Hi, On 22/09/2016 19:24, Markus Armbruster wrote: > Eric Auger <eric.au...@redhat.com> writes: > >> This patch converts VFIO PCI to realize function. >> >> Also original initfn errors now are propagated using QEMU >> error objects. All errors are formatted with the same pattern: >> "vfio: %s: the error description" >> >> Signed-off-by: Eric Auger <eric.au...@redhat.com> >> >> --- >> >> v1 -> v2: >> - correct error_setg_errno with positive error values >> --- >> hw/vfio/pci.c | 52 >> ++++++++++++++++++++++------------------------------ >> hw/vfio/trace-events | 2 +- >> 2 files changed, 23 insertions(+), 31 deletions(-) >> >> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c >> index 3d43718..857d89f 100644 >> --- a/hw/vfio/pci.c >> +++ b/hw/vfio/pci.c >> @@ -2511,7 +2511,7 @@ static void vfio_unregister_req_notifier(VFIOPCIDevice >> *vdev) >> vdev->req_enabled = false; >> } >> >> -static int vfio_initfn(PCIDevice *pdev) >> +static void vfio_realize(PCIDevice *pdev, Error **errp) >> { >> VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev); >> VFIODevice *vbasedev_iter; >> @@ -2531,9 +2531,9 @@ static int vfio_initfn(PCIDevice *pdev) >> } >> >> if (stat(vdev->vbasedev.sysfsdev, &st) < 0) { >> - error_setg(&err, "no such host device"); >> - ret = -errno; >> - goto error; >> + error_setg(errp, "no such host device"); >> + error_prepend(errp, ERR_PREFIX, vdev->vbasedev.sysfsdev); >> + return; > > Could do > > error_setg(errp, "no such host device"); > goto error; > > Your choice. At that stage the vdev->vbasedev.name is not populated yet. > >> } >> >> vdev->vbasedev.name = g_strdup(basename(vdev->vbasedev.sysfsdev)); >> @@ -2545,9 +2545,8 @@ static int vfio_initfn(PCIDevice *pdev) >> g_free(tmp); >> >> if (len <= 0 || len >= sizeof(group_path)) { >> - error_setg_errno(&err, len < 0 ? errno : ENAMETOOLONG, >> + error_setg_errno(errp, len < 0 ? errno : ENAMETOOLONG, >> "no iommu_group found"); >> - ret = len < 0 ? -errno : -ENAMETOOLONG; >> goto error; >> } >> > > Due to this change and others below, ret is no longer valid at the error > label (fine, it's not used), and the error is set either via err or via > errp. Works, because error_propagate(errp, err) does the right thing > then: nothing when err is null. However, changing the goto to jump > behind the error_propagate when using errp rather than err might be > clearer. Let's use a local error when I can't do otherwise then. > > Continuing to set the error via err also works. Less churn. > > Your choice. > >> @@ -2555,24 +2554,21 @@ static int vfio_initfn(PCIDevice *pdev) >> >> group_name = basename(group_path); >> if (sscanf(group_name, "%d", &groupid) != 1) { >> - error_setg_errno(&err, errno, "failed to read %s", group_path); >> - ret = -errno; >> + error_setg_errno(errp, errno, "failed to read %s", group_path); >> goto error; >> } >> >> - trace_vfio_initfn(vdev->vbasedev.name, groupid); >> + trace_vfio_realize(vdev->vbasedev.name, groupid); >> >> group = vfio_get_group(groupid, pci_device_iommu_address_space(pdev), >> &err); >> if (!group) { >> - ret = -ENOENT; >> goto error; >> } > > Since you don't examine the error, you could use errp rather than &err. > Perhaps not worth the churn unless you can get rid of err entirely. Not possible to completely get rid of local err due to vfio_pci_igd_opregion_init - since can't dereference errp -but I can do a local error_propagate. > >> >> QLIST_FOREACH(vbasedev_iter, &group->device_list, next) { >> if (strcmp(vbasedev_iter->name, vdev->vbasedev.name) == 0) { >> - error_setg(&err, "device is already attached"); >> + error_setg(errp, "device is already attached"); >> vfio_put_group(group); >> - ret = -EBUSY; >> goto error; >> } >> } >> @@ -2594,7 +2590,7 @@ static int vfio_initfn(PCIDevice *pdev) >> vdev->config_offset); >> if (ret < (int)MIN(pci_config_size(&vdev->pdev), vdev->config_size)) { >> ret = ret < 0 ? -errno : -EFAULT; >> - error_setg_errno(&err, -ret, "failed to read device config space"); >> + error_setg_errno(errp, -ret, "failed to read device config space"); >> goto error; >> } >> >> @@ -2611,8 +2607,7 @@ static int vfio_initfn(PCIDevice *pdev) >> */ >> if (vdev->vendor_id != PCI_ANY_ID) { >> if (vdev->vendor_id >= 0xffff) { >> - error_setg(&err, "invalid PCI vendor ID provided"); >> - ret = -EINVAL; >> + error_setg(errp, "invalid PCI vendor ID provided"); >> goto error; >> } >> vfio_add_emulated_word(vdev, PCI_VENDOR_ID, vdev->vendor_id, ~0); >> @@ -2623,8 +2618,7 @@ static int vfio_initfn(PCIDevice *pdev) >> >> if (vdev->device_id != PCI_ANY_ID) { >> if (vdev->device_id > 0xffff) { >> - error_setg(&err, "invalid PCI device ID provided"); >> - ret = -EINVAL; >> + error_setg(errp, "invalid PCI device ID