eprintf
extern int eprintf(int level, int var, const char *fmt, ...);
eprintf(0, verbose, pr_fmt(fmt), ##__VA_ARGS__)
eprintf(1, verbose, pr_fmt(fmt), ##__VA_ARGS__)
eprintf(2, verbose, pr_fmt(fmt), ##__VA_ARGS__)
eprintf("Malformed IRQ %u.\n", irqid);
eprintf("No active vcpu\n");
eprintf("Timer not enabled\n");
eprintf("Timer condition not met\n");