Re: [PATCH v4 1/1] vringh: IOMEM support

From: Michael S. Tsirkin
Date: Fri Jun 02 2023 - 07:00:54 EST

On Fri, Jun 02, 2023 at 05:56:12PM +0800, kernel test robot wrote:
> Hi Shunsuke,
>
> kernel test robot noticed the following build warnings:
>
> [auto build test WARNING on mst-vhost/linux-next]
> [also build test WARNING on linus/master horms-ipvs/master v6.4-rc4 next-20230602]
> [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/Shunsuke-Mie/vringh-IOMEM-support/20230602-135351
> base: https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
> patch link: https://lore.kernel.org/r/20230602055211.309960-2-mie%40igel.co.jp
> patch subject: [PATCH v4 1/1] vringh: IOMEM support
> config: alpha-allyesconfig (https://download.01.org/0day-ci/archive/20230602/202306021725.3otSfXPF-lkp@xxxxxxxxx/config)
> compiler: alpha-linux-gcc (GCC) 12.3.0
> reproduce (this is a W=1 build):
> mkdir -p ~/bin
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # https://github.com/intel-lab-lkp/linux/commit/de2a1f5220c32e953400f225aba6bd294a8d41b8
> git remote add linux-review https://github.com/intel-lab-lkp/linux
> git fetch --no-tags linux-review Shunsuke-Mie/vringh-IOMEM-support/20230602-135351
> git checkout de2a1f5220c32e953400f225aba6bd294a8d41b8
> # save the config file
> mkdir build_dir && cp config build_dir/.config
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=alpha olddefconfig
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=alpha SHELL=/bin/bash drivers/
>
> If you fix the issue, kindly add following tag where applicable
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202306021725.3otSfXPF-lkp@xxxxxxxxx/
>
> All warnings (new ones prefixed by >>):
>
> >> drivers/vhost/vringh.c:1661:5: warning: no previous prototype for 'vringh_init_iomem' [-Wmissing-prototypes]
> 1661 | int vringh_init_iomem(struct vringh *vrh, u64 features, unsigned int num,
> | ^~~~~~~~~~~~~~~~~
> >> drivers/vhost/vringh.c:1683:5: warning: no previous prototype for 'vringh_getdesc_iomem' [-Wmissing-prototypes]
> 1683 | int vringh_getdesc_iomem(struct vringh *vrh, struct vringh_kiov *riov,
> | ^~~~~~~~~~~~~~~~~~~~
> >> drivers/vhost/vringh.c:1714:9: warning: no previous prototype for 'vringh_iov_pull_iomem' [-Wmissing-prototypes]
> 1714 | ssize_t vringh_iov_pull_iomem(struct vringh *vrh, struct vringh_kiov *riov,
> | ^~~~~~~~~~~~~~~~~~~~~
> >> drivers/vhost/vringh.c:1729:9: warning: no previous prototype for 'vringh_iov_push_iomem' [-Wmissing-prototypes]
> 1729 | ssize_t vringh_iov_push_iomem(struct vringh *vrh, struct vringh_kiov *wiov,
> | ^~~~~~~~~~~~~~~~~~~~~
> >> drivers/vhost/vringh.c:1744:6: warning: no previous prototype for 'vringh_abandon_iomem' [-Wmissing-prototypes]
> 1744 | void vringh_abandon_iomem(struct vringh *vrh, unsigned int num)
> | ^~~~~~~~~~~~~~~~~~~~
> >> drivers/vhost/vringh.c:1759:5: warning: no previous prototype for 'vringh_complete_iomem' [-Wmissing-prototypes]
> 1759 | int vringh_complete_iomem(struct vringh *vrh, u16 head, u32 len)
> | ^~~~~~~~~~~~~~~~~~~~~
> >> drivers/vhost/vringh.c:1777:6: warning: no previous prototype for 'vringh_notify_enable_iomem' [-Wmissing-prototypes]
> 1777 | bool vringh_notify_enable_iomem(struct vringh *vrh)
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~
> >> drivers/vhost/vringh.c:1790:6: warning: no previous prototype for 'vringh_notify_disable_iomem' [-Wmissing-prototypes]
> 1790 | void vringh_notify_disable_iomem(struct vringh *vrh)
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~
> >> drivers/vhost/vringh.c:1802:5: warning: no previous prototype for 'vringh_need_notify_iomem' [-Wmissing-prototypes]
> 1802 | int vringh_need_notify_iomem(struct vringh *vrh)
> | ^~~~~~~~~~~~~~~~~~~~~~~~
>
>
> vim +/vringh_init_iomem +1661 drivers/vhost/vringh.c


You probably should put the relevant code within ifdef.

