From 44b6911233ea62a6a57afd90b259064fac3855ea Mon Sep 17 00:00:00 2001
From: qihao <qihao_yewu@cmss.chinamobile.com>
Date: Tue, 18 Jun 2024 09:50:38 +0800
Subject: [PATCH] migration/dirtyrate: Fix segmentation fault

cheery-pick from e65152d5483b2c847ec7a947ed52650152cfdcc0

Since the kvm_dirty_ring_enabled function accesses a null kvm_state
pointer when the KVM acceleration parameter is not specified, running
calc_dirty_rate with the -r or -b option causes a segmentation fault.

Signed-off-by: Masato Imai <mii@sfc.wide.ad.jp>
Message-ID: <20240507025010.1968881-1-mii@sfc.wide.ad.jp>
[Assert kvm_state when kvm_dirty_ring_enabled was called to fix it. - Hyman]
Signed-off-by: Hyman Huang <yong.huang@smartx.com>
Signed-off-by: qihao_yewu <qihao_yewu@cmss.chinamobile.com>
---
 accel/kvm/kvm-all.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index b791aad1d6..ade7841ca3 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -2343,7 +2343,7 @@ bool kvm_vcpu_id_is_valid(int vcpu_id)
 
 bool kvm_dirty_ring_enabled(void)
 {
-    return kvm_state->kvm_dirty_ring_size ? true : false;
+    return kvm_state && kvm_state->kvm_dirty_ring_size;
 }
 
 static void query_stats_cb(StatsResultList **result, StatsTarget target,
-- 
2.41.0.windows.1