[libvirt] [PATCH V2 0/2] libxl: fix handling of <disk> driver and format settings
V2 of https://www.redhat.com/archives/libvir-list/2017-February/msg00185.html Patch1 is new in V2 and essentially moves default setting of disk format from domain build time to device post-parse, which addresses Michal's comment from V1. Patch2 is mostly unchanged. The hunk setting format of virDomainDiskDef in libxlMakeDisk is removed since that is now handled by patch1. Jim Fehlig (2): libxl: set default disk format in device post-parse libxl: fix disk detach when <driver> not specified src/libxl/libxl_conf.c | 42 ++++++++++++++++++++++++++++++++++-------- src/libxl/libxl_conf.h | 4 ++++ src/libxl/libxl_domain.c | 32 +++++++++++++++++++++++++++++++- src/libxl/libxl_driver.c | 1 + 4 files changed, 70 insertions(+), 9 deletions(-) -- 2.9.2
When starting a domian, a libxl_domain_config object is created from virDomainDef. Any virDomainDiskDef devices with a format of VIR_STORAGE_FILE_NONE are mapped to LIBXL_DISK_FORMAT_RAW in the corresponding libxl_disk_device, but the virDomainDiskDef format is never updated to reflect the change. A better place to set a default format for disk devices is the device post-parse callback, ensuring the virDomainDiskDef object reflects the default format. Signed-off-by: Jim Fehlig <jfehlig@suse.com> --- src/libxl/libxl_conf.c | 10 ++-------- src/libxl/libxl_domain.c | 7 ++++++- 2 files changed, 8 insertions(+), 9 deletions(-) diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c index b5186f2..da63105 100644 --- a/src/libxl/libxl_conf.c +++ b/src/libxl/libxl_conf.c @@ -765,8 +765,6 @@ libxlMakeDisk(virDomainDiskDefPtr l_disk, libxl_device_disk *x_disk) x_disk->format = LIBXL_DISK_FORMAT_VHD; x_disk->backend = LIBXL_DISK_BACKEND_TAP; break; - case VIR_STORAGE_FILE_NONE: - /* No subtype specified, default to raw/tap */ case VIR_STORAGE_FILE_RAW: x_disk->format = LIBXL_DISK_FORMAT_RAW; x_disk->backend = LIBXL_DISK_BACKEND_TAP; @@ -802,8 +800,6 @@ libxlMakeDisk(virDomainDiskDefPtr l_disk, libxl_device_disk *x_disk) case VIR_STORAGE_FILE_VHD: x_disk->format = LIBXL_DISK_FORMAT_VHD; break; - case VIR_STORAGE_FILE_NONE: - /* No subtype specified, default to raw */ case VIR_STORAGE_FILE_RAW: x_disk->format = LIBXL_DISK_FORMAT_RAW; break; @@ -816,8 +812,7 @@ libxlMakeDisk(virDomainDiskDefPtr l_disk, libxl_device_disk *x_disk) return -1; } } else if (STREQ(driver, "file")) { - if (format != VIR_STORAGE_FILE_NONE && - format != VIR_STORAGE_FILE_RAW) { + if (format != VIR_STORAGE_FILE_RAW) { virReportError(VIR_ERR_INTERNAL_ERROR, _("libxenlight does not support disk format %s " "with disk driver %s"), @@ -828,8 +823,7 @@ libxlMakeDisk(virDomainDiskDefPtr l_disk, libxl_device_disk *x_disk) x_disk->format = LIBXL_DISK_FORMAT_RAW; x_disk->backend = LIBXL_DISK_BACKEND_QDISK; } else if (STREQ(driver, "phy")) { - if (format != VIR_STORAGE_FILE_NONE && - format != VIR_STORAGE_FILE_RAW) { + if (format != VIR_STORAGE_FILE_RAW) { virReportError(VIR_ERR_INTERNAL_ERROR, _("libxenlight does not support disk format %s " "with disk driver %s"), diff --git a/src/libxl/libxl_domain.c b/src/libxl/libxl_domain.c index ed73cd2..c0ace33 100644 --- a/src/libxl/libxl_domain.c +++ b/src/libxl/libxl_domain.c @@ -362,16 +362,21 @@ libxlDomainDeviceDefPostParse(virDomainDeviceDefPtr dev, } } - /* for network-based disks, set 'qemu' as the default driver */ if (dev->type == VIR_DOMAIN_DEVICE_DISK) { virDomainDiskDefPtr disk = dev->data.disk; int actual_type = virStorageSourceGetActualType(disk->src); + int format = virDomainDiskGetFormat(disk); + /* for network-based disks, set 'qemu' as the default driver */ if (actual_type == VIR_STORAGE_TYPE_NETWORK) { if (!virDomainDiskGetDriver(disk) && virDomainDiskSetDriver(disk, "qemu") < 0) return -1; } + + /* xl.cfg default format is raw. See xl-disk-configuration(5) */ + if (format == VIR_STORAGE_FILE_NONE) + virDomainDiskSetFormat(disk, VIR_STORAGE_FILE_RAW); } return 0; -- 2.9.2
On 02/07/2017 08:46 PM, Jim Fehlig wrote:
When starting a domian, a libxl_domain_config object is created from virDomainDef. Any virDomainDiskDef devices with a format of VIR_STORAGE_FILE_NONE are mapped to LIBXL_DISK_FORMAT_RAW in the corresponding libxl_disk_device, but the virDomainDiskDef format is never updated to reflect the change.
