diff options
| author | James Hogan <james.hogan@imgtec.com> | 2017-03-14 10:15:40 +0000 |
|---|---|---|
| committer | James Hogan <james.hogan@imgtec.com> | 2017-03-28 14:54:00 +0100 |
| commit | edec9d7bdc4eb3845ec7a3f9610f0d54a7152e90 (patch) | |
| tree | 89b4d3c4b8c0f549d9aa9c4f379142bce3e85bed /arch/mips/kvm/trace.h | |
| parent | f4474d50c7d483dd4432d5b0891b0bb9ad0eefc9 (diff) | |
KVM: MIPS/VZ: Trace guest mode changes
Create a trace event for guest mode changes, and enable VZ's
GuestCtl0.MC bit after the trace event is enabled to trap all guest mode
changes.
The MC bit causes Guest Hardware Field Change (GHFC) exceptions whenever
a guest mode change occurs (such as an exception entry or return from
exception), so we need to handle this exception now. The MC bit is only
enabled when restoring register state, so enabling the trace event won't
take immediate effect.
Tracing guest mode changes can be particularly handy when trying to work
out what a guest OS gets up to before something goes wrong, especially
if the problem occurs as a result of some previous guest userland
exception which would otherwise be invisible in the trace.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Diffstat (limited to 'arch/mips/kvm/trace.h')
| -rw-r--r-- | arch/mips/kvm/trace.h | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/arch/mips/kvm/trace.h b/arch/mips/kvm/trace.h index affde8a2c584..a8c7fd7bf6d2 100644 --- a/arch/mips/kvm/trace.h +++ b/arch/mips/kvm/trace.h @@ -18,6 +18,13 @@ #define TRACE_INCLUDE_FILE trace /* + * arch/mips/kvm/mips.c + */ +extern bool kvm_trace_guest_mode_change; +int kvm_guest_mode_change_trace_reg(void); +void kvm_guest_mode_change_trace_unreg(void); + +/* * Tracepoints for VM enters */ DECLARE_EVENT_CLASS(kvm_transition, @@ -303,6 +310,36 @@ TRACE_EVENT(kvm_guestid_change, __entry->guestid) ); +TRACE_EVENT_FN(kvm_guest_mode_change, + TP_PROTO(struct kvm_vcpu *vcpu), + TP_ARGS(vcpu), + TP_STRUCT__entry( + __field(unsigned long, epc) + __field(unsigned long, pc) + __field(unsigned long, badvaddr) + __field(unsigned int, status) + __field(unsigned int, cause) + ), + + TP_fast_assign( + __entry->epc = kvm_read_c0_guest_epc(vcpu->arch.cop0); + __entry->pc = vcpu->arch.pc; + __entry->badvaddr = kvm_read_c0_guest_badvaddr(vcpu->arch.cop0); + __entry->status = kvm_read_c0_guest_status(vcpu->arch.cop0); + __entry->cause = kvm_read_c0_guest_cause(vcpu->arch.cop0); + ), + + TP_printk("EPC: 0x%08lx PC: 0x%08lx Status: 0x%08x Cause: 0x%08x BadVAddr: 0x%08lx", + __entry->epc, + __entry->pc, + __entry->status, + __entry->cause, + __entry->badvaddr), + + kvm_guest_mode_change_trace_reg, + kvm_guest_mode_change_trace_unreg +); + #endif /* _TRACE_KVM_H */ /* This part must be outside protection */ |