linux/include/xen/events.h
Juergen Gross df54eca9ae xen/events: add a new "late EOI" evtchn framework
commit 54c9de8989 upstream.

In order to avoid tight event channel related IRQ loops add a new
framework of "late EOI" handling: the IRQ the event channel is bound
to will be masked until the event has been handled and the related
driver is capable to handle another event. The driver is responsible
for unmasking the event channel via the new function xen_irq_lateeoi().

This is similar to binding an event channel to a threaded IRQ, but
without having to structure the driver accordingly.

In order to support a future special handling in case a rogue guest
is sending lots of unsolicited events, add a flag to xen_irq_lateeoi()
which can be set by the caller to indicate the event was a spurious
one.

This is part of XSA-332.

Cc: stable@vger.kernel.org
Reported-by: Julien Grall <julien@xen.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Wei Liu <wl@xen.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-05 11:43:10 +01:00

155 lines
5.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _XEN_EVENTS_H
#define _XEN_EVENTS_H
#include <linux/interrupt.h>
#include <linux/irq.h>
#ifdef CONFIG_PCI_MSI
#include <linux/msi.h>
#endif
#include <xen/interface/event_channel.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/events.h>
unsigned xen_evtchn_nr_channels(void);
int bind_evtchn_to_irq(evtchn_port_t evtchn);
int bind_evtchn_to_irq_lateeoi(evtchn_port_t evtchn);
int bind_evtchn_to_irqhandler(evtchn_port_t evtchn,
irq_handler_t handler,
unsigned long irqflags, const char *devname,
void *dev_id);
int bind_evtchn_to_irqhandler_lateeoi(evtchn_port_t evtchn,
irq_handler_t handler,
unsigned long irqflags, const char *devname,
void *dev_id);
int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu);
int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
irq_handler_t handler,
unsigned long irqflags, const char *devname,
void *dev_id);
int bind_ipi_to_irqhandler(enum ipi_vector ipi,
unsigned int cpu,
irq_handler_t handler,
unsigned long irqflags,
const char *devname,
void *dev_id);
int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
evtchn_port_t remote_port);
int bind_interdomain_evtchn_to_irq_lateeoi(unsigned int remote_domain,
evtchn_port_t remote_port);
int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
evtchn_port_t remote_port,
irq_handler_t handler,
unsigned long irqflags,
const char *devname,
void *dev_id);
int bind_interdomain_evtchn_to_irqhandler_lateeoi(unsigned int remote_domain,
evtchn_port_t remote_port,
irq_handler_t handler,
unsigned long irqflags,
const char *devname,
void *dev_id);
/*
* Common unbind function for all event sources. Takes IRQ to unbind from.
* Automatically closes the underlying event channel (even for bindings
* made with bind_evtchn_to_irqhandler()).
*/
void unbind_from_irqhandler(unsigned int irq, void *dev_id);
/*
* Send late EOI for an IRQ bound to an event channel via one of the *_lateeoi
* functions above.
*/
void xen_irq_lateeoi(unsigned int irq, unsigned int eoi_flags);
/* Signal an event was spurious, i.e. there was no action resulting from it. */
#define XEN_EOI_FLAG_SPURIOUS 0x00000001
#define XEN_IRQ_PRIORITY_MAX EVTCHN_FIFO_PRIORITY_MAX
#define XEN_IRQ_PRIORITY_DEFAULT EVTCHN_FIFO_PRIORITY_DEFAULT
#define XEN_IRQ_PRIORITY_MIN EVTCHN_FIFO_PRIORITY_MIN
int xen_set_irq_priority(unsigned irq, unsigned priority);
/*
* Allow extra references to event channels exposed to userspace by evtchn
*/
int evtchn_make_refcounted(unsigned int evtchn);
int evtchn_get(unsigned int evtchn);
void evtchn_put(unsigned int evtchn);
void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector);
void rebind_evtchn_irq(int evtchn, int irq);
int xen_set_affinity_evtchn(struct irq_desc *desc, unsigned int tcpu);
static inline void notify_remote_via_evtchn(int port)
{
struct evtchn_send send = { .port = port };
(void)HYPERVISOR_event_channel_op(EVTCHNOP_send, &send);
}
void notify_remote_via_irq(int irq);
void xen_irq_resume(void);
/* Clear an irq's pending state, in preparation for polling on it */
void xen_clear_irq_pending(int irq);
void xen_set_irq_pending(int irq);
bool xen_test_irq_pending(int irq);
/* Poll waiting for an irq to become pending. In the usual case, the
irq will be disabled so it won't deliver an interrupt. */
void xen_poll_irq(int irq);
/* Poll waiting for an irq to become pending with a timeout. In the usual case,
* the irq will be disabled so it won't deliver an interrupt. */
void xen_poll_irq_timeout(int irq, u64 timeout);
/* Determine the IRQ which is bound to an event channel */
unsigned irq_from_evtchn(unsigned int evtchn);
int irq_from_virq(unsigned int cpu, unsigned int virq);
unsigned int evtchn_from_irq(unsigned irq);
#ifdef CONFIG_XEN_PVHVM
/* Xen HVM evtchn vector callback */
void xen_hvm_callback_vector(void);
#ifdef CONFIG_TRACING
#define trace_xen_hvm_callback_vector xen_hvm_callback_vector
#endif
#endif
int xen_set_callback_via(uint64_t via);
void xen_evtchn_do_upcall(struct pt_regs *regs);
void xen_hvm_evtchn_do_upcall(void);
/* Bind a pirq for a physical interrupt to an irq. */
int xen_bind_pirq_gsi_to_irq(unsigned gsi,
unsigned pirq, int shareable, char *name);
#ifdef CONFIG_PCI_MSI
/* Allocate a pirq for a MSI style physical interrupt. */
int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc);
/* Bind an PSI pirq to an irq. */
int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
int pirq, int nvec, const char *name, domid_t domid);
#endif
/* De-allocates the above mentioned physical interrupt. */
int xen_destroy_irq(int irq);
/* Return irq from pirq */
int xen_irq_from_pirq(unsigned pirq);
/* Return the pirq allocated to the irq. */
int xen_pirq_from_irq(unsigned irq);
/* Return the irq allocated to the gsi */
int xen_irq_from_gsi(unsigned gsi);
/* Determine whether to ignore this IRQ if it is passed to a guest. */
int xen_test_irq_shared(int irq);
/* initialize Xen IRQ subsystem */
void xen_init_IRQ(void);
#endif /* _XEN_EVENTS_H */