August 2012 - Devel - libvirt List Archives

[libvirt] [PATCH] build: ship stamp files
by Eric Blake 16 Aug '12

16 Aug '12

'make distcheck' fails because the generated ESX and HyperV files are (intentionally) marked read-only, but since the stamp file was missing, make assumes they need to be rebuilt. Shipping the stamp file solves the problem. * src/Makefile.am (EXTRA_DIST): Ship stamp files. --- Pushing under the build-breaker rule. src/Makefile.am | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/Makefile.am b/src/Makefile.am index ac5a27f..213bd83 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -930,6 +930,8 @@ BUILT_SOURCES += $(ESX_DRIVER_GENERATED) ESX_GENERATED_STAMP = .esx_vi_generator.stamp +EXTRA_DIST += $(ESX_GENERATED_STAMP) + $(ESX_DRIVER_GENERATED): $(ESX_GENERATED_STAMP) $(ESX_GENERATED_STAMP): $(srcdir)/esx/esx_vi_generator.input \ @@ -956,6 +958,8 @@ BUILT_SOURCES += $(HYPERV_DRIVER_GENERATED) HYPERV_GENERATED_STAMP = .hyperv_wmi_generator.stamp +EXTRA_DIST += $(HYPERV_GENERATED_STAMP) + $(HYPERV_DRIVER_GENERATED): $(HYPERV_GENERATED_STAMP) $(HYPERV_GENERATED_STAMP): $(srcdir)/hyperv/hyperv_wmi_generator.input \ -- 1.7.11.2

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[libvirt] [PATCH 0/2] qemu: support setting vlan tag for <interface
by Laine Stump 16 Aug '12

16 Aug '12

This would have been just one small patch, but there was a deficiency in the low level functions to save and restore pre-existing state of a virtual function. I have tested these patches on a RHEL6 machine with an SR-IOV adapter, and it properly handled the save/set .. [attach-to-guest] .. [detach] .. restore cycle both when the original state of the VF had a vlan tag and not, and when the guest was requesting a vlan tag, and not. (Now I'm wondering if this would also work for macvtap "passthrough" mode when the adapter used is a VF - it looks like the only thing stopping it is that the code to save / set / restore in that mode uses the device name of the vf, rather than referring to it as <physical device> vf <n>; since only VFs understand setting the vlan tag, the lower level code just assumes it can't be done)

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[libvirt] [PATCH v2] qemu: Set swap_hard_limit before hard_limit
by Osier Yang 16 Aug '12

