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[libvirt] [PATCH 0/3] qemu: Improve handling of format for 'network' and 'volume' disks (blockdev-add saga)
by Peter Krempa 01 Feb '19

01 Feb '19

Peter Krempa (3): tests: qemu: Test network disks without format specified explicitly qemu: domain: Assume 'raw' default storage format also for network storage qemu: domain: Treat 'volume' disks as 'raw' if neiter user nor pool provided format src/qemu/qemu_domain.c | 8 ++++++-- tests/qemuxml2argvdata/disk-network-gluster.xml | 2 +- tests/qemuxml2argvdata/disk-network-iscsi.xml | 2 +- tests/qemuxml2argvdata/disk-network-nbd.xml | 2 +- tests/qemuxml2argvdata/disk-source-pool-mode.args | 6 +++--- tests/qemuxml2argvdata/disk-source-pool.args | 4 ++-- 6 files changed, 14 insertions(+), 10 deletions(-) -- 2.20.1

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[libvirt] [PATCH] docs: news: Update the release notes with the SEV permission fix
by Erik Skultety 01 Feb '19

01 Feb '19

Signed-off-by: Erik Skultety <eskultet(a)redhat.com> --- docs/news.xml | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/docs/news.xml b/docs/news.xml index 55d6a3926b..fcc42698b3 100644 --- a/docs/news.xml +++ b/docs/news.xml @@ -50,6 +50,18 @@ <section title="Improvements"> </section> <section title="Bug fixes"> + <change> + <summary> + qemu: Use CAP_DAC_OVERRIDE during QEMU capabilities probing + </summary> + <description> + By default, libvirt runs the QEMU process as qemu:qemu which could + cause issues during probing as some features (like AMD SEV) might be + inaccesible to QEMU because of file system permissions. Therefore, + CAP_DAC_OVERRIDE is granted to overcome these for the purposes of + probing. + </description> + </change> <change> <summary> storage: Add default mount options for fs/netfs storage pools -- 2.20.1

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[libvirt] [PATCH v2 0/7] network: fix networking for firewalld+nftables
by Laine Stump 01 Feb '19

01 Feb '19

Resolves: https://bugzilla.redhat.com/1638342 Creates-and-Resolves: https://bugzilla.redhat.com/1650320 V1: https://www.redhat.com/archives/libvir-list/2019-January/msg00227.html The detailed explanation of this is in Patch 4/7 and 5/7. Basically, when firewalld enables their new nftables backend, libvirt virtual networks lose all ability to forward packets from guests out to the physical network, and can only communicate with the host itself as much as firewalld's "public" zone will allow (which isn't much, and doesn't include DHCP or DNS). I *think* I've addressed everything in Daniel and John's review comments. In particular, I've made installation of the libvirt zone file optional, and if the libvirt zone is missing, I only log an error if the firewalld backend is set to nftables. Laine Stump (7): configure: change HAVE_FIREWALLD to WITH_FIREWALLD util: move all firewalld-specific stuff into its own files util: new virFirewallD APIs + docs configure: selectively install a firewalld 'libvirt' zone network: set firewalld zone of bridges to "libvirt" zone when appropriate network: allow configuring firewalld zone for virtual network bridge device docs: update news.xml for firewalld zone changes configure.ac | 3 + docs/firewall.html.in | 38 +++ docs/formatnetwork.html.in | 17 + docs/news.xml | 40 +++ docs/schemas/basictypes.rng | 6 + docs/schemas/network.rng | 6 + include/libvirt/virterror.h | 1 + libvirt.spec.in | 31 ++ m4/virt-firewalld-zone.m4 | 45 +++ m4/virt-firewalld.m4 | 4 +- src/conf/network_conf.c | 14 +- src/conf/network_conf.h | 1 + src/libvirt_private.syms | 10 + src/network/Makefile.inc.am | 10 +- src/network/bridge_driver.c | 6 +- src/network/bridge_driver_linux.c | 67 ++++ src/network/libvirt.zone | 23 ++ src/nwfilter/nwfilter_driver.c | 6 +- src/util/Makefile.inc.am | 3 + src/util/virerror.c | 3 +- src/util/virfirewall.c | 86 +---- src/util/virfirewalld.c | 373 +++++++++++++++++++++ src/util/virfirewalld.h | 46 +++ src/util/virfirewalldpriv.h | 30 ++ src/util/virfirewallpriv.h | 2 - tests/networkxml2xmlin/routed-network.xml | 2 +- tests/networkxml2xmlout/routed-network.xml | 2 +- tests/virfirewalltest.c | 2 + 28 files changed, 779 insertions(+), 98 deletions(-) create mode 100644 m4/virt-firewalld-zone.m4 create mode 100644 src/network/libvirt.zone create mode 100644 src/util/virfirewalld.c create mode 100644 src/util/virfirewalld.h create mode 100644 src/util/virfirewalldpriv.h -- 2.20.1

