When building on macOS 12, we get:

  In file included from ../target/i386/hvf/hvf.c:59:
  ../target/i386/hvf/vmx.h:174:5: error: 'hv_vcpu_flush' is deprecated: first deprecated in macOS 11.0 - This API has no effect and always returns HV_UNSUPPORTED [-Werror,-Wdeprecated-declarations]
      hv_vcpu_flush(vcpu);
      ^
  /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Hypervisor.framework/Headers/hv.h:364:20: note: 'hv_vcpu_flush' has been explicitly marked deprecated here
  extern hv_return_t hv_vcpu_flush(hv_vcpuid_t vcpu)
                     ^

Since this call "has no effect", simply remove it ¯\_(ツ)_/¯

Not very useful deprecation doc:
https://developer.apple.com/documentation/hypervisor/1441386-hv_vcpu_flush

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 target/i386/hvf/vmx.h      | 2 --
 target/i386/hvf/x86_task.c | 1 -
 target/i386/hvf/x86hvf.c   | 2 --
 3 files changed, 5 deletions(-)

diff --git a/target/i386/hvf/vmx.h b/target/i386/hvf/vmx.h
index 6df87116f62..094fb9b9dc9 100644
--- a/target/i386/hvf/vmx.h
+++ b/target/i386/hvf/vmx.h
@@ -159,7 +159,6 @@ static inline void macvm_set_cr0(hv_vcpuid_t vcpu, uint64_t cr0)
     wvmcs(vcpu, VMCS_GUEST_CR0, cr0 | CR0_NE | CR0_ET);
 
     hv_vcpu_invalidate_tlb(vcpu);
-    hv_vcpu_flush(vcpu);
 }
 
 static inline void macvm_set_cr4(hv_vcpuid_t vcpu, uint64_t cr4)
@@ -171,7 +170,6 @@ static inline void macvm_set_cr4(hv_vcpuid_t vcpu, uint64_t cr4)
     wvmcs(vcpu, VMCS_CR4_MASK, CR4_VMXE);
 
     hv_vcpu_invalidate_tlb(vcpu);
-    hv_vcpu_flush(vcpu);
 }
 
 static inline void macvm_set_rip(CPUState *cpu, uint64_t rip)
diff --git a/target/i386/hvf/x86_task.c b/target/i386/hvf/x86_task.c
index 422156128b7..c8dc3d48fa8 100644
--- a/target/i386/hvf/x86_task.c
+++ b/target/i386/hvf/x86_task.c
@@ -181,5 +181,4 @@ void vmx_handle_task_switch(CPUState *cpu, x68_segment_selector tss_sel, int rea
     store_regs(cpu);
 
     hv_vcpu_invalidate_tlb(cpu->hvf->fd);
-    hv_vcpu_flush(cpu->hvf->fd);
 }
diff --git a/target/i386/hvf/x86hvf.c b/target/i386/hvf/x86hvf.c
index 907f09f1b43..bec9fc58146 100644
--- a/target/i386/hvf/x86hvf.c
+++ b/target/i386/hvf/x86hvf.c
@@ -125,8 +125,6 @@ static void hvf_put_segments(CPUState *cpu_state)
 
     hvf_set_segment(cpu_state, &seg, &env->ldt, false);
     vmx_write_segment_descriptor(cpu_state, &seg, R_LDTR);
-    
-    hv_vcpu_flush(cpu_state->hvf->fd);
 }
     
 void hvf_put_msrs(CPUState *cpu_state)
-- 
2.33.1