<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git, branch v5.4.97</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Linux 5.4.97</title>
<updated>2021-02-10T08:25:33+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2021-02-10T08:25:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5e1942063dc3633f7a127aa2b159c13507580d21'/>
<id>5e1942063dc3633f7a127aa2b159c13507580d21</id>
<content type='text'>
Tested-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Tested-by: Shuah Khan &lt;skhan@linuxfoundation.org&gt;
Tested-by: Linux Kernel Functional Testing &lt;lkft@linaro.org&gt;
Tested-by: Igor Matheus Andrade Torrente &lt;igormtorrente@gmail.com&gt;
Tested-by: Jason Self &lt;jason@bluehome.net&gt;
Tested-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Tested-by: Ross Schmidt &lt;ross.schm.dev@gmail.com&gt;
Link: https://lore.kernel.org/r/20210208145810.230485165@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Tested-by: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Tested-by: Shuah Khan &lt;skhan@linuxfoundation.org&gt;
Tested-by: Linux Kernel Functional Testing &lt;lkft@linaro.org&gt;
Tested-by: Igor Matheus Andrade Torrente &lt;igormtorrente@gmail.com&gt;
Tested-by: Jason Self &lt;jason@bluehome.net&gt;
Tested-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Tested-by: Ross Schmidt &lt;ross.schm.dev@gmail.com&gt;
Link: https://lore.kernel.org/r/20210208145810.230485165@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: host: xhci: mvebu: make USB 3.0 PHY optional for Armada 3720</title>
<updated>2021-02-10T08:25:33+00:00</updated>
<author>
<name>Pali Rohár</name>
<email>pali@kernel.org</email>
</author>
<published>2021-02-01T15:08:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=40af962eb1d4ce963cf8ada21924aa4179b23b9b'/>
<id>40af962eb1d4ce963cf8ada21924aa4179b23b9b</id>
<content type='text'>
commit 3241929b67d28c83945d3191c6816a3271fd6b85 upstream.

Older ATF does not provide SMC call for USB 3.0 phy power on functionality
and therefore initialization of xhci-hcd is failing when older version of
ATF is used. In this case phy_power_on() function returns -EOPNOTSUPP.

[    3.108467] mvebu-a3700-comphy d0018300.phy: unsupported SMC call, try updating your firmware
[    3.117250] phy phy-d0018300.phy.0: phy poweron failed --&gt; -95
[    3.123465] xhci-hcd: probe of d0058000.usb failed with error -95

This patch introduces a new plat_setup callback for xhci platform drivers
which is called prior calling usb_add_hcd() function. This function at its
beginning skips PHY init if hcd-&gt;skip_phy_initialization is set.

Current init_quirk callback for xhci platform drivers is called from
xhci_plat_setup() function which is called after chip reset completes.
It happens in the middle of the usb_add_hcd() function and therefore this
callback cannot be used for setting if PHY init should be skipped or not.

For Armada 3720 this patch introduce a new xhci_mvebu_a3700_plat_setup()
function configured as a xhci platform plat_setup callback. This new
function calls phy_power_on() and in case it returns -EOPNOTSUPP then
XHCI_SKIP_PHY_INIT quirk is set to instruct xhci-plat to skip PHY
initialization.

This patch fixes above failure by ignoring 'not supported' error in
xhci-hcd driver. In this case it is expected that phy is already power on.

It fixes initialization of xhci-hcd on Espressobin boards where is older
Marvell's Arm Trusted Firmware without SMC call for USB 3.0 phy power.

This is regression introduced in commit bd3d25b07342 ("arm64: dts: marvell:
armada-37xx: link USB hosts with their PHYs") where USB 3.0 phy was defined
and therefore xhci-hcd on Espressobin with older ATF started failing.

Fixes: bd3d25b07342 ("arm64: dts: marvell: armada-37xx: link USB hosts with their PHYs")
Cc: &lt;stable@vger.kernel.org&gt; # 5.1+: ea17a0f153af: phy: marvell: comphy: Convert internal SMCC firmware return codes to errno
Cc: &lt;stable@vger.kernel.org&gt; # 5.1+: f768e718911e: usb: host: xhci-plat: add priv quirk for skip PHY initialization
Tested-by: Tomasz Maciej Nowak &lt;tmn505@gmail.com&gt;
Tested-by: Yoshihiro Shimoda &lt;yoshihiro.shimoda.uh@renesas.com&gt; # On R-Car
Reviewed-by: Yoshihiro Shimoda &lt;yoshihiro.shimoda.uh@renesas.com&gt; # xhci-plat
Acked-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Signed-off-by: Pali Rohár &lt;pali@kernel.org&gt;
Link: https://lore.kernel.org/r/20210201150803.7305-1-pali@kernel.org
[pali: Backported to 5.4 by replacing of_phy_put() with phy_put()]
Signed-off-by: Pali Rohár &lt;pali@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 3241929b67d28c83945d3191c6816a3271fd6b85 upstream.

Older ATF does not provide SMC call for USB 3.0 phy power on functionality
and therefore initialization of xhci-hcd is failing when older version of
ATF is used. In this case phy_power_on() function returns -EOPNOTSUPP.

[    3.108467] mvebu-a3700-comphy d0018300.phy: unsupported SMC call, try updating your firmware
[    3.117250] phy phy-d0018300.phy.0: phy poweron failed --&gt; -95
[    3.123465] xhci-hcd: probe of d0058000.usb failed with error -95

This patch introduces a new plat_setup callback for xhci platform drivers
which is called prior calling usb_add_hcd() function. This function at its
beginning skips PHY init if hcd-&gt;skip_phy_initialization is set.

Current init_quirk callback for xhci platform drivers is called from
xhci_plat_setup() function which is called after chip reset completes.
It happens in the middle of the usb_add_hcd() function and therefore this
callback cannot be used for setting if PHY init should be skipped or not.

