| Message ID | 1435611725-15161-7-git-send-email-konrad.wilk@oracle.com |
|---|---|
| State | New |
| Headers | show |
On Mon, 29 Jun 2015, Konrad Rzeszutek Wilk wrote: > To deal with xen_host_pci_[set|get]_ functions returning error values > and clearing ourselves in the init function we should make the > .exit (xen_pt_unregister_device) function be idempotent in case > the generic code starts calling .exit (or for fun does it before > calling .init!). > > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > --- > hw/xen/xen-host-pci-device.c | 5 +++++ > hw/xen/xen-host-pci-device.h | 1 + > hw/xen/xen_pt.c | 22 ++++++++++++++++------ > hw/xen/xen_pt.h | 2 ++ > 4 files changed, 24 insertions(+), 6 deletions(-) > > diff --git a/hw/xen/xen-host-pci-device.c b/hw/xen/xen-host-pci-device.c > index 743b37b..5b20570 100644 > --- a/hw/xen/xen-host-pci-device.c > +++ b/hw/xen/xen-host-pci-device.c > @@ -387,6 +387,11 @@ error: > return rc; > } > > +bool xen_host_pci_device_closed(XenHostPCIDevice *d) > +{ > + return d->config_fd == -1; > +} > + > void xen_host_pci_device_put(XenHostPCIDevice *d) > { > if (d->config_fd >= 0) { > diff --git a/hw/xen/xen-host-pci-device.h b/hw/xen/xen-host-pci-device.h > index c2486f0..16f4805 100644 > --- a/hw/xen/xen-host-pci-device.h > +++ b/hw/xen/xen-host-pci-device.h > @@ -38,6 +38,7 @@ typedef struct XenHostPCIDevice { > int xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain, > uint8_t bus, uint8_t dev, uint8_t func); > void xen_host_pci_device_put(XenHostPCIDevice *pci_dev); > +bool xen_host_pci_device_closed(XenHostPCIDevice *d); > > int xen_host_pci_get_byte(XenHostPCIDevice *d, int pos, uint8_t *p); > int xen_host_pci_get_word(XenHostPCIDevice *d, int pos, uint16_t *p); > diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c > index 2535352..cda6a2d 100644 > --- a/hw/xen/xen_pt.c > +++ b/hw/xen/xen_pt.c > @@ -810,6 +810,7 @@ out: > > memory_listener_register(&s->memory_listener, &s->dev.bus_master_as); > memory_listener_register(&s->io_listener, &address_space_io); > + s->listener_set = true; > XEN_PT_LOG(d, > "Real physical device %02x:%02x.%d registered successfully!\n", > s->hostaddr.bus, s->hostaddr.slot, s->hostaddr.function); > @@ -821,10 +822,13 @@ static void xen_pt_unregister_device(PCIDevice *d) > { > XenPCIPassthroughState *s = XEN_PT_DEVICE(d); > uint8_t machine_irq = s->machine_irq; > - uint8_t intx = xen_pt_pci_intx(s); > + uint8_t intx; > int rc; > > - if (machine_irq) { > + /* Note that if xen_host_pci_device_put had closed config_fd, then > + * intx value becomes 0xff. */ > + intx = xen_pt_pci_intx(s); > + if (machine_irq && !xen_host_pci_device_closed(&s->real_device)) { > rc = xc_domain_unbind_pt_irq(xen_xc, xen_domid, machine_irq, > PT_IRQ_TYPE_PCI, > pci_bus_num(d->bus), > @@ -839,6 +843,7 @@ static void xen_pt_unregister_device(PCIDevice *d) > } > } > > + /* N.B. xen_pt_config_delete takes care of freeing them. */ > if (s->msi) { > xen_pt_msi_disable(s); > } > @@ -858,15 +863,20 @@ static void xen_pt_unregister_device(PCIDevice *d) > machine_irq, errno); > } > } > + s->machine_irq = 0; > } > > /* delete all emulated config registers */ > xen_pt_config_delete(s); > > - memory_listener_unregister(&s->memory_listener); > - memory_listener_unregister(&s->io_listener); > - > - xen_host_pci_device_put(&s->real_device); > + if (s->listener_set) { > + memory_listener_unregister(&s->memory_listener); > + memory_listener_unregister(&s->io_listener); > + s->listener_set = false; If you call QTAILQ_INIT on memory_listener and io_listener, then you simply check on QTAILQ_EMPTY and remove listener_set. > + } > + if (!xen_host_pci_device_closed(&s->real_device)) { > + xen_host_pci_device_put(&s->real_device); > + } > } > > static Property xen_pci_passthrough_properties[] = { > diff --git a/hw/xen/xen_pt.h b/hw/xen/xen_pt.h > index 09358b1..98eb74c 100644 > --- a/hw/xen/xen_pt.h > +++ b/hw/xen/xen_pt.h > @@ -217,6 +217,7 @@ struct XenPCIPassthroughState { > > MemoryListener memory_listener; > MemoryListener io_listener; > + bool listener_set; > }; > > int xen_pt_config_init(XenPCIPassthroughState *s); > @@ -282,6 +283,7 @@ static inline uint8_t xen_pt_pci_intx(XenPCIPassthroughState *s) > " value=%i, acceptable range is 1 - 4\n", r_val); > r_val = 0; > } else { > + /* Note that if s.real_device.config_fd is closed we make 0xff. */ > r_val -= 1; > } > > -- > 2.1.0 >
> > @@ -858,15 +863,20 @@ static void xen_pt_unregister_device(PCIDevice *d) > > machine_irq, errno); > > } > > } > > + s->machine_irq = 0; > > } > > > > /* delete all emulated config registers */ > > xen_pt_config_delete(s); > > > > - memory_listener_unregister(&s->memory_listener); > > - memory_listener_unregister(&s->io_listener); > > - > > - xen_host_pci_device_put(&s->real_device); > > + if (s->listener_set) { > > + memory_listener_unregister(&s->memory_listener); > > + memory_listener_unregister(&s->io_listener); > > + s->listener_set = false; > > If you call QTAILQ_INIT on memory_listener and io_listener, then you > simply check on QTAILQ_EMPTY and remove listener_set. No dice. For that to work they need to be QTAIL_HEAD while they are of QTAILQ_ENTRY. That is, the include/exec/memory.h: struct MemoryListener { ... AddressSpace *address_space_filter; QTAILQ_ENTRY(MemoryListener) link; } And the QTAILQ_EMPTY checks for '>tqh_first' while the QTAILQ_ENTRY only defines two pointers: tqe_next and tqe_prev.
On Thu, 2 Jul 2015, Konrad Rzeszutek Wilk wrote: > > > @@ -858,15 +863,20 @@ static void xen_pt_unregister_device(PCIDevice *d) > > > machine_irq, errno); > > > } > > > } > > > + s->machine_irq = 0; > > > } > > > > > > /* delete all emulated config registers */ > > > xen_pt_config_delete(s); > > > > > > - memory_listener_unregister(&s->memory_listener); > > > - memory_listener_unregister(&s->io_listener); > > > - > > > - xen_host_pci_device_put(&s->real_device); > > > + if (s->listener_set) { > > > + memory_listener_unregister(&s->memory_listener); > > > + memory_listener_unregister(&s->io_listener); > > > + s->listener_set = false; > > > > If you call QTAILQ_INIT on memory_listener and io_listener, then you > > simply check on QTAILQ_EMPTY and remove listener_set. > > No dice. For that to work they need to be QTAIL_HEAD while > they are of QTAILQ_ENTRY. > > That is, the include/exec/memory.h: > struct MemoryListener { > ... > AddressSpace *address_space_filter; > QTAILQ_ENTRY(MemoryListener) link; > } > > And the QTAILQ_EMPTY checks for '>tqh_first' while the > QTAILQ_ENTRY only defines two pointers: tqe_next and tqe_prev. Ah, that is true. In that case maybe it is OK to introduce listener_set, rather than messing up with QTAILQ definitions or having checks like memory_listener->link->tqe_next == memory_listener->link->tqe_prev.
diff --git a/hw/xen/xen-host-pci-device.c b/hw/xen/xen-host-pci-device.c index 743b37b..5b20570 100644 --- a/hw/xen/xen-host-pci-device.c +++ b/hw/xen/xen-host-pci-device.c @@ -387,6 +387,11 @@ error: return rc; } +bool xen_host_pci_device_closed(XenHostPCIDevice *d) +{ + return d->config_fd == -1; +} + void xen_host_pci_device_put(XenHostPCIDevice *d) { if (d->config_fd >= 0) { diff --git a/hw/xen/xen-host-pci-device.h b/hw/xen/xen-host-pci-device.h index c2486f0..16f4805 100644 --- a/hw/xen/xen-host-pci-device.h +++ b/hw/xen/xen-host-pci-device.h @@ -38,6 +38,7 @@ typedef struct XenHostPCIDevice { int xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain, uint8_t bus, uint8_t dev, uint8_t func); void xen_host_pci_device_put(XenHostPCIDevice *pci_dev); +bool xen_host_pci_device_closed(XenHostPCIDevice *d); int xen_host_pci_get_byte(XenHostPCIDevice *d, int pos, uint8_t *p); int xen_host_pci_get_word(XenHostPCIDevice *d, int pos, uint16_t *p); diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c index 2535352..cda6a2d 100644 --- a/hw/xen/xen_pt.c +++ b/hw/xen/xen_pt.c @@ -810,6 +810,7 @@ out: memory_listener_register(&s->memory_listener, &s->dev.bus_master_as); memory_listener_register(&s->io_listener, &address_space_io); + s->listener_set = true; XEN_PT_LOG(d, "Real physical device %02x:%02x.%d registered successfully!\n", s->hostaddr.bus, s->hostaddr.slot, s->hostaddr.function); @@ -821,10 +822,13 @@ static void xen_pt_unregister_device(PCIDevice *d) { XenPCIPassthroughState *s = XEN_PT_DEVICE(d); uint8_t machine_irq = s->machine_irq; - uint8_t intx = xen_pt_pci_intx(s); + uint8_t intx; int rc; - if (machine_irq) { + /* Note that if xen_host_pci_device_put had closed config_fd, then + * intx value becomes 0xff. */ + intx = xen_pt_pci_intx(s); + if (machine_irq && !xen_host_pci_device_closed(&s->real_device)) { rc = xc_domain_unbind_pt_irq(xen_xc, xen_domid, machine_irq, PT_IRQ_TYPE_PCI, pci_bus_num(d->bus), @@ -839,6 +843,7 @@ static void xen_pt_unregister_device(PCIDevice *d) } } + /* N.B. xen_pt_config_delete takes care of freeing them. */ if (s->msi) { xen_pt_msi_disable(s); } @@ -858,15 +863,20 @@ static void xen_pt_unregister_device(PCIDevice *d) machine_irq, errno); } } + s->machine_irq = 0; } /* delete all emulated config registers */ xen_pt_config_delete(s); - memory_listener_unregister(&s->memory_listener); - memory_listener_unregister(&s->io_listener); - - xen_host_pci_device_put(&s->real_device); + if (s->listener_set) { + memory_listener_unregister(&s->memory_listener); + memory_listener_unregister(&s->io_listener); + s->listener_set = false; + } + if (!xen_host_pci_device_closed(&s->real_device)) { + xen_host_pci_device_put(&s->real_device); + } } static Property xen_pci_passthrough_properties[] = { diff --git a/hw/xen/xen_pt.h b/hw/xen/xen_pt.h index 09358b1..98eb74c 100644 --- a/hw/xen/xen_pt.h +++ b/hw/xen/xen_pt.h @@ -217,6 +217,7 @@ struct XenPCIPassthroughState { MemoryListener memory_listener; MemoryListener io_listener; + bool listener_set; }; int xen_pt_config_init(XenPCIPassthroughState *s); @@ -282,6 +283,7 @@ static inline uint8_t xen_pt_pci_intx(XenPCIPassthroughState *s) " value=%i, acceptable range is 1 - 4\n", r_val); r_val = 0; } else { + /* Note that if s.real_device.config_fd is closed we make 0xff. */ r_val -= 1; }
To deal with xen_host_pci_[set|get]_ functions returning error values and clearing ourselves in the init function we should make the .exit (xen_pt_unregister_device) function be idempotent in case the generic code starts calling .exit (or for fun does it before calling .init!). Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- hw/xen/xen-host-pci-device.c | 5 +++++ hw/xen/xen-host-pci-device.h | 1 + hw/xen/xen_pt.c | 22 ++++++++++++++++------ hw/xen/xen_pt.h | 2 ++ 4 files changed, 24 insertions(+), 6 deletions(-)