qemu-kvm/SOURCES/kvm-accel-mshv-implement-cpu_thread_is_idle-hook.patch
2026-07-07 06:01:02 -04:00

60 lines
2.3 KiB
Diff

From 65a864175fc2ace2862993871fb0da783db2f09e Mon Sep 17 00:00:00 2001
From: Magnus Kulke <magnuskulke@linux.microsoft.com>
Date: Tue, 21 Apr 2026 05:21:54 +0000
Subject: [PATCH 2/2] accel/mshv: implement cpu_thread_is_idle() hook
RH-Author: Miroslav Rezanina <mrezanin@redhat.com>
RH-MergeRequest: 559: accel/mshv: backport required patches for mshv guests
RH-Jira: RHEL-184951
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Jon Maloy <jmaloy@redhat.com>
RH-Commit: [2/2] ffcc0f3b6d3e7e04d28797d9fb31d88df4827230 (mrezanin/rhel-src-qemu-kvm)
In MSHV the hypervisor APIC is always used, so we to implement this hook
to make sure the AP's vcpu thread is not blocked waiting for an INIT SIPI
by the BSP. Without this change soft reboots with -smp cpus>=2 will
hang.
Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com>
Reviewed-by: Mohamed Mediouni <mohamed@unpredictable.fr>
Link: https://lore.kernel.org/r/20260421-mshv_accel_arm64_supp-v3-9-469f544778ba@linux.microsoft.com
[Make comment not x86 specific. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit dbfb680772d5184544f7c0a8bba96bec229c96e6)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
accel/mshv/mshv-all.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/accel/mshv/mshv-all.c b/accel/mshv/mshv-all.c
index 88b66f2992..d7df89dbd2 100644
--- a/accel/mshv/mshv-all.c
+++ b/accel/mshv/mshv-all.c
@@ -699,11 +699,23 @@ static const TypeInfo mshv_accel_type = {
.instance_size = sizeof(MshvState),
};
+/*
+ * MSHV manages secondary processors in the hypervisor. SIPI for x86 and
+ * PSCI for Arm are handled internally. Halted vCPUs must still enter
+ * mshv_cpu_exec() so that MSHV_RUN_VP is called and the hypervisor will
+ * wake APs.
+ */
+static bool mshv_vcpu_thread_is_idle(CPUState *cpu)
+{
+ return false;
+}
+
static void mshv_accel_ops_class_init(ObjectClass *oc, const void *data)
{
AccelOpsClass *ops = ACCEL_OPS_CLASS(oc);
ops->create_vcpu_thread = mshv_start_vcpu_thread;
+ ops->cpu_thread_is_idle = mshv_vcpu_thread_is_idle;
ops->synchronize_post_init = mshv_cpu_synchronize_post_init;
ops->synchronize_post_reset = mshv_cpu_synchronize_post_reset;
ops->synchronize_state = mshv_cpu_synchronize;
--
2.52.0