6:53 a.m.
If you're running libvirt master on a remote host, and connect
to it using virt-manager, the remote daemon will crash. The
same will happen if you run 'virsh nodedev-dumpxml' for a PCI
device that happens *not* to be a virtual function.
The first patch fixes the crash. The second one fixes something
that could potentially cause trouble down the line, and also
makes the code a tiny bit nicer.
Andrea Bolognani (2):
nodedev: sysfs: Set PCI_PHYSICAL_FUNCTION flag more carefully
conf: nodedev: Set PCI_PHYSICAL_FUNCTION flag more carefully
src/conf/node_device_conf.c | 4 ++--
src/node_device/node_device_linux_sysfs.c | 10 ++++++++--
2 files changed, 10 insertions(+), 4 deletions(-)
--
2.5.5
6:53 a.m.
New subject: [libvirt] [PATCH 1/2] nodedev: sysfs: Set PCI_PHYSICAL_FUNCTION flag more carefully
The flag was set if virPCIGetPhysicalFunction() did not return
an error; unfortunately, the 'physfn' sysfs file not being
present is not considered an error, which means that the flag
was set pretty much unconditionally.
This, in turn, caused libvirtd to crash in
virNodeDeviceDefFormat(), where the presence of the flag
is considered a reliable indicator of the fact that
pci_dev.physical_function has been filled in.
Change the code to check pci_dev.physical_function before
setting the flag.
---
src/node_device/node_device_linux_sysfs.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/src/node_device/node_device_linux_sysfs.c
b/src/node_device/node_device_linux_sysfs.c
index 24a6a2e..b337d2d 100644
--- a/src/node_device/node_device_linux_sysfs.c
+++ b/src/node_device/node_device_linux_sysfs.c
@@ -154,19 +154,25 @@ nodeDeviceSysfsGetPCISRIOVCaps(const char *sysfsPath,
data->pci_dev.flags &= ~VIR_NODE_DEV_CAP_FLAG_PCI_VIRTUAL_FUNCTION;
data->pci_dev.flags &= ~VIR_NODE_DEV_CAP_FLAG_PCI_PHYSICAL_FUNCTION;
- if (!virPCIGetPhysicalFunction(sysfsPath, &data->pci_dev.physical_function))
+ ret = virPCIGetPhysicalFunction(sysfsPath,
+ &data->pci_dev.physical_function);
+ if (ret < 0)
+ goto out;
+
+ if (data->pci_dev.physical_function)
data->pci_dev.flags |= VIR_NODE_DEV_CAP_FLAG_PCI_PHYSICAL_FUNCTION;
ret = virPCIGetVirtualFunctions(sysfsPath, &data->pci_dev.virtual_functions,
&data->pci_dev.num_virtual_functions,
&data->pci_dev.max_virtual_functions);
if (ret < 0)
- return ret;
+ goto out;
if (data->pci_dev.num_virtual_functions > 0 ||
data->pci_dev.max_virtual_functions > 0)
data->pci_dev.flags |= VIR_NODE_DEV_CAP_FLAG_PCI_VIRTUAL_FUNCTION;
+ out:
return ret;
}
--
2.5.5
2:21 p.m.
New subject: [libvirt] [PATCH 1/2] nodedev: sysfs: Set PCI_PHYSICAL_FUNCTION flag more carefully
On 05/23/2016 07:53 AM, Andrea Bolognani wrote:
The flag was set if virPCIGetPhysicalFunction() did not return
an error; unfortunately, the 'physfn' sysfs file not being
present is not considered an error, which means that the flag
was set pretty much unconditionally.
This behavior is the result of commit c8b1a83605:
https://www.redhat.com/archives/libvir-list/2016-May/msg01348.html
Prior to this, virPCIGetPhysicalFunction had returned the return value
from virPCIGetDeviceAddressFromSysfsLink(), which would be -1 if the
physfn file didn't exist. That patch discards the return value and
hardcodes a "return 0".
I think that virPCIGetPhysicalFunction should be restored to its
original glory (No, I didn't write it). Either that, or the other caller
to virPCIGetPhysicalFunction (virPCIGetVirtualFunctionInfo) should also
be fixed so that it doesn't crash due to the changed semantics of
virPCIGetPhysicalFunction.
(A more correct fix may be to change the semantics of
virPCIGetPhysicalFunction() to return -1 only in the case of a bonafide
error (OOM, failure to parse the contents of an existing physfn file),
but that would also require modifying
virPCIGetDeviceAddressFromSysfsLink() to return 0/-1 rather than a
virPCIDeviceAddresPtr so that we can tell the difference between "no
physfn" and "there was a physfn but I encountered some other error". In
other words - 1) revert commit c1faf309 (part of the same "coverity
fixes" series as x8b1a83605), then 2) adjust the function to set *bdf =
0 and return 0 when the physfn file doesn't exist.)
This, in turn, caused libvirtd to crash in
virNodeDeviceDefFormat(), where the presence of the flag
is considered a reliable indicator of the fact that
pci_dev.physical_function has been filled in.
Change the code to check pci_dev.physical_function before
setting the flag.
