October 2018 - Devel - libvirt List Archives

[libvirt] BugFix - Libvirt Ruby Binding Memory Stats Val Method
by iletisim＠muhammetdilmac.com.tr 22 Oct '18

22 Oct '18

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[libvirt] [PATCH 0/2] syntax-check: revert expensive cosmetic checks
by Ján Tomko 22 Oct '18

22 Oct '18

Also do not bother taking C++ style comments into account. Ján Tomko (2): syntax-check: revert indentation checks check-spacing: do not kill C++-style comments build-aux/check-spacing.pl | 459 ++++++++++++++------------------------------- src/libvirt.c | 4 +- 2 files changed, 142 insertions(+), 321 deletions(-) -- 2.16.4

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[libvirt] [PATCH RFC 0/4]] nwfilter: don't reinstantiate filters if they are not changed
by Nikolay Shirokovskiy 22 Oct '18

22 Oct '18

The series adds optimization in network filters instantiation as suggested in [1]. Applied on top of [2]. However this approach has drawback I'm unfortunately discovered too late) Next steps will left us with no network filters after this series applied: systemctl stop libvirtd systemctl restart firewalld systemctl start libvirtd In case of system update libvirt binaries ctime will change and filters will be reinstalled. [1] https://www.redhat.com/archives/libvir-list/2018-October/msg00657.html [2] https://www.redhat.com/archives/libvir-list/2018-October/msg00787.html Nikolay Shirokovskiy (4): nwfilter: add nwfilter hash nwfilter: don't reinstantiate filters if they are not changed nwfilter: force filters reinstantiation on firewalld reload nwfilter: force filters reinstantiation on binary update src/conf/virnwfilterbindingobj.c | 40 +++++++++ src/conf/virnwfilterbindingobj.h | 10 +++ src/conf/virnwfilterobj.c | 145 +++++++++++++++++++++++++++++++++ src/conf/virnwfilterobj.h | 9 ++ src/libvirt_private.syms | 6 ++ src/nwfilter/nwfilter_driver.c | 11 ++- src/nwfilter/nwfilter_gentech_driver.c | 67 +++++++++++++-- src/nwfilter/nwfilter_gentech_driver.h | 6 +- 8 files changed, 283 insertions(+), 11 deletions(-) -- 1.8.3.1

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[libvirt] [PATCHv6 00/18] Introduce x86 Cache Monitoring Technology (CMT)
by Wang Huaqiang 22 Oct '18