For Armada 3720 this patch introduce a new xhci_mvebu_a3700_plat_setup()
function configured as a xhci platform plat_setup callback. This new
function calls phy_power_on() and in case it returns -EOPNOTSUPP then
XHCI_SKIP_PHY_INIT quirk is set to instruct xhci-plat to skip PHY
initialization.

This patch fixes above failure by ignoring 'not supported' error in
xhci-hcd driver. In this case it is expected that phy is already power on.

It fixes initialization of xhci-hcd on Espressobin boards where is older
Marvell's Arm Trusted Firmware without SMC call for USB 3.0 phy power.

This is regression introduced in commit bd3d25b07342 ("arm64: dts: marvell:
armada-37xx: link USB hosts with their PHYs") where USB 3.0 phy was defined
and therefore xhci-hcd on Espressobin with older ATF started failing.

Fixes: bd3d25b07342 ("arm64: dts: marvell: armada-37xx: link USB hosts with their PHYs")
Cc: &lt;stable@vger.kernel.org&gt; # 5.1+: ea17a0f153af: phy: marvell: comphy: Convert internal SMCC firmware return codes to errno
Cc: &lt;stable@vger.kernel.org&gt; # 5.1+: f768e718911e: usb: host: xhci-plat: add priv quirk for skip PHY initialization
Tested-by: Tomasz Maciej Nowak &lt;tmn505@gmail.com&gt;
Tested-by: Yoshihiro Shimoda &lt;yoshihiro.shimoda.uh@renesas.com&gt; # On R-Car
Reviewed-by: Yoshihiro Shimoda &lt;yoshihiro.shimoda.uh@renesas.com&gt; # xhci-plat
Acked-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Signed-off-by: Pali Rohár &lt;pali@kernel.org&gt;
Link: https://lore.kernel.org/r/20210201150803.7305-1-pali@kernel.org
[pali: Backported to 5.4 by replacing of_phy_put() with phy_put()]
Signed-off-by: Pali Rohár &lt;pali@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: sched: replaced invalid qdisc tree flush helper in qdisc_replace</title>
<updated>2021-02-10T08:25:33+00:00</updated>
<author>
<name>Alexander Ovechkin</name>
<email>ovov@yandex-team.ru</email>
</author>
<published>2021-02-01T20:00:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=76ab33055fbc6ac0b05e4b0c9dc6a56d76663482'/>
<id>76ab33055fbc6ac0b05e4b0c9dc6a56d76663482</id>
<content type='text'>
commit 938e0fcd3253efdef8924714158911286d08cfe1 upstream.

Commit e5f0e8f8e456 ("net: sched: introduce and use qdisc tree flush/purge helpers")
introduced qdisc tree flush/purge helpers, but erroneously used flush helper
instead of purge helper in qdisc_replace function.
This issue was found in our CI, that tests various qdisc setups by configuring
qdisc and sending data through it. Call of invalid helper sporadically leads
to corruption of vt_tree/cf_tree of hfsc_class that causes kernel oops:

 Oops: 0000 [#1] SMP PTI
 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.11.0-8f6859df #1
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
 RIP: 0010:rb_insert_color+0x18/0x190
 Code: c3 31 c0 c3 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 48 8b 07 48 85 c0 0f 84 05 01 00 00 48 8b 10 f6 c2 01 0f 85 34 01 00 00 &lt;48&gt; 8b 4a 08 49 89 d0 48 39 c1 74 7d 48 85 c9 74 32 f6 01 01 75 2d
 RSP: 0018:ffffc900000b8bb0 EFLAGS: 00010246
 RAX: ffff8881ef4c38b0 RBX: ffff8881d956e400 RCX: ffff8881ef4c38b0
 RDX: 0000000000000000 RSI: ffff8881d956f0a8 RDI: ffff8881d956e4b0
 RBP: 0000000000000000 R08: 000000d5c4e249da R09: 1600000000000000
 R10: ffffc900000b8be0 R11: ffffc900000b8b28 R12: 0000000000000001
 R13: 000000000000005a R14: ffff8881f0905000 R15: ffff8881f0387d00
 FS:  0000000000000000(0000) GS:ffff8881f8b00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000008 CR3: 00000001f4796004 CR4: 0000000000060ee0
 Call Trace:
  &lt;IRQ&gt;
  init_vf.isra.19+0xec/0x250 [sch_hfsc]
  hfsc_enqueue+0x245/0x300 [sch_hfsc]
  ? fib_rules_lookup+0x12a/0x1d0
  ? __dev_queue_xmit+0x4b6/0x930
  ? hfsc_delete_class+0x250/0x250 [sch_hfsc]
  __dev_queue_xmit+0x4b6/0x930
  ? ip6_finish_output2+0x24d/0x590
  ip6_finish_output2+0x24d/0x590
  ? ip6_output+0x6c/0x130
  ip6_output+0x6c/0x130
  ? __ip6_finish_output+0x110/0x110
  mld_sendpack+0x224/0x230
  mld_ifc_timer_expire+0x186/0x2c0
  ? igmp6_group_dropped+0x200/0x200
  call_timer_fn+0x2d/0x150
  run_timer_softirq+0x20c/0x480
  ? tick_sched_do_timer+0x60/0x60
  ? tick_sched_timer+0x37/0x70
  __do_softirq+0xf7/0x2cb
  irq_exit+0xa0/0xb0
  smp_apic_timer_interrupt+0x74/0x150
  apic_timer_interrupt+0xf/0x20
  &lt;/IRQ&gt;

Fixes: e5f0e8f8e456 ("net: sched: introduce and use qdisc tree flush/purge helpers")
Signed-off-by: Alexander Ovechkin &lt;ovov@yandex-team.ru&gt;
Reported-by: Alexander Kuznetsov &lt;wwfq@yandex-team.ru&gt;
Acked-by: Dmitry Monakhov &lt;dmtrmonakhov@yandex-team.ru&gt;
Acked-by: Dmitry Yakunin &lt;zeil@yandex-team.ru&gt;
Acked-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Link: https://lore.kernel.org/r/20210201200049.299153-1-ovov@yandex-team.ru
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 938e0fcd3253efdef8924714158911286d08cfe1 upstream.

