* [PATCH] [gatesgarth 2/3] arm-autonomy: Fix XenStore initialisation for host kernels < 5.4.95
2021-02-18 16:14 [PATCH] [gatesgarth 1/3] arm-autonomy/linux-arm-autonomy: apply runstate fix to kernels older than 5.10 Diego Sueiro
@ 2021-02-18 16:15 ` Diego Sueiro
2021-02-18 16:16 ` [PATCH] [gatesgarth 3/3] arm-autonomy: Fix xenbus probe for guest kernels < 5.4.99 Diego Sueiro
1 sibling, 0 replies; 3+ messages in thread
From: Diego Sueiro @ 2021-02-18 16:15 UTC (permalink / raw)
To: meta-arm; +Cc: nd
The arm-autonomy-host kernels older than 5.4.95 need to backport the
0001-xen-Fix-XenStore-initialisation-for-XS_LOCAL.patch in order to be able to
use the `xl block-attach` and fix this issue:
```
xl block-attach 0 "phy:/dev/vg-xen-vda3/base" xvda w
libxl: error: libxl_xshelp.c:201:libxl__xs_read_mandatory: xenstore read failed: `/libxl/0/type': No such file or directory
libxl: warning: libxl_dom.c:52:libxl__domain_type: unable to get domain type for domid=0, assuming HVM
libxl: error: libxl_disk.c:314:device_disk_add: device already exists in xenstore
libxl: error: libxl_device.c:1407:device_addrm_aocomplete: unable to add device
```
This issue is not present in linux-linaro-arm[-rt] 5.4.0 used by N1SDP, hence
we do not apply this patch for it.
Issue-Id: SCM-2151
Signed-off-by: Diego Sueiro <diego.sueiro@arm.com>
Change-Id: Iea22c54e86db17952662faf75cae94d0ef18d4f3
---
...XenStore-initialisation-for-XS_LOCAL.patch | 98 +++++++++++++++++++
.../linux/linux-arm-autonomy.inc | 7 ++
2 files changed, 105 insertions(+)
create mode 100644 meta-arm-autonomy/recipes-kernel/linux/files/0001-xen-Fix-XenStore-initialisation-for-XS_LOCAL.patch
diff --git a/meta-arm-autonomy/recipes-kernel/linux/files/0001-xen-Fix-XenStore-initialisation-for-XS_LOCAL.patch b/meta-arm-autonomy/recipes-kernel/linux/files/0001-xen-Fix-XenStore-initialisation-for-XS_LOCAL.patch
new file mode 100644
index 0000000..5bf9b74
--- /dev/null
+++ b/meta-arm-autonomy/recipes-kernel/linux/files/0001-xen-Fix-XenStore-initialisation-for-XS_LOCAL.patch
@@ -0,0 +1,98 @@
+From 5f3d54c00f1f2682cee9c590c22655b0330ffd18 Mon Sep 17 00:00:00 2001
+Message-Id: <5f3d54c00f1f2682cee9c590c22655b0330ffd18.1612780458.git.diego.sueiro@arm.com>
+From: David Woodhouse <dwmw@amazon.co.uk>
+Date: Tue, 26 Jan 2021 17:01:49 +0000
+Subject: [PATCH] xen: Fix XenStore initialisation for XS_LOCAL
+
+commit 5f46400f7a6a4fad635d5a79e2aa5a04a30ffea1 upstream.
+
+In commit 3499ba8198ca ("xen: Fix event channel callback via INTX/GSI")
+I reworked the triggering of xenbus_probe().
+
+I tried to simplify things by taking out the workqueue based startup
+triggered from wake_waiting(); the somewhat poorly named xenbus IRQ
+handler.
+
+I missed the fact that in the XS_LOCAL case (Dom0 starting its own
+xenstored or xenstore-stubdom, which happens after the kernel is booted
+completely), that IRQ-based trigger is still actually needed.
+
+So... put it back, except more cleanly. By just spawning a xenbus_probe
+thread which waits on xb_waitq and runs the probe the first time it
+gets woken, just as the workqueue-based hack did.
