From baacc5ed528a5259286622482a01e3e848aed57e Mon Sep 17 00:00:00 2001
From: Keqian Zhu <zhukeqian1@huawei.com>
Date: Mon, 29 Apr 2024 17:14:47 +0800
Subject: [PATCH] kvm/arm: Fix compatibility of cold-plug CPU with SVE

For arm virt machine, besides hotplugged vcpu, the kvm state of
coldplugged CPU is also pre-inited and thus SVE is finalized.

And a flag in ARMCPU state and skip finalize SVE again.

Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
---
 hw/arm/virt.c      | 5 +++++
 target/arm/cpu.h   | 3 +++
 target/arm/kvm64.c | 2 +-
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 507b09d96c..dfe4d9e129 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -3282,6 +3282,11 @@ static void virt_cpu_pre_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
     if (!dev->hotplugged) {
         cs->cold_booted = true;
     }
+#ifdef CONFIG_KVM
+    if (cs->cpu_index >= ms->smp.cpus) {
+        cpu->kvm_sve_finalized = true;
+    }
+#endif
 }
 
 static void virt_cpu_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index c51a0e3467..a5ba7f2a26 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -971,6 +971,9 @@ struct ArchCPU {
 
     /* KVM steal time */
     OnOffAuto kvm_steal_time;
+
+    /* KVM SVE has been finalized for this CPU */
+    bool kvm_sve_finalized;
 #endif /* CONFIG_KVM */
 
     /* Uniprocessor system with MP extensions */
diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
index 615e8bbbdf..8f01d485b0 100644
--- a/target/arm/kvm64.c
+++ b/target/arm/kvm64.c
@@ -647,7 +647,7 @@ int kvm_arch_init_vcpu(CPUState *cs)
         return ret;
     }
 
-    if (cpu_isar_feature(aa64_sve, cpu) && !DEVICE(cpu)->hotplugged) {
+    if (cpu_isar_feature(aa64_sve, cpu) && !cpu->kvm_sve_finalized) {
         ret = kvm_arm_sve_set_vls(cs);
         if (ret) {
             return ret;
-- 
2.27.0