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[libvirt] [PATCH v2 0/4] storage: More uniquely identify NPIV LUNs
by John Ferlan 01 Feb '19

01 Feb '19

v1: https://www.redhat.com/archives/libvir-list/2018-December/msg00562.html but no review until January, see: https://www.redhat.com/archives/libvir-list/2019-January/msg00079.html Changes since v1: * Rework code to have virStorageBackendSCSISerial use the existing virStorageFileGetSCSIKey * Then introduce and use virStorageFileGetNPIVKey in order to get a more unique key for NPIV LUNs. Follows same fallback policy as SCSI LUNs if the called *Key function either doesn't exist or fails to return a valid value. John Ferlan (4): util: Modify virStorageFileGetSCSIKey return storage: Rework virStorageBackendSCSISerial util: Introduce virStorageFileGetNPIVKey storage: Fetch a unique key for vHBA/NPIV LUNs src/libvirt_private.syms | 1 + src/storage/storage_util.c | 45 +++++++---------- src/util/virstoragefile.c | 101 +++++++++++++++++++++++++++++++++++-- src/util/virstoragefile.h | 2 + 4 files changed, 118 insertions(+), 31 deletions(-) -- 2.20.1

3 14

[libvirt] [PATCH] tests: Update qemucaps2xml for QEMU 4.0.0 on x86_64
by Andrea Bolognani 01 Feb '19

01 Feb '19

Commit fb0d0d6c5492 added capabilities data and updated qemucapabilitiestest but forgot to update qemucaps2xmltest at the same time. Signed-off-by: Andrea Bolognani <abologna(a)redhat.com> --- *cough* and of course the reviewer didn't notice *cough* .../qemucaps2xmloutdata/caps_4.0.0.x86_64.xml | 28 +++++++++++++++++++ tests/qemucaps2xmltest.c | 1 + 2 files changed, 29 insertions(+) create mode 100644 tests/qemucaps2xmloutdata/caps_4.0.0.x86_64.xml diff --git a/tests/qemucaps2xmloutdata/caps_4.0.0.x86_64.xml b/tests/qemucaps2xmloutdata/caps_4.0.0.x86_64.xml new file mode 100644 index 0000000000..d41693a001 --- /dev/null +++ b/tests/qemucaps2xmloutdata/caps_4.0.0.x86_64.xml @@ -0,0 +1,28 @@ +<capabilities> + + <host> + <cpu> + <arch>x86_64</arch> + </cpu> + <power_management/> + <iommu support='no'/> + </host> + + <guest> + <os_type>hvm</os_type> + <arch name='x86_64'> + <wordsize>64</wordsize> + <emulator>/usr/bin/qemu-system-x86_64</emulator> + <domain type='qemu'/> + <domain type='kvm'/> + </arch> + <features> + <cpuselection/> + <deviceboot/> + <disksnapshot default='on' toggle='no'/> + <acpi default='on' toggle='yes'/> + <apic default='on' toggle='no'/> + </features> + </guest> + +</capabilities> diff --git a/tests/qemucaps2xmltest.c b/tests/qemucaps2xmltest.c index dd9fc6917a..9d6b6f474c 100644 --- a/tests/qemucaps2xmltest.c +++ b/tests/qemucaps2xmltest.c @@ -198,6 +198,7 @@ mymain(void) DO_TEST("x86_64", "caps_2.12.0"); DO_TEST("x86_64", "caps_3.0.0"); DO_TEST("x86_64", "caps_3.1.0"); + DO_TEST("x86_64", "caps_4.0.0"); DO_TEST("aarch64", "caps_2.6.0"); DO_TEST("aarch64", "caps_2.10.0"); DO_TEST("aarch64", "caps_2.12.0"); -- 2.20.1

