accel/mshv: write synthetic MSRs after migration
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> Link: https://lore.kernel.org/r/20260710101534.664604-10-magnuskulke@linux.microsoft.com Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Magnus Kulke committed
Jul 10, 2026 at 12:15 UTC
49cd174b56ae5db509a075752a8a9e5247ebbc2e
4 files changed
+34
accel/mshv/mshv-all.c
+15
@@ -60,6 +60,20 @@ static int init_mshv(int *mshv_fd)
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return 0;
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}
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+static int mshv_load_cleanup(void *opaque)
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+{
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+ int ret;
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+
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+ ret = mshv_arch_set_partition_msrs(first_cpu);
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+ if (ret < 0) {
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+ error_report("Failed to set partition MSRs: %s", strerror(-ret));
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+ return -1;
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+ }
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+
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+ return 0;
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+}
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+
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+
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static int get_host_partition_property(int mshv_fd, uint32_t property_code,
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uint64_t *value)
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{
@@ -496,6 +510,7 @@ static int mshv_init_vcpu(CPUState *cpu)
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}
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static SaveVMHandlers savevm_mshv = {
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+ .load_cleanup = mshv_load_cleanup,
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};
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static int mshv_init(AccelState *as, MachineState *ms)
include/hw/hyperv/hvgdk_mini.h
+3
@@ -23,6 +23,9 @@
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#define HV_X64_MSR_APIC_FREQUENCY 0x40000023
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typedef enum hv_register_name {
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+ /* VP Management Registers */
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+ HV_REGISTER_INTERNAL_ACTIVITY_STATE = 0x00000004,
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+
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/* Pending Interruption Register */
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HV_REGISTER_PENDING_INTERRUPTION = 0x00010002,
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HV_REGISTER_INTERRUPT_STATE = 0x00010003,
include/system/mshv_int.h
+1
@@ -98,6 +98,7 @@ int mshv_get_generic_regs(CPUState *cpu, hv_register_assoc *assocs,
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size_t n_regs);
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int mshv_arch_store_vcpu_state(const CPUState *cpu);
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int mshv_arch_load_vcpu_state(CPUState *cpu);
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+int mshv_arch_set_partition_msrs(const CPUState *cpu);
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void mshv_arch_init_vcpu(CPUState *cpu);
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void mshv_arch_destroy_vcpu(CPUState *cpu);
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void mshv_arch_amend_proc_features(
target/i386/mshv/mshv-cpu.c
+15
@@ -1506,6 +1506,21 @@ int mshv_arch_store_vcpu_state(const CPUState *cpu)
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return 0;
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}
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+int mshv_arch_set_partition_msrs(const CPUState *cpu)
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+{
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+ CPUX86State *env = &X86_CPU(cpu)->env;
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+ struct hv_register_assoc assocs[] = {
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+ { .name = HV_REGISTER_GUEST_OS_ID,
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+ .value.reg64 = env->msr_hv_guest_os_id },
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+ { .name = HV_REGISTER_REFERENCE_TSC,
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+ .value.reg64 = env->msr_hv_tsc },
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+ { .name = HV_X64_REGISTER_HYPERCALL,
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+ .value.reg64 = env->msr_hv_hypercall },
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+ };
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+
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+ return mshv_set_generic_regs(cpu, assocs, ARRAY_SIZE(assocs));
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+}
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+
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void mshv_arch_amend_proc_features(
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union hv_partition_synthetic_processor_features *features)
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{