Commit e5f0e8f8e456 ("net: sched: introduce and use qdisc tree flush/purge helpers")
introduced qdisc tree flush/purge helpers, but erroneously used flush helper
instead of purge helper in qdisc_replace function.
This issue was found in our CI, that tests various qdisc setups by configuring
qdisc and sending data through it. Call of invalid helper sporadically leads
to corruption of vt_tree/cf_tree of hfsc_class that causes kernel oops:

 Oops: 0000 [#1] SMP PTI
 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.11.0-8f6859df #1
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
 RIP: 0010:rb_insert_color+0x18/0x190
 Code: c3 31 c0 c3 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 48 8b 07 48 85 c0 0f 84 05 01 00 00 48 8b 10 f6 c2 01 0f 85 34 01 00 00 &lt;48&gt; 8b 4a 08 49 89 d0 48 39 c1 74 7d 48 85 c9 74 32 f6 01 01 75 2d
 RSP: 0018:ffffc900000b8bb0 EFLAGS: 00010246
 RAX: ffff8881ef4c38b0 RBX: ffff8881d956e400 RCX: ffff8881ef4c38b0
 RDX: 0000000000000000 RSI: ffff8881d956f0a8 RDI: ffff8881d956e4b0
 RBP: 0000000000000000 R08: 000000d5c4e249da R09: 1600000000000000
 R10: ffffc900000b8be0 R11: ffffc900000b8b28 R12: 0000000000000001
 R13: 000000000000005a R14: ffff8881f0905000 R15: ffff8881f0387d00
 FS:  0000000000000000(0000) GS:ffff8881f8b00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000008 CR3: 00000001f4796004 CR4: 0000000000060ee0
 Call Trace:
  &lt;IRQ&gt;
  init_vf.isra.19+0xec/0x250 [sch_hfsc]
  hfsc_enqueue+0x245/0x300 [sch_hfsc]
  ? fib_rules_lookup+0x12a/0x1d0
  ? __dev_queue_xmit+0x4b6/0x930
  ? hfsc_delete_class+0x250/0x250 [sch_hfsc]
  __dev_queue_xmit+0x4b6/0x930
  ? ip6_finish_output2+0x24d/0x590
  ip6_finish_output2+0x24d/0x590
  ? ip6_output+0x6c/0x130
  ip6_output+0x6c/0x130
  ? __ip6_finish_output+0x110/0x110
  mld_sendpack+0x224/0x230
  mld_ifc_timer_expire+0x186/0x2c0
  ? igmp6_group_dropped+0x200/0x200
  call_timer_fn+0x2d/0x150
  run_timer_softirq+0x20c/0x480
  ? tick_sched_do_timer+0x60/0x60
  ? tick_sched_timer+0x37/0x70
  __do_softirq+0xf7/0x2cb
  irq_exit+0xa0/0xb0
  smp_apic_timer_interrupt+0x74/0x150
  apic_timer_interrupt+0xf/0x20
  &lt;/IRQ&gt;

Fixes: e5f0e8f8e456 ("net: sched: introduce and use qdisc tree flush/purge helpers")
Signed-off-by: Alexander Ovechkin &lt;ovov@yandex-team.ru&gt;
Reported-by: Alexander Kuznetsov &lt;wwfq@yandex-team.ru&gt;
Acked-by: Dmitry Monakhov &lt;dmtrmonakhov@yandex-team.ru&gt;
Acked-by: Dmitry Yakunin &lt;zeil@yandex-team.ru&gt;
Acked-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Link: https://lore.kernel.org/r/20210201200049.299153-1-ovov@yandex-team.ru
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: mv88e6xxx: override existent unicast portvec in port_fdb_add</title>
<updated>2021-02-10T08:25:33+00:00</updated>
<author>
<name>DENG Qingfang</name>
<email>dqfext@gmail.com</email>
</author>
<published>2021-01-30T13:43:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e65d331755deb98a39267ff10f7746e4fd237cea'/>
<id>e65d331755deb98a39267ff10f7746e4fd237cea</id>
<content type='text'>
commit f72f2fb8fb6be095b98af5d740ac50cffd0b0cae upstream.

Having multiple destination ports for a unicast address does not make
sense.
Make port_db_load_purge override existent unicast portvec instead of
adding a new port bit.

Fixes: 884729399260 ("net: dsa: mv88e6xxx: handle multiple ports in ATU")
Signed-off-by: DENG Qingfang &lt;dqfext@gmail.com&gt;
Reviewed-by: Vladimir Oltean &lt;olteanv@gmail.com&gt;
Link: https://lore.kernel.org/r/20210130134334.10243-1-dqfext@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit f72f2fb8fb6be095b98af5d740ac50cffd0b0cae upstream.

Having multiple destination ports for a unicast address does not make
sense.
Make port_db_load_purge override existent unicast portvec instead of
adding a new port bit.

Fixes: 884729399260 ("net: dsa: mv88e6xxx: handle multiple ports in ATU")
Signed-off-by: DENG Qingfang &lt;dqfext@gmail.com&gt;
Reviewed-by: Vladimir Oltean &lt;olteanv@gmail.com&gt;
Link: https://lore.kernel.org/r/20210130134334.10243-1-dqfext@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: ip_tunnel: fix mtu calculation</title>
<updated>2021-02-10T08:25:32+00:00</updated>
<author>
<name>Vadim Fedorenko</name>
<email>vfedorenko@novek.ru</email>
</author>
<published>2021-01-29T22:27:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5d3007b6cc7b4c242f2965f08824f9c73947749c'/>
<id>5d3007b6cc7b4c242f2965f08824f9c73947749c</id>
<content type='text'>
commit 28e104d00281ade30250b24e098bf50887671ea4 upstream.

dev-&gt;hard_header_len for tunnel interface is set only when header_ops
are set too and already contains full overhead of any tunnel encapsulation.
That's why there is not need to use this overhead twice in mtu calc.

