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authorLinus Torvalds <torvalds@linux-foundation.org>2020-04-14 11:58:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-04-14 11:58:04 -0700
commit8632e9b5645bbc2331d21d892b0d6961c1a08429 (patch)
treedf3fbdae9311a15b7c36da9db915e6b0a5f53ddc /drivers/hv
parentMerge tag 'for-5.7-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux (diff)
parentx86/Hyper-V: Report crash data in die() when panic_on_oops is set (diff)
downloadlinux-dev-8632e9b5645bbc2331d21d892b0d6961c1a08429.tar.xz
linux-dev-8632e9b5645bbc2331d21d892b0d6961c1a08429.zip
Merge tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv fixes from Wei Liu: - a series from Tianyu Lan to fix crash reporting on Hyper-V - three miscellaneous cleanup patches * tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/Hyper-V: Report crash data in die() when panic_on_oops is set x86/Hyper-V: Report crash register data when sysctl_record_panic_msg is not set x86/Hyper-V: Report crash register data or kmsg before running crash kernel x86/Hyper-V: Trigger crash enlightenment only once during system crash. x86/Hyper-V: Free hv_panic_page when fail to register kmsg dump x86/Hyper-V: Unload vmbus channel in hv panic callback x86: hyperv: report value of misc_features hv_debugfs: Make hv_debug_root static hv: hyperv_vmbus.h: Replace zero-length array with flexible-array member
Diffstat (limited to 'drivers/hv')
-rw-r--r--drivers/hv/channel_mgmt.c3
-rw-r--r--drivers/hv/hv_debugfs.c2
-rw-r--r--drivers/hv/hyperv_vmbus.h2
-rw-r--r--drivers/hv/vmbus_drv.c62
4 files changed, 49 insertions, 20 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 0370364169c4..501c43c5851d 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -839,6 +839,9 @@ void vmbus_initiate_unload(bool crash)
{
struct vmbus_channel_message_header hdr;
+ if (xchg(&vmbus_connection.conn_state, DISCONNECTED) == DISCONNECTED)
+ return;
+
/* Pre-Win2012R2 hosts don't support reconnect */
if (vmbus_proto_version < VERSION_WIN8_1)
return;
diff --git a/drivers/hv/hv_debugfs.c b/drivers/hv/hv_debugfs.c
index 8a2878573582..ccf752b6659a 100644
--- a/drivers/hv/hv_debugfs.c
+++ b/drivers/hv/hv_debugfs.c
@@ -11,7 +11,7 @@
#include "hyperv_vmbus.h"
-struct dentry *hv_debug_root;
+static struct dentry *hv_debug_root;
static int hv_debugfs_delay_get(void *data, u64 *val)
{
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index f5fa3b3c9baf..70b30e223a57 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -292,7 +292,7 @@ struct vmbus_msginfo {
struct list_head msglist_entry;
/* The message itself */
- unsigned char msg[0];
+ unsigned char msg[];
};
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 029378c27421..a68bce4d0ddb 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -31,6 +31,7 @@
#include <linux/kdebug.h>
#include <linux/efi.h>
#include <linux/random.h>
+#include <linux/kernel.h>
#include <linux/syscore_ops.h>
#include <clocksource/hyperv_timer.h>
#include "hyperv_vmbus.h"
@@ -48,14 +49,35 @@ static int hyperv_cpuhp_online;
static void *hv_panic_page;
+/*
+ * Boolean to control whether to report panic messages over Hyper-V.
+ *
+ * It can be set via /proc/sys/kernel/hyperv/record_panic_msg
+ */
+static int sysctl_record_panic_msg = 1;
+
+static int hyperv_report_reg(void)
+{
+ return !sysctl_record_panic_msg || !hv_panic_page;
+}
+
static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
void *args)
{
struct pt_regs *regs;
- regs = current_pt_regs();
+ vmbus_initiate_unload(true);
- hyperv_report_panic(regs, val);
+ /*
+ * Hyper-V should be notified only once about a panic. If we will be
+ * doing hyperv_report_panic_msg() later with kmsg data, don't do
+ * the notification here.
+ */
+ if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE
+ && hyperv_report_reg()) {
+ regs = current_pt_regs();
+ hyperv_report_panic(regs, val, false);
+ }
return NOTIFY_DONE;
}
@@ -65,7 +87,13 @@ static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
struct die_args *die = (struct die_args *)args;
struct pt_regs *regs = die->regs;
- hyperv_report_panic(regs, val);
+ /*
+ * Hyper-V should be notified only once about a panic. If we will be
+ * doing hyperv_report_panic_msg() later with kmsg data, don't do
+ * the notification here.
+ */
+ if (hyperv_report_reg())
+ hyperv_report_panic(regs, val, true);
return NOTIFY_DONE;
}
@@ -1253,13 +1281,6 @@ static void vmbus_isr(void)
}
/*
- * Boolean to control whether to report panic messages over Hyper-V.
- *
- * It can be set via /proc/sys/kernel/hyperv/record_panic_msg
- */
-static int sysctl_record_panic_msg = 1;
-
-/*
* Callback from kmsg_dump. Grab as much as possible from the end of the kmsg
* buffer and call into Hyper-V to transfer the data.
*/
@@ -1382,19 +1403,29 @@ static int vmbus_bus_init(void)
hv_panic_page = (void *)hv_alloc_hyperv_zeroed_page();
if (hv_panic_page) {
ret = kmsg_dump_register(&hv_kmsg_dumper);
- if (ret)
+ if (ret) {
pr_err("Hyper-V: kmsg dump register "
"error 0x%x\n", ret);
+ hv_free_hyperv_page(
+ (unsigned long)hv_panic_page);
+ hv_panic_page = NULL;
+ }
} else
pr_err("Hyper-V: panic message page memory "
"allocation failed");
}
register_die_notifier(&hyperv_die_block);
- atomic_notifier_chain_register(&panic_notifier_list,
- &hyperv_panic_block);
}
+ /*
+ * Always register the panic notifier because we need to unload
+ * the VMbus channel connection to prevent any VMbus
+ * activity after the VM panics.
+ */
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &hyperv_panic_block);
+
vmbus_request_offers();
return 0;
@@ -1407,7 +1438,6 @@ err_alloc:
hv_remove_vmbus_irq();
bus_unregister(&hv_bus);
- hv_free_hyperv_page((unsigned long)hv_panic_page);
unregister_sysctl_table(hv_ctl_table_hdr);
hv_ctl_table_hdr = NULL;
return ret;
@@ -2204,8 +2234,6 @@ static int vmbus_bus_suspend(struct device *dev)
vmbus_initiate_unload(false);
- vmbus_connection.conn_state = DISCONNECTED;
-
/* Reset the event for the next resume. */
reinit_completion(&vmbus_connection.ready_for_resume_event);
@@ -2289,7 +2317,6 @@ static void hv_kexec_handler(void)
{
hv_stimer_global_cleanup();
vmbus_initiate_unload(false);
- vmbus_connection.conn_state = DISCONNECTED;
/* Make sure conn_state is set as hv_synic_cleanup checks for it */
mb();
cpuhp_remove_state(hyperv_cpuhp_online);
@@ -2306,7 +2333,6 @@ static void hv_crash_handler(struct pt_regs *regs)
* doing the cleanup for current CPU only. This should be sufficient
* for kdump.
*/
- vmbus_connection.conn_state = DISCONNECTED;
cpu = smp_processor_id();
hv_stimer_cleanup(cpu);
hv_synic_disable_regs(cpu);