From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49244) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bjRme-0006bK-79 for qemu-devel@nongnu.org; Mon, 12 Sep 2016 10:00:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bjRmY-0007GF-M4 for qemu-devel@nongnu.org; Mon, 12 Sep 2016 10:00:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36070) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bjRmY-0007Ei-Dv for qemu-devel@nongnu.org; Mon, 12 Sep 2016 10:00:22 -0400 References: <1473145893-17088-1-git-send-email-eric.auger@redhat.com> <1473145893-17088-2-git-send-email-eric.auger@redhat.com> <87y42xxp5m.fsf@dusky.pond.sub.org> From: Auger Eric Message-ID: Date: Mon, 12 Sep 2016 16:00:18 +0200 MIME-Version: 1.0 In-Reply-To: <87y42xxp5m.fsf@dusky.pond.sub.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 1/3] vfio/pci: conversion to realize List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: alex.williamson@redhat.com, qemu-devel@nongnu.org, eric.auger.pro@gmail.com Hi Markus, On 12/09/2016 14:45, Markus Armbruster wrote: > Eric Auger 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" > > Example: > > $ upstream-qemu -device vfio-pci > upstream-qemu: -device vfio-pci: vfio: 0000:00:00.0: no iommu_group found: Unknown error -2 > > Two remarks: > > * "Unknown error -2" should be "No such file or directory". See below. Hum. I noticed that but I didn't have the presence of mind to get it was due to -errno! > > * Five colons, not counting the ones in the PCI address. Do we need the > "vfio: 0000:00:00.0:" part? If yes, could we find a nicer way to > print it? Up to you. Well we have quite a lot of traces with such format, hence my choice. Alex do you want to change this? > > Always, always, always test your error messages :) > >> Subsequent patches will pass the error objects to >> - vfio_populate_device, >> - vfio_msix_early_setup. >> >> At this point if those functions fail let's just report an error >> at realize level. >> >> Signed-off-by: Eric Auger >> --- >> hw/vfio/pci.c | 81 ++++++++++++++++++++++++++++------------------------ >> hw/vfio/trace-events | 2 +- >> 2 files changed, 44 insertions(+), 39 deletions(-) >> >> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c >> index 7bfa17c..ae1967c 100644 >> --- a/hw/vfio/pci.c >> +++ b/hw/vfio/pci.c >> @@ -2485,7 +2485,7 @@ 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; >> @@ -2504,9 +2504,9 @@ static int vfio_initfn(PCIDevice *pdev) >> } >> >> if (stat(vdev->vbasedev.sysfsdev, &st) < 0) { >> - error_report("vfio: error: no such host device: %s", >> - vdev->vbasedev.sysfsdev); >> - return -errno; >> + error_setg_errno(errp, -errno, "vfio: error: no such host device: %s", > > error_setg_errno() takes a *positive* errno. Same elsewhere. OK thanks! > >> + vdev->vbasedev.sysfsdev); >> + return; >> } >> >> vdev->vbasedev.name = g_strdup(basename(vdev->vbasedev.sysfsdev)); >> @@ -2518,45 +2518,46 @@ static int vfio_initfn(PCIDevice *pdev) >> g_free(tmp); >> >> if (len <= 0 || len >= sizeof(group_path)) { >> - error_report("vfio: error no iommu_group for device"); >> - return len < 0 ? -errno : -ENAMETOOLONG; >> + error_setg_errno(errp, len < 0 ? -errno : -ENAMETOOLONG, >> + "no iommu_group found"); >> + goto error; >> } >> >> group_path[len] = 0; >> >> group_name = basename(group_path); >> if (sscanf(group_name, "%d", &groupid) != 1) { >> - error_report("vfio: error reading %s: %m", group_path); >> - return -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)); >> if (!group) { >> - error_report("vfio: failed to get group %d", groupid); >> - return -ENOENT; >> + error_setg_errno(errp, -ENOENT, "failed to get group %d", groupid); >> + goto error; > > I understand this is a mechanical conversion, but are you sure the ": No > such file or directory" suffix we get from passing ENOENT buys us > anything? More of the same below. At that stage I prefered to stick to the original messages since Alex & VFIO users may have their habits. > >> } >> >> QLIST_FOREACH(vbasedev_iter, &group->device_list, next) { >> if (strcmp(vbasedev_iter->name, vdev->vbasedev.name) == 0) { >> - error_report("vfio: error: device %s is already attached", >> - vdev->vbasedev.name); >> + error_setg_errno(errp, -EBUSY, "device is already attached"); >> vfio_put_group(group); >> - return -EBUSY; >> + goto error; >> } >> } >> >> ret = vfio_get_device(group, vdev->vbasedev.name, &vdev->vbasedev); >> if (ret) { >> - error_report("vfio: failed to get device %s", vdev->vbasedev.name); >> + error_setg_errno(errp, ret, "failed to get the device"); >> vfio_put_group(group); >> - return ret; >> + goto error; >> } >> >> ret = vfio_populate_device(vdev); >> if (ret) { >> - return ret; >> + error_setg_errno(errp, ret, "failed to populate the device"); >> + goto error; >> } > > vfio_populate_device() reports