provided"); >> goto error; >> } >> vfio_add_emulated_word(vdev, PCI_DEVICE_ID, vdev->device_id, ~0); >> @@ -2635,8 +2629,7 @@ static int vfio_initfn(PCIDevice *pdev) >> >> if (vdev->sub_vendor_id != PCI_ANY_ID) { >> if (vdev->sub_vendor_id > 0xffff) { >> - error_setg(&err, "invalid PCI subsystem vendor ID provided"); >> - ret = -EINVAL; >> + error_setg(errp, "invalid PCI subsystem vendor ID provided"); >> goto error; >> } >> vfio_add_emulated_word(vdev, PCI_SUBSYSTEM_VENDOR_ID, >> @@ -2647,8 +2640,7 @@ static int vfio_initfn(PCIDevice *pdev) >> >> if (vdev->sub_device_id != PCI_ANY_ID) { >> if (vdev->sub_device_id > 0xffff) { >> - error_setg(&err, "invalid PCI subsystem device ID provided"); >> - ret = -EINVAL; >> + error_setg(errp, "invalid PCI subsystem device ID provided"); >> goto error; >> } >> vfio_add_emulated_word(vdev, PCI_SUBSYSTEM_ID, vdev->sub_device_id, >> ~0); >> @@ -2702,10 +2694,9 @@ static int vfio_initfn(PCIDevice *pdev) >> struct vfio_region_info *opregion; >> >> if (vdev->pdev.qdev.hotplugged) { >> - error_setg(&err, >> + error_setg(errp, >> "cannot support IGD OpRegion feature on hotplugged " >> "device"); >> - ret = -EINVAL; >> goto out_teardown; >> } >> >> @@ -2713,7 +2704,7 @@ static int vfio_initfn(PCIDevice *pdev) >> VFIO_REGION_TYPE_PCI_VENDOR_TYPE | >> PCI_VENDOR_ID_INTEL, >> VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION, &opregion); >> if (ret) { >> - error_setg_errno(&err, -ret, >> + error_setg_errno(errp, -ret, >> "does not support requested IGD OpRegion >> feature"); >> goto out_teardown; >> } >> @@ -2721,7 +2712,6 @@ static int vfio_initfn(PCIDevice *pdev) >> vfio_pci_igd_opregion_init(vdev, opregion, &err); >> g_free(opregion); >> if (err) { >> - ret = -EINVAL; >> goto out_teardown; >> } >> } >> @@ -2743,6 +2733,7 @@ static int vfio_initfn(PCIDevice *pdev) >> pci_device_set_intx_routing_notifier(&vdev->pdev, vfio_intx_update); >> ret = vfio_intx_enable(vdev, &err); >> if (ret) { >> + error_setg_errno(errp, -ret, "failed to enable intx"); > > If vfio_intx_enable() sets an error on any failure (as it should), then > the later error_propagate(errp, err) will simply free err. Adding the > error_setg_errno() here overrides the specific error set by > vfio_intx_enable() with a generic one. Looks wrong to me. Yes this is definitively wrong! > > If it doesn't, then the error_propagate() will work around that > misbehavior. You should fix vfio_intx_enable() then. > >> goto out_teardown; >> } >> } >> @@ -2751,17 +2742,18 @@ static int vfio_initfn(PCIDevice *pdev) >> vfio_register_req_notifier(vdev); >> vfio_setup_resetfn_quirk(vdev); >> >> - return 0; >> + return; >> >> out_teardown: >> pci_device_set_intx_routing_notifier(&vdev->pdev, NULL); >> vfio_teardown_msi(vdev); >> vfio_bars_exit(vdev); >> error: >> - if (err) { >> - error_reportf_err(err, ERR_PREFIX, vdev->vbasedev.name); >> + error_propagate(errp, err); >> + >> + if (*errp) { >> + error_prepend(errp, ERR_PREFIX, vdev->vbasedev.name); >> } > > Dereferencing errp is unclean, because callers may pass null to ignore > errors. The qdev core doesn't. However, error_prepend() does the right > thing when passed null, namely nothing. Simply call it unconditionally. understood.
Thank you for your time! Best Regards Eric > >> - return ret; >> } >> >> static void vfio_instance_finalize(Object *obj) >> @@ -2890,7 +2882,7 @@ static void vfio_pci_dev_class_init(ObjectClass >> *klass, void *data) >> dc->vmsd = &vfio_pci_vmstate; >> dc->desc = "VFIO-based PCI device assignment"; >> set_bit(DEVICE_CATEGORY_MISC, dc->categories); >> - pdc->init = vfio_initfn; >> + pdc->realize = vfio_realize; >> pdc->exit = vfio_exitfn; >> pdc->config_read = vfio_pci_read_config; >> pdc->config_write = vfio_pci_write_config; >> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events >> index da13322..ef81609 100644 >> --- a/hw/vfio/trace-events >> +++ b/hw/vfio/trace-events >> @@ -36,7 +36,7 @@ vfio_pci_hot_reset_dep_devices(int domain, int bus, int >> slot, int function, int >> vfio_pci_hot_reset_result(const char *name, const char *result) "%s hot >> reset: %s" >> vfio_populate_device_config(const char *name, unsigned long size, unsigned >> long offset, unsigned long flags) "Device %s config:\n size: 0x%lx, offset: >> 0x%lx, flags: 0x%lx" >> vfio_populate_device_get_irq_info_failure(void) "VFIO_DEVICE_GET_IRQ_INFO >> failure: %m" >> -vfio_initfn(const char *name, int group_id) " (%s) group %d" >> +vfio_realize(const char *name, int group_id) " (%s) group %d" >> vfio_add_ext_cap_dropped(const char *name, uint16_t cap, uint16_t offset) >> "%s %x@%x" >> vfio_pci_reset(const char *name) " (%s)" >> vfio_pci_reset_flr(const char *name) "%s FLR/VFIO_DEVICE_RESET" >