Fixes: fdafed459998 ("ip_gre: set dev-&gt;hard_header_len and dev-&gt;needed_headroom properly")
Reported-by: Slava Bacherikov &lt;mail@slava.cc&gt;
Signed-off-by: Vadim Fedorenko &lt;vfedorenko@novek.ru&gt;
Link: https://lore.kernel.org/r/1611959267-20536-1-git-send-email-vfedorenko@novek.ru
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 28e104d00281ade30250b24e098bf50887671ea4 upstream.

dev-&gt;hard_header_len for tunnel interface is set only when header_ops
are set too and already contains full overhead of any tunnel encapsulation.
That's why there is not need to use this overhead twice in mtu calc.

Fixes: fdafed459998 ("ip_gre: set dev-&gt;hard_header_len and dev-&gt;needed_headroom properly")
Reported-by: Slava Bacherikov &lt;mail@slava.cc&gt;
Signed-off-by: Vadim Fedorenko &lt;vfedorenko@novek.ru&gt;
Link: https://lore.kernel.org/r/1611959267-20536-1-git-send-email-vfedorenko@novek.ru
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>neighbour: Prevent a dead entry from updating gc_list</title>
<updated>2021-02-10T08:25:32+00:00</updated>
<author>
<name>Chinmay Agarwal</name>
<email>chinagar@codeaurora.org</email>
</author>
<published>2021-01-27T16:54:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=90d7459d24b88b84595c6cf9b3f40186625aae86'/>
<id>90d7459d24b88b84595c6cf9b3f40186625aae86</id>
<content type='text'>
commit eb4e8fac00d1e01ada5e57c05d24739156086677 upstream.

Following race condition was detected:
&lt;CPU A, t0&gt; - neigh_flush_dev() is under execution and calls
neigh_mark_dead(n) marking the neighbour entry 'n' as dead.

&lt;CPU B, t1&gt; - Executing: __netif_receive_skb() -&gt;
__netif_receive_skb_core() -&gt; arp_rcv() -&gt; arp_process().arp_process()
calls __neigh_lookup() which takes a reference on neighbour entry 'n'.

&lt;CPU A, t2&gt; - Moves further along neigh_flush_dev() and calls
neigh_cleanup_and_release(n), but since reference count increased in t2,
'n' couldn't be destroyed.

&lt;CPU B, t3&gt; - Moves further along, arp_process() and calls
neigh_update()-&gt; __neigh_update() -&gt; neigh_update_gc_list(), which adds
the neighbour entry back in gc_list(neigh_mark_dead(), removed it
earlier in t0 from gc_list)

&lt;CPU B, t4&gt; - arp_process() finally calls neigh_release(n), destroying
the neighbour entry.

This leads to 'n' still being part of gc_list, but the actual
neighbour structure has been freed.

The situation can be prevented from happening if we disallow a dead
entry to have any possibility of updating gc_list. This is what the
patch intends to achieve.

Fixes: 9c29a2f55ec0 ("neighbor: Fix locking order for gc_list changes")
Signed-off-by: Chinmay Agarwal &lt;chinagar@codeaurora.org&gt;
Reviewed-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Reviewed-by: David Ahern &lt;dsahern@kernel.org&gt;
Link: https://lore.kernel.org/r/20210127165453.GA20514@chinagar-linux.qualcomm.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit eb4e8fac00d1e01ada5e57c05d24739156086677 upstream.

Following race condition was detected:
&lt;CPU A, t0&gt; - neigh_flush_dev() is under execution and calls
neigh_mark_dead(n) marking the neighbour entry 'n' as dead.

&lt;CPU B, t1&gt; - Executing: __netif_receive_skb() -&gt;
__netif_receive_skb_core() -&gt; arp_rcv() -&gt; arp_process().arp_process()
calls __neigh_lookup() which takes a reference on neighbour entry 'n'.

&lt;CPU A, t2&gt; - Moves further along neigh_flush_dev() and calls
neigh_cleanup_and_release(n), but since reference count increased in t2,
'n' couldn't be destroyed.

&lt;CPU B, t3&gt; - Moves further along, arp_process() and calls
neigh_update()-&gt; __neigh_update() -&gt; neigh_update_gc_list(), which adds
the neighbour entry back in gc_list(neigh_mark_dead(), removed it
earlier in t0 from gc_list)

&lt;CPU B, t4&gt; - arp_process() finally calls neigh_release(n), destroying
the neighbour entry.

This leads to 'n' still being part of gc_list, but the actual
neighbour structure has been freed.

The situation can be prevented from happening if we disallow a dead
entry to have any possibility of updating gc_list. This is what the
patch intends to achieve.

Fixes: 9c29a2f55ec0 ("neighbor: Fix locking order for gc_list changes")
Signed-off-by: Chinmay Agarwal &lt;chinagar@codeaurora.org&gt;
Reviewed-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Reviewed-by: David Ahern &lt;dsahern@kernel.org&gt;
Link: https://lore.kernel.org/r/20210127165453.GA20514@chinagar-linux.qualcomm.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>igc: Report speed and duplex as unknown when device is runtime suspended</title>
<updated>2021-02-10T08:25:32+00:00</updated>
<author>
<name>Kai-Heng Feng</name>
<email>kai.heng.feng@canonical.com</email>
</author>
<published>2020-12-02T07:50:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=271ea7072901b157e38a4e64b8d32abdc287fa9c'/>
<id>271ea7072901b157e38a4e64b8d32abdc287fa9c</id>
<content type='text'>
commit 2e99dedc73f004f650b197c9b269c15c7e01ad15 upstream.

