[libvirt] [PATCH] qemu: Fix segfault when CPU host is empty
In case libvirtd cannot detect host CPU model (which may happen if it runs inside a virtual machine), the daemon is likely to segfault when starting a new qemu domain. It segfaults when domain XML asks for host (either model or passthrough) CPU or does not ask for any specific CPU model at all. --- src/qemu/qemu_command.c | 24 ++++++++++++------------ 1 files changed, 12 insertions(+), 12 deletions(-) diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 99d7129..5633dfd 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -3508,22 +3508,13 @@ qemuBuildCpuArgStr(const struct qemud_driver *driver, *hasHwVirt = false; - if (def->cpu && - (def->cpu->mode != VIR_CPU_MODE_CUSTOM || def->cpu->model)) { - if (!(cpu = virCPUDefCopy(def->cpu))) - goto cleanup; - if (cpu->mode != VIR_CPU_MODE_CUSTOM && - !migrating && - cpuUpdate(cpu, host) < 0) - goto cleanup; - } - if (STREQ(def->os.arch, "i686")) default_model = "qemu32"; else default_model = "qemu64"; - if (cpu) { + if (def->cpu && + (def->cpu->mode != VIR_CPU_MODE_CUSTOM || def->cpu->model)) { virCPUCompareResult cmp; const char *preferred; int hasSVM; @@ -3539,6 +3530,14 @@ qemuBuildCpuArgStr(const struct qemud_driver *driver, goto cleanup; } + if (!(cpu = virCPUDefCopy(def->cpu))) + goto cleanup; + + if (cpu->mode != VIR_CPU_MODE_CUSTOM && + !migrating && + cpuUpdate(cpu, host) < 0) + goto cleanup; + cmp = cpuGuestData(host, cpu, &data); switch (cmp) { case VIR_CPU_COMPARE_INCOMPATIBLE: @@ -3647,7 +3646,8 @@ qemuBuildCpuArgStr(const struct qemud_driver *driver, ret = 0; cleanup: - cpuDataFree(host->arch, data); + if (host) + cpuDataFree(host->arch, data); virCPUDefFree(guest); virCPUDefFree(cpu); -- 1.7.8.4
On 02/15/2012 04:33 AM, Jiri Denemark wrote:
In case libvirtd cannot detect host CPU model (which may happen if it runs inside a virtual machine), the daemon is likely to segfault when starting a new qemu domain.
Nested virt - what fun.
It segfaults when domain XML asks for host (either model or passthrough) CPU or does not ask for any specific CPU model at all. --- src/qemu/qemu_command.c | 24 ++++++++++++------------ 1 files changed, 12 insertions(+), 12 deletions(-)
ACK. -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
On 02/16/2012 12:57 AM, Eric Blake wrote:
On 02/15/2012 04:33 AM, Jiri Denemark wrote:
In case libvirtd cannot detect host CPU model (which may happen if it runs inside a virtual machine), the daemon is likely to segfault when starting a new qemu domain. Nested virt - what fun.
I want to know whether libvirt officially supports nested virtualization? in addition, need we a bug/case to trace this issue? Thanks & Regards, Alex
It segfaults when domain XML asks for host (either model or passthrough) CPU or does not ask for any specific CPU model at all. --- src/qemu/qemu_command.c | 24 ++++++++++++------------ 1 files changed, 12 insertions(+), 12 deletions(-) ACK.
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On Wed, Feb 15, 2012 at 09:57:37 -0700, Eric Blake wrote:
On 02/15/2012 04:33 AM, Jiri Denemark wrote:
In case libvirtd cannot detect host CPU model (which may happen if it runs inside a virtual machine), the daemon is likely to segfault when starting a new qemu domain.
Nested virt - what fun.
It segfaults when domain XML asks for host (either model or passthrough) CPU or does not ask for any specific CPU model at all. --- src/qemu/qemu_command.c | 24 ++++++++++++------------ 1 files changed, 12 insertions(+), 12 deletions(-)
ACK.
Pushed, thanks. Jirka
participants (3)
-
Alex Jia -
Eric Blake -
Jiri Denemark