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[libvirt] [PATCH 0/5] Override the permissions on /dev/sev when probing
by Erik Skultety 01 Feb '19

01 Feb '19

The problem with /dev/sev's default permissions (0600 root:root) is that we can't make it more permissive at the moment otherwise we'd weaken the security of SEV and potentially open the door for a DOS attack. Therefore, the alternative approach is to set CAP_DAC_OVERRIDE capability for the probing QEMU process (and *only* when probing) so that libvirt truly works with SEV. As a necessary side job, this series also makes /dev/sev only available to machines that need it, thus mitigating the possible attack surface even more. Erik Skultety (5): qemu: conf: Remove /dev/sev from the default cgroup device acl list qemu: cgroup: Expose /dev/sev/ only to domains that require SEV qemu: domain: Add /dev/sev into the domain mount namespace selectively security: dac: Relabel /dev/sev in the namespace qemu: caps: Use CAP_DAC_OVERRIDE for probing to avoid permission issues docs/drvqemu.html.in | 2 +- src/qemu/qemu.conf | 2 +- src/qemu/qemu_capabilities.c | 11 +++++++ src/qemu/qemu_cgroup.c | 21 +++++++++++- src/qemu/qemu_domain.c | 24 ++++++++++++++ src/qemu/test_libvirtd_qemu.aug.in | 1 - src/security/security_dac.c | 51 ++++++++++++++++++++++++++++++ src/util/virutil.c | 31 ++++++++++++++++-- 8 files changed, 137 insertions(+), 6 deletions(-) -- 2.20.1

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[libvirt] [PATCH v2] qemu: Rework setting process affinity
by Michal Privoznik 01 Feb '19