+
+This is actually a nicer approach for *all* the back ends with different
+interrupt methods, and we can switch them all over to that without the
+complex conditions for when to trigger it. But not in -rc6. This is
+the minimal fix for the regression, although it's a step in the right
+direction instead of doing a partial revert and actually putting the
+workqueue back. It's also simpler than the workqueue.
+
+Fixes: 3499ba8198ca ("xen: Fix event channel callback via INTX/GSI")
+Reported-by: Juergen Gross <jgross@suse.com>
+Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
+Reviewed-by: Juergen Gross <jgross@suse.com>
+Link: https://lore.kernel.org/r/4c9af052a6e0f6485d1de43f2c38b1461996db99.camel@infradead.org
+Signed-off-by: Juergen Gross <jgross@suse.com>
+Cc: Salvatore Bonaccorso <carnil@debian.org>
+Cc: Jason Andryuk <jandryuk@gmail.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+Upstream-Status: Backport
+Signed-off-by: Diego Sueiro <diego.sueiro@arm.com>
+---
+ drivers/xen/xenbus/xenbus_probe.c | 31 +++++++++++++++++++++++++++++++
+ 1 file changed, 31 insertions(+)
+
+diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
+index c8f0282bb649..18ffd0551b54 100644
+--- a/drivers/xen/xenbus/xenbus_probe.c
++++ b/drivers/xen/xenbus/xenbus_probe.c
+@@ -714,6 +714,23 @@ static bool xs_hvm_defer_init_for_callback(void)
+ #endif
+ }
+
++static int xenbus_probe_thread(void *unused)
++{
++ DEFINE_WAIT(w);
++
++ /*
++ * We actually just want to wait for *any* trigger of xb_waitq,
++ * and run xenbus_probe() the moment it occurs.
++ */
++ prepare_to_wait(&xb_waitq, &w, TASK_INTERRUPTIBLE);
++ schedule();
++ finish_wait(&xb_waitq, &w);
++
++ DPRINTK("probing");
++ xenbus_probe();
++ return 0;
++}
++
+ static int __init xenbus_probe_initcall(void)
+ {
+ /*
+@@ -725,6 +742,20 @@ static int __init xenbus_probe_initcall(void)
+ !xs_hvm_defer_init_for_callback()))
+ xenbus_probe();
+
++ /*
++ * For XS_LOCAL, spawn a thread which will wait for xenstored
++ * or a xenstore-stubdom to be started, then probe. It will be
++ * triggered when communication starts happening, by waiting
++ * on xb_waitq.
++ */
++ if (xen_store_domain_type == XS_LOCAL) {
++ struct task_struct *probe_task;
++
++ probe_task = kthread_run(xenbus_probe_thread, NULL,
++ "xenbus_probe");
++ if (IS_ERR(probe_task))
++ return PTR_ERR(probe_task);
++ }
+ return 0;
+ }
+ device_initcall(xenbus_probe_initcall);
+--
+2.17.1
+
diff --git a/meta-arm-autonomy/recipes-kernel/linux/linux-arm-autonomy.inc b/meta-arm-autonomy/recipes-kernel/linux/linux-arm-autonomy.inc
index 89c9fce..bef56d2 100644
--- a/meta-arm-autonomy/recipes-kernel/linux/linux-arm-autonomy.inc
+++ b/meta-arm-autonomy/recipes-kernel/linux/linux-arm-autonomy.inc
@@ -38,8 +38,15 @@ python() {
from distutils.version import LooseVersion
kernelVersion = d.getVar('LINUX_VERSION')
+ pn = d.getVar('PN')
if kernelVersion and LooseVersion(kernelVersion) < '5.10':
if oe.utils.any_distro_features(d, "arm-autonomy-host arm-autonomy-guest"):
