Write partition-wide synthetic MSRs. This ensures the hypercall page and
SynIC facilities are set up before vCPUs attempt to use it.

Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com>
---
 accel/mshv/mshv-all.c          |  7 +++++++
 include/hw/hyperv/hvgdk_mini.h |  3 +++
 include/system/mshv_int.h      |  1 +
 target/i386/mshv/mshv-cpu.c    | 15 +++++++++++++++
 4 files changed, 26 insertions(+)

diff --git a/accel/mshv/mshv-all.c b/accel/mshv/mshv-all.c
index 365288b901..22e838ede6 100644
--- a/accel/mshv/mshv-all.c
+++ b/accel/mshv/mshv-all.c
@@ -137,6 +137,13 @@ static int mshv_load_setup(QEMUFile *f, void *opaque, Error **errp)
 static int mshv_load_cleanup(void *opaque)
 {
     MshvState *s = opaque;
+    int ret;
+
+    ret = mshv_arch_set_partition_msrs(first_cpu);
+    if (ret < 0) {
+        error_report("Failed to set partition MSRs: %s", strerror(-ret));
+        return -1;
+    }
 
     resume_vm(s->vm);
 
diff --git a/include/hw/hyperv/hvgdk_mini.h b/include/hw/hyperv/hvgdk_mini.h
index a47bc6212e..00daac0431 100644
--- a/include/hw/hyperv/hvgdk_mini.h
+++ b/include/hw/hyperv/hvgdk_mini.h
@@ -23,6 +23,9 @@
 #define HV_X64_MSR_APIC_FREQUENCY   0x40000023
 
 typedef enum hv_register_name {
+    /* VP Management Registers */
+    HV_REGISTER_INTERNAL_ACTIVITY_STATE = 0x00000004,
+
     /* Pending Interruption Register */
     HV_REGISTER_PENDING_INTERRUPTION = 0x00010002,
 
diff --git a/include/system/mshv_int.h b/include/system/mshv_int.h
index 7d685fc647..7052f20a00 100644
--- a/include/system/mshv_int.h
+++ b/include/system/mshv_int.h
@@ -84,6 +84,7 @@ int mshv_get_generic_regs(CPUState *cpu, hv_register_assoc *assocs,
                           size_t n_regs);
 int mshv_arch_store_vcpu_state(const CPUState *cpu);
 int mshv_arch_load_vcpu_state(CPUState *cpu);
+int mshv_arch_set_partition_msrs(const CPUState *cpu);
 void mshv_arch_init_vcpu(CPUState *cpu);
 void mshv_arch_destroy_vcpu(CPUState *cpu);
 void mshv_arch_amend_proc_features(
diff --git a/target/i386/mshv/mshv-cpu.c b/target/i386/mshv/mshv-cpu.c
index ec1caf4e7a..0b08f478ce 100644
--- a/target/i386/mshv/mshv-cpu.c
+++ b/target/i386/mshv/mshv-cpu.c
@@ -1141,6 +1141,21 @@ int mshv_arch_store_vcpu_state(const CPUState *cpu)
     return 0;
 }
 
+int mshv_arch_set_partition_msrs(const CPUState *cpu)
+{
+    CPUX86State *env = &X86_CPU(cpu)->env;
+    struct hv_register_assoc assocs[] = {
+        { .name = HV_REGISTER_GUEST_OS_ID,
+          .value.reg64 = env->msr_hv_guest_os_id },
+        { .name = HV_REGISTER_REFERENCE_TSC,
+          .value.reg64 = env->msr_hv_tsc },
+        { .name = HV_X64_REGISTER_HYPERCALL,
+          .value.reg64 = env->msr_hv_hypercall },
+    };
+
+    return mshv_set_generic_regs(cpu, assocs, ARRAY_SIZE(assocs));
+}
+
 void mshv_arch_amend_proc_features(
     union hv_partition_synthetic_processor_features *features)
 {
-- 
2.34.1