01 Feb '19

https://bugzilla.redhat.com/show_bug.cgi?id=1503284 The way we currently start qemu from CPU affinity POV is as follows: 1) the child process is set affinity to all online CPUs (unless some vcpu pinning was given in the domain XML) 2) Once qemu is running, cpuset cgroup is configured taking memory pinning into account Problem is that we let qemu allocate its memory just anywhere in 1) and then rely in 2) to be able to move the memory to configured NUMA nodes. This might not be always possible (e.g. qemu might lock some parts of its memory) and is very suboptimal (copying large memory between NUMA nodes takes significant amount of time). The solution is to set affinity to one of (in priority order): - The CPUs associated with NUMA memory affinity mask - The CPUs associated with emulator pinning - All online host CPUs Later (once QEMU has allocated its memory) we then change this again to (again in priority order): - The CPUs associated with emulator pinning - The CPUs returned by numad - The CPUs associated with vCPU pinning - All online host CPUs Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com> --- diff to v1 (both points suggested by Dan): - Expanded the commit message - fixed qemuProcessGetAllCpuAffinity so that it returns online CPU map only src/qemu/qemu_process.c | 132 +++++++++++++++++++--------------------- 1 file changed, 63 insertions(+), 69 deletions(-) diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 7592c98b74..dace5aaca1 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -2435,6 +2435,21 @@ qemuProcessDetectIOThreadPIDs(virQEMUDriverPtr driver, } +static int +qemuProcessGetAllCpuAffinity(virBitmapPtr *cpumapRet) +{ + *cpumapRet = NULL; + + if (!virHostCPUHasBitmap()) + return 0; + + if (!(*cpumapRet = virHostCPUGetOnlineBitmap())) + return -1; + + return 0; +} + + /* * To be run between fork/exec of QEMU only */ @@ -2443,9 +2458,9 @@ static int qemuProcessInitCpuAffinity(virDomainObjPtr vm) { int ret = -1; - virBitmapPtr cpumap = NULL; virBitmapPtr cpumapToSet = NULL; - virBitmapPtr hostcpumap = NULL; + VIR_AUTOPTR(virBitmap) hostcpumap = NULL; + virDomainNumatuneMemMode mem_mode; qemuDomainObjPrivatePtr priv = vm->privateData; if (!vm->pid) { @@ -2454,59 +2469,39 @@ qemuProcessInitCpuAffinity(virDomainObjPtr vm) return -1; } - if (vm->def->placement_mode == VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO) { - VIR_DEBUG("Set CPU affinity with advisory nodeset from numad"); - cpumapToSet = priv->autoCpuset; + /* Here is the deal, we can't set cpuset.mems before qemu is + * started as it clashes with KVM allocation. Therefore, we + * used to let qemu allocate its memory anywhere as we would + * then move the memory to desired NUMA node via CGroups. + * However, that might not be always possible because qemu + * might lock some parts of its memory (e.g. due to VFIO). + * Even if it possible, memory has to be copied between NUMA + * nodes which is suboptimal. + * Solution is to set affinity that matches the best what we + * would have set in CGroups and then fix it later, once qemu + * is already running. */ + if (virDomainNumaGetNodeCount(vm->def->numa) <= 1 && + virDomainNumatuneGetMode(vm->def->numa, -1, &mem_mode) == 0 && + mem_mode == VIR_DOMAIN_NUMATUNE_MEM_STRICT) { + if (virDomainNumatuneMaybeGetNodeset(vm->def->numa, + priv->autoNodeset, + &cpumapToSet, + -1) < 0) + goto cleanup; + } else if (vm->def->cputune.emulatorpin) { + cpumapToSet = vm->def->cputune.emulatorpin; } else { - VIR_DEBUG("Set CPU affinity with specified cpuset"); - if (vm->def->cpumask) { - cpumapToSet = vm->def->cpumask; - } else { - /* You may think this is redundant, but we can't assume libvirtd - * itself is running on all pCPUs, so we need to explicitly set - * the spawned QEMU instance to all pCPUs if no map is given in - * its config file */ - int hostcpus; - - if (virHostCPUHasBitmap()) { - hostcpumap = virHostCPUGetOnlineBitmap(); - cpumap = virProcessGetAffinity(vm->pid); - } - - if (hostcpumap && cpumap && virBitmapEqual(hostcpumap, cpumap)) { - /* we're using all available CPUs, no reason to set - * mask. If libvirtd is running without explicit - * affinity, we can use hotplugged CPUs for this VM */ - ret = 0; - goto cleanup; - } else { - /* setaffinity fails if you set bits for CPUs which - * aren't present, so we have to limit ourselves */ - if ((hostcpus = virHostCPUGetCount()) < 0) - goto cleanup; - - if (hostcpus > QEMUD_CPUMASK_LEN) - hostcpus = QEMUD_CPUMASK_LEN; - - virBitmapFree(cpumap); - if (!