Similar to commit 165ae7a8feb5 ("igb: Report speed and duplex as unknown
when device is runtime suspended"), if we try to read speed and duplex
sysfs while the device is runtime suspended, igc will complain and
stops working:

[  123.449883] igc 0000:03:00.0 enp3s0: PCIe link lost, device now detached
[  123.450052] BUG: kernel NULL pointer dereference, address: 0000000000000008
[  123.450056] #PF: supervisor read access in kernel mode
[  123.450058] #PF: error_code(0x0000) - not-present page
[  123.450059] PGD 0 P4D 0
[  123.450064] Oops: 0000 [#1] SMP NOPTI
[  123.450068] CPU: 0 PID: 2525 Comm: udevadm Tainted: G     U  W  OE     5.10.0-1002-oem #2+rkl2-Ubuntu
[  123.450078] RIP: 0010:igc_rd32+0x1c/0x90 [igc]
[  123.450080] Code: c0 5d c3 b8 fd ff ff ff c3 0f 1f 44 00 00 0f 1f 44 00 00 55 89 f0 48 89 e5 41 56 41 55 41 54 49 89 c4 53 48 8b 57 08 48 01 d0 &lt;44&gt; 8b 28 41 83 fd ff 74 0c 5b 44 89 e8 41 5c 41 5d 4

[  123.450083] RSP: 0018:ffffb0d100d6fcc0 EFLAGS: 00010202
[  123.450085] RAX: 0000000000000008 RBX: ffffb0d100d6fd30 RCX: 0000000000000000
[  123.450087] RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff945a12716c10
[  123.450089] RBP: ffffb0d100d6fce0 R08: ffff945a12716550 R09: ffff945a09874000
[  123.450090] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000008
[  123.450092] R13: ffff945a12716000 R14: ffff945a037da280 R15: ffff945a037da290
[  123.450094] FS:  00007f3b34c868c0(0000) GS:ffff945b89200000(0000) knlGS:0000000000000000
[  123.450096] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  123.450098] CR2: 0000000000000008 CR3: 00000001144de006 CR4: 0000000000770ef0
[  123.450100] PKRU: 55555554
[  123.450101] Call Trace:
[  123.450111]  igc_ethtool_get_link_ksettings+0xd6/0x1b0 [igc]
[  123.450118]  __ethtool_get_link_ksettings+0x71/0xb0
[  123.450123]  duplex_show+0x74/0xc0
[  123.450129]  dev_attr_show+0x1d/0x40
[  123.450134]  sysfs_kf_seq_show+0xa1/0x100
[  123.450137]  kernfs_seq_show+0x27/0x30
[  123.450142]  seq_read+0xb7/0x400
[  123.450148]  ? common_file_perm+0x72/0x170
[  123.450151]  kernfs_fop_read+0x35/0x1b0
[  123.450155]  vfs_read+0xb5/0x1b0
[  123.450157]  ksys_read+0x67/0xe0
[  123.450160]  __x64_sys_read+0x1a/0x20
[  123.450164]  do_syscall_64+0x38/0x90
[  123.450168]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  123.450170] RIP: 0033:0x7f3b351fe142
[  123.450173] Code: c0 e9 c2 fe ff ff 50 48 8d 3d 3a ca 0a 00 e8 f5 19 02 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 &lt;48&gt; 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24
[  123.450174] RSP: 002b:00007fffef2ec138 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[  123.450177] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3b351fe142
[  123.450179] RDX: 0000000000001001 RSI: 00005644c047f070 RDI: 0000000000000003
[  123.450180] RBP: 00007fffef2ec340 R08: 00005644c047f070 R09: 00007f3b352d9320
[  123.450182] R10: 00005644c047c010 R11: 0000000000000246 R12: 00005644c047cbf0
[  123.450184] R13: 00005644c047e6d0 R14: 0000000000000003 R15: 00007fffef2ec140
[  123.450189] Modules linked in: rfcomm ccm cmac algif_hash algif_skcipher af_alg bnep toshiba_acpi industrialio toshiba_haps hp_accel lis3lv02d btusb btrtl btbcm btintel bluetooth ecdh_generic ecc joydev input_leds nls_iso8859_1 snd_sof_pci snd_sof_intel_byt snd_sof_intel_ipc snd_sof_intel_hda_common snd_soc_hdac_hda snd_hda_codec_hdmi snd_sof_xtensa_dsp snd_sof_intel_hda snd_sof snd_hda_ext_core snd_soc_acpi_intel_match snd_soc_acpi snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio snd_hda_intel snd_intel_dspcfg soundwire_intel soundwire_generic_allocation soundwire_cadence snd_hda_codec snd_hda_core ath10k_pci snd_hwdep intel_rapl_msr intel_rapl_common ath10k_core soundwire_bus snd_soc_core x86_pkg_temp_thermal ath intel_powerclamp snd_compress ac97_bus snd_pcm_dmaengine mac80211 snd_pcm coretemp snd_seq_midi snd_seq_midi_event snd_rawmidi kvm_intel cfg80211 snd_seq snd_seq_device snd_timer mei_hdcp kvm libarc4 snd crct10dif_pclmul ghash_clmulni_intel aesni_intel
 mei_me dell_wmi
[  123.450266]  dell_smbios soundcore sparse_keymap dcdbas crypto_simd cryptd mei dell_uart_backlight glue_helper ee1004 wmi_bmof intel_wmi_thunderbolt dell_wmi_descriptor mac_hid efi_pstore acpi_pad acpi_tad intel_cstate sch_fq_codel parport_pc ppdev lp parport ip_tables x_tables autofs4 btrfs blake2b_generic raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear dm_mirror dm_region_hash dm_log hid_generic usbhid hid i915 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec crc32_pclmul rc_core drm intel_lpss_pci i2c_i801 ahci igc intel_lpss i2c_smbus idma64 xhci_pci libahci virt_dma xhci_pci_renesas wmi video pinctrl_tigerlake
[  123.450335] CR2: 0000000000000008
[  123.450338] ---[ end trace 9f731e38b53c35cc ]---

The more generic approach will be wrap get_link_ksettings() with begin()
and complete() callbacks, and calls runtime resume and runtime suspend
routine respectively. However, igc is like igb, runtime resume routine
uses rtnl_lock() which upper ethtool layer also uses.

