Merge tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git...

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

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index b0da5320bcff8420f00037468a17e61e353b5f49..624f5d9b0f79f9c37e2b6e9fad21a6ee31ea7e3f 100644 (file)
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -20,6 +20,7 @@
 #include <linux/mm.h>
 #include <linux/hyperv.h>
 #include <linux/slab.h>
+#include <linux/kernel.h>
 #include <linux/cpuhotplug.h>
 #include <linux/syscore_ops.h>
 #include <clocksource/hyperv_timer.h>
@@ -419,11 +420,14 @@ void hyperv_cleanup(void)
 }
 EXPORT_SYMBOL_GPL(hyperv_cleanup);
 
-void hyperv_report_panic(struct pt_regs *regs, long err)
+void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die)
 {
        static bool panic_reported;
        u64 guest_id;
 
+       if (in_die && !panic_on_oops)
+               return;
+
        /*
         * We prefer to report panic on 'die' chain as we have proper
         * registers to report, but if we miss it (e.g. on BUG()) we need

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index caa032ce3fe311507e6168f4ec0a0d742cf7a0b9..ebf34c7bc8bc0dfcb0cac217d522358c8c192b04 100644 (file)
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -227,8 +227,8 @@ static void __init ms_hyperv_init_platform(void)
        ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES);
        ms_hyperv.hints    = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
 
-       pr_info("Hyper-V: features 0x%x, hints 0x%x\n",
-               ms_hyperv.features, ms_hyperv.hints);
+       pr_info("Hyper-V: features 0x%x, hints 0x%x, misc 0x%x\n",
+               ms_hyperv.features, ms_hyperv.hints, ms_hyperv.misc_features);
 
        ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS);
        ms_hyperv.max_lp_index = cpuid_ebx(HYPERV_CPUID_IMPLEMENT_LIMITS);
@@ -263,6 +263,16 @@ static void __init ms_hyperv_init_platform(void)
                        cpuid_eax(HYPERV_CPUID_NESTED_FEATURES);
        }
 
+       /*
+        * Hyper-V expects to get crash register data or kmsg when
+        * crash enlightment is available and system crashes. Set
+        * crash_kexec_post_notifiers to be true to make sure that
+        * calling crash enlightment interface before running kdump
+        * kernel.
+        */
+       if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE)
+               crash_kexec_post_notifiers = true;
+
 #ifdef CONFIG_X86_LOCAL_APIC
        if (ms_hyperv.features & HV_X64_ACCESS_FREQUENCY_MSRS &&
            ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 0370364169c4ec2ebc09218395f41615b9f49cd5..501c43c5851dcc503edaff6c19cfc5b0d4df4a66 100644 (file)
--- 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 8a28785735820b61f6a85adca84f61022c133f3a..ccf752b6659a773584f97b133f0cb1155a1bcfc4 100644 (file)
--- 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 f5fa3b3c9baf762c8c02422fbffaa88d859e865b..70b30e223a578be42378342891541b560bae627b 100644 (file)
--- 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 029378c27421d1b30a168dbe25c1ba13c4c8de57..a68bce4d0ddbe925beabc2ca6a3499c6e25ea202 100644 (file)
--- 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;
 }
 
@@ -1252,13 +1280,6 @@ static void vmbus_isr(void)
        add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
 }
 
-/*
- * 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);

diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index b3f1082cc435c84efccaa11ec4a0bfc0260568dd..1c4fd950f09123d6802b0dd82be00757eb815992 100644 (file)
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -163,7 +163,7 @@ static inline int cpumask_to_vpset(struct hv_vpset *vpset,
        return nr_bank;
 }
 
-void hyperv_report_panic(struct pt_regs *regs, long err);
+void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
 void hyperv_report_panic_msg(phys_addr_t pa, size_t size);
 bool hv_is_hyperv_initialized(void);
 bool hv_is_hibernation_supported(void);