16 Aug '12

Setting hard_limit larger than previous swap_hard_limit must fail, it's not that good if one wants to change the swap_hard_limit and hard_limit together. E.g. % virsh memtune rhel6 hard_limit : 1000000 soft_limit : 1000000 swap_hard_limit: 1000000 % virsh memtune rhel6 --hard-limit 1000020 --soft-limit 1000020 \ --swap-hard-limit 1000020 --live This patch reoder the limits setting to set the swap_hard_limit first, hard_limit then, and soft_limit last if it's greater than current swap_hard_limit. And soft_limit first, hard_limit then, swap_hard_limit last, if not. --- src/qemu/qemu_driver.c | 59 +++++++++++++++++++++++++++++++++++++++++------ 1 files changed, 51 insertions(+), 8 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 80cfa84..a26d3cd 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -6651,11 +6651,18 @@ qemuDomainSetMemoryParameters(virDomainPtr dom, virDomainDefPtr persistentDef = NULL; virCgroupPtr group = NULL; virDomainObjPtr vm = NULL; + virTypedParameterPtr hard_limit = NULL; + virTypedParameterPtr soft_limit = NULL; + virTypedParameterPtr swap_hard_limit = NULL; + virTypedParameterPtr sorted_params[nparams]; + unsigned long long val = 0; + int ret = -1; int rc; virCheckFlags(VIR_DOMAIN_AFFECT_LIVE | VIR_DOMAIN_AFFECT_CONFIG, -1); + if (virTypedParameterArrayValidate(params, nparams, VIR_DOMAIN_MEMORY_HARD_LIMIT, VIR_TYPED_PARAM_ULLONG, @@ -6694,13 +6701,49 @@ qemuDomainSetMemoryParameters(virDomainPtr dom, } } + for (i = 0; i < nparams; i++) { + if (STREQ(params[i].field, VIR_DOMAIN_MEMORY_HARD_LIMIT)) + hard_limit = &params[i]; + else if (STREQ(params[i].field, VIR_DOMAIN_MEMORY_SOFT_LIMIT)) + soft_limit = &params[i]; + else if (STREQ(params[i].field, VIR_DOMAIN_MEMORY_SWAP_HARD_LIMIT)) + swap_hard_limit = &params[i]; + } + + /* It will fail if hard limit greater than swap hard limit anyway */ + if (swap_hard_limit && + hard_limit && + (hard_limit->value.ul > swap_hard_limit->value.ul)) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("hard limit must be lower than swap hard limit")); + goto cleanup; + } + + /* Get current swap hard limit */ + rc = virCgroupGetMemSwapHardLimit(group, &val); + if (rc != 0) { + virReportSystemError(-rc, "%s", + _("unable to get swap hard limit")); + goto cleanup; + } + + if (swap_hard_limit->value.ul > val) { + sorted_params[0] = swap_hard_limit; + sorted_params[1] = hard_limit; + sorted_params[2] = soft_limit; + } else { + sorted_params[0] = soft_limit; + sorted_params[1] = hard_limit; + sorted_params[2] = swap_hard_limit; + } + ret = 0; for (i = 0; i < nparams; i++) { - virTypedParameterPtr param = &params[i]; + virTypedParameterPtr param = sorted_params[i]; if (STREQ(param->field, VIR_DOMAIN_MEMORY_HARD_LIMIT)) { if (flags & VIR_DOMAIN_AFFECT_LIVE) { - rc = virCgroupSetMemoryHardLimit(group, params[i].value.ul); + rc = virCgroupSetMemoryHardLimit(group, sorted_params[i]->value.ul); if (rc != 0) { virReportSystemError(-rc, "%s", _("unable to set memory hard_limit tunable")); @@ -6709,11 +6752,11 @@ qemuDomainSetMemoryParameters(virDomainPtr dom, } if (flags & VIR_DOMAIN_AFFECT_CONFIG) { - persistentDef->mem.hard_limit = params[i].value.ul; + persistentDef->mem.hard_limit = sorted_params[i]->value.ul; } } else if (STREQ(param->field, VIR_DOMAIN_MEMORY_SOFT_LIMIT)) { if (flags & VIR_DOMAIN_AFFECT_LIVE) { - rc = virCgroupSetMemorySoftLimit(group, params[i].value.ul); + rc = virCgroupSetMemorySoftLimit(group, sorted_params[i]->value.ul); if (rc != 0) { virReportSystemError(-rc, "%s", _("unable to set memory soft_limit tunable")); @@ -6722,11 +6765,11 @@ qemuDomainSetMemoryParameters(virDomainPtr dom, } if (flags & VIR_DOMAIN_AFFECT_CONFIG) { - persistentDef->mem.soft_limit = params[i].value.ul; + persistentDef->mem.soft_limit = sorted_params[i]->value.ul; } } else if (STREQ(param->field, VIR_DOMAIN_MEMORY_SWAP_HARD_LIMIT)) { if (flags & VIR_DOMAIN_AFFECT_LIVE) { - rc = virCgroupSetMemSwapHardLimit(group, params[i].value.ul); + rc = virCgroupSetMemSwapHardLimit(group, sorted_params[i]->value.ul); if (rc != 0) { virReportSystemError(-rc, "%s", _("unable to set swap_hard_limit tunable")); @@ -6734,7 +6777,7 @@ qemuDomainSetMemoryParameters(virDomainPtr dom, } } if (flags & VIR_DOMAIN_AFFECT_CONFIG) { - persistentDef->mem.swap_hard_limit = params[i].value.ul; + persistentDef->mem.swap_hard_limit = sorted_params[i]->value.ul; } } } @@ -7011,7 +7054,7 @@ qemuDomainSetNumaParameters(virDomainPtr dom, continue; } - /* Ensure the cpuset string is formated before passing to cgroup */ + /* Ensure the cpuset string is formatted before passing to cgroup */ if (!(nodeset_str = virDomainCpuSetFormat(nodeset, VIR_DOMAIN_CPUMASK_LEN))) { virReportError(VIR_ERR_INTERNAL_ERROR, "%s", -- 1.7.7.3

