handle TRAP exceptions from guest kernel
Trap instructions are used by Linux to implement BUG_ON(), however KVM
doesn't pass trap exceptions on to the guest if they occur in guest
kernel mode, instead triggering an internal error "Exception Code: 13,
not yet handled". The guest kernel then doesn't get a chance to print
the usual BUG message and stack trace.
Implement handling of the trap exception so that it gets passed to the
guest and the user is left with a more useful log message.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Diffstat (limited to 'arch/mips/kvm/mips.c')
| -rw-r--r-- | arch/mips/kvm/mips.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c index f5e7ddab02f7..399b5517ecb8 100644 --- a/arch/mips/kvm/mips.c +++ b/arch/mips/kvm/mips.c @@ -48,6 +48,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { { "syscall", VCPU_STAT(syscall_exits), KVM_STAT_VCPU }, { "resvd_inst", VCPU_STAT(resvd_inst_exits), KVM_STAT_VCPU }, { "break_inst", VCPU_STAT(break_inst_exits), KVM_STAT_VCPU }, + { "trap_inst", VCPU_STAT(trap_inst_exits), KVM_STAT_VCPU }, { "flush_dcache", VCPU_STAT(flush_dcache_exits), KVM_STAT_VCPU }, { "halt_successful_poll", VCPU_STAT(halt_successful_poll), KVM_STAT_VCPU }, { "halt_wakeup", VCPU_STAT(halt_wakeup), KVM_STAT_VCPU }, @@ -1119,6 +1120,12 @@ int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu) ret = kvm_mips_callbacks->handle_break(vcpu); break; + case T_TRAP: + ++vcpu->stat.trap_inst_exits; + trace_kvm_exit(vcpu, TRAP_INST_EXITS); + ret = kvm_mips_callbacks->handle_trap(vcpu); + break; + case T_MSADIS: ret = kvm_mips_callbacks->handle_msa_disabled(vcpu); break; |