[PATCH v2 3/4] x86/vmware: Report guest crash to the hypervisor

[Alexey Makhalov]

Register the guest crash reporter to panic_notifier_list,
which will be called at panic time. Guest crash reporter
will report the crash to the hypervisor through
a hypercall.

Co-developed-by: Brennan Lamoreaux <brennan.lamoreaux@xxxxxxxxxxxx>
Signed-off-by: Brennan Lamoreaux <brennan.lamoreaux@xxxxxxxxxxxx>
Signed-off-by: Alexey Makhalov <alexey.makhalov@xxxxxxxxxxxx>
---
 arch/x86/include/asm/vmware.h |  1 +
 arch/x86/kernel/cpu/vmware.c  | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/arch/x86/include/asm/vmware.h b/arch/x86/include/asm/vmware.h
index c23164503e54..bf6141353774 100644
--- a/arch/x86/include/asm/vmware.h
+++ b/arch/x86/include/asm/vmware.h
@@ -97,6 +97,7 @@
 #define VMWARE_CMD_GETHZ		45
 #define VMWARE_CMD_GETVCPU_INFO		68
 #define VMWARE_CMD_STEALCLOCK		91
+#define VMWARE_CMD_REPORTGUESTCRASH	102
 /*
  * Hypercall command mask:
  *   bits [6:0] command, range [0, 127]
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 9955f2ea0c84..c631e577348a 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -31,6 +31,7 @@
 #include <linux/static_call.h>
 #include <linux/sched/cputime.h>
 #include <linux/kmsg_dump.h>
+#include <linux/panic_notifier.h>
 #include <asm/div64.h>
 #include <asm/x86_init.h>
 #include <asm/hypervisor.h>
@@ -451,6 +452,24 @@ static void __init vmware_paravirt_ops_setup(void)
 #define vmware_paravirt_ops_setup() do {} while (0)
 #endif
 
+static int vmware_report_guest_crash(struct notifier_block *self,
+				     unsigned long action, void *data)
+{
+	vmware_hypercall1(VMWARE_CMD_REPORTGUESTCRASH, 0);
+	return 0;
+}
+
+static struct notifier_block guest_crash_reporter = {
+	.notifier_call = vmware_report_guest_crash
+};
+
+static int __init register_guest_crash_reporter(void)
+{
+	atomic_notifier_chain_register(&panic_notifier_list,
+					&guest_crash_reporter);
+
+	return 0;
+}
 /*
  * VMware hypervisor takes care of exporting a reliable TSC to the guest.
  * Still, due to timing difference when running on virtual cpus, the TSC can
@@ -545,6 +564,8 @@ static void __init vmware_platform_setup(void)
 	vmware_set_capabilities();
 
 	kmsg_dump_register(&kmsg_dumper);
+
+	register_guest_crash_reporter();
 }
 
 static u8 __init get_hypercall_mode(void)
-- 
2.43.7