KVM: Use __print_symbolic() for vmexit tracepoints
The vmexit tracepoints format the exit_reason to make it human-readable. Since the exit_reason depends on the instruction set (vmx or svm), formatting is handled with ftrace_print_symbols_seq() by referring to the appropriate exit reason table. However, the ftrace_print_symbols_seq() function is not meant to be used directly in tracepoints since it does not export the formatting table which userspace tools like trace-cmd and perf use to format traces. In practice perf dies when formatting vmexit-related events and trace-cmd falls back to printing the numeric value (with extra formatting code in the kvm plugin to paper over this limitation). Other userspace consumers of vmexit-related tracepoints would be in similar trouble. To avoid significant changes to the kvm_exit tracepoint, this patch moves the vmx and svm exit reason tables into arch/x86/kvm/trace.h and selects the right table with __print_symbolic() depending on the instruction set. Note that __print_symbolic() is designed for exporting the formatting table to userspace and allows trace-cmd and perf to work. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
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