d.appendVar('SRC_URI', ' file://files/0001-xen-arm-do-not-setup-the-runstate-info-page-if-kpti-.patch' )
+
+ if kernelVersion and LooseVersion(kernelVersion) < '5.4.95' \
+ and pn != 'linux-libc-headers' \
+ and not pn.startswith('linux-linaro-arm') \
+ and oe.utils.any_distro_features(d, "arm-autonomy-host"):
+ d.appendVar('SRC_URI', ' file://files/0001-xen-Fix-XenStore-initialisation-for-XS_LOCAL.patch' )
}
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH] [gatesgarth 3/3] arm-autonomy: Fix xenbus probe for guest kernels < 5.4.99
2021-02-18 16:14 [PATCH] [gatesgarth 1/3] arm-autonomy/linux-arm-autonomy: apply runstate fix to kernels older than 5.10 Diego Sueiro
2021-02-18 16:15 ` [PATCH] [gatesgarth 2/3] arm-autonomy: Fix XenStore initialisation for host kernels < 5.4.95 Diego Sueiro
@ 2021-02-18 16:16 ` Diego Sueiro
1 sibling, 0 replies; 3+ messages in thread
From: Diego Sueiro @ 2021-02-18 16:16 UTC (permalink / raw)
To: meta-arm; +Cc: nd
The arm64-autonomy-guest kernel from commit a09d4e7acdbf ("xen: Fix event
channel callback via INTX/GSI") are hanging at `hw-breakpoint: found 6
breakpoint and 4 watchpoint registers.`.
The arm-autonomy-guest kernels older than 5.4.99 need to backport the
0001-arm-xen-Don-t-probe-xenbus-as-part-of-an-early-initc.patch in order
to be able to boot.
Issue-Id: SCM-2151
Signed-off-by: Diego Sueiro <diego.sueiro@arm.com>
Change-Id: I56c558f518336567eadd5dc69fd9334c23b19cd8
---
...obe-xenbus-as-part-of-an-early-initc.patch | 95 +++++++++++++++++++
.../linux/linux-arm-autonomy.inc | 5 +
2 files changed, 100 insertions(+)
create mode 100644 meta-arm-autonomy/recipes-kernel/linux/files/0001-arm-xen-Don-t-probe-xenbus-as-part-of-an-early-initc.patch
diff --git a/meta-arm-autonomy/recipes-kernel/linux/files/0001-arm-xen-Don-t-probe-xenbus-as-part-of-an-early-initc.patch b/meta-arm-autonomy/recipes-kernel/linux/files/0001-arm-xen-Don-t-probe-xenbus-as-part-of-an-early-initc.patch
new file mode 100644
index 0000000..c38798f
--- /dev/null
+++ b/meta-arm-autonomy/recipes-kernel/linux/files/0001-arm-xen-Don-t-probe-xenbus-as-part-of-an-early-initc.patch
@@ -0,0 +1,95 @@
+From 18d691d837b340c941ad778bc8dfa77446e48bb4 Mon Sep 17 00:00:00 2001
+Message-Id: <18d691d837b340c941ad778bc8dfa77446e48bb4.1613579395.git.diego.sueiro@arm.com>
+From: Julien Grall <jgrall@amazon.com>
+Date: Wed, 10 Feb 2021 17:06:54 +0000
+Subject: [PATCH] arm/xen: Don't probe xenbus as part of an early initcall
+
+commit c4295ab0b485b8bc50d2264bcae2acd06f25caaf upstream.
+
+After Commit 3499ba8198cad ("xen: Fix event channel callback via
+INTX/GSI"), xenbus_probe() will be called too early on Arm. This will
+recent to a guest hang during boot.
+
+If the hang wasn't there, we would have ended up to call
+xenbus_probe() twice (the second time is in xenbus_probe_initcall()).
+
+We don't need to initialize xenbus_probe() early for Arm guest.
+Therefore, the call in xen_guest_init() is now removed.
+
+After this change, there is no more external caller for xenbus_probe().
+So the function is turned to a static one. Interestingly there were two
+prototypes for it.
