Re: [PATCH 2/3] vmd: disable MSI remapping bypass under Xen

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

Hi Roger,

kernel test robot noticed the following build errors:

[auto build test ERROR on pci/next]
[also build test ERROR on pci/for-linus tip/irq/core linus/master v6.13-rc6 next-20250110]
[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/Roger-Pau-Monne/xen-pci-do-not-register-devices-outside-of-PCI-segment-scope/20250110-220331
base:   https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git next
patch link:    https://lore.kernel.org/r/20250110140152.27624-3-roger.pau%40citrix.com
patch subject: [PATCH 2/3] vmd: disable MSI remapping bypass under Xen
config: x86_64-buildonly-randconfig-001-20250112 (https://download.01.org/0day-ci/archive/20250112/202501121029.dJk0TBPr-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250112/202501121029.dJk0TBPr-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/202501121029.dJk0TBPr-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/pci/controller/vmd.c: In function 'vmd_probe':
>> drivers/pci/controller/vmd.c:973:13: error: implicit declaration of function 'xen_domain' [-Werror=implicit-function-declaration]
     973 |         if (xen_domain())
         |             ^~~~~~~~~~
   cc1: some warnings being treated as errors


vim +/xen_domain +973 drivers/pci/controller/vmd.c

   966	
   967	static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
   968	{
   969		unsigned long features = (unsigned long) id->driver_data;
   970		struct vmd_dev *vmd;
   971		int err;
   972	
 > 973		if (xen_domain())
   974			/*
   975			 * Xen doesn't have knowledge about devices in the VMD bus.
   976			 * Bypass of MSI remapping won't work in that case as direct
   977			 * write to the MSI entries won't result in functional
   978			 * interrupts.
   979			 */
   980			features &= ~VMD_FEAT_CAN_BYPASS_MSI_REMAP;
   981	
   982		if (resource_size(&dev->resource[VMD_CFGBAR]) < (1 << 20))
   983			return -ENOMEM;
   984	
   985		vmd = devm_kzalloc(&dev->dev, sizeof(*vmd), GFP_KERNEL);
   986		if (!vmd)
   987			return -ENOMEM;
   988	
   989		vmd->dev = dev;
   990		vmd->instance = ida_alloc(&vmd_instance_ida, GFP_KERNEL);
   991		if (vmd->instance < 0)
   992			return vmd->instance;
   993	
   994		vmd->name = devm_kasprintf(&dev->dev, GFP_KERNEL, "vmd%d",
   995					   vmd->instance);
   996		if (!vmd->name) {
   997			err = -ENOMEM;
   998			goto out_release_instance;
   999		}
  1000	
  1001		err = pcim_enable_device(dev);
  1002		if (err < 0)
  1003			goto out_release_instance;
  1004	
  1005		vmd->cfgbar = pcim_iomap(dev, VMD_CFGBAR, 0);
  1006		if (!vmd->cfgbar) {
  1007			err = -ENOMEM;
  1008			goto out_release_instance;
  1009		}
  1010	
  1011		pci_set_master(dev);
  1012		if (dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(64)) &&
  1013		    dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(32))) {
  1014			err = -ENODEV;
  1015			goto out_release_instance;
  1016		}
  1017	
  1018		if (features & VMD_FEAT_OFFSET_FIRST_VECTOR)
  1019			vmd->first_vec = 1;
  1020	
  1021		spin_lock_init(&vmd->cfg_lock);
  1022		pci_set_drvdata(dev, vmd);
  1023		err = vmd_enable_domain(vmd, features);
  1024		if (err)
  1025			goto out_release_instance;
  1026	
  1027		dev_info(&vmd->dev->dev, "Bound to PCI domain %04x\n",
  1028			 vmd->sysdata.domain);
  1029		return 0;
  1030	
  1031	 out_release_instance:
  1032		ida_free(&vmd_instance_ida, vmd->instance);
  1033		return err;
  1034	}
  1035	

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