The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.14.y git checkout FETCH_HEAD git cherry-pick -x ef5dd8ec88ac11e8e353164407d55b73c988b369 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2023112214-slaw-bootlace-8f7a@gregkh' --subject-prefix 'PATCH 4.14.y' HEAD^.. Possible dependencies: ef5dd8ec88ac ("hvc/xen: fix event channel handling for secondary consoles") fe415186b43d ("xen/console: harden hvc_xen against event channel storms") 3bd5371a4da6 ("xen/events: Remove unused bind_evtchn_to_irq_lateeoi()") 54c9de89895e ("xen/events: add a new "late EOI" evtchn framework") 0102e4efda76 ("xen: Use evtchn_type_t as a type for event channels") bce5963bcb4f ("xen/events: fix binding user event channels to cpus") 9f51c05dc41a ("pvcalls-front: Avoid get_free_pages(GFP_KERNEL) under spinlock") 975ef94a0284 ("pvcalls-front: fixes incorrect error handling") 1d3145675538 ("xen/gntdev: Make private routines/structures accessible") 975ef7ff81bb ("xen/gntdev: Allow mappings for DMA buffers") 64d6871827b1 ("pvcalls-front: introduce a per sock_mapping refcount") a9a08845e9ac ("vfs: do bulk POLL* -> EPOLL* replacement") 68c5735eaa5e ("Merge tag 'media/v4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From ef5dd8ec88ac11e8e353164407d55b73c988b369 Mon Sep 17 00:00:00 2001 From: David Woodhouse <dwmw@xxxxxxxxxxxx> Date: Fri, 20 Oct 2023 17:15:27 +0100 Subject: [PATCH] hvc/xen: fix event channel handling for secondary consoles MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The xencons_connect_backend() function allocates a local interdomain event channel with xenbus_alloc_evtchn(), then calls bind_interdomain_evtchn_to_irq_lateeoi() to bind to that port# on the *remote* domain. That doesn't work very well: (qemu) device_add xen-console,id=con1,chardev=pty0 [ 44.323872] xenconsole console-1: 2 xenbus_dev_probe on device/console/1 [ 44.323995] xenconsole: probe of console-1 failed with error -2 Fix it to use bind_evtchn_to_irq_lateeoi(), which does the right thing by just binding that *local* event channel to an irq. The backend will do the interdomain binding. This didn't affect the primary console because the setup for that is special — the toolstack allocates the guest event channel and the guest discovers it with HVMOP_get_param. Fixes: fe415186b43d ("xen/console: harden hvc_xen against event channel storms") Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx> Reviewed-by: Juergen Gross <jgross@xxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20231020161529.355083-2-dwmw2@xxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c index 98764e740c07..f24e285b6441 100644 --- a/drivers/tty/hvc/hvc_xen.c +++ b/drivers/tty/hvc/hvc_xen.c @@ -433,7 +433,7 @@ static int xencons_connect_backend(struct xenbus_device *dev, if (ret) return ret; info->evtchn = evtchn; - irq = bind_interdomain_evtchn_to_irq_lateeoi(dev, evtchn); + irq = bind_evtchn_to_irq_lateeoi(evtchn); if (irq < 0) return irq; info->irq = irq;
