[Qemu-devel] [PATCH 5/5] i386: add hyperv-stub for CONFIG_HYPERV=n

[Roman Kagan]

This will allow to build slightly leaner QEMU that supports some HyperV
features of KVM (e.g. SynIC timers, PV spinlocks, APIC assists, etc.)
but nothing else on the QEMU side.

Signed-off-by: Roman Kagan <address@hidden>
---
 target/i386/hyperv-stub.c | 33 +++++++++++++++++++++++++++++++++
 target/i386/Makefile.objs |  4 +++-
 2 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 target/i386/hyperv-stub.c

diff --git a/target/i386/hyperv-stub.c b/target/i386/hyperv-stub.c
new file mode 100644
index 0000000000..cba4ce774e
--- /dev/null
+++ b/target/i386/hyperv-stub.c
@@ -0,0 +1,33 @@
+/*
+ * Stubs for CONFIG_HYPERV=n
+ *
+ * Copyright (c) 2015-2018 Virtuozzo International GmbH.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "hyperv.h"
+
+int kvm_hv_handle_exit(X86CPU *cpu, struct kvm_hyperv_exit *exit)
+{
+    switch (exit->type) {
+    case KVM_EXIT_HYPERV_SYNIC:
+        if (!cpu->hyperv_synic) {
+            return -1;
+        }
+
+        /*
+         * Tracking the changes in the MSRs is unnecessary as there are no
+         * users for them beside save/load, which is handled nicely by the
+         * generic MSR save/load code
+         */
+        return 0;
+    case KVM_EXIT_HYPERV_HCALL:
+        exit->u.hcall.result = HV_STATUS_INVALID_HYPERCALL_CODE;
+        return 0;
+    default:
+        return -1;
+    }
+}
diff --git a/target/i386/Makefile.objs b/target/i386/Makefile.objs
index 04678f5503..ca85de79d3 100644
--- a/target/i386/Makefile.objs
+++ b/target/i386/Makefile.objs
@@ -4,7 +4,9 @@ obj-$(CONFIG_TCG) += bpt_helper.o cc_helper.o excp_helper.o 
fpu_helper.o
 obj-$(CONFIG_TCG) += int_helper.o mem_helper.o misc_helper.o mpx_helper.o
 obj-$(CONFIG_TCG) += seg_helper.o smm_helper.o svm_helper.o
 obj-$(CONFIG_SOFTMMU) += machine.o arch_memory_mapping.o arch_dump.o monitor.o
-obj-$(CONFIG_KVM) += kvm.o hyperv.o
+obj-$(CONFIG_KVM) += kvm.o
+obj-$(CONFIG_HYPERV) += hyperv.o
+obj-$(call lnot,$(CONFIG_HYPERV)) += hyperv-stub.o
 obj-$(CONFIG_SEV) += sev.o
 obj-$(call lnot,$(CONFIG_KVM)) += kvm-stub.o
 obj-$(call lnot,$(CONFIG_SEV)) += sev-stub.o
-- 
2.17.1