22 Oct '18

This series of patches and the series already been merged introduce the x86 Cache Monitoring Technology (CMT) to libvirt by interacting with kernel resource control (resctrl) interface. CMT is one of the Intel(R) x86 CPU feature which belongs to the Resource Director Technology (RDT). CMT reports the occupancy of the last level cache, which is shared by all CPU cores. In the v1 series, an original and complete feature for CMT was introduced The v2 and v3 patches address the feature for the host capability of CMT. v4 is addressing the feature for monitoring VM vcpu thread set cache occupancy and reporting it through a virsh command. We have serval discussion about the enabling of CMT, please refer to following links for the RFCs. RFCv3 https://www.redhat.com/archives/libvir-list/2018-August/msg01213.html RFCv2 https://www.redhat.com/archives/libvir-list/2018-July/msg00409.html https://www.redhat.com/archives/libvir-list/2018-July/msg01241.html RFCv1 https://www.redhat.com/archives/libvir-list/2018-June/msg00674.html And the merged commits are list as below, for host capability of CMT. 6af8417415508c31f8ce71234b573b4999f35980 8f6887998bf63594ae26e3db18d4d5896c5f2cb4 58fcee6f3a2b7e89c21c1fb4ec21429c31a0c5b8 12093f1feaf8f5023dcd9d65dff111022842183d a5d293c18831dcf69ec6195798387fbb70c9f461 1. About reason why CMT is necessary in libvirt? The perf events of 'CMT, MBML, MBMT' have been phased out since Linux kernel commit c39a0e2c8850f08249383f2425dbd8dbe4baad69, in libvirt the perf based cmt,mbm will not work with the latest linux kernel. These patches add CMT feature to libvirt through kernel resctrlfs interface. 2 Create cache monitoring group (cache monitor). The main interface for creating monitoring group is through XML file. The proposed configuration is like: <cputune> <cachetune vcpus='1'> <cache id='0' level='3' type='code' size='7680' unit='KiB'/> <cache id='1' level='3' type='data' size='3840' unit='KiB'/> + <monitor level='3' vcpus='1'/> </cachetune> <cachetune vcpus='4-7'> + <monitor level='3' vcpus='4-6'/> </cachetune> </cputune> In above XML, created 2 cache resctrl allocation groups and 2 resctrl monitoring groups. The changes of cache monitor will be effective in next booting of VM. 2 Show CMT result through command 'domstats' Adding the interface in qemu to report this information for resource monitor group through command 'virsh domstats --cpu-total'. Below is a typical output: # virsh domstats 1 --cpu-total Domain: 'ubuntu16.04-base' ... cpu.cache.monitor.count=2 cpu.cache.monitor.0.name=vcpus_1 cpu.cache.monitor.0.vcpus=1 cpu.cache.monitor.0.bank.count=2 cpu.cache.monitor.0.bank.0.id=0 cpu.cache.monitor.0.bank.0.bytes=4505600 cpu.cache.monitor.0.bank.1.id=1 cpu.cache.monitor.0.bank.1.bytes=5586944 cpu.cache.monitor.1.name=vcpus_4-6 cpu.cache.monitor.1.vcpus=4,5,6 cpu.cache.monitor.1.bank.count=2 cpu.cache.monitor.1.bank.0.id=0 cpu.cache.monitor.1.bank.0.bytes=17571840 cpu.cache.monitor.1.bank.1.id=1 cpu.cache.monitor.1.bank.1.bytes=29106176 Changes in v6: - Addressing John's review comments for v5. - Removed and cleaned the concepts of 'default allocation' and 'default monitor'. - qemu: virsh domstats --cpu-total output for CMT, add identifier 'monitor' for each itm. Changes in v5: - qemu: Setting up vcpu and adding pids to resctrl monitor groups during re-connection. - Add the document for domain configuration related to resctrl monitor. Changes in v4: v4 is addressing the feature for monitoring VM vcpu thread set cache occupancy and reporting it through a virsh command. - Introduced resctrl default allocation - Introduced resctrl monitor and default monitor Changes in v3: - Addressed John Ferlan's review. - Typo fixed. - Removed VIR_ENUM_DECL(virMonitor); Changes in v2: - Introduced MBM capability. - Capability layout changed * Moved <monitor> from cahe <bank> to <cache> * Renamed <Threshold> to <reuseThreshold> - Document for 'reuseThreshold' changed. - Introduced API virResctrlInfoGetMonitorPrefix - Added more tests, covering standalone CMT, fake new feature. - Creating CMT resource control group will be subsequent job. Wang Huaqiang (18): docs,util: Refactor schemas and virresctrl to support optional cache util: Introduce resctrl monitor for CMT util: Refactor code for determining allocation path util: Add interface to determine monitor path util: Refactor code for adding PID to the resource group util: Add interface for adding PID to the monitor util: Refactor code for creating resctrl group util: Add interface for creating monitor group util: Add more interfaces for resctrl monitor conf: Remove virDomainResctrlAppend and introduce virDomainResctrlNew conf: move virResctrlAllocIsEmpty to a place a litter lower conf: Introduce cache monitor element in cachetune qemu: enable resctrl monitor in qemu util: Add function for checking if monitor is running conf: Add 'id' to virDomainResctrlDef qemu: refactor qemuDomainGetStatsCpu qemu: Report cache occupancy (CMT) with domstats qemu: Setting up vcpu and adding pids to resctrl monitor groups during reconnection docs/formatdomain.html.in | 30 +- docs/schemas/domaincommon.rng | 14 +- src/conf/domain_conf.c | 310 ++++++++++-- src/conf/domain_conf.h | 12 + src/libvirt-domain.c | 9 + src/libvirt_private.syms | 10 + src/qemu/qemu_driver.c | 270 +++++++++- src/qemu/qemu_process.c | 69 ++- src/util/virresctrl.c | 563 +++++++++++++++++++-- src/util/virresctrl.h | 49 ++ tests/genericxml2xmlindata/cachetune-cdp.xml | 3 + .../cachetune-colliding-monitor.xml | 30 ++ tests/genericxml2xmlindata/cachetune-small.xml | 7 + tests/genericxml2xmltest.c | 2 + 14 files changed, 1282 insertions(+), 96 deletions(-) create mode 100644 tests/genericxml2xmlindata/cachetune-colliding-monitor.xml -- 2.7.4

