linux/drivers/xen, branch v4.9

Merge tag 'for-linus-4.9-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2016-10-25T02:52:24Z

Pull xen fixes from David Vrabel: - advertise control feature flags in xenstore - fix x86 build when XEN_PVHVM is disabled * tag 'for-linus-4.9-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xenbus: check return value of xenbus_scanf() xenbus: prefer list_for_each() x86: xen: move cpu_up functions out of ifdef xenbus: advertise control feature flags

xenbus: check return value of xenbus_scanf()

2016-10-24T15:08:21Z

Don't ignore errors here: Set backend state to unknown when unsuccessful. Signed-off-by: Jan Beulich Signed-off-by: David Vrabel

xenbus: prefer list_for_each()

2016-10-24T15:08:04Z

This is more efficient than list_for_each_safe() when list modification is accompanied by breaking out of the loop. Signed-off-by: Jan Beulich Reviewed-by: Juergen Gross Signed-off-by: David Vrabel

xenbus: advertise control feature flags

2016-10-24T14:48:40Z

The Xen docs specify several flags which a guest can set to advertise which values of the xenstore control/shutdown key it will recognize. This patch adds code to write all the relevant feature-flag keys. Based-on-patch-by: Paul Durrant Signed-off-by: Juergen Gross Reviewed-by: David Vrabel Reviewed-by: Paul Durrant Signed-off-by: David Vrabel

Merge tag 'for-linus-4.9-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2016-10-06T18:19:10Z

Pull xen updates from David Vrabel: "xen features and fixes for 4.9: - switch to new CPU hotplug mechanism - support driver_override in pciback - require vector callback for HVM guests (the alternate mechanism via the platform device has been broken for ages)" * tag 'for-linus-4.9-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/x86: Update topology map for PV VCPUs xen/x86: Initialize per_cpu(xen_vcpu, 0) a little earlier xen/pciback: support driver_override xen/pciback: avoid multiple entries in slot list xen/pciback: simplify pcistub device handling xen: Remove event channel notification through Xen PCI platform device xen/events: Convert to hotplug state machine xen/x86: Convert to hotplug state machine x86/xen: add missing \n at end of printk warning message xen/grant-table: Use kmalloc_array() in arch_gnttab_valloc() xen: Make VPMU init message look less scary xen: rename xen_pmu_init() in sys-hypervisor.c hotplug: Prevent alloc/free of irq descriptors during cpu up/down (again) xen/x86: Move irq allocation from Xen smp_op.cpu_up()

xen/pciback: support driver_override

2016-09-30T10:49:02Z

Support the driver_override scheme introduced with commit 782a985d7af2 ("PCI: Introduce new device binding path using pci_dev.driver_override") As pcistub_probe() is called for all devices (it has to check for a match based on the slot address rather than device type) it has to check for driver_override set to "pciback" itself. Up to now for assigning a pci device to pciback you need something like: echo 0000:07:10.0 > /sys/bus/pci/devices/0000\:07\:10.0/driver/unbind echo 0000:07:10.0 > /sys/bus/pci/drivers/pciback/new_slot echo 0000:07:10.0 > /sys/bus/pci/drivers_probe while with the patch you can use the same mechanism as for similar drivers like pci-stub and vfio-pci: echo pciback > /sys/bus/pci/devices/0000\:07\:10.0/driver_override echo 0000:07:10.0 > /sys/bus/pci/devices/0000\:07\:10.0/driver/unbind echo 0000:07:10.0 > /sys/bus/pci/drivers_probe So e.g. libvirt doesn't need special handling for pciback. Signed-off-by: Juergen Gross Signed-off-by: David Vrabel

xen/pciback: avoid multiple entries in slot list

2016-09-30T10:48:55Z

The Xen pciback driver has a list of all pci devices it is ready to seize. There is no check whether a to be added entry already exists. While this might be no problem in the common case it might confuse those which consume the list via sysfs. Modify the handling of this list by not adding an entry which already exists. As this will be needed later split out the list handling into a separate function. Signed-off-by: Juergen Gross Signed-off-by: David Vrabel

xen/pciback: simplify pcistub device handling

2016-09-30T10:48:33Z

The Xen pciback driver maintains a list of all its seized devices. There are two functions searching the list for a specific device with basically the same semantics just returning different structures in case of a match. Split out the search function. Signed-off-by: Juergen Gross Signed-off-by: David Vrabel

xen: Remove event channel notification through Xen PCI platform device

2016-09-30T10:44:34Z

Ever since commit 254d1a3f02eb ("xen/pv-on-hvm kexec: shutdown watches from old kernel") using the INTx interrupt from Xen PCI platform device for event channel notification would just lockup the guest during bootup. postcore_initcall now calls xs_reset_watches which will eventually try to read a value from XenStore and will get stuck on read_reply at XenBus forever since the platform driver is not probed yet and its INTx interrupt handler is not registered yet. That means that the guest can not be notified at this moment of any pending event channels and none of the per-event handlers will ever be invoked (including the XenStore one) and the reply will never be picked up by the kernel. The exact stack where things get stuck during xenbus_init: -xenbus_init -xs_init -xs_reset_watches -xenbus_scanf -xenbus_read -xs_single -xs_single -xs_talkv Vector callbacks have always been the favourite event notification mechanism since their introduction in commit 38e20b07efd5 ("x86/xen: event channels delivery on HVM.") and the vector callback feature has always been advertised for quite some time by Xen that's why INTx was broken for several years now without impacting anyone. Luckily this also means that event channel notification through INTx is basically dead-code which can be safely removed without impacting anybody since it has been effectively disabled for more than 4 years with nobody complaining about it (at least as far as I'm aware of). This commit removes event channel notification through Xen PCI platform device. Cc: Boris Ostrovsky Cc: David Vrabel Cc: Juergen Gross Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: x86@kernel.org Cc: Konrad Rzeszutek Wilk Cc: Bjorn Helgaas Cc: Stefano Stabellini Cc: Julien Grall Cc: Vitaly Kuznetsov Cc: Paul Gortmaker Cc: Ross Lagerwall Cc: xen-devel@lists.xenproject.org Cc: linux-kernel@vger.kernel.org Cc: linux-pci@vger.kernel.org Cc: Anthony Liguori Signed-off-by: KarimAllah Ahmed Reviewed-by: Boris Ostrovsky Signed-off-by: David Vrabel

xen/events: Convert to hotplug state machine

2016-09-30T10:23:04Z

Install the callbacks via the state machine. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Boris Ostrovsky Signed-off-by: David Vrabel