Commit 6c21a067a7 for qemu.org

commit 6c21a067a7e446c6c6c89c895c8f2cb574b09235
Author: Ani Sinha <anisinha@redhat.com>
Date:   Thu Mar 19 17:51:36 2026 +0530

    hw/i386/hyperv: add stubs for synic enablement

    Add a new call hyperv_enable_synic() that can be called whether or not
    CONFIG_HYPERV is enabled. This way genetic code in i396/kvm.c can call this
    function to enable synic for hyperv. For non-hyperv cases, the stub will
    be a noop.

    Reported-by: Michale Tokarev <mjt@tls.msk.ru>
    Signed-off-by: Ani Sinha <anisinha@redhat.com>
    Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
    Tested-by: Michael Tokarev <mjt@tls.msk.ru>
    Message-ID: <20260319122137.142178-3-anisinha@redhat.com>
    Tested-by: Xudong Hao <xudong.hao@intel.com>
    Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

diff --git a/target/i386/kvm/hyperv-stub.c b/target/i386/kvm/hyperv-stub.c
index 5836f53c23..767a4c7e1a 100644
--- a/target/i386/kvm/hyperv-stub.c
+++ b/target/i386/kvm/hyperv-stub.c
@@ -61,3 +61,8 @@ uint64_t hyperv_syndbg_query_options(void)
 {
     return 0;
 }
+
+int hyperv_enable_synic(X86CPU *cpu)
+{
+    return 0;
+}
diff --git a/target/i386/kvm/hyperv.c b/target/i386/kvm/hyperv.c
index f7a81bd270..bd3c26d02b 100644
--- a/target/i386/kvm/hyperv.c
+++ b/target/i386/kvm/hyperv.c
@@ -24,6 +24,15 @@ int hyperv_x86_synic_add(X86CPU *cpu)
     return 0;
 }

+int hyperv_enable_synic(X86CPU *cpu)
+{
+    int ret = 0;
+    if (!hyperv_is_synic_enabled()) {
+        ret = hyperv_x86_synic_add(cpu);
+    }
+    return ret;
+}
+
 /*
  * All devices possibly using SynIC have to be reset before calling this to let
  * them remove their SINT routes first.
diff --git a/target/i386/kvm/hyperv.h b/target/i386/kvm/hyperv.h
index e45a4512fe..a393a5d428 100644
--- a/target/i386/kvm/hyperv.h
+++ b/target/i386/kvm/hyperv.h
@@ -23,6 +23,7 @@ int kvm_hv_handle_exit(X86CPU *cpu, struct kvm_hyperv_exit *exit);
 #endif

 int hyperv_x86_synic_add(X86CPU *cpu);
+int hyperv_enable_synic(X86CPU *cpu);
 void hyperv_x86_synic_reset(X86CPU *cpu);
 void hyperv_x86_synic_update(X86CPU *cpu);

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index a29f757c16..9e352882c8 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -1754,13 +1754,11 @@ static int hyperv_init_vcpu(X86CPU *cpu)
             return ret;
         }

-        if (!hyperv_is_synic_enabled()) {
-            ret = hyperv_x86_synic_add(cpu);
-            if (ret < 0) {
-                error_report("failed to create HyperV SynIC: %s",
-                             strerror(-ret));
-                return ret;
-            }
+        ret = hyperv_enable_synic(cpu);
+        if (ret < 0) {
+            error_report("failed to create HyperV SynIC: %s",
+                         strerror(-ret));
+            return ret;
         }
     }