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[libvirt] [PULL 00/45] Machine queue, 2018-10-18
by Eduardo Habkost 20 Oct '18

20 Oct '18

The following changes since commit 09558375a634e17cea6cfbfec883ac2376d2dc7f: Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20181016-1' into staging (2018-10-16 17:42:56 +0100) are available in the Git repository at: git://github.com/ehabkost/qemu.git tags/machine-next-pull-request for you to fetch changes up to 6d8e1bcc7dd5e819ce81e6a87fffe23e39c700cc: numa: Clean up error reporting in parse_numa() (2018-10-17 16:33:40 -0300) ---------------------------------------------------------------- Machine queue, 2018-10-18 * sysbus init/realize cleanups (Cédric Le Goater, Philippe Mathieu-Daudé) * memory-device refactoring (David Hildenbrand) * -smp: deprecate incorrect CPUs topology (Igor Mammedov) * -numa parsing cleanups (Markus Armbruster) * Fix hostmem-file memory leak (Zhang Yi) * Typo fix (Li Qiang) ---------------------------------------------------------------- Queue for Machine Core patches Cédric Le Goater (11): net: etraxfs_eth: convert SysBus init method to a realize method net: etraxfs_eth: add a reset method net: lan9118: convert SysBus init method to a realize method net: lance: convert SysBus init method to a realize method net: milkymist_minimac2: convert SysBus init method to a realize method net: mipsnet: convert SysBus init method to a realize method net: opencores_eth: convert SysBus init method to a realize method net: smc91c111: convert SysBus init method to a realize method net: stellaris_enet: convert SysBus init method to a realize method net: stellaris_enet: add a reset method net: xgmac: convert SysBus init method to a realize method David Hildenbrand (16): memory-device: fix alignment error message memory-device: fix error message when hinted address is too small memory-device: improve "range conflicts" error message pc-dimm: pass PCDIMMDevice to pc_dimm_.*plug memory-device: use memory device terminology in error messages memory-device: introduce separate config option memory-device: forward errors in get_region_size()/get_plugged_size() memory-device: document MemoryDeviceClass memory-device: add and use memory_device_get_region_size() memory-device: factor out get_memory_region() from pc-dimm memory-device: drop get_region_size() memory-device: add device class function set_addr() memory-device: complete factoring out pre_plug handling memory-device: complete factoring out plug handling memory-device: complete factoring out unplug handling memory-device: trace when pre_plugging/plugging/unplugging Igor Mammedov (2): vl.c deprecate incorrect CPUs topology vl:c: make sure that sockets are calculated correctly in '-smp X' case Li Qiang (1): machine: fix a typo Markus Armbruster (2): numa: Fix QMP command set-numa-node error handling numa: Clean up error reporting in parse_numa() Philippe Mathieu-Daudé (12): trace-events: Fix copy/paste typo hw/timer/sun4v-rtc: Convert from DPRINTF() macro to trace events hw/timer/sun4v-rtc: Use DeviceState::realize rather than SysBusDevice::init hw/ssi/xilinx_spi: Use DeviceState::realize rather than SysBusDevice::init hw/sh4/sh_pci: Use DeviceState::realize rather than SysBusDevice::init hw/pci-host/bonito: Use DeviceState::realize rather than SysBusDevice::init hw/mips/gt64xxx_pci: Convert gt64120_reset() function into Device reset method hw/mips/gt64xxx_pci: Mark as bridge device hw/sparc64/niagara: Model the I/O Bridge with the 'unimplemented_device' hw/alpha/typhoon: Remove unuseful code hw/hppa/dino: Remove unuseful code hw/mips/malta: Remove unuseful code Zhang Yi (1): hostmem-file: fixed the memory leak while get pmem path. default-configs/i386-softmmu.mak | 3 +- default-configs/ppc64-softmmu.mak | 3 +- default-configs/sparc64-softmmu.mak | 1 - qapi/misc.json | 2 +- include/hw/mem/memory-device.h | 74 +++++++++++++++++--- include/hw/mem/pc-dimm.h | 10 +-- include/sysemu/numa.h | 1 - backends/hostmem-file.c | 10 ++- hw/alpha/typhoon.c | 13 ---- hw/core/machine.c | 2 +- hw/hppa/dino.c | 7 -- hw/i386/pc.c | 6 +- hw/mem/memory-device.c | 103 ++++++++++++++++++++++------ hw/mem/nvdimm.c | 9 ++- hw/mem/pc-dimm.c | 84 ++++++++--------------- hw/mips/gt64xxx_pci.c | 18 ++--- hw/mips/mips_malta.c | 13 ---- hw/net/etraxfs_eth.c | 44 ++++++++---- hw/net/lan9118.c | 9 +-- hw/net/lance.c | 8 +-- hw/net/milkymist-minimac2.c | 9 +-- hw/net/mipsnet.c | 9 +-- hw/net/opencores_eth.c | 8 +-- hw/net/smc91c111.c | 8 +-- hw/net/stellaris_enet.c | 15 ++-- hw/net/xgmac.c | 9 +-- hw/pci-host/bonito.c | 9 +-- hw/ppc/spapr.c | 29 +++----- hw/sh4/sh_pci.c | 20 +++--- hw/sparc64/niagara.c | 4 +- hw/ssi/xilinx_spi.c | 9 +-- hw/timer/sun4v-rtc.c | 23 +++---- numa.c | 21 +++--- vl.c | 12 +++- hw/Makefile.objs | 2 +- hw/mem/Makefile.objs | 4 +- hw/mem/trace-events | 5 +- hw/timer/trace-events | 6 +- qemu-deprecated.texi | 12 ++++ 39 files changed, 347 insertions(+), 287 deletions(-) -- 2.18.0.rc1.1.g3f1ff2140