+
+Cc: stable@vger.kernel.org
+Fixes: 3499ba8198cad ("xen: Fix event channel callback via INTX/GSI")
+Reported-by: Ian Jackson <iwj@xenproject.org>
+Signed-off-by: Julien Grall <jgrall@amazon.com>
+Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
+Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
+Link: https://lore.kernel.org/r/20210210170654.5377-1-julien@xen.org
+Signed-off-by: Juergen Gross <jgross@suse.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+Upstream-Status: Backport
+Signed-off-by: Diego Sueiro <diego.sueiro@arm.com>
+---
+ arch/arm/xen/enlighten.c | 2 --
+ drivers/xen/xenbus/xenbus.h | 1 -
+ drivers/xen/xenbus/xenbus_probe.c | 2 +-
+ include/xen/xenbus.h | 2 --
+ 4 files changed, 1 insertion(+), 6 deletions(-)
+
+diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
+index f45bff158fc2..57dfc13b2752 100644
+--- a/arch/arm/xen/enlighten.c
++++ b/arch/arm/xen/enlighten.c
+@@ -370,8 +370,6 @@ static int __init xen_guest_init(void)
+ return -ENOMEM;
+ }
+ gnttab_init();
+- if (!xen_initial_domain())
+- xenbus_probe();
+
+ /*
+ * Making sure board specific code will not set up ops for
+diff --git a/drivers/xen/xenbus/xenbus.h b/drivers/xen/xenbus/xenbus.h
+index a9bb5f91082d..88516a8a9f93 100644
+--- a/drivers/xen/xenbus/xenbus.h
++++ b/drivers/xen/xenbus/xenbus.h
+@@ -115,7 +115,6 @@ int xenbus_probe_node(struct xen_bus_type *bus,
+ const char *type,
+ const char *nodename);
+ int xenbus_probe_devices(struct xen_bus_type *bus);
+-void xenbus_probe(void);
+
+ void xenbus_dev_changed(const char *node, struct xen_bus_type *bus);
+
+diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
+index 786494bb7f20..652894d61967 100644
+--- a/drivers/xen/xenbus/xenbus_probe.c
++++ b/drivers/xen/xenbus/xenbus_probe.c
+@@ -683,7 +683,7 @@ void unregister_xenstore_notifier(struct notifier_block *nb)
+ }
+ EXPORT_SYMBOL_GPL(unregister_xenstore_notifier);
+
+-void xenbus_probe(void)
++static void xenbus_probe(void)
+ {
+ xenstored_ready = 1;
+
+diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h
+index fe9a9fa2ebc4..14d47ed4114f 100644
+--- a/include/xen/xenbus.h
++++ b/include/xen/xenbus.h
+@@ -187,8 +187,6 @@ void xs_suspend_cancel(void);
+
+ struct work_struct;
+
+-void xenbus_probe(void);
+-
+ #define XENBUS_IS_ERR_READ(str) ({ \
+ if (!IS_ERR(str) && strlen(str) == 0) { \
+ kfree(str); \
+--
+2.17.1
+
diff --git a/meta-arm-autonomy/recipes-kernel/linux/linux-arm-autonomy.inc b/meta-arm-autonomy/recipes-kernel/linux/linux-arm-autonomy.inc
index bef56d2..77cea96 100644
--- a/meta-arm-autonomy/recipes-kernel/linux/linux-arm-autonomy.inc
+++ b/meta-arm-autonomy/recipes-kernel/linux/linux-arm-autonomy.inc
@@ -49,4 +49,9 @@ python() {
and not pn.startswith('linux-linaro-arm') \
and oe.utils.any_distro_features(d, "arm-autonomy-host"):
d.appendVar('SRC_URI', ' file://files/0001-xen-Fix-XenStore-initialisation-for-XS_LOCAL.patch' )
+
+ if kernelVersion and LooseVersion(kernelVersion) < '5.4.99' \
+ and pn != 'linux-libc-headers' \
+ and oe.utils.any_distro_features(d, "arm-autonomy-guest"):
+ d.appendVar('SRC_URI', ' file://files/0001-arm-xen-Don-t-probe-xenbus-as-part-of-an-early-initc.patch' )
}
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread