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path: root/drivers/xen/platform-pci.c
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2017-08-31xen-platform: constify pci_device_id.Arvind Yadav1-1/+1
pci_device_id are not supposed to change at runtime. All functions working with pci_device_id provided by <linux/pci.h> work with const pci_device_id. So mark the non-const structs as const. Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-05-02xen: Revert commits da72ff5bfcb0 and 72a9b186292dBoris Ostrovsky1-10/+4
Recent discussion (http://marc.info/?l=xen-devel&m=149192184523741) established that commit 72a9b186292d ("xen: Remove event channel notification through Xen PCI platform device") (and thus commit da72ff5bfcb0 ("partially revert "xen: Remove event channel notification through Xen PCI platform device"")) are unnecessary and, in fact, prevent HVM guests from booting on Xen releases prior to 4.0 Therefore we revert both of those commits. The summary of that discussion is below: Here is the brief summary of the current situation: Before the offending commit (72a9b186292): 1) INTx does not work because of the reset_watches path. 2) The reset_watches path is only taken if you have Xen > 4.0 3) The Linux Kernel by default will use vector inject if the hypervisor support. So even INTx does not work no body running the kernel with Xen > 4.0 would notice. Unless he explicitly disabled this feature either in the kernel or in Xen (and this can only be disabled by modifying the code, not user-supported way to do it). After the offending commit (+ partial revert): 1) INTx is no longer support for HVM (only for PV guests). 2) Any HVM guest The kernel will not boot on Xen < 4.0 which does not have vector injection support. Since the only other mode supported is INTx which. So based on this summary, I think before commit (72a9b186292) we were in much better position from a user point of view. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-01-13partially revert "xen: Remove event channel notification through Xen PCI ↵Stefano Stabellini1-0/+71
platform device" Commit 72a9b186292d ("xen: Remove event channel notification through Xen PCI platform device") broke Linux when booting as Dom0 on Xen in a nested Xen environment (Xen installed inside a Xen VM). In this scenario, Linux is a PV guest, but at the same time it uses the platform-pci driver to receive notifications from L0 Xen. vector callbacks are not available because L1 Xen doesn't allow them. Partially revert the offending commit, by restoring IRQ based notifications for PV guests only. I restored only the code which is strictly needed and replaced the xen_have_vector_callback checks within it with xen_pv_domain() checks. Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2016-11-17xen-platform: use builtin_pci_driverGeliang Tang1-5/+1
Use builtin_pci_driver() helper to simplify the code. Signed-off-by: Geliang Tang <geliangtang@gmail.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2016-09-30xen: Remove event channel notification through Xen PCI platform deviceKarimAllah Ahmed1-64/+0
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 <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Juergen Gross <jgross@suse.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Julien Grall <julien.grall@citrix.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Ross Lagerwall <ross.lagerwall@citrix.com> Cc: xen-devel@lists.xenproject.org Cc: linux-kernel@vger.kernel.org Cc: linux-pci@vger.kernel.org Cc: Anthony Liguori <aliguori@amazon.com> Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-03-21drivers/xen: make platform-pci.c explicitly non-modularPaul Gortmaker1-13/+9
The Kconfig currently controlling compilation of this code is: arch/x86/xen/Kconfig:config XEN_PVHVM arch/x86/xen/Kconfig: def_bool y ...meaning that it currently is not being built as a module by anyone. Lets remove the modular code that is essentially orphaned, so that when reading the driver there is no doubt it is builtin-only. Since module_init translates to device_initcall in the non-modular case, the init ordering remains unchanged with this commit. Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code. We also delete the MODULE_LICENSE tag etc. since all that information was (or is now) contained at the top of the file in the comments. In removing "module" from the init fcn name, we observe a namespace collision with the probe function, so we use "probe" in the name of the probe function, and "init" in the registration fcn, as per standard convention, as suggested by Stefano. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-02-28drivers: xen: Mark function as static in platform-pci.cRashika Kheria1-1/+1
