From: "Andrea Parri (Microsoft)" <parri.andrea@xxxxxxxxx>
[ Upstream commit 9f8b577f7b43b2170628d6c537252785dcc2dcea ]
hv_panic_page might contain guest-sensitive information, do not dump it
over to Hyper-V by default in isolated guests.
While at it, update some comments in hyperv_{panic,die}_event().
Reported-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@xxxxxxxxx>
Reviewed-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220301141135.2232-1-parri.andrea@xxxxxxxxx
Signed-off-by: Wei Liu <wei.liu@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/hv/vmbus_drv.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 12a2b37e87f3..a963b970ffb2 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -77,8 +77,8 @@ static int hyperv_panic_event(struct notifier_block *nb, unsigned long 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.
+ * doing hv_kmsg_dump() with kmsg data later, don't do the notification
+ * here.
*/
if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE
&& hyperv_report_reg()) {
@@ -100,8 +100,8 @@ static int hyperv_die_event(struct notifier_block *nb, unsigned long 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.
+ * doing hv_kmsg_dump() with kmsg data later, don't do the notification
+ * here.
*/
if (hyperv_report_reg())
hyperv_report_panic(regs, val, true);
@@ -1546,14 +1546,20 @@ static int vmbus_bus_init(void)
if (ret)
goto err_connect;
+ if (hv_is_isolation_supported())
+ sysctl_record_panic_msg = 0;
+
/*
* Only register if the crash MSRs are available
*/
if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
u64 hyperv_crash_ctl;
/*
- * Sysctl registration is not fatal, since by default
- * reporting is enabled.
+ * Panic message recording (sysctl_record_panic_msg)
+ * is enabled by default in non-isolated guests and
+ * disabled by default in isolated guests; the panic
+ * message recording won't be available in isolated
+ * guests should the following registration fail.
*/
hv_ctl_table_hdr = register_sysctl_table(hv_root_table);
if (!hv_ctl_table_hdr)
--
2.35.1