A better place to set a default format for disk devices is the device post-parse callback, ensuring the virDomainDiskDef object reflects the default format.
Signed-off-by: Jim Fehlig <jfehlig@suse.com> --- src/libxl/libxl_conf.c | 10 ++-------- src/libxl/libxl_domain.c | 7 ++++++- 2 files changed, 8 insertions(+), 9 deletions(-)
ACK. BTW looks like you forgot about one other location: src/libxl/libxl_driver.c=5452=libxlDomainBlockStatsGatherSingle(virDomainObjPtr vm, -- src/libxl/libxl_driver.c-5469- src/libxl/libxl_driver.c-5470- if (STREQ(disk_drv, "phy")) { src/libxl/libxl_driver.c-5471- if (disk_fmt != VIR_STORAGE_FILE_RAW && src/libxl/libxl_driver.c:5472: disk_fmt != VIR_STORAGE_FILE_NONE) { src/libxl/libxl_driver.c-5473- virReportError(VIR_ERR_OPERATION_UNSUPPORTED, src/libxl/libxl_driver.c-5474- _("unsupported format %s"), src/libxl/libxl_driver.c-5475- virStorageFileFormatTypeToString(disk_fmt)); Michal
Michal Privoznik wrote:
On 02/07/2017 08:46 PM, Jim Fehlig wrote:
When starting a domian, a libxl_domain_config object is created from virDomainDef. Any virDomainDiskDef devices with a format of VIR_STORAGE_FILE_NONE are mapped to LIBXL_DISK_FORMAT_RAW in the corresponding libxl_disk_device, but the virDomainDiskDef format is never updated to reflect the change.
A better place to set a default format for disk devices is the device post-parse callback, ensuring the virDomainDiskDef object reflects the default format.
Signed-off-by: Jim Fehlig <jfehlig@suse.com> --- src/libxl/libxl_conf.c | 10 ++-------- src/libxl/libxl_domain.c | 7 ++++++- 2 files changed, 8 insertions(+), 9 deletions(-)
ACK.
BTW looks like you forgot about one other location:
src/libxl/libxl_driver.c=5452=libxlDomainBlockStatsGatherSingle(virDomainObjPtr vm, -- src/libxl/libxl_driver.c-5469- src/libxl/libxl_driver.c-5470- if (STREQ(disk_drv, "phy")) { src/libxl/libxl_driver.c-5471- if (disk_fmt != VIR_STORAGE_FILE_RAW && src/libxl/libxl_driver.c:5472: disk_fmt != VIR_STORAGE_FILE_NONE) { src/libxl/libxl_driver.c-5473- virReportError(VIR_ERR_OPERATION_UNSUPPORTED, src/libxl/libxl_driver.c-5474- _("unsupported format %s"), src/libxl/libxl_driver.c-5475- virStorageFileFormatTypeToString(disk_fmt));
Ah, thanks. I've added that one to the patch and pushed the series. Regards, Jim
When a user does not explicitly set a <driver> in the disk config, libvirt defers selection of a default to libxl. This approach works fine when starting a domain with such configuration or attaching a disk to a running domain. But when detaching such a disk, libxl will fail with "unrecognized disk backend type: 0". libxl makes no attempt to recalculate a default backend (driver) on detach and simply fails when uninitialized. This patch updates the libvirt disk config with the backend selected by libxl when starting a domain or attaching a disk to a running domain. Another benefit of this approach is that the live XML is also updated with the backend driver selected by libxl. Signed-off-by: Jim Fehlig <jfehlig@suse.com> --- src/libxl/libxl_conf.c | 32 ++++++++++++++++++++++++++++++++ src/libxl/libxl_conf.h | 4 ++++ src/libxl/libxl_domain.c | 25 +++++++++++++++++++++++++ src/libxl/libxl_driver.c | 1 + 4 files changed, 62 insertions(+) diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c index da63105..4e38676 100644 --- a/src/libxl/libxl_conf.c +++ b/src/libxl/libxl_conf.c @@ -907,6 +907,38 @@ libxlMakeDiskList(virDomainDefPtr def, libxl_domain_config *d_config) return -1; } +/* + * Update libvirt disk config with libxl disk config. + * + * This function can be used to update the libvirt disk config with default + * values selected by libxl. Currently