(cpumap = virBitmapNew(hostcpus))) - goto cleanup; - - virBitmapSetAll(cpumap); - - cpumapToSet = cpumap; - } - } + if (qemuProcessGetAllCpuAffinity(&hostcpumap) < 0) + goto cleanup; + cpumapToSet = hostcpumap; } - if (virProcessSetAffinity(vm->pid, cpumapToSet) < 0) + if (cpumapToSet && + virProcessSetAffinity(vm->pid, cpumapToSet) < 0) goto cleanup; ret = 0; - cleanup: - virBitmapFree(cpumap); - virBitmapFree(hostcpumap); return ret; } #else /* !defined(HAVE_SCHED_GETAFFINITY) && !defined(HAVE_BSD_CPU_AFFINITY) */ @@ -2586,7 +2581,8 @@ qemuProcessSetupPid(virDomainObjPtr vm, qemuDomainObjPrivatePtr priv = vm->privateData; virDomainNumatuneMemMode mem_mode; virCgroupPtr cgroup = NULL; - virBitmapPtr use_cpumask; + virBitmapPtr use_cpumask = NULL; + VIR_AUTOPTR(virBitmap) hostcpumap = NULL; char *mem_mask = NULL; int ret = -1; @@ -2598,12 +2594,21 @@ qemuProcessSetupPid(virDomainObjPtr vm, } /* Infer which cpumask shall be used. */ - if (cpumask) + if (cpumask) { use_cpumask = cpumask; - else if (vm->def->placement_mode == VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO) + } else if (vm->def->placement_mode == VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO) { use_cpumask = priv->autoCpuset; - else + } else if (vm->def->cpumask) { use_cpumask = vm->def->cpumask; + } else { + /* You may think this is redundant, but we can't assume libvirtd + * itself is running on all pCPUs, so we need to explicitly set + * the spawned QEMU instance to all pCPUs if no map is given in + * its config file */ + if (qemuProcessGetAllCpuAffinity(&hostcpumap) < 0) + goto cleanup; + use_cpumask = hostcpumap; + } /* * If CPU cgroup controller is not initialized here, then we need @@ -2628,13 +2633,7 @@ qemuProcessSetupPid(virDomainObjPtr vm, qemuSetupCgroupCpusetCpus(cgroup, use_cpumask) < 0) goto cleanup; - /* - * Don't setup cpuset.mems for the emulator, they need to - * be set up after initialization in order for kvm - * allocations to succeed. - */ - if (nameval != VIR_CGROUP_THREAD_EMULATOR && - mem_mask && virCgroupSetCpusetMems(cgroup, mem_mask) < 0) + if (mem_mask && virCgroupSetCpusetMems(cgroup, mem_mask) < 0) goto cleanup; } @@ -6634,12 +6633,7 @@ qemuProcessLaunch(virConnectPtr conn, /* This must be done after cgroup placement to avoid resetting CPU * affinity */ - if (!vm->def->cputune.emulatorpin && - qemuProcessInitCpuAffinity(vm) < 0) - goto cleanup; - - VIR_DEBUG("Setting emulator tuning/settings"); - if (qemuProcessSetupEmulator(vm) < 0) + if (qemuProcessInitCpuAffinity(vm) < 0) goto cleanup; VIR_DEBUG("Setting cgroup for external devices (if required)"); @@ -6708,10 +6702,6 @@ qemuProcessLaunch(virConnectPtr conn, if (qemuProcessUpdateAndVerifyCPU(driver, vm, asyncJob) < 0) goto cleanup; - VIR_DEBUG("Setting up post-init cgroup restrictions"); - if (qemuSetupCpusetMems(vm) < 0) - goto cleanup; - VIR_DEBUG("setting up hotpluggable cpus"); if (qemuDomainHasHotpluggableStartupVcpus(vm->def)) { if (qemuDomainRefreshVcpuInfo(driver, vm, asyncJob, false) < 0) @@ -6737,6 +6727,10 @@ qemuProcessLaunch(virConnectPtr conn, if (qemuProcessDetectIOThreadPIDs(driver, vm, asyncJob) < 0) goto cleanup; + VIR_DEBUG("Setting emulator tuning/settings"); + if (qemuProcessSetupEmulator(vm) < 0) + goto cleanup; + VIR_DEBUG("Setting global CPU cgroup (if required)"); if (qemuSetupGlobalCpuCgroup(vm) < 0) goto cleanup; -- 2.19.2

