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* Merge tag 'for-linus-5.12-rc1-tag' of ↵Linus Torvalds2021-02-212-19/+22
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from Juergen Gross: "A series of Xen related security fixes, all related to limited error handling in Xen backend drivers" * tag 'for-linus-5.12-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen-blkback: fix error handling in xen_blkbk_map() xen-scsiback: don't "handle" error by BUG() xen-netback: don't "handle" error by BUG() xen-blkback: don't "handle" error by BUG() xen/arm: don't ignore return errors from set_phys_to_machine Xen/gntdev: correct error checking in gntdev_map_grant_pages() Xen/gntdev: correct dev_bus_addr handling in gntdev_map_grant_pages() Xen/x86: also check kernel mapping in set_foreign_p2m_mapping() Xen/x86: don't bail early from clear_foreign_p2m_mapping()
| * xen-scsiback: don't "handle" error by BUG()Jan Beulich2021-02-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In particular -ENOMEM may come back here, from set_foreign_p2m_mapping(). Don't make problems worse, the more that handling elsewhere (together with map's status fields now indicating whether a mapping wasn't even attempted, and hence has to be considered failed) doesn't require this odd way of dealing with errors. This is part of XSA-362. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: stable@vger.kernel.org Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
| * Xen/gntdev: correct error checking in gntdev_map_grant_pages()Jan Beulich2021-02-151-8/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Failure of the kernel part of the mapping operation should also be indicated as an error to the caller, or else it may assume the respective kernel VA is okay to access. Furthermore gnttab_map_refs() failing still requires recording successfully mapped handles, so they can be unmapped subsequently. This in turn requires there to be a way to tell full hypercall failure from partial success - preset map_op status fields such that they won't "happen" to look as if the operation succeeded. Also again use GNTST_okay instead of implying its value (zero). This is part of XSA-361. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: stable@vger.kernel.org Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
| * Xen/gntdev: correct dev_bus_addr handling in gntdev_map_grant_pages()Jan Beulich2021-02-151-11/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We may not skip setting the field in the unmap structure when GNTMAP_device_map is in use - such an unmap would fail to release the respective resources (a page ref in the hypervisor). Otoh the field doesn't need setting at all when GNTMAP_device_map is not in use. To record the value for unmapping, we also better don't use our local p2m: In particular after a subsequent change it may not have got updated for all the batch elements. Instead it can simply be taken from the respective map's results. We can additionally avoid playing this game altogether for the kernel part of the mappings in (x86) PV mode. This is part of XSA-361. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: stable@vger.kernel.org Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Juergen Gross <jgross@suse.com>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextLinus Torvalds2021-02-204-21/+28
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking updates from David Miller: "Here is what we have this merge window: 1) Support SW steering for mlx5 Connect-X6Dx, from Yevgeny Kliteynik. 2) Add RSS multi group support to octeontx2-pf driver, from Geetha Sowjanya. 3) Add support for KS8851 PHY. From Marek Vasut. 4) Add support for GarfieldPeak bluetooth controller from Kiran K. 5) Add support for half-duplex tcan4x5x can controllers. 6) Add batch skb rx processing to bcrm63xx_enet, from Sieng Piaw Liew. 7) Rework RX port offload infrastructure, particularly wrt, UDP tunneling, from Jakub Kicinski. 8) Add BCM72116 PHY support, from Florian Fainelli. 9) Remove Dsa specific notifiers, they are unnecessary. From Vladimir Oltean. 10) Add support for picosecond rx delay in dwmac-meson8b chips. From Martin Blumenstingl. 11) Support TSO on xfrm interfaces from Eyal Birger. 12) Add support for MP_PRIO to mptcp stack, from Geliang Tang. 13) Support BCM4908 integrated switch, from Rafał Miłecki. 14) Support for directly accessing kernel module variables via module BTF info, from Andrii Naryiko. 15) Add DASH (esktop and mobile Architecture for System Hardware) support to r8169 driver, from Heiner Kallweit. 16) Add rx vlan filtering to dpaa2-eth, from Ionut-robert Aron. 17) Add support for 100 base0x SFP devices, from Bjarni Jonasson. 18) Support link aggregation in DSA, from Tobias Waldekranz. 19) Support for bitwidse atomics in bpf, from Brendan Jackman. 20) SmartEEE support in at803x driver, from Russell King. 21) Add support for flow based tunneling to GTP, from Pravin B Shelar. 22) Allow arbitrary number of interconnrcts in ipa, from Alex Elder. 23) TLS RX offload for bonding, from Tariq Toukan. 24) RX decap offklload support in mac80211, from Felix Fietkou. 25) devlink health saupport in octeontx2-af, from George Cherian. 26) Add TTL attr to SCM_TIMESTAMP_OPT_STATS, from Yousuk Seung 27) Delegated actionss support in mptcp, from Paolo Abeni. 28) Support receive timestamping when doin zerocopy tcp receive. From Arjun Ray. 29) HTB offload support for mlx5, from Maxim Mikityanskiy. 30) UDP GRO forwarding, from Maxim Mikityanskiy. 31) TAPRIO offloading in dsa hellcreek driver, from Kurt Kanzenbach. 32) Weighted random twos choice algorithm for ipvs, from Darby Payne. 33) Fix netdev registration deadlock, from Johannes Berg. 34) Various conversions to new tasklet api, from EmilRenner Berthing. 35) Bulk skb allocations in veth, from Lorenzo Bianconi. 36) New ethtool interface for lane setting, from Danielle Ratson. 37) Offload failiure notifications for routes, from Amit Cohen. 38) BCM4908 support, from Rafał Miłecki. 39) Support several new iwlwifi chips, from Ihab Zhaika. 40) Flow drector support for ipv6 in i40e, from Przemyslaw Patynowski. 41) Support for mhi prrotocols, from Loic Poulain. 42) Optimize bpf program stats. 43) Implement RFC6056, for better port randomization, from Eric Dumazet. 44) hsr tag offloading support from George McCollister. 45) Netpoll support in qede, from Bhaskar Upadhaya. 46) 2005/400g speed support in bonding 3ad mode, from Nikolay Aleksandrov. 47) Netlink event support in mptcp, from Florian Westphal. 48) Better skbuff caching, from Alexander Lobakin. 49) MRP (Media Redundancy Protocol) offloading in DSA and a few drivers, from Horatiu Vultur. 50) mqprio saupport in mvneta, from Maxime Chevallier. 51) Remove of_phy_attach, no longer needed, from Florian Fainelli" * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1766 commits) octeontx2-pf: Fix otx2_get_fecparam() cteontx2-pf: cn10k: Prevent harmless double shift bugs net: stmmac: Add PCI bus info to ethtool driver query output ptp: ptp_clockmatrix: clean-up - parenthesis around a == b are unnecessary ptp: ptp_clockmatrix: Simplify code - remove unnecessary `err` variable. ptp: ptp_clockmatrix: Coding style - tighten vertical spacing. ptp: ptp_clockmatrix: Clean-up dev_*() messages. ptp: ptp_clockmatrix: Remove unused header declarations. ptp: ptp_clockmatrix: Add alignment of 1 PPS to idtcm_perout_enable. ptp: ptp_clockmatrix: Add wait_for_sys_apll_dpll_lock. net: stmmac: dwmac-sun8i: Add a shutdown callback net: stmmac: dwmac-sun8i: Minor probe function cleanup net: stmmac: dwmac-sun8i: Use reset_control_reset net: stmmac: dwmac-sun8i: Remove unnecessary PHY power check net: stmmac: dwmac-sun8i: Return void from PHY unpower r8169: use macro pm_ptr net: mdio: Remove of_phy_attach() net: mscc: ocelot: select PACKING in the Kconfig net: re-solve some conflicts after net -> net-next merge net: dsa: tag_rtl4_a: Support also egress tags ...
| * xen/events: link interdomain events to associated xenbus deviceJuergen Gross2021-02-114-21/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to support the possibility of per-device event channel settings (e.g. lateeoi spurious event thresholds) add a xenbus device pointer to struct irq_info() and modify the related event channel binding interfaces to take the pointer to the xenbus device as a parameter instead of the domain id of the other side. While at it remove the stale prototype of bind_evtchn_to_irq_lateeoi(). Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Paul Durrant <paul@xen.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge tag 'for-linus-5.11-rc8-tag' of ↵Linus Torvalds2021-02-122-2/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fix from Juergen Gross: "A single fix for an issue introduced this development cycle: when running as a Xen guest on Arm systems the kernel will hang during boot" * tag 'for-linus-5.11-rc8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: arm/xen: Don't probe xenbus as part of an early initcall
| * arm/xen: Don't probe xenbus as part of an early initcallJulien Grall2021-02-112-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After Commit 3499ba8198cad ("xen: Fix event channel callback via INTX/GSI"), xenbus_probe() will be called too early on Arm. This will recent to a guest hang during boot. If the hang wasn't there, we would have ended up to call xenbus_probe() twice (the second time is in xenbus_probe_initcall()). We don't need to initialize xenbus_probe() early for Arm guest. Therefore, the call in xen_guest_init() is now removed. After this change, there is no more external caller for xenbus_probe(). So the function is turned to a static one. Interestingly there were two prototypes for it. Cc: stable@vger.kernel.org Fixes: 3499ba8198cad ("xen: Fix event channel callback via INTX/GSI") Reported-by: Ian Jackson <iwj@xenproject.org> Signed-off-by: Julien Grall <jgrall@amazon.com> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Link: https://lore.kernel.org/r/20210210170654.5377-1-julien@xen.org Signed-off-by: Juergen Gross <jgross@suse.com>
* | Merge tag 'for-linus-5.11-rc6-tag' of ↵Linus Torvalds2021-01-281-0/+31
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fixes from Juergen Gross: - A fix for a regression introduced in 5.11 resulting in Xen dom0 having problems to correctly initialize Xenstore. - A fix for avoiding WARN splats when booting as Xen dom0 with CONFIG_AMD_MEM_ENCRYPT enabled due to a missing trap handler for the #VC exception (even if the handler should never be called). - A fix for the Xen bklfront driver adapting to the correct but unexpected behavior of new qemu. * tag 'for-linus-5.11-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: x86/xen: avoid warning in Xen pv guest with CONFIG_AMD_MEM_ENCRYPT enabled xen: Fix XenStore initialisation for XS_LOCAL xen-blkfront: allow discard-* nodes to be optional
| * xen: Fix XenStore initialisation for XS_LOCALDavid Woodhouse2021-01-271-0/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit 3499ba8198ca ("xen: Fix event channel callback via INTX/GSI") I reworked the triggering of xenbus_probe(). I tried to simplify things by taking out the workqueue based startup triggered from wake_waiting(); the somewhat poorly named xenbus IRQ handler. I missed the fact that in the XS_LOCAL case (Dom0 starting its own xenstored or xenstore-stubdom, which happens after the kernel is booted completely), that IRQ-based trigger is still actually needed. So... put it back, except more cleanly. By just spawning a xenbus_probe thread which waits on xb_waitq and runs the probe the first time it gets woken, just as the workqueue-based hack did. This is actually a nicer approach for *all* the back ends with different interrupt methods, and we can switch them all over to that without the complex conditions for when to trigger it. But not in -rc6. This is the minimal fix for the regression, although it's a step in the right direction instead of doing a partial revert and actually putting the workqueue back. It's also simpler than the workqueue. Fixes: 3499ba8198ca ("xen: Fix event channel callback via INTX/GSI") Reported-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/4c9af052a6e0f6485d1de43f2c38b1461996db99.camel@infradead.org Signed-off-by: Juergen Gross <jgross@suse.com>
* | Merge tag 'for-linus-5.11-rc4-tag' of ↵Linus Torvalds2021-01-156-39/+94
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fixes from Juergen Gross: - A series to fix a regression when running as a fully virtualized guest on an old Xen hypervisor not supporting PV interrupt callbacks for HVM guests. - A patch to add support to query Xen resource sizes (setting was possible already) from user mode. * tag 'for-linus-5.11-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: x86/xen: Fix xen_hvm_smp_init() when vector callback not available x86/xen: Don't register Xen IPIs when they aren't going to be used x86/xen: Add xen_no_vector_callback option to test PCI INTX delivery xen: Set platform PCI device INTX affinity to CPU0 xen: Fix event channel callback via INTX/GSI xen/privcmd: allow fetching resource sizes
| * xen: Set platform PCI device INTX affinity to CPU0David Woodhouse2021-01-131-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | With INTX or GSI delivery, Xen uses the event channel structures of CPU0. If the interrupt gets handled by Linux on a different CPU, then no events are seen as pending. Rather than introducing locking to allow other CPUs to process CPU0's events, just ensure that the PCI interrupts happens only on CPU0. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20210106153958.584169-3-dwmw2@infradead.org Signed-off-by: Juergen Gross <jgross@suse.com>
| * xen: Fix event channel callback via INTX/GSIDavid Woodhouse2021-01-135-33/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For a while, event channel notification via the PCI platform device has been broken, because we attempt to communicate with xenstore before we even have notifications working, with the xs_reset_watches() call in xs_init(). We tend to get away with this on Xen versions below 4.0 because we avoid calling xs_reset_watches() anyway, because xenstore might not cope with reading a non-existent key. And newer Xen *does* have the vector callback support, so we rarely fall back to INTX/GSI delivery. To fix it, clean up a bit of the mess of xs_init() and xenbus_probe() startup. Call xs_init() directly from xenbus_init() only in the !XS_HVM case, deferring it to be called from xenbus_probe() in the XS_HVM case instead. Then fix up the invocation of xenbus_probe() to happen either from its device_initcall if the callback is available early enough, or when the callback is finally set up. This means that the hack of calling xenbus_probe() from a workqueue after the first interrupt, or directly from the PCI platform device setup, is no longer needed. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20210113132606.422794-2-dwmw2@infradead.org Signed-off-by: Juergen Gross <jgross@suse.com>
| * xen/privcmd: allow fetching resource sizesRoger Pau Monne2021-01-131-6/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow issuing an IOCTL_PRIVCMD_MMAP_RESOURCE ioctl with num = 0 and addr = 0 in order to fetch the size of a specific resource. Add a shortcut to the default map resource path, since fetching the size requires no address to be passed in, and thus no VMA to setup. This is missing from the initial implementation, and causes issues when mapping resources that don't have fixed or known sizes. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Juergen Gross <jgross@suse.com> Tested-by: Andrew Cooper <andrew.cooper3@citrix.com> Cc: stable@vger.kernel.org # >= 4.18 Link: https://lore.kernel.org/r/20210112115358.23346-1-roger.pau@citrix.com Signed-off-by: Juergen Gross <jgross@suse.com>
* | Merge tag 'irq-core-2020-12-23' of ↵Linus Torvalds2020-12-242-99/+117