Mark function as static in xen/platform-pci.c because it is not used outside this file. This eliminates the following warning in xen/platform-pci.c: drivers/xen/platform-pci.c:48:15: warning: no previous prototype for ‘alloc_xen_mmio’ [-Wmissing-prototypes] Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com>
2014-01-07xen-platform: fix error return code in platform_pci_init()Wei Yongjun1-1/+2
Fix to return a negative error code from the error handling case instead of 0, otherwise the error condition cann't be reflected from the return value. Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2014-01-06xen/grant: Implement an grant frame array struct (v3).Konrad Rzeszutek Wilk1-3/+7
The 'xen_hvm_resume_frames' used to be an 'unsigned long' and contain the virtual address of the grants. That was OK for most architectures (PVHVM, ARM) were the grants are contiguous in memory. That however is not the case for PVH - in which case we will have to do a lookup for each virtual address for the PFN. Instead of doing that, lets make it a structure which will contain the array of PFNs, the virtual address and the count of said PFNs. Also provide a generic functions: gnttab_setup_auto_xlat_frames and gnttab_free_auto_xlat_frames to populate said structure with appropriate values for PVHVM and ARM. To round it off, change the name from 'xen_hvm_resume_frames' to a more descriptive one - 'xen_auto_xlat_grant_frames'. For PVH, in patch "xen/pvh: Piggyback on PVHVM for grant driver" we will populate the 'xen_auto_xlat_grant_frames' by ourselves. v2 moves the xen_remap in the gnttab_setup_auto_xlat_frames and also introduces xen_unmap for gnttab_free_auto_xlat_frames. Suggested-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [v3: Based on top of 'asm/xen/page.h: remove redundant semicolon'] Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2013-11-06xen: remove deprecated IRQF_DISABLEDMichael Opdenacker1-1/+1
This patch proposes to remove the IRQF_DISABLED flag from drivers/xen code. It's a NOOP since 2.6.35 and it will be removed one day. Note that architecture dependent fixes for IRQF_DISABLED were already submitted through separate patches. Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-01-03Drivers: xen: remove __dev* attributes.Greg Kroah-Hartman1-3/+3
CONFIG_HOTPLUG is going away as an option. As a result, the __dev* markings need to be removed. This change removes the use of __devinit, and __devinitdata from these drivers. Based on patches originally written by Bill Pemberton, but redone by me in order to handle some of the coding style issues better, by hand. Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Jan Beulich <jbeulich@suse.com> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Bill Pemberton <wfp5p@virginia.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-16Revert "xen PVonHVM: move shared_info to MMIO before kexec"Konrad Rzeszutek Wilk1-15/+0
This reverts commit 00e37bdb0113a98408de42db85be002f21dbffd3. During shutdown of PVHVM guests with more than 2VCPUs on certain machines we can hit the race where the replaced shared_info is not replaced fast enough and the PV time clock retries reading the same area over and over without any any success and is stuck in an infinite loop. Acked-by: Olaf Hering <olaf@aepfle.de> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-07-19xen PVonHVM: move shared_info to MMIO before kexecOlaf Hering1-0/+15
Currently kexec in a PVonHVM guest fails with a triple fault because the new kernel overwrites the shared info page. The exact failure depends on the size of the kernel image. This patch moves the pfn from RAM into MMIO space before the kexec boot. The pfn containing the shared_info is located somewhere in RAM. This will cause trouble if the current kernel is doing a kexec boot into a new kernel. The new kernel (and its startup code) can not know where the pfn is, so it can not reserve the page. The hypervisor will continue to update the pfn, and as a result memory corruption occours in the new kernel. One way to work around this issue is to allocate a page in the xen-platform pci device's BAR memory range. But pci init is done very late and the shared_info page is already in use very early to read the pvclock. So moving the pfn from RAM to MMIO is racy because some code paths on other vcpus could access the pfn during the small window when the