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[libvirt] [PATCH 0/4] qemu: Add PCI support for RISC-V guests
by Andrea Bolognani 01 Feb '19

01 Feb '19

Now that the QEMU part has been merged, it's time to make the feature available to libvirt users as well. Andrea Bolognani (4): tests: Add capabilities data for QEMU 4.0.0 on RISC-V qemu: Add PCI support for RISC-V guests tests: Add test for PCI usage on RISC-V news: Update for PCI support on RISC-V docs/news.xml | 10 + src/qemu/qemu_capabilities.c | 4 +- src/qemu/qemu_domain.c | 2 + src/qemu/qemu_domain_address.c | 3 +- .../caps_4.0.0.riscv32.replies | 17625 ++++++++++++++++ .../caps_4.0.0.riscv32.xml | 180 + .../caps_4.0.0.riscv64.replies | 17625 ++++++++++++++++ .../caps_4.0.0.riscv64.xml | 180 + tests/qemucapabilitiestest.c | 2 + .../caps_4.0.0.riscv32.xml | 25 + .../caps_4.0.0.riscv64.xml | 25 + tests/qemucaps2xmltest.c | 2 + .../riscv64-virt-headless.riscv64-latest.args | 3 +- tests/qemuxml2argvdata/riscv64-virt-pci.args | 27 + tests/qemuxml2argvdata/riscv64-virt-pci.xml | 24 + tests/qemuxml2argvtest.c | 2 + tests/qemuxml2xmloutdata/riscv64-virt-pci.xml | 28 + tests/qemuxml2xmltest.c | 2 + 18 files changed, 35766 insertions(+), 3 deletions(-) create mode 100644 tests/qemucapabilitiesdata/caps_4.0.0.riscv32.replies create mode 100644 tests/qemucapabilitiesdata/caps_4.0.0.riscv32.xml create mode 100644 tests/qemucapabilitiesdata/caps_4.0.0.riscv64.replies create mode 100644 tests/qemucapabilitiesdata/caps_4.0.0.riscv64.xml create mode 100644 tests/qemucaps2xmloutdata/caps_4.0.0.riscv32.xml create mode 100644 tests/qemucaps2xmloutdata/caps_4.0.0.riscv64.xml create mode 100644 tests/qemuxml2argvdata/riscv64-virt-pci.args create mode 100644 tests/qemuxml2argvdata/riscv64-virt-pci.xml create mode 100644 tests/qemuxml2xmloutdata/riscv64-virt-pci.xml -- 2.20.1

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[libvirt] add ivshmem property master
by 吴雨霖 01 Feb '19

01 Feb '19

[Problem Description] I read qemu-doc.texi in qemu-mster source code, which have a explain of migrating ivshmem below “With device property @option{master=on}, the guest will copy the shared.memory on migration to the destination host. With @option{master=off}, the guest will not be able to migrate with the device attached.” However, libvirt library can not recognize the property “master=on”. When I directly used command "qemu-kvm -device ivshmem-plain,id=shmem0,memdev=shmmem-shmem0,master=on,bus=pci.0,addr=0xa” to launch a guest, qemu support ivshmem property master=on. So, I suggest adding code to support property master=on in libvirt. [Code Review] The below is the part of source code in qemu-master. There's no definition here about ivshmem master. domain_conf.h struct _virDomainShmemDef { char *name; unsigned long long size; int model; /* enum virDomainShmemModel */ struct { bool enabled; virDomainChrSourceDef chr; } server; struct { bool enabled; unsigned vectors; virTristateSwitch ioeventfd; } msi; virDomainDeviceInfo info; }; [changed code] src/conf/domain_conf.c src/conf/domain_conf.h [Detail of Source Code Modification] diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 9f75dc4..b41be37 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -14665,7 +14665,6 @@ virDomainShmemDefParseXML(virDomainXMLOptionPtr xmlopt, xmlNodePtr save = ctxt->node; xmlNodePtr server = NULL; - if (VIR_ALLOC(def) < 0) return NULL; - if (VIR_ALLOC(def) < 0) return NULL; @@ -14685,12 +14684,28 @@ virDomainShmemDefParseXML(virDomainXMLOptionPtr xmlopt, VIR_FREE(tmp); } + if (!(def->name = virXMLPropString(node, "name"))) { virReportError(VIR_ERR_XML_ERROR, "%s", _("shmem element must contain 'name' attribute")); goto cleanup; } + + if ((tmp = virXMLPropString(node, "master"))) { + int val; + + if ((val = virTristateSwitchTypeFromString(tmp)) <= 0) { + virReportError(VIR_ERR_XML_ERROR, + _("invalid ivshmem master setting for shmem: '%s'"), + tmp); + goto cleanup; + } + def->master = val; + VIR_FREE(tmp); + } + + if (virDomainParseScaledValue("./size[1]", NULL, ctxt, &def->size, 1, ULLONG_MAX, false) < 0) goto cleanup; diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index f1e6e4e..615d721 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -1727,8 +1727,10 @@ typedef enum { struct _virDomainShmemDef { char *name; + unsigned long long size; int model; /* enum virDomainShmemModel */ + virTristateSwitch master; struct { bool enabled; virDomainChrSourceDef chr; }