only the backend type is selected by + * libxl when not explicitly specified by the user. + */ +void +libxlUpdateDiskDef(virDomainDiskDefPtr l_disk, libxl_device_disk *x_disk) +{ + const char *driver = NULL; + + if (virDomainDiskGetDriver(l_disk)) + return; + + switch (x_disk->backend) { + case LIBXL_DISK_BACKEND_QDISK: + driver = "qemu"; + break; + case LIBXL_DISK_BACKEND_TAP: + driver = "tap"; + break; + case LIBXL_DISK_BACKEND_PHY: + driver = "phy"; + break; + case LIBXL_DISK_BACKEND_UNKNOWN: + break; + } + if (driver) + ignore_value(virDomainDiskSetDriver(l_disk, driver)); +} + int libxlMakeNic(virDomainDefPtr def, virDomainNetDefPtr l_nic, diff --git a/src/libxl/libxl_conf.h b/src/libxl/libxl_conf.h index 69d7885..b944f6c 100644 --- a/src/libxl/libxl_conf.h +++ b/src/libxl/libxl_conf.h @@ -175,6 +175,10 @@ int libxlDriverConfigLoadFile(libxlDriverConfigPtr cfg, int libxlMakeDisk(virDomainDiskDefPtr l_dev, libxl_device_disk *x_dev); + +void +libxlUpdateDiskDef(virDomainDiskDefPtr l_dev, libxl_device_disk *x_dev); + int libxlMakeNic(virDomainDefPtr def, virDomainNetDefPtr l_nic, diff --git a/src/libxl/libxl_domain.c b/src/libxl/libxl_domain.c index c0ace33..57ec661 100644 --- a/src/libxl/libxl_domain.c +++ b/src/libxl/libxl_domain.c @@ -1072,6 +1072,30 @@ libxlDomainCreateIfaceNames(virDomainDefPtr def, libxl_domain_config *d_config) } } +static void +libxlDomainUpdateDiskParams(virDomainDefPtr def, libxl_ctx *ctx) +{ + libxl_device_disk *disks; + int num_disks = 0; + size_t i; + int idx; + + disks = libxl_device_disk_list(ctx, def->id, &num_disks); + if (!disks) + return; + + for (i = 0; i < num_disks; i++) { + if ((idx = virDomainDiskIndexByName(def, disks[i].vdev, false)) < 0) + continue; + + libxlUpdateDiskDef(def->disks[idx], &disks[i]); + } + + for (i = 0; i < num_disks; i++) + libxl_device_disk_dispose(&disks[i]); + VIR_FREE(disks); +} + #ifdef LIBXL_HAVE_DEVICE_CHANNEL static void libxlDomainCreateChannelPTY(virDomainDefPtr def, libxl_ctx *ctx) @@ -1315,6 +1339,7 @@ libxlDomainStart(libxlDriverPrivatePtr driver, goto destroy_dom; libxlDomainCreateIfaceNames(vm->def, &d_config); + libxlDomainUpdateDiskParams(vm->def, cfg->ctx); #ifdef LIBXL_HAVE_DEVICE_CHANNEL if (vm->def->nchannels > 0) diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c index 3a69720..e7827cc 100644 --- a/src/libxl/libxl_driver.c +++ b/src/libxl/libxl_driver.c @@ -3028,6 +3028,7 @@ libxlDomainAttachDeviceDiskLive(virDomainObjPtr vm, virDomainDeviceDefPtr dev) goto cleanup; } + libxlUpdateDiskDef(l_disk, &x_disk); virDomainDiskInsertPreAlloced(vm->def, l_disk); } else { -- 2.9.2
On 02/07/2017 08:46 PM, Jim Fehlig wrote:
When a user does not explicitly set a <driver> in the disk config, libvirt defers selection of a default to libxl. This approach works fine when starting a domain with such configuration or attaching a disk to a running domain. But when detaching such a disk, libxl will fail with "unrecognized disk backend type: 0". libxl makes no attempt to recalculate a default backend (driver) on detach and simply fails when uninitialized.
This patch updates the libvirt disk config with the backend selected by libxl when starting a domain or attaching a disk to a running domain. Another benefit of this approach is that the live XML is also updated with the backend driver selected by libxl.
Signed-off-by: Jim Fehlig <jfehlig@suse.com> --- src/libxl/libxl_conf.c | 32 ++++++++++++++++++++++++++++++++ src/libxl/libxl_conf.h | 4 ++++ src/libxl/libxl_domain.c | 25 +++++++++++++++++++++++++ src/libxl/libxl_driver.c | 1 + 4 files changed, 62 insertions(+)
ACK Michal
participants (2)
-
Jim Fehlig -
Michal Privoznik