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[libvirt] [PATCH] qemu: fix device name passed to error report
by Daniel P. Berrangé 20 Oct '18

20 Oct '18

Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com> --- src/qemu/qemu_hotplug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c index 0a63741b9e..12bef16fd6 100644 --- a/src/qemu/qemu_hotplug.c +++ b/src/qemu/qemu_hotplug.c @@ -5814,7 +5814,7 @@ qemuDomainDetachNetDevice(virQEMUDriverPtr driver, if (qemuIsMultiFunctionDevice(vm->def, &detach->info)) { virReportError(VIR_ERR_OPERATION_FAILED, _("cannot hot unplug multifunction PCI device: %s"), - dev->data.disk->dst); + net->ifname); goto cleanup; } -- 2.17.2

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[libvirt] [PATCH] qemu: Fix IOThread pids lost after qemuProcessReconnect
by Jie Wang 19 Oct '18

19 Oct '18

>From fca1732c0e1f691fb25c614349d5486bbc73a109 Mon Sep 17 00:00:00 2001 From: Jie Wang <wangjie88(a)huawei.com> Date: Wed, 17 Oct 2018 22:55:51 +0800 Subject: [PATCH] qemu: Fix IOThread pids lost after qemuProcessReconnect IOThread pids info will lost after libvirtd restart, then if we call pinIOThread, sched_setaffinity will be called with pid 0, not IOThread pid. So pinIOThread cannot work normally. Signed-off-by: Jie Wang <wangjie88.huawei.com> --- src/qemu/qemu_process.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 40d35cbe6b..5bf55721d2 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -7650,6 +7650,9 @@ qemuProcessReconnect(void *opaque) qemuDomainVcpuPersistOrder(obj->def); + if (qemuProcessDetectIOThreadPIDs(driver, obj, QEMU_ASYNC_JOB_NONE) < 0) + goto error; + if (qemuSecurityReserveLabel(driver->securityManager, obj->def, obj->pid) < 0) goto error; -- 2.16.2.windows.1

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[libvirt] [PATCH v4 0/5] libxl: PVHv2 support
by Marek Marczykowski-Górecki 19 Oct '18