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[libvirt] [PATCH] qemu: Ensure the cpuset is formated as expected before passing to cgroup
by Osier Yang 16 Aug '12

16 Aug '12

The parameter value for cpuset could be in special format like "0-10,^7", which is not recongnized by cgroup. This patch is to ensure the cpuset is formated as expected before passing it to cgroup. As a side effect, after the patch, it parses the cpuset early before cgroup setting, to avoid the rollback if cpuset parsing fails afterwards. --- src/qemu/qemu_driver.c | 77 +++++++++++++++++++++++++---------------------- 1 files changed, 41 insertions(+), 36 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 369e8ed..fc412a1 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -6952,8 +6952,23 @@ qemuDomainSetNumaParameters(virDomainPtr dom, } } else if (STREQ(param->field, VIR_DOMAIN_NUMA_NODESET)) { int rc; - bool savedmask; - char oldnodemask[VIR_DOMAIN_CPUMASK_LEN]; + char *nodeset = NULL; + char *nodeset_str = NULL; + + if (VIR_ALLOC_N(nodeset, VIR_DOMAIN_CPUMASK_LEN) < 0) { + virReportOOMError(); + ret = -1; + goto cleanup; + }; + + if (virDomainCpuSetParse(params[i].value.s, + 0, nodeset, + VIR_DOMAIN_CPUMASK_LEN) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("Failed to parse nodeset")); + ret = -1; + continue; + } if (flags & VIR_DOMAIN_AFFECT_LIVE) { if (vm->def->numatune.memory.mode != @@ -6961,72 +6976,62 @@ qemuDomainSetNumaParameters(virDomainPtr dom, virReportError(VIR_ERR_OPERATION_INVALID, "%s", _("change of nodeset for running domain " "requires strict numa mode")); + VIR_FREE(nodeset); ret = -1; continue; } - rc = virCgroupSetCpusetMems(group, params[i].value.s); - if (rc != 0) { + + /* Ensure the cpuset string is formated before passing to cgroup */ + if (!(nodeset_str = virDomainCpuSetFormat(nodeset, + VIR_DOMAIN_CPUMASK_LEN))) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("Failed to format nodeset")); + VIR_FREE(nodeset); + ret = -1; + continue; + } + + if ((rc = virCgroupSetCpusetMems(group, nodeset_str) != 0)) { virReportSystemError(-rc, "%s", _("unable to set numa tunable")); + VIR_FREE(nodeset); + VIR_FREE(nodeset_str); ret = -1; continue; } + VIR_FREE(nodeset_str); /* update vm->def here so that dumpxml can read the new * values from vm->def. */ - savedmask = false; if (!vm->def->numatune.memory.nodemask) { if (VIR_ALLOC_N(vm->def->numatune.memory.nodemask, VIR_DOMAIN_CPUMASK_LEN) < 0) { virReportOOMError(); + VIR_FREE(nodeset); ret = -1; goto cleanup; } } else { - memcpy(oldnodemask, vm->def->numatune.memory.nodemask, - VIR_DOMAIN_CPUMASK_LEN); - savedmask = true; - } - if (virDomainCpuSetParse(params[i].value.s, - 0, - vm->def->numatune.memory.nodemask, - VIR_DOMAIN_CPUMASK_LEN) < 0) { - if (savedmask) - memcpy(vm->def->numatune.memory.nodemask, - oldnodemask, VIR_DOMAIN_CPUMASK_LEN); - else - VIR_FREE(vm->def->numatune.memory.nodemask); - ret = -1; - continue; + VIR_FREE(vm->def->numatune.memory.nodemask); } + + vm->def->numatune.memory.nodemask = nodeset; } if (flags & VIR_DOMAIN_AFFECT_CONFIG) { - savedmask = false; if (!persistentDef->numatune.memory.nodemask) { if (VIR_ALLOC_N(persistentDef->numatune.memory.nodemask, VIR_DOMAIN_CPUMASK_LEN) < 0) { virReportOOMError(); + VIR_FREE(nodeset); ret = -1; goto cleanup; } } else { - memcpy(oldnodemask, persistentDef->numatune.memory.nodemask, - VIR_DOMAIN_CPUMASK_LEN); - savedmask = true; - } - if (virDomainCpuSetParse(params[i].value.s, - 0, - persistentDef->numatune.memory.nodemask, - VIR_DOMAIN_CPUMASK_LEN) < 0) { - if (savedmask) - memcpy(persistentDef->numatune.memory.nodemask, - oldnodemask, VIR_DOMAIN_CPUMASK_LEN); - else - VIR_FREE(persistentDef->numatune.memory.nodemask); - ret = -1; - continue; + VIR_FREE(persistentDef->numatune.memory.nodemask); } + + persistentDef->numatune.memory.nodemask = nodeset; } } } -- 1.7.7.3