---
src/node_device/node_device_linux_sysfs.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/src/node_device/node_device_linux_sysfs.c
b/src/node_device/node_device_linux_sysfs.c
index 24a6a2e..b337d2d 100644
--- a/src/node_device/node_device_linux_sysfs.c
+++ b/src/node_device/node_device_linux_sysfs.c
@@ -154,19 +154,25 @@ nodeDeviceSysfsGetPCISRIOVCaps(const char *sysfsPath,
data->pci_dev.flags &= ~VIR_NODE_DEV_CAP_FLAG_PCI_VIRTUAL_FUNCTION;
data->pci_dev.flags &= ~VIR_NODE_DEV_CAP_FLAG_PCI_PHYSICAL_FUNCTION;
- if (!virPCIGetPhysicalFunction(sysfsPath, &data->pci_dev.physical_function))
+ ret = virPCIGetPhysicalFunction(sysfsPath,
+ &data->pci_dev.physical_function);
+ if (ret < 0)
+ goto out;
+
+ if (data->pci_dev.physical_function)
data->pci_dev.flags |= VIR_NODE_DEV_CAP_FLAG_PCI_PHYSICAL_FUNCTION;
ret = virPCIGetVirtualFunctions(sysfsPath,
&data->pci_dev.virtual_functions,
&data->pci_dev.num_virtual_functions,
&data->pci_dev.max_virtual_functions);
if (ret < 0)
- return ret;
+ goto out;
if (data->pci_dev.num_virtual_functions > 0 ||
data->pci_dev.max_virtual_functions > 0)
data->pci_dev.flags |= VIR_NODE_DEV_CAP_FLAG_PCI_VIRTUAL_FUNCTION;
+ out:
return ret;
}
6:13 a.m.
New subject: [libvirt] [PATCH 1/2] nodedev: sysfs: Set PCI_PHYSICAL_FUNCTION flag more carefully
On Mon, 2016-05-23 at 15:21 -0400, Laine Stump wrote:
On 05/23/2016 07:53 AM, Andrea Bolognani wrote:
>
> The flag was set if virPCIGetPhysicalFunction() did not return
> an error; unfortunately, the 'physfn' sysfs file not being
> present is not considered an error, which means that the flag
> was set pretty much unconditionally.
This behavior is the result of commit c8b1a83605:
https://www.redhat.com/archives/libvir-list/2016-May/msg01348.html
Prior to this, virPCIGetPhysicalFunction had returned the return value
from virPCIGetDeviceAddressFromSysfsLink(), which would be -1 if the
physfn file didn't exist. That patch discards the return value and
hardcodes a "return 0".
I think that virPCIGetPhysicalFunction should be restored to its
original glory (No, I didn't write it). Either that, or the other caller
to virPCIGetPhysicalFunction (virPCIGetVirtualFunctionInfo) should also
be fixed so that it doesn't crash due to the changed semantics of
virPCIGetPhysicalFunction.
(A more correct fix may be to change the semantics of
virPCIGetPhysicalFunction() to return -1 only in the case of a bonafide
error (OOM, failure to parse the contents of an existing physfn file),
but that would also require modifying
virPCIGetDeviceAddressFromSysfsLink() to return 0/-1 rather than a
virPCIDeviceAddresPtr so that we can tell the difference between "no
physfn" and "there was a physfn but I encountered some other error". In
other words - 1) revert commit c1faf309 (part of the same "coverity
fixes" series as x8b1a83605), then 2) adjust the function to set *bdf =
0 and return 0 when the physfn file doesn't exist.)
Thanks for the analysis.
Fixing the remaining caller looked like the simpler fix,
so I've gone that route. Patch 2/2 is unchanged.
https://www.redhat.com/archives/libvir-list/2016-May/msg01783.html
--
Andrea Bolognani
Software Engineer - Virtualization Team
6:53 a.m.
New subject: [libvirt] [PATCH 2/2] conf: nodedev: Set PCI_PHYSICAL_FUNCTION flag more carefully
Instead of setting the flag before parsing the PCI address, set
it afterwards. This ensure we can never end up in a situation
where the flag has been set but pci_dev.physical_function has
not been filled in.
---
src/conf/node_device_conf.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/src/conf/node_device_conf.c b/src/conf/node_device_conf.c
index aed95d5..a23d8ef 100644
--- a/src/conf/node_device_conf.c
+++ b/src/conf/node_device_conf.c
@@ -1293,8 +1293,6 @@ virNodeDevPCICapabilityParseXML(xmlXPathContextPtr ctxt,
if (VIR_ALLOC(data->pci_dev.physical_function) < 0)
goto out;
- data->pci_dev.flags |= VIR_NODE_DEV_CAP_FLAG_PCI_PHYSICAL_FUNCTION;
-
if (!address) {
virReportError(VIR_ERR_XML_ERROR, "%s",
_("Missing address in 'phys_function'
capability"));
@@ -1304,6 +1302,8 @@ virNodeDevPCICapabilityParseXML(xmlXPathContextPtr ctxt,
if (virPCIDeviceAddressParseXML(address,
data->pci_dev.physical_function) < 0)
goto out;
+
+ data->pci_dev.flags |= VIR_NODE_DEV_CAP_FLAG_PCI_PHYSICAL_FUNCTION;
} else if (STREQ(type, "virt_functions")) {
int naddresses;
--
2.5.5
3134
days inactive
3135
days old
4 comments
2 participants
participants (2)
-
Andrea Bolognani -
Laine Stump