linux/include/xen/events.h
Stefano Stabellini af42b8d12f xen: fix MSI setup and teardown for PV on HVM guests
When remapping MSIs into pirqs for PV on HVM guests, qemu is responsible
for doing the actual mapping and unmapping.
We only give qemu the desired pirq number when we ask to do the mapping
the first time, after that we should be reading back the pirq number
from qemu every time we want to re-enable the MSI.

This fixes a bug in xen_hvm_setup_msi_irqs that manifests itself when
trying to enable the same MSI for the second time: the old MSI to pirq
mapping is still valid at this point but xen_hvm_setup_msi_irqs would
try to assign a new pirq anyway.
A simple way to reproduce this bug is to assign an MSI capable network
card to a PV on HVM guest, if the user brings down the corresponding
ethernet interface and up again, Linux would fail to enable MSIs on the
device.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2010-12-02 14:34:25 +00:00

97 lines
3.2 KiB
C

#ifndef _XEN_EVENTS_H
#define _XEN_EVENTS_H
#include <linux/interrupt.h>
#include <xen/interface/event_channel.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/events.h>
int bind_evtchn_to_irq(unsigned int evtchn);
int bind_evtchn_to_irqhandler(unsigned int 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);
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);
/*
* 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);
void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector);
int resend_irq_on_evtchn(unsigned int irq);
void rebind_evtchn_irq(int evtchn, int irq);
static inline void notify_remote_via_evtchn(int port)
{
struct evtchn_send send = { .port = port };
(void)HYPERVISOR_event_channel_op(EVTCHNOP_send, &send);
}
extern void notify_remote_via_irq(int irq);
extern 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);
/* Xen HVM evtchn vector callback */
extern void xen_hvm_callback_vector(void);
extern int xen_have_vector_callback;
int xen_set_callback_via(uint64_t via);
void xen_evtchn_do_upcall(struct pt_regs *regs);
void xen_hvm_evtchn_do_upcall(void);
/* Allocate an irq for a physical interrupt, given a gsi. "Legacy"
* GSIs are identity mapped; others are dynamically allocated as
* usual. */
int xen_allocate_pirq(unsigned gsi, int shareable, char *name);
int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int shareable, char *name);
#ifdef CONFIG_PCI_MSI
/* Allocate an irq and a pirq to be used with MSIs. */
#define XEN_ALLOC_PIRQ (1 << 0)
#define XEN_ALLOC_IRQ (1 << 1)
void xen_allocate_pirq_msi(char *name, int *irq, int *pirq, int alloc_mask);
int xen_create_msi_irq(struct pci_dev *dev, struct msi_desc *msidesc, int type);
#endif
/* De-allocates the above mentioned physical interrupt. */
int xen_destroy_irq(int irq);
/* Return vector allocated to pirq */
int xen_vector_from_irq(unsigned pirq);
/* Return gsi allocated to pirq */
int xen_gsi_from_irq(unsigned pirq);
/* Return irq from pirq */
int xen_irq_from_pirq(unsigned pirq);
#endif /* _XEN_EVENTS_H */