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[libvirt] [cim PATCH] Ensure nul termination of hostname
by Daniel P. Berrangé 01 Feb '19

01 Feb '19

Newest GCC warns that the string copying is potentially truncated and thus not nul terminated. In file included from /usr/include/string.h:494, from ../../src/Virt_HostSystem.c:23: In function ‘strncpy’, inlined from ‘resolve_host’ at ../../src/Virt_HostSystem.c:55:28, inlined from ‘get_fqdn’ at ../../src/Virt_HostSystem.c:92:23, inlined from ‘set_host_system_properties’ at ../../src/Virt_HostSystem.c:109:13: /usr/include/bits/string_fortified.h:106:10: error: ‘__builtin_strncpy’ specified bound 256 equals destination size [-Werror=stringop-truncation] 106 | return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In function ‘strncpy’, inlined from ‘resolve_host’ at ../../src/Virt_HostSystem.c:67:17, inlined from ‘get_fqdn’ at ../../src/Virt_HostSystem.c:92:23, inlined from ‘set_host_system_properties’ at ../../src/Virt_HostSystem.c:109:13: /usr/include/bits/string_fortified.h:106:10: error: ‘__builtin_strncpy’ specified bound 256 equals destination size [-Werror=stringop-truncation] 106 | return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com> --- src/Virt_HostSystem.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/src/Virt_HostSystem.c b/src/Virt_HostSystem.c index ebe8184..5bc52ca 100644 --- a/src/Virt_HostSystem.c +++ b/src/Virt_HostSystem.c @@ -38,7 +38,7 @@ const static CMPIBroker *_BROKER; -static int resolve_host(char *host, char *buf, int size) +static int resolve_host(char *host, int size) { struct hostent *he; int i; @@ -52,7 +52,8 @@ static int resolve_host(char *host, char *buf, int size) for (i = 0; he->h_aliases[i] != NULL; i++) { if ((strchr(he->h_aliases[i], '.') != NULL) && (strstr(he->h_aliases[i], "localhost") == NULL)) { - strncpy(buf, he->h_aliases[i], size); + strncpy(host, he->h_aliases[i], size - 1); + host[size - 1] = '\0'; return 0; } } @@ -63,12 +64,13 @@ static int resolve_host(char *host, char *buf, int size) // but also be sure the value isn't empty and that it doesn't // contain "localhost" if ((he->h_name != NULL) && (!STREQC(he->h_name, "")) && - (strstr(he->h_name, "localhost") == NULL)) - strncpy(buf, he->h_name, size); - else if ((host != NULL) && (!STREQC(host, "")) && - (strstr(host, "localhost") == NULL)) - strncpy(buf, host, size); - else { + (strstr(he->h_name, "localhost") == NULL)) { + strncpy(host, he->h_name, size - 1); + host[size - 1] = '\0'; + } else if ((host != NULL) && (!STREQC(host, "")) && + (strstr(host, "localhost") == NULL)) { + return 0; + } else { CU_DEBUG("Unable to find valid hostname value."); return -1; } @@ -76,20 +78,18 @@ static int resolve_host(char *host, char *buf, int size) return 0; } -static int get_fqdn(char *buf, int size) +static int get_fqdn(char *host, int size) { - char host[256]; int ret = 0; - if (gethostname(host, sizeof(host)) != 0) { + if (gethostname(host, size) != 0) { CU_DEBUG("gethostname(): %m"); return -1; } - if (strchr(host, '.') != NULL) - strncpy(buf, host, size); - else - ret = resolve_host(host, buf, size); + if (strchr(host, '.') == NULL) { + ret = resolve_host(host, size); + } return ret; } -- 2.20.1

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