> 1647
> 1648 /**
> 1649 * vringh_init_iomem - initialize a vringh for a vring on io-memory.
> 1650 * @vrh: the vringh to initialize.
> 1651 * @features: the feature bits for this ring.
> 1652 * @num: the number of elements.
> 1653 * @weak_barriers: true if we only need memory barriers, not I/O.
> 1654 * @desc: the userspace descriptor pointer.
> 1655 * @avail: the userspace avail pointer.
> 1656 * @used: the userspace used pointer.
> 1657 *
> 1658 * Returns an error if num is invalid: you should check pointers
> 1659 * yourself!
> 1660 */
> > 1661 int vringh_init_iomem(struct vringh *vrh, u64 features, unsigned int num,
> 1662 bool weak_barriers, struct vring_desc *desc,
> 1663 struct vring_avail *avail, struct vring_used *used)
> 1664 {
> 1665 return vringh_init_kern(vrh, features, num, weak_barriers, desc, avail,
> 1666 used);
> 1667 }
> 1668 EXPORT_SYMBOL(vringh_init_iomem);
> 1669
> 1670 /**
> 1671 * vringh_getdesc_iomem - get next available descriptor from vring on io-memory.
> 1672 * @vrh: the vring on io-memory.
> 1673 * @riov: where to put the readable descriptors (or NULL)
> 1674 * @wiov: where to put the writable descriptors (or NULL)
> 1675 * @head: head index we received, for passing to vringh_complete_iomem().
> 1676 * @gfp: flags for allocating larger riov/wiov.
> 1677 *
> 1678 * Returns 0 if there was no descriptor, 1 if there was, or -errno.
> 1679 *
> 1680 * There some notes, and those are same with vringh_getdesc_kern(). Please see
> 1681 * it.
> 1682 */
> > 1683 int vringh_getdesc_iomem(struct vringh *vrh, struct vringh_kiov *riov,
> 1684 struct vringh_kiov *wiov, u16 *head, gfp_t gfp)
> 1685 {
> 1686 int err;
> 1687
> 1688 err = __vringh_get_head(vrh, getu16_iomem, &vrh->last_avail_idx);
> 1689 if (err < 0)
> 1690 return err;
> 1691
> 1692 /* Empty... */
> 1693 if (err == vrh->vring.num)
> 1694 return 0;
> 1695
> 1696 *head = err;
> 1697 err = __vringh_iov(vrh, *head, riov, wiov, no_range_check, NULL, gfp,
> 1698 copydesc_iomem);
> 1699 if (err)
> 1700 return err;
> 1701
> 1702 return 1;
> 1703 }
> 1704 EXPORT_SYMBOL(vringh_getdesc_iomem);
> 1705
> 1706 /**
> 1707 * vringh_iov_pull_iomem - copy bytes from vring_iov.
> 1708 * @riov: the riov as passed to vringh_getdesc_iomem() (updated as we consume)
> 1709 * @dst: the place to copy.
> 1710 * @len: the maximum length to copy.
> 1711 *
> 1712 * Returns the bytes copied <= len or a negative errno.
> 1713 */
> > 1714 ssize_t vringh_iov_pull_iomem(struct vringh *vrh, struct vringh_kiov *riov,
> 1715 void *dst, size_t len)
> 1716 {
> 1717 return vringh_iov_xfer(vrh, riov, dst, len, xfer_from_iomem);
> 1718 }
> 1719 EXPORT_SYMBOL(vringh_iov_pull_iomem);
> 1720
> 1721 /**
> 1722 * vringh_iov_push_iomem - copy bytes into vring_iov.
> 1723 * @wiov: the wiov as passed to vringh_getdesc_iomem() (updated as we consume)
> 1724 * @src: the place to copy from.
> 1725 * @len: the maximum length to copy.
> 1726 *
> 1727 * Returns the bytes copied <= len or a negative errno.
> 1728 */
> > 1729 ssize_t vringh_iov_push_iomem(struct vringh *vrh, struct vringh_kiov *wiov,
> 1730 const void *src, size_t len)
> 1731 {
> 1732 return vringh_iov_xfer(vrh, wiov, (void *)src, len, xfer_to_iomem);
> 1733 }
> 1734 EXPORT_SYMBOL(vringh_iov_push_iomem);
> 1735
> 1736 /**
> 1737 * vringh_abandon_iomem - we've decided not to handle the descriptor(s).
> 1738 * @vrh: the vring.
> 1739 * @num: the number of descriptors to put back (ie. num
> 1740 * vringh_getdesc_iomem() to undo).
> 1741 *
> 1742 * The next vringh_get_kern() will return the old descriptor(s) again.
> 1743 */
> > 1744 void vringh_abandon_iomem(struct vringh *vrh, unsigned int num)
> 1745 {
> 1746 vringh_abandon_kern(vrh, num);
> 1747 }
> 1748 EXPORT_SYMBOL(vringh_abandon_iomem);
> 1749
> 1750 /**
> 1751 * vringh_complete_iomem - we've finished with descriptor, publish it.
> 1752 * @vrh: the vring.
> 1753 * @head: the head as filled in by vringh_getdesc_iomem().
> 1754 * @len: the length of data we have written.
> 1755 *
> 1756 * You should check vringh_need_notify_iomem() after one or more calls
> 1757 * to this function.
> 1758 */
> > 1759 int vringh_complete_iomem(struct vringh *vrh, u16 head, u32 len)
> 1760 {
> 1761 struct vring_used_elem used;
> 1762
> 1763 used.id = cpu_to_vringh32(vrh, head);
> 1764 used.len = cpu_to_vringh32(vrh, len);
> 1765
> 1766 return __vringh_complete(vrh, &used, 1, putu16_iomem, putused_iomem);
> 1767 }
> 1768 EXPORT_SYMBOL(vringh_complete_iomem);
> 1769
> 1770 /**
> 1771 * vringh_notify_enable_iomem - we want to know if something changes.
> 1772 * @vrh: the vring.
> 1773 *
> 1774 * This always enables notifications, but returns false if there are
> 1775 * now more buffers available in the vring.
> 1776 */
> > 1777 bool vringh_notify_enable_iomem(struct vringh *vrh)
> 1778 {
> 1779 return __vringh_notify_enable(vrh, getu16_iomem, putu16_iomem);
> 1780 }
> 1781 EXPORT_SYMBOL(vringh_notify_enable_iomem);
> 1782
> 1783 /**
> 1784 * vringh_notify_disable_iomem - don't tell us if something changes.
> 1785 * @vrh: the vring.
> 1786 *
> 1787 * This is our normal running state: we disable and then only enable when
> 1788 * we're going to sleep.
> 1789 */
> > 1790 void vringh_notify_disable_iomem(struct vringh *vrh)
> 1791 {
> 1792 __vringh_notify_disable(vrh, putu16_iomem);
> 1793 }
> 1794 EXPORT_SYMBOL(vringh_notify_disable_iomem);
> 1795
> 1796 /**
> 1797 * vringh_need_notify_iomem - must we tell the other side about used buffers?
> 1798 * @vrh: the vring we've called vringh_complete_iomem() on.
> 1799 *
> 1800 * Returns -errno or 0 if we don't need to tell the other side, 1 if we do.
> 1801 */
> > 1802 int vringh_need_notify_iomem(struct vringh *vrh)
> 1803 {
> 1804 return __vringh_need_notify(vrh, getu16_iomem);
> 1805 }
> 1806 EXPORT_SYMBOL(vringh_need_notify_iomem);
> 1807
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki