Re: [RFC PATCH 4/4] vfio-nvme: implement TP4159 live migration cmds

[kernel test robot <lkp@intel.com>]

Hi Chaitanya,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build warnings:

[auto build test WARNING on awilliam-vfio/next]
[also build test WARNING on axboe-block/for-next linus/master v6.16 next-20250801]
[cannot apply to linux-nvme/for-next awilliam-vfio/for-linus]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Chaitanya-Kulkarni/vfio-nvme-add-vfio-nvme-lm-driver-infrastructure/20250803-105056
base:   https://github.com/awilliam/linux-vfio.git next
patch link:    https://lore.kernel.org/r/20250803024705.10256-5-kch%40nvidia.com
patch subject: [RFC PATCH 4/4] vfio-nvme: implement TP4159 live migration cmds
config: loongarch-allmodconfig (https://download.01.org/0day-ci/archive/20250804/202508040432.A5v60BDB-lkp@intel.com/config)
compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project cd708029e0b2869e80abe31ddb175f7c35361f90)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250804/202508040432.A5v60BDB-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202508040432.A5v60BDB-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/vfio/pci/nvme/nvme.c:332:18: warning: variable 'hdr' is uninitialized when used here [-Wuninitialized]
     332 |         if (le16_to_cpu(hdr->nvmecss) > NVME_LM_MAX_NVMECS ||
         |                         ^~~
   include/linux/byteorder/generic.h:91:21: note: expanded from macro 'le16_to_cpu'
      91 | #define le16_to_cpu __le16_to_cpu
         |                     ^
   include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
      37 | #define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
         |                                                   ^
   drivers/vfio/pci/nvme/nvme.c:310:32: note: initialize the variable 'hdr' to silence this warning
     310 |         struct nvme_lm_ctrl_state *hdr;
         |                                       ^
         |                                        = NULL
   1 warning generated.


vim +/hdr +332 drivers/vfio/pci/nvme/nvme.c

   303	
   304	static int nvmevf_get_ctrl_state(struct pci_dev *dev,
   305					__u8 csvi, __u8 csuuidi, __u8 csuidxp,
   306					struct nvmevf_migration_file *migf,
   307					struct nvme_lm_ctrl_state_info *state)
   308	{
   309		struct nvme_command c = { };
   310		struct nvme_lm_ctrl_state *hdr;
   311		/* Make sure hdr_len is a multiple of 4 */
   312		size_t hdr_len = ALIGN(sizeof(*hdr), 4);
   313		__u16 id = nvme_get_ctrl_id(dev);
   314		void *local_buf;
   315		size_t len;
   316		int ret;
   317	
   318		/* Step 1: Issue Migration Receive (Select = 0) to get header */
   319		local_buf = kzalloc(hdr_len, GFP_KERNEL);
   320		if (!local_buf)
   321			return -ENOMEM;
   322	
   323		nvmevf_init_get_ctrl_state_cmd(&c, id, csvi, csuuidi, csuidxp, hdr_len);
   324		ret = nvme_submit_vf_cmd(dev, &c, NULL, local_buf, hdr_len);
   325		if (ret) {
   326			dev_warn(&dev->dev,
   327				"nvme_admin_lm_recv failed (ret=0x%x)\n", ret);
   328			kfree(local_buf);
   329			return ret;
   330		}
   331	
 > 332		if (le16_to_cpu(hdr->nvmecss) > NVME_LM_MAX_NVMECS ||
   333		    le16_to_cpu(hdr->vss) > NVME_LM_MAX_VSD) {
   334			kfree(local_buf);
   335			return -EINVAL;
   336		}
   337	
   338		hdr = local_buf;
   339		len = hdr_len + 4 * (le16_to_cpu(hdr->nvmecss) + le16_to_cpu(hdr->vss));
   340	
   341		kfree(local_buf);
   342	
   343		if (len == hdr_len)
   344			dev_warn(&dev->dev, "nvmecss == 0 or vss = 0\n");
   345	
   346		/* Step 2: Allocate full buffer */
   347		migf->total_length = len;
   348		migf->vf_data = kvzalloc(migf->total_length, GFP_KERNEL);
   349		if (!migf->vf_data)
   350			return -ENOMEM;
   351	
   352		memset(&c, 0, sizeof(c));
   353		nvmevf_init_get_ctrl_state_cmd(&c, id, csvi, csuuidi, csuidxp, len);
   354		ret = nvme_submit_vf_cmd(dev, &c, NULL, migf->vf_data, len);
   355		if (ret)
   356			goto free_big;
   357	
   358		/* Populate state struct */
   359		hdr = (struct nvme_lm_ctrl_state *)migf->vf_data;
   360		state->raw = hdr;
   361		state->total_len = len;
   362		state->version = hdr->version;
   363		state->csattr = hdr->csattr;
   364		state->nvmecss = hdr->nvmecss;
   365		state->vss = hdr->vss;
   366		state->nvme_cs = hdr->data;
   367		state->vsd = hdr->data + le16_to_cpu(hdr->nvmecss) * 4;
   368	
   369		return ret;
   370	
   371	free_big:
   372		kvfree(migf->vf_data);
   373		return ret;
   374	}
   375	

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