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Thomas Gleixner: "This is the second attempt after the first one failed miserably and got zapped to unblock the rest of the interrupt related patches. A treewide cleanup of interrupt descriptor (ab)use with all sorts of racy accesses, inefficient and disfunctional code. The goal is to remove the export of irq_to_desc() to prevent these things from creeping up again" * tag 'irq-core-2020-12-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits) genirq: Restrict export of irq_to_desc() xen/events: Implement irq distribution xen/events: Reduce irq_info:: Spurious_cnt storage size xen/events: Only force affinity mask for percpu interrupts xen/events: Use immediate affinity setting xen/events: Remove disfunct affinity spreading xen/events: Remove unused bind_evtchn_to_irq_lateeoi() net/mlx5: Use effective interrupt affinity net/mlx5: Replace irq_to_desc() abuse net/mlx4: Use effective interrupt affinity net/mlx4: Replace irq_to_desc() abuse PCI: mobiveil: Use irq_data_get_irq_chip_data() PCI: xilinx-nwl: Use irq_data_get_irq_chip_data() NTB/msi: Use irq_has_action() mfd: ab8500-debugfs: Remove the racy fiddling with irq_desc pinctrl: nomadik: Use irq_has_action() drm/i915/pmu: Replace open coded kstat_irqs() copy drm/i915/lpe_audio: Remove pointless irq_to_desc() usage s390/irq: Use irq_desc_kstat_cpu() in show_msi_interrupt() parisc/irq: Use irq_desc_kstat_cpu() in show_interrupts() ...
| * | xen/events: Implement irq distributionThomas Gleixner2020-12-151-8/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Keep track of the assignments of event channels to CPUs and select the online CPU with the least assigned channels in the affinity mask which is handed to irq_chip::irq_set_affinity() from the core code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Link: https://lore.kernel.org/r/20201210194045.457218278@linutronix.de
| * | xen/events: Reduce irq_info:: Spurious_cnt storage sizeThomas Gleixner2020-12-151-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To prepare for interrupt spreading reduce the storage size of irq_info::spurious_cnt to u8 so the required flag for the spreading logic will not increase the storage size. Protect the usage site against overruns. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Link: https://lore.kernel.org/r/20201210194045.360198201@linutronix.de
| * | xen/events: Only force affinity mask for percpu interruptsThomas Gleixner2020-12-151-14/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All event channel setups bind the interrupt on CPU0 or the target CPU for percpu interrupts and overwrite the affinity mask with the corresponding cpumask. That does not make sense. The XEN implementation of irqchip::irq_set_affinity() already picks a single target CPU out of the affinity mask and the actual target is stored in the effective CPU mask, so destroying the user chosen affinity mask which might contain more than one CPU is wrong. Change the implementation so that the channel is bound to CPU0 at the XEN level and leave the affinity mask alone. At startup of the interrupt affinity will be assigned out of the affinity mask and the XEN binding will be updated. Only keep the enforcement for real percpu interrupts. On resume the overwrite is not required either because info->cpu and the affinity mask are still the same as at the time of suspend. Same for rebind_evtchn_irq(). This also prepares for proper interrupt spreading. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Link: https://lore.kernel.org/r/20201210194045.250321315@linutronix.de
| * | xen/events: Use immediate affinity settingThomas Gleixner2020-12-151-26/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is absolutely no reason to mimic the x86 deferred affinity setting. This mechanism is required to handle the hardware induced issues of IO/APIC and MSI and is not in use when the interrupts are remapped. XEN does not need this and can simply change the affinity from the calling context. The core code invokes this with the interrupt descriptor lock held so it is fully serialized against any other operation. Mark the interrupts with IRQ_MOVE_PCNTXT to disable the deferred affinity setting. The conditional mask/unmask operation is already handled in xen_rebind_evtchn_to_cpu(). This makes XEN on x86 use the same mechanics as on e.g. ARM64 where deferred affinity setting is not required and not implemented and the code path in the ack functions is compiled out. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Link: https://lore.kernel.org/r/20201210194045.157601122@linutronix.de
| * | xen/events: Remove disfunct affinity spreadingThomas Gleixner2020-12-152-42/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This function can only ever work when the event channels: - are already established - interrupts assigned to them - the affinity has been set by user space already because any newly set up event channel is forced to be bound to CPU0 and the affinity mask of the interrupt is forced to contain cpumask_of(0). As the CPU0 enforcement was in place _before_ this was implemented it's entirely unclear how that can ever have worked at all. Remove it as preparation for doing it proper. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Link: https://lore.kernel.org/r/20201210194045.065115500@linutronix.de
| * | xen/events: Remove unused bind_evtchn_to_irq_lateeoi()Thomas Gleixner2020-12-151-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Link: https://lore.kernel.org/r/20201210194044.972064156@linutronix.de
* | | Merge tag 'for-linus-5.11-rc1b-tag' of ↵Linus Torvalds2020-12-192-1/+2
|\ \ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull more xen updates from Juergen Gross: "Some minor cleanup patches and a small series disentangling some Xen related Kconfig options" * tag 'for-linus-5.11-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: Kconfig: remove X86_64 depends from XEN_512GB xen/manage: Fix fall-through warnings for Clang xen-blkfront: Fix fall-through warnings for Clang xen: remove trailing semicolon in macro definition xen: Kconfig: nest Xen guest options xen: Remove Xen PVH/PVHVM dependency on PCI x86/xen: Convert to DEFINE_SHOW_ATTRIBUTE
| * | xen/manage: Fix fall-through warnings for ClangGustavo A. R. Silva2020-12-161-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning by explicitly adding a break statement instead of letting the code fall through to the next case. Link: https://github.com/KSPP/linux/issues/115 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/5cfc00b1d8ed68eb2c2b6317806a0aa7e57d27f1.1605896060.git.gustavoars@kernel.org Signed-off-by: Juergen Gross <jgross@suse.com>
| * | xen: Remove Xen PVH/PVHVM dependency on PCIJason Andryuk2020-12-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A Xen PVH domain doesn't have a PCI bus or devices, so it doesn't need PCI support built in. Currently, XEN_PVH depends on XEN_PVHVM which depends on PCI. Introduce XEN_PVHVM_GUEST as a toplevel item and change XEN_PVHVM to a hidden variable. This allows XEN_PVH to depend on XEN_PVHVM without PCI while XEN_PVHVM_GUEST depends on PCI. In drivers/xen, compile platform-pci depending on XEN_PVHVM_GUEST since that pulls in the PCI dependency for linking. Signed-off-by: Jason Andryuk <jandryuk@gmail.com> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20201014175342.152712-2-jandryuk@gmail.com Signed-off-by: Juergen Gross <jgross@suse.com>
* | | Merge tag 'for-linus-5.11-rc1-tag' of ↵Linus Torvalds2020-12-166-14/+40
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from Juergen Gross: "Fixes for security issues just having been disclosed: - a five patch series for fixing of XSA-349 (DoS via resource depletion in Xen dom0) - a patch fixing XSA-350 (access of stale pointer in a Xen dom0)" * tag 'for-linus-5.11-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen-blkback: set ring->xenblkd to NULL after kthread_stop() xenbus/xenbus_backend: Disallow pending watch messages xen/xenbus: Count pending messages for each watch xen/xenbus/xen_bus_type: Support will_handle watch callback xen/xenbus: Add 'will_handle' callback support in xenbus_watch_path() xen/xenbus: Allow watches discard events before queueing
| * | xenbus/xenbus_backend: Disallow pending watch messagesSeongJae Park2020-12-141-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'xenbus_backend' watches 'state' of devices, which is writable by guests. Hence, if guests intensively updates it, dom0 will have lots of pending events that exhausting memory of dom0. In other words, guests can trigger dom0 memory pressure. This is known as XSA-349. However, the watch callback of it, 'frontend_changed()', reads only 'state', so doesn't need to have the pending events. To avoid the problem, this commit disallows pending watch messages for 'xenbus_backend' using the 'will_handle()' watch callback. This is part of XSA-349 Cc: stable@vger.kernel.org Signed-off-by: SeongJae Park <sjpark@amazon.de> Reported-by: Michael Kurth <mku@amazon.de> Reported-by: Pawel Wieczorkiewicz <wipawel@amazon.de> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
| * | xen/xenbus: Count pending messages for each watchSeongJae Park2020-12-141-11/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds a counter of pending messages for each watch in the struct. It is used to skip unnecessary pending messages lookup in 'unregister_xenbus_watch()'. It could also be used in 'will_handle' callback. This is part of XSA-349 Cc: stable@vger.kernel.org Signed-off-by: SeongJae Park <sjpark@amazon.de> Reported-by: Michael Kurth <mku@amazon.de> Reported-by: Pawel Wieczorkiewicz <wipawel@amazon.de> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
| * | xen/xenbus/xen_bus_type: Support will_handle watch callbackSeongJae Park2020-12-142-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds support of the 'will_handle' watch callback for 'xen_bus_type' users. This is part of XSA-349 Cc: stable@vger.kernel.org Signed-off-by: SeongJae Park <sjpark@amazon.de> Reported-by: Michael Kurth <mku@amazon.de> Reported-by: Pawel Wieczorkiewicz <wipawel@amazon.de> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
| * | xen/xenbus: Add 'will_handle' callback support in xenbus_watch_path()SeongJae Park2020-12-143-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some code does not directly make 'xenbus_watch' object and call 'register_xenbus_watch()' but use 'xenbus_watch_path()' instead. This commit adds support of 'will_handle' callback in the 'xenbus_watch_path()' and it's wrapper, 'xenbus_watch_pathfmt()'. This is part of XSA-349 Cc: stable@vger.kernel.org Signed-off-by: SeongJae Park <sjpark@amazon.de> Reported-by: Michael Kurth <mku@amazon.de> Reported-by: Pawel Wieczorkiewicz <wipawel@amazon.de> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