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[libvirt] [PATCHv2] build: avoid warnings on older gcc
by Eric Blake 16 Aug '12

16 Aug '12

The previous patch pulled in a newer version of stat-time.h from gnulib, which tries to suppress some stupid gcc warnings (see <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54113>) by exploiting a feature of newer gcc. But we still aim to compile on RHEL 6.3, with gcc 4.4.6 (not to mention even older devel platforms like RHEL 5), which fails to build thanks to our development -Werror. It took me a while to figure out how to make our set of warnings smaller on older gcc without losing the benefit of the warnings when using newer gcc (such as the one on Fedora 17), but this should do the trick. * m4/virt-compile-warnings.m4 (LIBVIRT_COMPILE_WARNINGS): Avoid warnings that gnulib can't silence on older gcc. --- v2: Use AC_CACHE_CHECK, add -Werror, and test further. Pushing under the build-breaker rule. m4/virt-compile-warnings.m4 | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/m4/virt-compile-warnings.m4 b/m4/virt-compile-warnings.m4 index 9dee000..26f6134 100644 --- a/m4/virt-compile-warnings.m4 +++ b/m4/virt-compile-warnings.m4 @@ -58,6 +58,24 @@ AC_DEFUN([LIBVIRT_COMPILE_WARNINGS],[ # Gnulib's stat-time.h violates this dontwarn="$dontwarn -Waggregate-return" + # Gnulib uses '#pragma GCC diagnostic push' to silence some + # warnings, but older gcc doesn't support this. + AC_CACHE_CHECK([whether pragma GCC diagnostic push works], + [lv_cv_gcc_pragma_push_works], [ + save_CFLAGS=$CFLAGS + CFLAGS='-Wunknown-pragmas -Werror' + AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ + #pragma GCC diagnostic push + #pragma GCC diagnostic pop + ]])], + [lv_cv_gcc_pragma_push_works=yes], + [lv_cv_gcc_pragma_push_works=no]) + CFLAGS=$save_CFLAGS]) + if test $lv_cv_gcc_pragma_push_works = no; then + dontwarn="$dontwarn -Wmissing-prototypes" + dontwarn="$dontwarn -Wmissing-declarations" + fi + # We might fundamentally need some of these disabled forever, but # ideally we'd turn many of them on dontwarn="$dontwarn -Wfloat-equal" -- 1.7.11.2

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[libvirt] [PATCH v3 0/5] Per-guest configurable user/group for QEMU processes
by Marcelo Cerri 15 Aug '12

15 Aug '12

This is a v3 patch series that updates the libvirt's security driver mechanism to support per-guest configurable user and group for QEMU processes running together with other security drivers, such as SELinux and AppArmor. Comments and feedbacks are welcome. Marcelo Cerri (5): Internal refactory of data structures Multiple security drivers in XML data Update security layer to handle many security labels Support for multiple default security drivers in QEMU config Update the remote API daemon/remote.c | 63 ++++ docs/formatdomain.html.in | 11 +- docs/schemas/capability.rng | 18 +- docs/schemas/domaincommon.rng | 30 ++- include/libvirt/libvirt.h.in | 2 + python/generator.py | 1 + src/conf/capabilities.c | 17 +- src/conf/capabilities.h | 6 +- src/conf/domain_audit.c | 14 +- src/conf/domain_conf.c | 342 +++++++++++++++----- src/conf/domain_conf.h | 18 +- src/driver.h | 4 + src/libvirt.c | 47 +++ src/libvirt_private.syms | 5 + src/libvirt_public.syms | 5 + src/lxc/lxc_conf.c | 8 +- src/lxc/lxc_controller.c | 8 +- src/lxc/lxc_driver.c | 11 +- src/lxc/lxc_process.c | 23 +- src/qemu/qemu_conf.c | 38 ++- src/qemu/qemu_conf.h | 2 +- src/qemu/qemu_driver.c | 218 +++++++++++--- src/qemu/qemu_process.c | 50 ++- src/remote/remote_driver.c | 46 +++ src/remote/remote_protocol.x | 17 +- src/remote_protocol-structs | 1 + src/security/security_apparmor.c | 118 +++++-- src/security/security_dac.c | 324 +++++++++++++++++-- src/security/security_manager.c | 101 +++++-- src/security/security_manager.h | 8 +- src/security/security_selinux.c | 256 ++++++++++----- src/security/security_stack.c | 237 +++++++++----- src/security/security_stack.h | 13 + src/test/test_driver.c | 11 +- .../qemuxml2argv-seclabel-dynamic-override.xml | 4 +- .../qemuxml2argv-seclabel-dynamic.xml | 2 +- 36 files changed, 1634 insertions(+), 445 deletions(-)

