path: root/drivers/hv
diff options
authorDexuan Cui <>2020-12-21 22:55:41 -0800
committerWei Liu <>2021-01-05 17:52:04 +0000
commitdfe94d4086e40e92b1926bddcefa629b791e9b28 (patch)
treefb6fe7ef7968b71ca528444f532ecb757a358432 /drivers/hv
parente71ba9452f0b5b2e8dc8aa5445198cd9214a6a62 (diff)
x86/hyperv: Fix kexec panic/hang issues
Currently the kexec kernel can panic or hang due to 2 causes: 1) hv_cpu_die() is not called upon kexec, so the hypervisor corrupts the old VP Assist Pages when the kexec kernel runs. The same issue is fixed for hibernation in commit 421f090c819d ("x86/hyperv: Suspend/resume the VP assist page for hibernation"). Now fix it for kexec. 2) hyperv_cleanup() is called too early. In the kexec path, the other CPUs are stopped in hv_machine_shutdown() -> native_machine_shutdown(), so between hv_kexec_handler() and native_machine_shutdown(), the other CPUs can still try to access the hypercall page and cause panic. The workaround "hv_hypercall_pg = NULL;" in hyperv_cleanup() is unreliabe. Move hyperv_cleanup() to a better place. Signed-off-by: Dexuan Cui <> Reviewed-by: Michael Kelley <> Link: Signed-off-by: Wei Liu <>
Diffstat (limited to 'drivers/hv')
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 502f8cd95f6d..d491fdcee61f 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -2550,7 +2550,6 @@ static void hv_kexec_handler(void)
/* Make sure conn_state is set as hv_synic_cleanup checks for it */
- hyperv_cleanup();
static void hv_crash_handler(struct pt_regs *regs)
@@ -2566,7 +2565,6 @@ static void hv_crash_handler(struct pt_regs *regs)
cpu = smp_processor_id();
- hyperv_cleanup();
static int hv_synic_suspend(void)