old pfn is moved to the new pfn. There is even a small window were the old pfn is not backed by a mfn, and during that time all reads return -1. Because it is not known upfront where the MMIO region is located it can not be used right from the start in xen_hvm_init_shared_info. To minimise trouble the move of the pfn is done shortly before kexec. This does not eliminate the race because all vcpus are still online when the syscore_ops will be called. But hopefully there is no work pending at this point in time. Also the syscore_op is run last which reduces the risk further. Signed-off-by: Olaf Hering <olaf@aepfle.de> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-07-19xen: enable platform-pci only in a Xen guestOlaf Hering1-0/+3
While debugging kexec issues in a PVonHVM guest I modified xen_hvm_platform() to return false to disable all PV drivers. This caused a crash in platform_pci_init() because it expects certain data structures to be initialized properly. To avoid such a crash make sure the driver is initialized only if running in a Xen guest. Signed-off-by: Olaf Hering <olaf@aepfle.de> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-03-22xen: initialize platform-pci even if xen_emul_unplug=neverIgor Mammedov1-5/+0
When xen_emul_unplug=never is specified on kernel command line reading files from /sys/hypervisor is broken (returns -EBUSY). It is caused by xen_bus dependency on platform-pci and platform-pci isn't initialized when xen_emul_unplug=never is specified. Fix it by allowing platform-pci to ignore xen_emul_unplug=never, and do not intialize xen_[blk|net]front instead. Signed-off-by: Igor Mammedov <imammedo@redhat.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-02-25xen: no need to delay xen_setup_shutdown_event for hvm guests anymoreStefano Stabellini1-3/+0
Now that xenstore_ready is used correctly for PV on HVM guests too, we don't need to delay the initialization of xen_setup_shutdown_event anymore. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
2011-01-12xen-platform: use PCI interfaces to request IO and MEM resources.Ian Campbell1-14/+7
This is the correct interface to use and something has broken the use of the previous incorrect interface (which fails because the request conflicts with the resources assigned for the PCI device itself instead of nesting like the PCI interfaces do). Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: stable@kernel.org # 2.6.37 only
2010-07-26x86: Unplug emulated disks and nics.Stefano Stabellini1-0/+6
Add a xen_emul_unplug command line option to the kernel to unplug xen emulated disks and nics. Set the default value of xen_emul_unplug depending on whether or not the Xen PV frontends and the Xen platform PCI driver have been compiled for this kernel (modules or built-in are both OK). The user can specify xen_emul_unplug=ignore to enable PV drivers on HVM even if the host platform doesn't support unplug. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-22xen: Add suspend/resume support for PV on HVM guests.Stefano Stabellini1-1/+21
Suspend/resume requires few different things on HVM: the suspend hypercall is different; we don't need to save/restore memory related settings; except the shared info page and the callback mechanism. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-22xen: Xen PCI platform device driver.Stefano Stabellini1-0/+181
Add the xen pci platform device driver that is responsible for initializing the grant table and xenbus in PV on HVM mode. Few changes to xenbus and grant table are necessary to allow the delayed initialization in HVM mode. Grant table needs few additional modifications to work in HVM mode. The Xen PCI platform device raises an irq every time an event has been delivered to us. However these interrupts are only delivered to vcpu 0. The Xen PCI platform interrupt handler calls xen_hvm_evtchn_do_upcall that is a little wrapper around __xen_evtchn_do_upcall, the traditional Xen upcall handler, the very same used with traditional PV guests. When running on HVM the event channel upcall is never called while in progress because it is a normal Linux irq handler (and we cannot switch the irq chip wholesale to the Xen PV ones as we are running QEMU and might have passed in PCI devices), therefore we cannot be sure that evtchn_upcall_pending is 0 when returning. For this reason if evtchn_upcall_pending is set by Xen we need to loop again on the event channels set pending otherwise we might loose some event channel deliveries. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>