Commit Graph

1832 Commits

Author SHA1 Message Date
David Hildenbrand
26011267e1 mm/memory_hotplug: MEMHP_MERGE_RESOURCE -> MHP_MERGE_RESOURCE
Let's make "MEMHP_MERGE_RESOURCE" consistent with "MHP_NONE", "mhp_t" and
"mhp_flags".  As discussed recently [1], "mhp" is our internal acronym for
memory hotplug now.

[1] https://lore.kernel.org/linux-mm/c37de2d0-28a1-4f7d-f944-cfd7d81c334d@redhat.com/

Link: https://lkml.kernel.org/r/20210126115829.10909-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-26 09:41:00 -08:00
Linus Torvalds
4a037ad5d1 xen: branch for v5.12-rc1
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Merge tag 'for-linus-5.12-rc1-tag' of 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()
2021-02-21 13:06:08 -08:00
Linus Torvalds
51e6d17809 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
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
  ...
2021-02-20 17:45:32 -08:00
Jan Beulich
7c77474b2d xen-scsiback: don't "handle" error by BUG()
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>
2021-02-15 08:55:57 +01:00
Jan Beulich
ebee0eab08 Xen/gntdev: correct error checking in gntdev_map_grant_pages()
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>
2021-02-15 08:52:27 +01:00
Jan Beulich
dbe5283605 Xen/gntdev: correct dev_bus_addr handling in gntdev_map_grant_pages()
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>
2021-02-15 08:51:07 +01:00
Linus Torvalds
2dbbaae5f7 xen: branch for v5.11-rc8
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Merge tag 'for-linus-5.11-rc8-tag' of 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
2021-02-12 11:12:58 -08:00
Juergen Gross
f2fa0e5e9f xen/events: link interdomain events to associated xenbus device
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>
2021-02-11 14:47:00 -08:00
Julien Grall
c4295ab0b4 arm/xen: Don't probe xenbus as part of an early initcall
After Commit 3499ba8198 ("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: 3499ba8198 ("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>
2021-02-11 07:49:37 +01:00
Linus Torvalds
e5ff2cb9cf xen: branch for v5.11-rc6
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Merge tag 'for-linus-5.11-rc6-tag' of 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
2021-01-28 10:08:08 -08:00
David Woodhouse
5f46400f7a xen: Fix XenStore initialisation for XS_LOCAL
In commit 3499ba8198 ("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: 3499ba8198 ("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>
2021-01-27 08:59:52 +01:00
Linus Torvalds
dcda487c9c xen: branch for v5.11-rc4
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Merge tag 'for-linus-5.11-rc4-tag' of 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
2021-01-15 10:52:00 -08:00
David Woodhouse
8f4fd86aa5 xen: Set platform PCI device INTX affinity to CPU0
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>
2021-01-13 16:12:03 +01:00
David Woodhouse
3499ba8198 xen: Fix event channel callback via INTX/GSI
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>
2021-01-13 16:12:00 +01:00
Roger Pau Monne
ef3a575baf xen/privcmd: allow fetching resource sizes
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>
2021-01-13 12:31:17 +01:00
Linus Torvalds
3913d00ac5 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.
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Merge tag 'irq-core-2020-12-23' of 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()
  ...
2020-12-24 13:50:23 -08:00
Linus Torvalds
3872f516aa xen: branch for v5.11-rc1b
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Merge tag 'for-linus-5.11-rc1b-tag' of 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
2020-12-19 12:56:23 -08:00
Linus Torvalds
7acfd4274e xen: branch for v5.11-rc1
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Merge tag 'for-linus-5.11-rc1-tag' of 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
2020-12-16 11:53:09 -08:00
Gustavo A. R. Silva
5e65f524ed xen/manage: Fix fall-through warnings for Clang
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>
2020-12-16 07:58:44 +01:00
Jason Andryuk
34aff14580 xen: Remove Xen PVH/PVHVM dependency on PCI
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>
2020-12-16 07:55:05 +01:00
Dan Williams
3a250629d7 xen/unpopulated-alloc: consolidate pgmap manipulation
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>
2020-12-15 12:13:40 -08:00
Thomas Gleixner
88f0a9d066 xen/events: Implement irq distribution
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
2020-12-15 16:19:38 +01:00
Thomas Gleixner
62ebcda8a8 xen/events: Reduce irq_info:: Spurious_cnt storage size
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
2020-12-15 16:19:37 +01:00
Thomas Gleixner
f7a6f994b4 xen/events: Only force affinity mask for percpu interrupts
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
2020-12-15 16:19:36 +01:00
Thomas Gleixner
1ca1b4e2c0 xen/events: Use immediate affinity setting
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
2020-12-15 16:19:35 +01:00
Thomas Gleixner
67473b8194 xen/events: Remove disfunct affinity spreading
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
2020-12-15 16:19:35 +01:00
Thomas Gleixner
3bd5371a4d xen/events: Remove unused bind_evtchn_to_irq_lateeoi()
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
2020-12-15 16:19:34 +01:00
SeongJae Park
9996bd4947 xenbus/xenbus_backend: Disallow pending watch messages
'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>
2020-12-14 10:08:40 +01:00
SeongJae Park
3dc86ca6b4 xen/xenbus: Count pending messages for each watch
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>
2020-12-14 10:07:13 +01:00
SeongJae Park
be987200fb xen/xenbus/xen_bus_type: Support will_handle watch callback
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>
2020-12-14 10:05:47 +01:00
SeongJae Park
2e85d32b1c xen/xenbus: Add 'will_handle' callback support in xenbus_watch_path()
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>
2020-12-14 10:04:18 +01:00
SeongJae Park
fed1755b11 xen/xenbus: Allow watches discard events before queueing
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>
2020-12-14 10:02:45 +01:00
Juergen Gross
ee32f32335 xen: don't use page->lru for ZONE_DEVICE memory
Commit 9e2369c06c ("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: 9e2369c06c ("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>
2020-12-09 10:31:41 +01:00
Juergen Gross
ca33479cc7 xen: add helpers for caching grant mapping pages
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>
2020-12-09 10:31:37 +01:00
Christoph Hellwig
fc0021aa34 swiotlb: remove the tbl_dma_addr argument to swiotlb_tbl_map_single
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: 91ffe4ad53 ("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>
2020-11-02 10:10:39 -05:00
Linus Torvalds
bd6aabc7ca xen: branch for v5.10-rc1c
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Merge tag 'for-linus-5.10b-rc1c-tag' of 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
2020-10-25 10:55:35 -07:00
Juergen Gross
eabe741782 xen/events: unmask a fifo event channel only if it was masked
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>
2020-10-23 05:41:25 -05:00
Juergen Gross
d04b1ae5a9 xen/events: only register debug interrupt for 2-level events
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>
2020-10-23 05:41:25 -05:00
Juergen Gross
7e14cde10b xen/events: make struct irq_info private to events_base.c
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>
2020-10-23 05:41:25 -05:00
Juergen Gross
5894048775 xen: remove no longer used functions
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>
2020-10-23 05:41:25 -05:00
Linus Torvalds
4a5bb973fa xen: branch for v5.10-rc1b
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Merge tag 'for-linus-5.10b-rc1b-tag' of 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
2020-10-20 09:24:01 -07:00
Juergen Gross
5f7f77400a xen/events: block rogue events for some time
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>
2020-10-20 10:22:19 +02:00
Juergen Gross
e99502f762 xen/events: defer eoi in case of excessive number of events
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>
2020-10-20 10:22:16 +02:00
Juergen Gross
7beb290caa xen/events: use a common cpu hotplug hook for event channels
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>
2020-10-20 10:22:14 +02:00
Juergen Gross
c44b849cee xen/events: switch user event channels to lateeoi model
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>
2020-10-20 10:22:11 +02:00
Juergen Gross
c2711441bc xen/pciback: use lateeoi irq binding
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>
2020-10-20 10:22:08 +02:00
Juergen Gross
c8d647a326 xen/pvcallsback: use lateeoi irq binding
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>
2020-10-20 10:22:07 +02:00
Juergen Gross
86991b6e7e xen/scsiback: use lateeoi irq binding
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>
2020-10-20 10:22:04 +02:00
Juergen Gross
54c9de8989 xen/events: add a new "late EOI" evtchn framework
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>
2020-10-20 10:21:59 +02:00
Juergen Gross
f013371974 xen/events: fix race in evtchn_fifo_unmask()
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>
2020-10-20 10:21:58 +02:00