kernel/drivers/xen/privcmd.c, branch linux-6.18.y

xen: replace XENFEAT_auto_translated_physmap with xen_pv_domain()

2025-09-08T15:01:36Z

Instead of testing the XENFEAT_auto_translated_physmap feature, just use !xen_pv_domain() which is equivalent. This has the advantage that a kernel not built with CONFIG_XEN_PV will be smaller due to dead code elimination. Reviewed-by: Jason Andryuk Signed-off-by: Juergen Gross Message-ID: <20250826145608.10352-3-jgross@suse.com>

Merge tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2024-11-18T20:24:06Z

Pull 'struct fd' class updates from Al Viro: "The bulk of struct fd memory safety stuff Making sure that struct fd instances are destroyed in the same scope where they'd been created, getting rid of reassignments and passing them by reference, converting to CLASS(fd{,_pos,_raw}). We are getting very close to having the memory safety of that stuff trivial to verify" * tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits) deal with the last remaing boolean uses of fd_file() css_set_fork(): switch to CLASS(fd_raw, ...) memcg_write_event_control(): switch to CLASS(fd) assorted variants of irqfd setup: convert to CLASS(fd) do_pollfd(): convert to CLASS(fd) convert do_select() convert vfs_dedupe_file_range(). convert cifs_ioctl_copychunk() convert media_request_get_by_fd() convert spu_run(2) switch spufs_calls_{get,put}() to CLASS() use convert cachestat(2) convert do_preadv()/do_pwritev() fdget(), more trivial conversions fdget(), trivial conversions privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget() o2hb_region_dev_store(): avoid goto around fdget()/fdput() introduce "fd_pos" class, convert fdget_pos() users to it. fdget_raw() users: switch to CLASS(fd_raw) convert vmsplice() to CLASS(fd) ...

assorted variants of irqfd setup: convert to CLASS(fd)

2024-11-03T06:28:07Z

in all of those failure exits prior to fdget() are plain returns and the only thing done after fdput() is (on failure exits) a kfree(), which can be done before fdput() just fine. NOTE: in acrn_irqfd_assign() 'fail:' failure exit is wrong for eventfd_ctx_fileget() failure (we only want fdput() there) and once we stop doing that, it doesn't need to check if eventfd is NULL or ERR_PTR(...) there. NOTE: in privcmd we move fdget() up before the allocation - more to the point, before the copy_from_user() attempt. Signed-off-by: Al Viro

privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget()

2024-11-03T06:28:06Z

just call it, same as privcmd_ioeventfd_deassign() does... Signed-off-by: Al Viro

xen: Remove dependency between pciback and privcmd

2024-10-18T09:59:04Z

Commit 2fae6bb7be32 ("xen/privcmd: Add new syscall to get gsi from dev") adds a weak reverse dependency to the config XEN_PRIVCMD definition, that dependency causes xen-privcmd can't be loaded on domU, because dependent xen-pciback isn't always be loaded successfully on domU. To solve above problem, remove that dependency, and do not call pcistub_get_gsi_from_sbdf() directly, instead add a hook in drivers/xen/apci.c, xen-pciback register the real call function, then in privcmd_ioctl_pcidev_get_gsi call that hook. Fixes: 2fae6bb7be32 ("xen/privcmd: Add new syscall to get gsi from dev") Reported-by: Marek Marczykowski-Górecki Signed-off-by: Jiqian Chen Reviewed-by: Juergen Gross Message-ID: <20241012084537.1543059-1-Jiqian.Chen@amd.com> Signed-off-by: Juergen Gross

Merge tag 'for-linus-6.12-rc1a-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2024-09-27T16:55:30Z