So to prevent a deadlock on rtnl, take a different approach, use
pm_runtime_suspended() to avoid reading register while device is runtime
suspended.

Fixes: 8c5ad0dae93c ("igc: Add ethtool support")
Signed-off-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
Acked-by: Sasha Neftin &lt;sasha.neftin@intel.com&gt;
Signed-off-by: Tony Nguyen &lt;anthony.l.nguyen@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 2e99dedc73f004f650b197c9b269c15c7e01ad15 upstream.

Similar to commit 165ae7a8feb5 ("igb: Report speed and duplex as unknown
when device is runtime suspended"), if we try to read speed and duplex
sysfs while the device is runtime suspended, igc will complain and
stops working:

[  123.449883] igc 0000:03:00.0 enp3s0: PCIe link lost, device now detached
[  123.450052] BUG: kernel NULL pointer dereference, address: 0000000000000008
[  123.450056] #PF: supervisor read access in kernel mode
[  123.450058] #PF: error_code(0x0000) - not-present page
[  123.450059] PGD 0 P4D 0
[  123.450064] Oops: 0000 [#1] SMP NOPTI
[  123.450068] CPU: 0 PID: 2525 Comm: udevadm Tainted: G     U  W  OE     5.10.0-1002-oem #2+rkl2-Ubuntu
[  123.450078] RIP: 0010:igc_rd32+0x1c/0x90 [igc]
[  123.450080] Code: c0 5d c3 b8 fd ff ff ff c3 0f 1f 44 00 00 0f 1f 44 00 00 55 89 f0 48 89 e5 41 56 41 55 41 54 49 89 c4 53 48 8b 57 08 48 01 d0 &lt;44&gt; 8b 28 41 83 fd ff 74 0c 5b 44 89 e8 41 5c 41 5d 4

[  123.450083] RSP: 0018:ffffb0d100d6fcc0 EFLAGS: 00010202
[  123.450085] RAX: 0000000000000008 RBX: ffffb0d100d6fd30 RCX: 0000000000000000
[  123.450087] RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff945a12716c10
[  123.450089] RBP: ffffb0d100d6fce0 R08: ffff945a12716550 R09: ffff945a09874000
[  123.450090] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000008
[  123.450092] R13: ffff945a12716000 R14: ffff945a037da280 R15: ffff945a037da290
[  123.450094] FS:  00007f3b34c868c0(0000) GS:ffff945b89200000(0000) knlGS:0000000000000000
[  123.450096] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  123.450098] CR2: 0000000000000008 CR3: 00000001144de006 CR4: 0000000000770ef0
[  123.450100] PKRU: 55555554
[  123.450101] Call Trace:
[  123.450111]  igc_ethtool_get_link_ksettings+0xd6/0x1b0 [igc]
[  123.450118]  __ethtool_get_link_ksettings+0x71/0xb0
[  123.450123]  duplex_show+0x74/0xc0
[  123.450129]  dev_attr_show+0x1d/0x40
[  123.450134]  sysfs_kf_seq_show+0xa1/0x100
[  123.450137]  kernfs_seq_show+0x27/0x30
[  123.450142]  seq_read+0xb7/0x400
[  123.450148]  ? common_file_perm+0x72/0x170
[  123.450151]  kernfs_fop_read+0x35/0x1b0
[  123.450155]  vfs_read+0xb5/0x1b0
[  123.450157]  ksys_read+0x67/0xe0
[  123.450160]  __x64_sys_read+0x1a/0x20
[  123.450164]  do_syscall_64+0x38/0x90
[  123.450168]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  123.450170] RIP: 0033:0x7f3b351fe142
[  123.450173] Code: c0 e9 c2 fe ff ff 50 48 8d 3d 3a ca 0a 00 e8 f5 19 02 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 &lt;48&gt; 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24
[  123.450174] RSP: 002b:00007fffef2ec138 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[  123.450177] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3b351fe142
[  123.450179] RDX: 0000000000001001 RSI: 00005644c047f070 RDI: 0000000000000003
[  123.450180] RBP: 00007fffef2ec340 R08: 00005644c047f070 R09: 00007f3b352d9320
[  123.450182] R10: 00005644c047c010 R11: 0000000000000246 R12: 00005644c047cbf0
[  123.450184] R13: 00005644c047e6d0 R14: 0000000000000003 R15: 00007fffef2ec140
[  123.450189] Modules linked in: rfcomm ccm cmac algif_hash algif_skcipher af_alg bnep toshiba_acpi industrialio toshiba_haps hp_accel lis3lv02d btusb btrtl btbcm btintel bluetooth ecdh_generic ecc joydev input_leds nls_iso8859_1 snd_sof_pci snd_sof_intel_byt snd_sof_intel_ipc snd_sof_intel_hda_common snd_soc_hdac_hda snd_hda_codec_hdmi snd_sof_xtensa_dsp snd_sof_intel_hda snd_sof snd_hda_ext_core snd_soc_acpi_intel_match snd_soc_acpi snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio snd_hda_intel snd_intel_dspcfg soundwire_intel soundwire_generic_allocation soundwire_cadence snd_hda_codec snd_hda_core ath10k_pci snd_hwdep intel_rapl_msr intel_rapl_common ath10k_core soundwire_bus snd_soc_core x86_pkg_temp_thermal ath intel_powerclamp snd_compress ac97_bus snd_pcm_dmaengine mac80211 snd_pcm coretemp snd_seq_midi snd_seq_midi_event snd_rawmidi kvm_intel cfg80211 snd_seq snd_seq_device snd_timer mei_hdcp kvm libarc4 snd crct10dif_pclmul ghash_clmulni_intel aesni_intel
 mei_me dell_wmi
[  123.450266]  dell_smbios soundcore sparse_keymap dcdbas crypto_simd cryptd mei dell_uart_backlight glue_helper ee1004 wmi_bmof intel_wmi_thunderbolt dell_wmi_descriptor mac_hid efi_pstore acpi_pad acpi_tad intel_cstate sch_fq_codel parport_pc ppdev lp parport ip_tables x_tables autofs4 btrfs blake2b_generic raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear dm_mirror dm_region_hash dm_log hid_generic usbhid hid i915 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec crc32_pclmul rc_core drm intel_lpss_pci i2c_i801 ahci igc intel_lpss i2c_smbus idma64 xhci_pci libahci virt_dma xhci_pci_renesas wmi video pinctrl_tigerlake
[  123.450335] CR2: 0000000000000008
[  123.450338] ---[ end trace 9f731e38b53c35cc ]---

The more generic approach will be wrap get_link_ksettings() with begin()
and complete() callbacks, and calls runtime resume and runtime suspend
routine respectively. However, igc is like igb, runtime resume routine
uses rtnl_lock() which upper ethtool layer also uses.

So to prevent a deadlock on rtnl, take a different approach, use
pm_runtime_suspended() to avoid reading register while device is runtime
suspended.

Fixes: 8c5ad0dae93c ("igc: Add ethtool support")
Signed-off-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
Acked-by: Sasha Neftin &lt;sasha.neftin@intel.com&gt;
Signed-off-by: Tony Nguyen &lt;anthony.l.nguyen@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>md: Set prev_flush_start and flush_bio in an atomic way</title>
<updated>2021-02-10T08:25:32+00:00</updated>
<author>
<name>Xiao Ni</name>
<email>xni@redhat.com</email>
</author>
<published>2020-12-10T06:33:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7018edb19a926d124e07ba9825474bf68a437d10'/>
<id>7018edb19a926d124e07ba9825474bf68a437d10</id>
<content type='text'>
commit dc5d17a3c39b06aef866afca19245a9cfb533a79 upstream.

One customer reports a crash problem which causes by flush request. It
triggers a warning before crash.

        /* new request after previous flush is completed */
        if (ktime_after(req_start, mddev-&gt;prev_flush_start)) {
                WARN_ON(mddev-&gt;flush_bio);
                mddev-&gt;flush_bio = bio;
                bio = NULL;
        }

The WARN_ON is triggered. We use spin lock to protect prev_flush_start and
flush_bio in md_flush_request. But there is no lock protection in
md_submit_flush_data. It can set flush_bio to NULL first because of
compiler reordering write instructions.

For example, flush bio1 sets flush bio to NULL first in
md_submit_flush_data. An interrupt or vmware causing an extended stall
happen between updating flush_bio and prev_flush_start. Because flush_bio
is NULL, flush bio2 can get the lock and submit to underlayer disks. Then
flush bio1 updates prev_flush_start after the interrupt or extended stall.

Then flush bio3 enters in md_flush_request. The start time req_start is
behind prev_flush_start. The flush_bio is not NULL(flush bio2 hasn't
finished). So it can trigger the WARN_ON now. Then it calls INIT_WORK
again. INIT_WORK() will re-initialize the list pointers in the
work_struct, which then can result in a corrupted work list and the
work_struct queued a second time. With the work list corrupted, it can
lead in invalid work items being used and cause a crash in
process_one_work.

We need to make sure only one flush bio can be handled at one same time.
So add spin lock in md_submit_flush_data to protect prev_flush_start and
flush_bio in an atomic way.

Reviewed-by: David Jeffery &lt;djeffery@redhat.com&gt;
Signed-off-by: Xiao Ni &lt;xni@redhat.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: Jack Wang &lt;jinpu.wang@cloud.ionos.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit dc5d17a3c39b06aef866afca19245a9cfb533a79 upstream.

One customer reports a crash problem which causes by flush request. It
triggers a warning before crash.

        /* new request after previous flush is completed */
        if (ktime_after(req_start, mddev-&gt;prev_flush_start)) {
                WARN_ON(mddev-&gt;flush_bio);
                mddev-&gt;flush_bio = bio;
                bio = NULL;
        }

The WARN_ON is triggered. We use spin lock to protect prev_flush_start and
flush_bio in md_flush_request. But there is no lock protection in
md_submit_flush_data. It can set flush_bio to NULL first because of
compiler reordering write instructions.

For example, flush bio1 sets flush bio to NULL first in
md_submit_flush_data. An interrupt or vmware causing an extended stall
happen between updating flush_bio and prev_flush_start. Because flush_bio
is NULL, flush bio2 can get the lock and submit to underlayer disks. Then
flush bio1 updates prev_flush_start after the interrupt or extended stall.

Then flush bio3 enters in md_flush_request. The start time req_start is
behind prev_flush_start. The flush_bio is not NULL(flush bio2 hasn't
finished). So it can trigger the WARN_ON now. Then it calls INIT_WORK
again. INIT_WORK() will re-initialize the list pointers in the
work_struct, which then can result in a corrupted work list and the
work_struct queued a second time. With the work list corrupted, it can
lead in invalid work items being used and cause a crash in
process_one_work.

We need to make sure only one flush bio can be handled at one same time.
So add spin lock in md_submit_flush_data to protect prev_flush_start and
flush_bio in an atomic way.

Reviewed-by: David Jeffery &lt;djeffery@redhat.com&gt;
Signed-off-by: Xiao Ni &lt;xni@redhat.com&gt;
Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: Jack Wang &lt;jinpu.wang@cloud.ionos.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>iommu/vt-d: Do not use flush-queue when caching-mode is on</title>
<updated>2021-02-10T08:25:32+00:00</updated>
<author>
<name>Nadav Amit</name>
<email>namit@vmware.com</email>
</author>
<published>2021-01-27T17:53:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e857e21eb2008356cb6f3fb0d7531a8995dca93d'/>
<id>e857e21eb2008356cb6f3fb0d7531a8995dca93d</id>
<content type='text'>
commit 29b32839725f8c89a41cb6ee054c85f3116ea8b5 upstream.