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[libvirt] RFC: a <uuid> for every <interface> in each domain
by Laine Stump 15 Aug '12

15 Aug '12

A couple of situations have come up recently that could be solved by every interface in every domain always having a unique identifier associated with it: 1) In order to properly track information as a guest is disconnected and reconnected to an Open vSwitch bridge, the initial Open vSwitch support added an "interfaceid" parameter to virtualport. If the interfaceid isn't specified by the user when the interface is defined, one is automatically generated and placed into the persistent definition. But if the guest interface is just <interface type='network'>, it isn't known at the time of definition whether this interface will be using an Open vSwitch connection, or something else. Then, by the time we get into the network driver and decide that we're going to use Open vSwitch, it's too late to conveniently/cleanly generate an interfaceid and plug it back into the <virtualport> of the interface's persistent config. The result is that each time the guest is restarted, Open vSwitch gets a new interfaceid for it, and can't properly track things. If every interface had a uuid, the code that connects to an Open vSwitch network could just use the interface's uuid if interfaceid wasn't specified. 2) I'm about to write some patches that will allow enacting config changes to a network without needing to destroy/re-start the network. One thing that came up while I was mulling over what could and couldn't be modified without a restart is that it will be possible to allow removing physical interfaces from a network's interface pool (used for macvtap and hostdev modes), but only if that physical interface isn't currently in use. There is a use counter on each interface so we can easily tell when that situation occurs, but once we know of the failure, we have no way of pointing to which guest is causing the problem. If each interface had a uuid, we could save a list of the uuid's of all interfaces currently connected to a particular physical interface, and report that in the failure message. It would then be a fairly mechanical task to find that uuid in the guests' config. Does this sound like a reasonable idea? Any reasons *not* to do it? Problems we'll need to take care of if we add it (for example, existing guest interfaces will all need to get a uuid during the upgrade process, similar to the way we add a mac address to all existing networks that don't have one). Any other things you can think of doing with uuid if we add one?

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[libvirt] [PATCHv2 0/4] support <vlan> element for interfaces and networks
by Laine Stump 15 Aug '12

15 Aug '12

danpb raised a (valid) objection about the XML format in the first version of these patches, so I've redone it to be like this: <vlan trunk='yes'> <tag id='42'/> <tag id='30'/> </vlan> The downside is that for a single vlan tag, it's more verbose: <vlan> <tag id='42'/> </vlan> On the other hand, it's more consistent. The rest of the patches in the series were unchanged (and even the data definition is unchanged). === The purpose of these patches is to define a data type that can properly describe an interface's vlan configuration (including multiple vlans for trunking), provide XML parser and formatter to translate to and from the new data type, add the new <vlan> element to both domain <interface> and to <network> in appropriate places, and to provide the new vlan data to the hypervisor driver. Once these 4 patches are applied, all that will be left to support vlan configuration for any network connection that supports it, is to request the vlan data for the interface with virDomainNetGetActualVlan(netdef). If that function returns NULL, there is no vlan config for this interface; if it's non-zero, it is a pointer to virNetDevVlan, and you can grab the data from there. Since I currently know of only two types of network connection we will be able to easily support this for (sr-iov VFs using PCI passthrough, and openvswitch), any type other than those will refuse to start if a vlan has been requested (see PATCH 4/4). This covers validation for the qemu and lxc drivers (since they use common code), but I'm not sure about xen, esx, or any other driver - they will likely require extra code to either implement transparent vlan configuration, or log an error if it's requested (my guess is that, in spite of our best efforts, *many* people will misunderstand the limitations of this functionality, and try to put all sorts of interfaces on vlans; it will be much friendlier to inform them of the problem rather than simply ignore the vlan config.