19 Oct '18

This is a respin of my old PVHv1 patch[1], converted to PVHv2. The actual code use "PVH" name. The guest ostype reuse VIR_DOMAIN_OSTYPE_XEN, but to request PVH machine, machine="xenpvh" attribute is used. Since PVHv2 relies on features in newer Xen versions, I needed to convert also some older code. For example b_info->u.hvm.nested_hvm was deprecated in favor of b_info->nested_hvm. While the code do handle both old and new versions (obviously refusing PVHv2 if Xen is too old), this isn't the case for tests. How it should be handled, if at all? To test this with all supported Xen versions (4.6, 4.7, 4.8, 4.9, 4.10, 4.11, unstable), I've extended travis configuration for that[2]. It isn't exactly trivial to build Xen 4.6-4.8 on recent system, mostly thanks to -Werror and new warnings, but also other toolchain changes. Because of this, the configuration is rather hacky. But it may be a good idea to include multiple pre-built Xen versions in the base docker image and choose one using ./configure options (maybe together with some symlink or environment variable like PKG_CONFIG_PATH). [1] https://www.redhat.com/archives/libvir-list/2016-August/msg00376.html [2] https://github.com/marmarek/libvirt/tree/travis-xen-pvh Changes in v2: - drop "docs: don't refer to deprecated 'linux' ostype in example" patch - migrating further away from "linux" os type is offtopic to this series and apparently is a controversial thing - drop "docs: update domain schema for machine attribute" patch - already applied - apply review comments from Jim - rebase on master Changes in v3: - rebase on master, drop already applied patches - use #ifdef LIBXL_DOMAIN_TYPE_PVH to detect PVH support, fix compilation failure on older Xen - exclude PVH from VIR_DOMAIN_OSTYPE_XEN <-> VIR_DOMAIN_OSTYPE_LINUX conversion - fix reported capabilities for PVH Changes in v4: - change PVH support detection method Marek Marczykowski-Górecki (5): libxl: reorder libxlMakeDomBuildInfo for upcoming PVH support libxl: add support for PVH tests: add basic Xen PVH test xenconfig: add support for parsing type= xl config entry xenconfig: add support for type="pvh" docs/formatcaps.html.in | 4 +- docs/schemas/domaincommon.rng | 1 +- m4/virt-driver-libxl.m4 | 3 +- src/conf/domain_conf.c | 6 +- src/libxl/libxl_capabilities.c | 38 +++++++++-- src/libxl/libxl_conf.c | 76 ++++++++++++++++------ src/libxl/libxl_driver.c | 6 +- src/xenconfig/xen_common.c | 27 ++++++-- src/xenconfig/xen_xl.c | 5 +- tests/libxlxml2domconfigdata/basic-pvh.json | 49 ++++++++++++++- tests/libxlxml2domconfigdata/basic-pvh.xml | 28 ++++++++- tests/libxlxml2domconfigtest.c | 3 +- tests/testutilsxen.c | 3 +- tests/xlconfigdata/test-fullvirt-type.cfg | 21 ++++++- tests/xlconfigdata/test-fullvirt-type.xml | 27 ++++++++- tests/xlconfigdata/test-paravirt-type.cfg | 13 ++++- tests/xlconfigdata/test-paravirt-type.xml | 25 +++++++- tests/xlconfigdata/test-pvh-type.cfg | 13 ++++- tests/xlconfigdata/test-pvh-type.xml | 25 +++++++- tests/xlconfigtest.c | 3 +- 20 files changed, 341 insertions(+), 35 deletions(-) create mode 100644 tests/libxlxml2domconfigdata/basic-pvh.json create mode 100644 tests/libxlxml2domconfigdata/basic-pvh.xml create mode 100644 tests/xlconfigdata/test-fullvirt-type.cfg create mode 100644 tests/xlconfigdata/test-fullvirt-type.xml create mode 100644 tests/xlconfigdata/test-paravirt-type.cfg create mode 100644 tests/xlconfigdata/test-paravirt-type.xml create mode 100644 tests/xlconfigdata/test-pvh-type.cfg create mode 100644 tests/xlconfigdata/test-pvh-type.xml base-commit: 199eee6aae7af3d813fbe98660c7e0fa1a8ae7b7 -- git-series 0.9.1

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[libvirt] [PATCH v2 00/12] Allow modification of IOThread polling values (redux)
by John Ferlan 19 Oct '18