When an Intel IOMMU is virtualized, and a physical device is
passed-through to the VM, changes of the virtual IOMMU need to be
propagated to the physical IOMMU. The hypervisor therefore needs to
monitor PTE mappings in the IOMMU page-tables. Intel specifications
provide "caching-mode" capability that a virtual IOMMU uses to report
that the IOMMU is virtualized and a TLB flush is needed after mapping to
allow the hypervisor to propagate virtual IOMMU mappings to the physical
IOMMU. To the best of my knowledge no real physical IOMMU reports
"caching-mode" as turned on.

Synchronizing the virtual and the physical IOMMU tables is expensive if
the hypervisor is unaware which PTEs have changed, as the hypervisor is
required to walk all the virtualized tables and look for changes.
Consequently, domain flushes are much more expensive than page-specific
flushes on virtualized IOMMUs with passthrough devices. The kernel
therefore exploited the "caching-mode" indication to avoid domain
flushing and use page-specific flushing in virtualized environments. See
commit 78d5f0f500e6 ("intel-iommu: Avoid global flushes with caching
mode.")

This behavior changed after commit 13cf01744608 ("iommu/vt-d: Make use
of iova deferred flushing"). Now, when batched TLB flushing is used (the
default), full TLB domain flushes are performed frequently, requiring
the hypervisor to perform expensive synchronization between the virtual
TLB and the physical one.

Getting batched TLB flushes to use page-specific invalidations again in
such circumstances is not easy, since the TLB invalidation scheme
assumes that "full" domain TLB flushes are performed for scalability.

Disable batched TLB flushes when caching-mode is on, as the performance
benefit from using batched TLB invalidations is likely to be much
smaller than the overhead of the virtual-to-physical IOMMU page-tables
synchronization.

Fixes: 13cf01744608 ("iommu/vt-d: Make use of iova deferred flushing")
Signed-off-by: Nadav Amit &lt;namit@vmware.com&gt;
Cc: David Woodhouse &lt;dwmw2@infradead.org&gt;
Cc: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Cc: Joerg Roedel &lt;joro@8bytes.org&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: stable@vger.kernel.org
Acked-by: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20210127175317.1600473-1-namit@vmware.com
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Signed-off-by: Nadav Amit &lt;namit@vmware.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 29b32839725f8c89a41cb6ee054c85f3116ea8b5 upstream.

When an Intel IOMMU is virtualized, and a physical device is
passed-through to the VM, changes of the virtual IOMMU need to be
propagated to the physical IOMMU. The hypervisor therefore needs to
monitor PTE mappings in the IOMMU page-tables. Intel specifications
provide "caching-mode" capability that a virtual IOMMU uses to report
that the IOMMU is virtualized and a TLB flush is needed after mapping to
allow the hypervisor to propagate virtual IOMMU mappings to the physical
IOMMU. To the best of my knowledge no real physical IOMMU reports
"caching-mode" as turned on.

Synchronizing the virtual and the physical IOMMU tables is expensive if
the hypervisor is unaware which PTEs have changed, as the hypervisor is
required to walk all the virtualized tables and look for changes.
Consequently, domain flushes are much more expensive than page-specific
flushes on virtualized IOMMUs with passthrough devices. The kernel
therefore exploited the "caching-mode" indication to avoid domain
flushing and use page-specific flushing in virtualized environments. See
commit 78d5f0f500e6 ("intel-iommu: Avoid global flushes with caching
mode.")

This behavior changed after commit 13cf01744608 ("iommu/vt-d: Make use
of iova deferred flushing"). Now, when batched TLB flushing is used (the
default), full TLB domain flushes are performed frequently, requiring
the hypervisor to perform expensive synchronization between the virtual
TLB and the physical one.

Getting batched TLB flushes to use page-specific invalidations again in
such circumstances is not easy, since the TLB invalidation scheme
assumes that "full" domain TLB flushes are performed for scalability.

Disable batched TLB flushes when caching-mode is on, as the performance
benefit from using batched TLB invalidations is likely to be much
smaller than the overhead of the virtual-to-physical IOMMU page-tables
synchronization.

Fixes: 13cf01744608 ("iommu/vt-d: Make use of iova deferred flushing")
Signed-off-by: Nadav Amit &lt;namit@vmware.com&gt;
Cc: David Woodhouse &lt;dwmw2@infradead.org&gt;
Cc: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Cc: Joerg Roedel &lt;joro@8bytes.org&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: stable@vger.kernel.org
Acked-by: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20210127175317.1600473-1-namit@vmware.com
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Signed-off-by: Nadav Amit &lt;namit@vmware.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>Input: xpad - sync supported devices with fork on GitHub</title>
<updated>2021-02-10T08:25:32+00:00</updated>
<author>
<name>Benjamin Valentin</name>
<email>benpicco@googlemail.com</email>
</author>
<published>2021-01-22T03:24:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5fdf672759e9f94c8cfacd7f3ef9ffc426f01ab9'/>
<id>5fdf672759e9f94c8cfacd7f3ef9ffc426f01ab9</id>
<content type='text'>
commit 9bbd77d5bbc9aff8cb74d805c31751f5f0691ba8 upstream.

There is a fork of this driver on GitHub [0] that has been updated
with new device IDs.

Merge those into the mainline driver, so the out-of-tree fork is not
needed for users of those devices anymore.

[0] https://github.com/paroj/xpad

Signed-off-by: Benjamin Valentin &lt;benpicco@googlemail.com&gt;
Link: https://lore.kernel.org/r/20210121142523.1b6b050f@rechenknecht2k11
Signed-off-by: Dmitry Torokhov &lt;dmitry.torokhov@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 9bbd77d5bbc9aff8cb74d805c31751f5f0691ba8 upstream.

There is a fork of this driver on GitHub [0] that has been updated
with new device IDs.

Merge those into the mainline driver, so the out-of-tree fork is not
needed for users of those devices anymore.

[0] https://github.com/paroj/xpad

Signed-off-by: Benjamin Valentin &lt;benpicco@googlemail.com&gt;
Link: https://lore.kernel.org/r/20210121142523.1b6b050f@rechenknecht2k11
Signed-off-by: Dmitry Torokhov &lt;dmitry.torokhov@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