| * | xen/xenbus: Allow watches discard events before queueingSeongJae Park2020-12-142-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If handling logics of watch events are slower than the events enqueue logic and the events can be created from the guests, the guests could trigger memory pressure by intensively inducing the events, because it will create a huge number of pending events that exhausting the memory. Fortunately, some watch events could be ignored, depending on its handler callback. For example, if the callback has interest in only one single path, the watch wouldn't want multiple pending events. Or, some watches could ignore events to same path. To let such watches to volutarily help avoiding the memory pressure situation, this commit introduces new watch callback, 'will_handle'. If it is not NULL, it will be called for each new event just before enqueuing it. Then, if the callback returns false, the event will be discarded. No watch is using the callback for now, though. This is part of XSA-349 Cc: stable@vger.kernel.org Signed-off-by: SeongJae Park <sjpark@amazon.de> Reported-by: Michael Kurth <mku@amazon.de> Reported-by: Pawel Wieczorkiewicz <wipawel@amazon.de> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
* | | xen/unpopulated-alloc: consolidate pgmap manipulationDan Williams2020-12-151-7/+7
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | Cleanup fill_list() to keep all the pgmap manipulations in a single location of the function. Update the exit unwind path accordingly. Link: http://lore.kernel.org/r/6186fa28-d123-12db-6171-a75cb6e615a5@oracle.com Link: https://lkml.kernel.org/r/160272253442.3136502.16683842453317773487.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | xen: don't use page->lru for ZONE_DEVICE memoryJuergen Gross2020-12-092-16/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 9e2369c06c8a18 ("xen: add helpers to allocate unpopulated memory") introduced usage of ZONE_DEVICE memory for foreign memory mappings. Unfortunately this collides with using page->lru for Xen backend private page caches. Fix that by using page->zone_device_data instead. Cc: <stable@vger.kernel.org> # 5.9 Fixes: 9e2369c06c8a18 ("xen: add helpers to allocate unpopulated memory") Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovksy@oracle.com> Reviewed-by: Jason Andryuk <jandryuk@gmail.com> Signed-off-by: Juergen Gross <jgross@suse.com>
* | xen: add helpers for caching grant mapping pagesJuergen Gross2020-12-092-49/+83
|/ | | | | | | | | | | | Instead of having similar helpers in multiple backend drivers use common helpers for caching pages allocated via gnttab_alloc_pages(). Make use of those helpers in blkback and scsiback. Cc: <stable@vger.kernel.org> # 5.9 Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovksy@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
* swiotlb: remove the tbl_dma_addr argument to swiotlb_tbl_map_singleChristoph Hellwig2020-11-021-2/+1
| | | | | | | | | | | | | The tbl_dma_addr argument is used to check the DMA boundary for the allocations, and thus needs to be a dma_addr_t. swiotlb-xen instead passed a physical address, which could lead to incorrect results for strange offsets. Fix this by removing the parameter entirely and hard code the DMA address for io_tlb_start instead. Fixes: 91ffe4ad534a ("swiotlb-xen: introduce phys_to_dma/dma_to_phys translations") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* Merge tag 'for-linus-5.10b-rc1c-tag' of ↵Linus Torvalds2020-10-254-98/+82
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull more xen updates from Juergen Gross: - a series for the Xen pv block drivers adding module parameters for better control of resource usge - a cleanup series for the Xen event driver * tag 'for-linus-5.10b-rc1c-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: Documentation: add xen.fifo_events kernel parameter description xen/events: unmask a fifo event channel only if it was masked xen/events: only register debug interrupt for 2-level events xen/events: make struct irq_info private to events_base.c xen: remove no longer used functions xen-blkfront: Apply changed parameter name to the document xen-blkfront: add a parameter for disabling of persistent grants xen-blkback: add a parameter for disabling of persistent grants
| * xen/events: unmask a fifo event channel only if it was maskedJuergen Gross2020-10-231-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | Unmasking an event channel with fifo events channels being used can require a hypercall to be made, so try to avoid that by checking whether the event channel was really masked. Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Link: https://lore.kernel.org/r/20201022094907.28560-5-jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
| * xen/events: only register debug interrupt for 2-level eventsJuergen Gross2020-10-231-4/+6
| | | | | | | | | | | | | | | | | | | | xen_debug_interrupt() is specific to 2-level event handling. So don't register it with fifo event handling being active. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Link: https://lore.kernel.org/r/20201022094907.28560-4-jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
| * xen/events: make struct irq_info private to events_base.cJuergen Gross2020-10-234-73/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The struct irq_info of Xen's event handling is used only for two evtchn_ops functions outside of events_base.c. Those two functions can easily be switched to avoid that usage. This allows to make struct irq_info and its related access functions private to events_base.c. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Link: https://lore.kernel.org/r/20201022094907.28560-3-jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
| * xen: remove no longer used functionsJuergen Gross2020-10-231-21/+0
| | | | | | | | | | | | | | | | | | | | | | With the switch to the lateeoi model for interdomain event channels some functions are no longer in use. Remove them. Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Link: https://lore.kernel.org/r/20201022094907.28560-2-jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* | Merge tag 'for-linus-5.10b-rc1b-tag' of ↵Linus Torvalds2020-10-2011-143/+573
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull more xen updates from Juergen Gross: - A single patch to fix the Xen security issue XSA-331 (malicious guests can DoS dom0 by triggering NULL-pointer dereferences or access to stale data). - A larger series to fix the Xen security issue XSA-332 (malicious guests can DoS dom0 by sending events at high frequency leading to dom0's vcpus being busy in IRQ handling for elongated times). * tag 'for-linus-5.10b-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/events: block rogue events for some time xen/events: defer eoi in case of excessive number of events xen/events: use a common cpu hotplug hook for event channels xen/events: switch user event channels to lateeoi model xen/pciback: use lateeoi irq binding xen/pvcallsback: use lateeoi irq binding xen/scsiback: use lateeoi irq binding xen/netback: use lateeoi irq binding xen/blkback: use lateeoi irq binding xen/events: add a new "late EOI" evtchn framework xen/events: fix race in evtchn_fifo_unmask() xen/events: add a proper barrier to 2-level uevent unmasking xen/events: avoid removing an event channel while handling it
| * xen/events: block rogue events for some timeJuergen Gross2020-10-202-6/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to avoid high dom0 load due to rogue guests sending events at high frequency, block those events in case there was no action needed in dom0 to handle the events. This is done by adding a per-event counter, which set to zero in case an EOI without the XEN_EOI_FLAG_SPURIOUS is received from a backend driver, and incremented when this flag has been set. In case the counter is 2 or higher delay the EOI by 1 << (cnt - 2) jiffies, but not more than 1 second. In order not to waste memory shorten the per-event refcnt to two bytes (it should normally never exceed a value of 2). Add an overflow check to evtchn_get() to make sure the 2 bytes really won't overflow. This is part of XSA-332. Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Wei Liu <wl@xen.org>
| * xen/events: defer eoi in case of excessive number of eventsJuergen Gross2020-10-204-32/+208
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In case rogue guests are sending events at high frequency it might happen that xen_evtchn_do_upcall() won't stop processing events in dom0. As this is done in irq handling a crash might be the result. In order to avoid that, delay further inter-domain events after some time in xen_evtchn_do_upcall() by forcing eoi processing into a worker on the same cpu, thus inhibiting new events coming in. The time after which eoi processing is to be delayed is configurable via a new module parameter "event_loop_timeout" which specifies the maximum event loop time in jiffies (default: 2, the value was chosen after some tests showing that a value of 2 was the lowest with an only slight drop of dom0 network throughput while multiple guests performed an event storm). How long eoi processing will be delayed can be specified via another parameter "event_eoi_delay" (again in jiffies, default 10, again the value was chosen after testing with different delay values). This is part of XSA-332. Cc: stable@vger.kernel.org Reported-by: Julien Grall <julien@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Wei Liu <wl@xen.org>
| * xen/events: use a common cpu hotplug hook for event channelsJuergen Gross2020-10-203-21/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Today only fifo event channels have a cpu hotplug callback. In order to prepare for more percpu (de)init work move that callback into events_base.c and add percpu_init() and percpu_deinit() hooks to struct evtchn_ops. This is part of XSA-332. Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Wei Liu <wl@xen.org>
| * xen/events: switch user event channels to lateeoi modelJuergen Gross2020-10-201-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of disabling the irq when an event is received and enabling it again when handled by the user process use the lateeoi model. This is part of XSA-332. Cc: stable@vger.kernel.org Reported-by: Julien Grall <julien@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> Tested-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Wei Liu <wl@xen.org>