19 Oct '18

v1: https://www.redhat.com/archives/libvir-list/2018-October/msg00456.html Changes since v1 (from code review) Patch 2: Move the job back into qemuDomainGetIOThreadsLive Patch 3: Add check for ActiveJob before allowing, use true for *StatsWorker, and print 'iothread' in output not 'block' Patch 5: Use virCheckPositiveArgGoto(nparams, error) instead of using virCheckNonNegativeArgGoto(nparams, error). And then remove the if (nparams) before the virCheckNonNullArgGoto(params, error); Patch 6: Add ability to determine which parameter was set via bool set_poll_{max_ns|grow|shrink} values. Then use those in the macro that sets the value to determine whether or not the value will be set based on whether it was changed. Patch 10: Use bool's to set_ when the value is found in the incoming params list. Remove the check that says poll_max_ns needs to be set. Testing proves that if it's set to 0, then the grow and shrink values can be changed (although they do nothing) Patch 12: (NEW) - News article John Ferlan (12): qemu: Check for and return IOThread polling values if available qemu: Split qemuDomainGetIOThreadsLive qemu: Implement the ability to return IOThread stats virsh: Add ability to display IOThread stats lib: Introduce virDomainSetIOThreadParams qemu: Add monitor functions to set IOThread params qemu: Alter qemuDomainChgIOThread to take enum instead of bool qemu: Alter qemuDomainChgIOThread to take qemuMonitorIOThreadInfo qemu: Detect whether iothread polling is supported qemu: Introduce qemuDomainSetIOThreadParams tools: Add virsh iothreadset command docs: Add news article for IOThread polling docs/news.xml | 13 + include/libvirt/libvirt-domain.h | 45 ++ src/driver-hypervisor.h | 8 + src/libvirt-domain.c | 108 +++++ src/libvirt_public.syms | 5 + src/qemu/qemu_capabilities.c | 2 + src/qemu/qemu_capabilities.h | 1 + src/qemu/qemu_driver.c | 384 ++++++++++++++++-- src/qemu/qemu_monitor.c | 19 + src/qemu/qemu_monitor.h | 9 + src/qemu/qemu_monitor_json.c | 50 +++ src/qemu/qemu_monitor_json.h | 4 + src/remote/remote_driver.c | 1 + src/remote/remote_protocol.x | 21 +- src/remote_protocol-structs | 10 + .../caps_2.10.0.aarch64.xml | 1 + .../caps_2.10.0.ppc64.xml | 1 + .../caps_2.10.0.s390x.xml | 1 + .../caps_2.10.0.x86_64.xml | 1 + .../caps_2.11.0.s390x.xml | 1 + .../caps_2.11.0.x86_64.xml | 1 + .../caps_2.12.0.aarch64.xml | 1 + .../caps_2.12.0.ppc64.xml | 1 + .../caps_2.12.0.s390x.xml | 1 + .../caps_2.12.0.x86_64.xml | 1 + .../qemucapabilitiesdata/caps_2.9.0.ppc64.xml | 1 + .../qemucapabilitiesdata/caps_2.9.0.s390x.xml | 1 + .../caps_2.9.0.x86_64.xml | 1 + .../qemucapabilitiesdata/caps_3.0.0.ppc64.xml | 1 + .../caps_3.0.0.riscv32.xml | 1 + .../caps_3.0.0.riscv64.xml | 1 + .../qemucapabilitiesdata/caps_3.0.0.s390x.xml | 1 + .../caps_3.0.0.x86_64.xml | 1 + tools/virsh-domain-monitor.c | 7 + tools/virsh-domain.c | 110 +++++ tools/virsh.pod | 47 ++- 36 files changed, 825 insertions(+), 37 deletions(-) -- 2.17.2

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[libvirt] [PATCH] virFileInData: Preserve errno on error
by Michal Privoznik 19 Oct '18

19 Oct '18

The virFileInData() function should return to the caller if the current position the passed file is in is a data section or a hole (and also how long the current section is). At any rate, upon return from this function (be it successful or not) the original position in the file is restored. This may mess up with errno which might have been set earlier. Save the errno into a local variable so it can be restored for the caller's sake. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com> --- src/util/virfile.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/src/util/virfile.c b/src/util/virfile.c index e09992e41a..f6f01ec1e1 100644 --- a/src/util/virfile.c +++ b/src/util/virfile.c @@ -4072,11 +4072,18 @@ virFileInData(int fd, ret = 0; cleanup: /* At any rate, reposition back to where we started. */ - if (cur != (off_t) -1 && - lseek(fd, cur, SEEK_SET) == (off_t) -1) { - virReportSystemError(errno, "%s", - _("unable to restore position in file")); - ret = -1; + if (cur != (off_t) -1) { + int theerrno = errno; + + if (lseek(fd, cur, SEEK_SET) == (off_t) -1) { + virReportSystemError(errno, "%s", + _("unable to restore position in file")); + ret = -1; + if (theerrno == 0) + theerrno = errno; + } + + errno = theerrno; } return ret; } -- 2.18.1

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