Re: [libvirt] [PATCH 12/15] util: pci: Introduce virPCIGetMdevTypes helper

On 01/29/2018 01:24 PM, Erik Skultety wrote: > On Fri, Jan 26, 2018 at 12:39:00PM +0100, Michal Privoznik wrote: >> On 01/25/2018 10:23 AM, Erik Skultety wrote: >>> This is a replacement for the existing udevPCIGetMdevTypesCap which is >>> static to the udev backend. This simple helper constructs the sysfs path >>> from the device's base path for each mdev type and queries the >>> corresponding attributes of that type. >>> >>> Signed-off-by: Erik Skultety <eskultet(a)redhat.com&gt; >>> --- >>> src/libvirt_private.syms | 1 + >>> src/util/virpci.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++ >>> src/util/virpci.h | 4 ++++ >>> 3 files changed, 63 insertions(+) >>> >>> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms >>> index 75eaf1d4c..8d4c8dd3f 100644 >>> --- a/src/libvirt_private.syms >>> +++ b/src/libvirt_private.syms >>> @@ -2456,6 +2456,7 @@ virPCIDeviceWaitForCleanup; >>> virPCIEDeviceInfoFree; >>> virPCIGetDeviceAddressFromSysfsLink; >>> virPCIGetHeaderType; >>> +virPCIGetMdevTypes; >>> virPCIGetNetName; >>> virPCIGetPhysicalFunction; >>> virPCIGetVirtualFunctionIndex; >>> diff --git a/src/util/virpci.c b/src/util/virpci.c >>> index fe57bef32..12d7ef0e4 100644 >>> --- a/src/util/virpci.c >>> +++ b/src/util/virpci.c >>> @@ -3027,6 +3027,64 @@ virPCIGetVirtualFunctionInfo(const char *vf_sysfs_device_path, >>> return ret; >>> } >>> >>> + >>> +int >>> +virPCIGetMdevTypes(const char *sysfspath, >>> + virMediatedDeviceTypePtr **types) >> >> Since this function returns size_t on success, I guess the retval should >> be type of ssize_t at least. We are not guaranteed that size_t will fit > > ssize_t wouldn't really help, since assigning size_t might overflow, so the > only safe bet is long long, but I mean, do you really expect there to be more > than INT_MAX mdev types for a device? That would be a lot of types to support. In kernel, they do a lot of size_t -> ssize_t conversion in cases where's it's next to impossible to overflow. And I believe this is one of them.