Pull more xen updates from Juergen Gross: "A second round of Xen related changes and features: - a small fix of the xen-pciback driver for a warning issued by sparse - support PCI passthrough when using a PVH dom0 - enable loading the kernel in PVH mode at arbitrary addresses, avoiding conflicts with the memory map when running as a Xen dom0 using the host memory layout" * tag 'for-linus-6.12-rc1a-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: x86/pvh: Add 64bit relocation page tables x86/kernel: Move page table macros to header x86/pvh: Set phys_base when calling xen_prepare_pvh() x86/pvh: Make PVH entrypoint PIC for x86-64 xen: sync elfnote.h from xen tree xen/pciback: fix cast to restricted pci_ers_result_t and pci_power_t xen/privcmd: Add new syscall to get gsi from dev xen/pvh: Setup gsi for passthrough device xen/pci: Add a function to reset device for xen

xen/privcmd: Add new syscall to get gsi from dev

2024-09-25T07:54:55Z

On PVH dom0, when passthrough a device to domU, QEMU and xl tools want to use gsi number to do pirq mapping, see QEMU code xen_pt_realize->xc_physdev_map_pirq, and xl code pci_add_dm_done->xc_physdev_map_pirq, but in current codes, the gsi number is got from file /sys/bus/pci/devices//irq, that is wrong, because irq is not equal with gsi, they are in different spaces, so pirq mapping fails. And in current linux codes, there is no method to get gsi for userspace. For above purpose, record gsi of pcistub devices when init pcistub and add a new syscall into privcmd to let userspace can get gsi when they have a need. Signed-off-by: Jiqian Chen Signed-off-by: Huang Rui Signed-off-by: Jiqian Chen Reviewed-by: Stefano Stabellini Message-ID: <20240924061437.2636766-4-Jiqian.Chen@amd.com> Signed-off-by: Juergen Gross

introduce fd_file(), convert all accessors to it.

2024-08-13T02:00:43Z

For any changes of struct fd representation we need to turn existing accesses to fields into calls of wrappers. Accesses to struct fd::flags are very few (3 in linux/file.h, 1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in explicit initializers). Those can be dealt with in the commit converting to new layout; accesses to struct fd::file are too many for that. This commit converts (almost) all of f.file to fd_file(f). It's not entirely mechanical ('file' is used as a member name more than just in struct fd) and it does not even attempt to distinguish the uses in pointer context from those in boolean context; the latter will be eventually turned into a separate helper (fd_empty()). NOTE: mass conversion to fd_empty(), tempting as it might be, is a bad idea; better do that piecewise in commit that convert from fdget...() to CLASS(...). [conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c caught by git; fs/stat.c one got caught by git grep] [fs/xattr.c conflict] Reviewed-by: Christian Brauner Signed-off-by: Al Viro

xen: privcmd: Fix possible access to a freed kirqfd instance

2024-07-02T10:23:42Z

Nothing prevents simultaneous ioctl calls to privcmd_irqfd_assign() and privcmd_irqfd_deassign(). If that happens, it is possible that a kirqfd created and added to the irqfds_list by privcmd_irqfd_assign() may get removed by another thread executing privcmd_irqfd_deassign(), while the former is still using it after dropping the locks. This can lead to a situation where an already freed kirqfd instance may be accessed and cause kernel oops. Use SRCU locking to prevent the same, as is done for the KVM implementation for irqfds. Reported-by: Al Viro Suggested-by: Paolo Bonzini Signed-off-by: Viresh Kumar Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/9e884af1f1f842eacbb7afc5672c8feb4dea7f3f.1718703669.git.viresh.kumar@linaro.org Signed-off-by: Juergen Gross

xen: privcmd: Switch from mutex to spinlock for irqfds

2024-07-02T10:23:39Z

irqfd_wakeup() gets EPOLLHUP, when it is called by eventfd_release() by way of wake_up_poll(&ctx->wqh, EPOLLHUP), which gets called under spin_lock_irqsave(). We can't use a mutex here as it will lead to a deadlock. Fix it by switching over to a spin lock. Reported-by: Al Viro Signed-off-by: Viresh Kumar Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/a66d7a7a9001424d432f52a9fc3931a1f345464f.1718703669.git.viresh.kumar@linaro.org Signed-off-by: Juergen Gross