From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefano Stabellini Subject: Re: [PATCH v1 08/10] xen/pt: Make xen_pt_unregister_device idempotent Date: Fri, 17 Jul 2015 17:14:31 +0100 Message-ID: References: <1435866681-18468-1-git-send-email-konrad.wilk@oracle.com> <1435866681-18468-9-git-send-email-konrad.wilk@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1ZG8J3-00045k-Ry for xen-devel@lists.xenproject.org; Fri, 17 Jul 2015 16:16:14 +0000 In-Reply-To: <1435866681-18468-9-git-send-email-konrad.wilk@oracle.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Konrad Rzeszutek Wilk Cc: xen-devel@lists.xenproject.org, qemu-devel@nongnu.org, JBeulich@suse.com, stefano.stabellini@eu.citrix.com List-Id: xen-devel@lists.xenproject.org On Thu, 2 Jul 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 > --- > 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 7575311..a094f7c 100644 > --- a/hw/xen/xen_pt.c > +++ b/hw/xen/xen_pt.c > @@ -807,6 +807,7 @@ 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); > @@ -818,10 +819,13 @@ 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); Wouldn't it make sense to move this assignment inside the if below? Aside from this small item: Reviewed-by: Stefano Stabellini > + 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), > @@ -836,6 +840,7 @@ 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); > } > @@ -855,15 +860,20 @@ 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 586d055..2b58521 100644 > --- a/hw/xen/xen_pt.h > +++ b/hw/xen/xen_pt.h > @@ -221,6 +221,7 @@ struct XenPCIPassthroughState { > > MemoryListener memory_listener; > MemoryListener io_listener; > + bool listener_set; > }; > > int xen_pt_config_init(XenPCIPassthroughState *s); > @@ -286,6 +287,7 @@ 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 >