errors with error_report(). We get a > specific error via error_report(), and a generic error here. PATCH 2 > converts it to Error, getting rid of the generic error again. Works for > me, but I usually order conversion patches the other way: first convert > vfio_populate_device(), and report its Error like this: > > ret = vfio_populate_device(vdev, &err); > if (err) { > error_report_err(err); > return ret; > } > > PRO: no intermediate state with two errors. CON: have to touch > vfio_populate_device() again to drop the return value. Matter of taste, > thus your choice. > > Same for vfio_msix_early_setup() below. Yes it makes sense. I will respin adopting the above strategy. > >> >> /* Get a copy of config space */ >> @@ -2565,8 +2566,8 @@ 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_report("vfio: Failed to read device config space"); >> - return ret; >> + error_setg_errno(errp, ret, "failed to read device config space"); >> + goto error; >> } >> >> /* vfio emulates a lot for us, but some bits need extra love */ >> @@ -2582,8 +2583,8 @@ static int vfio_initfn(PCIDevice *pdev) >> */ >> if (vdev->vendor_id != PCI_ANY_ID) { >> if (vdev->vendor_id >= 0xffff) { >> - error_report("vfio: Invalid PCI vendor ID provided"); >> - return -EINVAL; >> + error_setg_errno(errp, -EINVAL, "invalid PCI vendor ID provided"); >> + goto error; >> } >> vfio_add_emulated_word(vdev, PCI_VENDOR_ID, vdev->vendor_id, ~0); >> trace_vfio_pci_emulated_vendor_id(vdev->vbasedev.name, vdev->vendor_id); >> @@ -2593,8 +2594,8 @@ static int vfio_initfn(PCIDevice *pdev) >> >> if (vdev->device_id != PCI_ANY_ID) { >> if (vdev->device_id > 0xffff) { >> - error_report("vfio: Invalid PCI device ID provided"); >> - return -EINVAL; >> + error_setg_errno(errp, -EINVAL, "invalid PCI device ID provided"); >> + goto error; >> } >> vfio_add_emulated_word(vdev, PCI_DEVICE_ID, vdev->device_id, ~0); >> trace_vfio_pci_emulated_device_id(vdev->vbasedev.name, vdev->device_id); >> @@ -2604,8 +2605,9 @@ static int vfio_initfn(PCIDevice *pdev) >> >> if (vdev->sub_vendor_id != PCI_ANY_ID) { >> if (vdev->sub_vendor_id > 0xffff) { >> - error_report("vfio: Invalid PCI subsystem vendor ID provided"); >> - return -EINVAL; >> + error_setg_errno(errp, -EINVAL, >> + "invalid PCI subsystem vendor ID provided"); >> + goto error; >> } >> vfio_add_emulated_word(vdev, PCI_SUBSYSTEM_VENDOR_ID, >> vdev->sub_vendor_id, ~0); >> @@ -2615,8 +2617,9 @@ static int vfio_initfn(PCIDevice *pdev) >> >> if (vdev->sub_device_id != PCI_ANY_ID) { >> if (vdev->sub_device_id > 0xffff) { >> - error_report("vfio: Invalid PCI subsystem device ID provided"); >> - return -EINVAL; >> + error_setg_errno(errp, -EINVAL, >> + "invalid PCI subsystem device ID provided"); >> + goto error; >> } >> vfio_add_emulated_word(vdev, PCI_SUBSYSTEM_ID, vdev->sub_device_id, ~0); >> trace_vfio_pci_emulated_sub_device_id(vdev->vbasedev.name, >> @@ -2646,7 +2649,8 @@ static int vfio_initfn(PCIDevice *pdev) >> >> ret = vfio_msix_early_setup(vdev); >> if (ret) { >> - return ret; >> + error_setg_errno(errp, ret, "msix early setup failure"); >> + goto error; >> } >> >> vfio_bars_setup(vdev); >> @@ -2669,9 +2673,9 @@ static int vfio_initfn(PCIDevice *pdev) >> struct vfio_region_info *opregion; >> >> if (vdev->pdev.qdev.hotplugged) { >> - error_report("Cannot support IGD OpRegion feature on hotplugged " >> - "device %s", vdev->vbasedev.name); >> - ret = -EINVAL; >> + error_setg_errno(errp, -EINVAL, >> + "cannot support IGD OpRegion feature on hotplugged " >> + "device"); >> goto out_teardown; >> } >> >> @@ -2679,16 +2683,15 @@ 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_report("Device %s does not support requested IGD OpRegion " >> - "feature", vdev->vbasedev.name); >> + error_setg_errno(errp, ret, >> + "does not support requested IGD OpRegion feature"); >> goto out_teardown; >> } >> >> ret = vfio_pci_igd_opregion_init(vdev, opregion); >> g_free(opregion); >> if (ret) { >> - error_report("Device %s IGD OpRegion initialization failed", >> - vdev->vbasedev.name); >> + error_setg_errno(errp, ret, "IGD OpRegion initialization failed"); >> goto out_teardown; >> } >> } >> @@ -2710,6 +2713,7 @@ static int vfio_initfn(PCIDevice *pdev) >> pci_device_set_intx_routing_notifier(&vdev->pdev, vfio_intx_update); >> ret = vfio_intx_enable(vdev); >> if (ret) { >> + error_setg_errno(errp, ret, "failed to enable intx"); >> goto out_teardown; >> } >> } >> @@ -2718,13 +2722,14 @@ 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); >> - return ret; >> +error: >> + error_prepend(errp, "vfio: %s: ", vdev->vbasedev.name); >> } >> >> static void vfio_instance_finalize(Object *obj) >> @@ -2853,7 +2858,7 @@ 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 4bb7690..14e3fc4 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" >