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[libvirt] [PATCHv2 0/9] network: properly support openvswitch in <network>
by Laine Stump 15 Aug '12

15 Aug '12

This is mainly a refresh of the initial version of the patch to rebase, but there have also been a couple of small bugs fixed. In particular, if not <virtualport/> is specified in the domain's interface element, connection of the interface to an ovs switch won't fail because of a missing interfaceid (see http://www.redhat.com/archives/libvir-list/2012-August/msg00874.html and it's parents) Many of these patches are trivial or mechanical. ====== Although it's been possible (ever since openvswitch was added to libvirt in 0.9.11) for a libvirt network to use an openvswitch bridge (by adding <virtualport type='openvswitch'>), the virtualport in the network would always have a default random interfaceid included, which would be re-used for all interfaces using that network, which doesn't really work at all. The alternative was to not specify openvswitch in the <network> definition, but to do it in the guest's <interface> definition instead - this of course goes against the principle of not having host-specific config embedded in guest config. This patch series enhances the functionality of <virtualport> elements, to allow omitting some attributes (and even the type), and to merge the interface, network, and portgroup virtualports rather than simply picking one. This not only makes openvswitch <network>s more practical (because the network can specify type='openvswitch' without also specifying an interfaceid), but also makes <virtualport> in networks and portgroups more useful in general - for example, an interface can specify an interfaceid (used only by openvswitch) *and* an instanceid (used only by 802.1Qbh), while the network's virtualport specifies only the type, and the portgroups specify the managerid, typeid, profileid, or whatever is appropriate for the type of switch used by the network. The result is that the guest config can be completely devoid of knowledge about the type of switch being used on the hardware, but can still enjoy full configurability for whatever switch ends up being used.

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[libvirt] [PATCH] build: avoid warnings on older gcc
by Eric Blake 15 Aug '12

15 Aug '12

The previous patch pulled in a newer version of stat-time.h from gnulib, which tries to suppress some stupid gcc warnings (see <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54113>) by exploiting a feature of newer gcc. But we still aim to compile on RHEL 6.3, with gcc 4.4.6 (not to mention even older devel platforms like RHEL 5), which fails to build thanks to our development -Werror. It took me a while to figure out how to make our set of warnings smaller on older gcc without losing the benefit of the warnings when using newer gcc (such as the one on Fedora 17), but this should do the trick. * m4/virt-compile-warnings.m4 (LIBVIRT_COMPILE_WARNINGS): Avoid warnings that gnulib can't silence on older gcc. --- If I don't get a review by tomorrow, I will go ahead and push this under the build-breaker rule. m4/virt-compile-warnings.m4 | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/m4/virt-compile-warnings.m4 b/m4/virt-compile-warnings.m4 index 9dee000..702506d 100644 --- a/m4/virt-compile-warnings.m4 +++ b/m4/virt-compile-warnings.m4 @@ -58,6 +58,23 @@ AC_DEFUN([LIBVIRT_COMPILE_WARNINGS],[ # Gnulib's stat-time.h violates this dontwarn="$dontwarn -Waggregate-return" + # Gnulib uses '#pragma GCC diagnostic push' to silence some + # warnings, but older gcc doesn't support this. + AC_CACHE_VAL([lv_cv_gcc_pragma_push_works], [ + save_CFLAGS=$CFLAGS + CFLAGS=-Wunknown-pragmas + AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ + #pragma GCC diagnostic push + #pragma GCC diagnostic pop + ]])], + [lv_cv_gcc_pragma_push_works=yes], + [lv_cv_gcc_pragma_push_works=no]) + CFLAGS=$save_CFLAGS]) + if test $lv_cv_gcc_pragma_push_works = no; then + dontwarn="$dontwarn -Wmissing-prototypes" + dontwarn="$dontwarn -Wmissing-declarations" + fi + # We might fundamentally need some of these disabled forever, but # ideally we'd turn many of them on dontwarn="$dontwarn -Wfloat-equal" -- 1.7.11.2

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