| * xen/pciback: use lateeoi irq bindingJuergen Gross2020-10-204-19/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to reduce the chance for the system becoming unresponsive due to event storms triggered by a misbehaving pcifront use the lateeoi irq binding for pciback and unmask the event channel only just before leaving the event handling function. Restructure the handling to support that scheme. Basically an event can come in for two reasons: either a normal request for a pciback action, which is handled in a worker, or in case the guest has finished an AER request which was requested by pciback. When an AER request is issued to the guest and a normal pciback action is currently active issue an EOI early in order to be able to receive another event when the AER request has been finished by the guest. Let the worker processing the normal requests run until no further request is pending, instead of starting a new worker ion that case. Issue the EOI only just before leaving the worker. This scheme allows to drop calling the generic function xen_pcibk_test_and_schedule_op() after processing of any request as the handling of both request types is now separated more cleanly. This is part of XSA-332. Cc: stable@vger.kernel.org Reported-by: Julien Grall <julien@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Wei Liu <wl@xen.org>
| * xen/pvcallsback: use lateeoi irq bindingJuergen Gross2020-10-201-30/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to reduce the chance for the system becoming unresponsive due to event storms triggered by a misbehaving pvcallsfront use the lateeoi irq binding for pvcallsback and unmask the event channel only after handling all write requests, which are the ones coming in via an irq. This requires modifying the logic a little bit to not require an event for each write request, but to keep the ioworker running until no further data is found on the ring page to be processed. This is part of XSA-332. Cc: stable@vger.kernel.org Reported-by: Julien Grall <julien@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Wei Liu <wl@xen.org>
| * xen/scsiback: use lateeoi irq bindingJuergen Gross2020-10-201-10/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to reduce the chance for the system becoming unresponsive due to event storms triggered by a misbehaving scsifront use the lateeoi irq binding for scsiback and unmask the event channel only just before leaving the event handling function. In case of a ring protocol error don't issue an EOI in order to avoid the possibility to use that for producing an event storm. This at once will result in no further call of scsiback_irq_fn(), so the ring_error struct member can be dropped and scsiback_do_cmd_fn() can signal the protocol error via a negative return value. This is part of XSA-332. Cc: stable@vger.kernel.org Reported-by: Julien Grall <julien@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Wei Liu <wl@xen.org>
| * xen/events: add a new "late EOI" evtchn frameworkJuergen Gross2020-10-201-17/+134
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to avoid tight event channel related IRQ loops add a new framework of "late EOI" handling: the IRQ the event channel is bound to will be masked until the event has been handled and the related driver is capable to handle another event. The driver is responsible for unmasking the event channel via the new function xen_irq_lateeoi(). This is similar to binding an event channel to a threaded IRQ, but without having to structure the driver accordingly. In order to support a future special handling in case a rogue guest is sending lots of unsolicited events, add a flag to xen_irq_lateeoi() which can be set by the caller to indicate the event was a spurious one. This is part of XSA-332. Cc: stable@vger.kernel.org Reported-by: Julien Grall <julien@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Wei Liu <wl@xen.org>
| * xen/events: fix race in evtchn_fifo_unmask()Juergen Gross2020-10-201-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Unmasking a fifo event channel can result in unmasking it twice, once directly in the kernel and once via a hypercall in case the event was pending. Fix that by doing the local unmask only if the event is not pending. This is part of XSA-332. Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
| * xen/events: add a proper barrier to 2-level uevent unmaskingJuergen Gross2020-10-201-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A follow-up patch will require certain write to happen before an event channel is unmasked. While the memory barrier is not strictly necessary for all the callers, the main one will need it. In order to avoid an extra memory barrier when using fifo event channels, mandate evtchn_unmask() to provide write ordering. The 2-level event handling unmask operation is missing an appropriate barrier, so add it. Fifo event channels are fine in this regard due to using sync_cmpxchg(). This is part of XSA-332. Cc: stable@vger.kernel.org Suggested-by: Julien Grall <julien@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Julien Grall <jgrall@amazon.com> Reviewed-by: Wei Liu <wl@xen.org>
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