lguest: use eventfds for device notification
Currently, when a Guest wants to perform I/O it calls LHCALL_NOTIFY with
an address: the main Launcher process returns with this address, and figures
out what device to run.
A far nicer model is to let processes bind an eventfd to an address: if we
find one, we simply signal the eventfd.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Davide Libenzi <davidel@xmailserver.org>
diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h
index 040cb70..32fefdc 100644
--- a/drivers/lguest/lg.h
+++ b/drivers/lguest/lg.h
@@ -82,6 +82,16 @@
struct lg_cpu_arch arch;
};
+struct lg_eventfd {
+ unsigned long addr;
+ struct file *event;
+};
+
+struct lg_eventfd_map {
+ unsigned int num;
+ struct lg_eventfd map[];
+};
+
/* The private info the thread maintains about the guest. */
struct lguest
{
@@ -102,6 +112,8 @@
unsigned int stack_pages;
u32 tsc_khz;
+ struct lg_eventfd_map *eventfds;
+
/* Dead? */
const char *dead;
};
@@ -154,6 +166,7 @@
void copy_traps(const struct lg_cpu *cpu, struct desc_struct *idt,
const unsigned long *def);
void guest_set_clockevent(struct lg_cpu *cpu, unsigned long delta);
+bool send_notify_to_eventfd(struct lg_cpu *cpu);
void init_clockdev(struct lg_cpu *cpu);
bool check_syscall_vector(struct lguest *lg);
int init_interrupts(void);