1 files changed, 15 insertions, 17 deletions

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index f36dfe3349..9060599cd7 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -358,7 +358,7 @@ int kvm_physical_memory_addr_from_host(KVMState *s, void *ram,
 static int kvm_set_user_memory_region(KVMMemoryListener *kml, KVMSlot *slot, bool new)
 {
     KVMState *s = kvm_state;
-    struct kvm_userspace_memory_region2 mem;
+    struct kvm_userspace_memory_region2 mem = {};
     int ret;
 
     mem.slot = slot->slot | (kml->as_id << 16);
@@ -1595,7 +1595,8 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml,
         mem->ram = ram;
         mem->flags = kvm_mem_flags(mr);
         mem->guest_memfd = mr->ram_block->guest_memfd;
-        mem->guest_memfd_offset = (uint8_t*)ram - mr->ram_block->host;
+        mem->guest_memfd_offset = mem->guest_memfd >= 0 ?
+                                  (uint8_t*)ram - mr->ram_block->host : 0;
 
         kvm_slot_init_dirty_bitmap(mem);
         err = kvm_set_user_memory_region(kml, mem, true);
@@ -2776,8 +2777,8 @@ static int kvm_init(AccelState *as, MachineState *ms)
 
     kvm_supported_memory_attributes = kvm_vm_check_extension(s, KVM_CAP_MEMORY_ATTRIBUTES);
     kvm_guest_memfd_supported =
-        kvm_check_extension(s, KVM_CAP_GUEST_MEMFD) &&
-        kvm_check_extension(s, KVM_CAP_USER_MEMORY2) &&
+        kvm_vm_check_extension(s, KVM_CAP_GUEST_MEMFD) &&
+        kvm_vm_check_extension(s, KVM_CAP_USER_MEMORY2) &&
         (kvm_supported_memory_attributes & KVM_MEMORY_ATTRIBUTE_PRIVATE);
     kvm_pre_fault_memory_supported = kvm_vm_check_extension(s, KVM_CAP_PRE_FAULT_MEMORY);
 
@@ -3029,10 +3030,6 @@ static void kvm_eat_signals(CPUState *cpu)
 
     if (kvm_immediate_exit) {
         qatomic_set(&cpu->kvm_run->immediate_exit, 0);
-        /* Write kvm_run->immediate_exit before the cpu->exit_request
-         * write in kvm_cpu_exec.
-         */
-        smp_wmb();
         return;
     }
 
@@ -3159,7 +3156,6 @@ int kvm_cpu_exec(CPUState *cpu)
     trace_kvm_cpu_exec();
 
     if (kvm_arch_process_async_events(cpu)) {
-        qatomic_set(&cpu->exit_request, 0);
         return EXCP_HLT;
     }
 
@@ -3187,7 +3183,8 @@ int kvm_cpu_exec(CPUState *cpu)
         }
 
         kvm_arch_pre_run(cpu, run);
-        if (qatomic_read(&cpu->exit_request)) {
+        /* Corresponding store-release is in cpu_exit. */
+        if (qatomic_load_acquire(&cpu->exit_request)) {
             trace_kvm_interrupt_exit_request();
             /*
              * KVM requires us to reenter the kernel after IO exits to complete
@@ -3197,13 +3194,15 @@ int kvm_cpu_exec(CPUState *cpu)
             kvm_cpu_kick_self();
         }
 
-        /* Read cpu->exit_request before KVM_RUN reads run->immediate_exit.
-         * Matching barrier in kvm_eat_signals.
-         */
-        smp_rmb();
-
         run_ret = kvm_vcpu_ioctl(cpu, KVM_RUN, 0);
 
+        /*
+         * After writing cpu->exit_request, cpu_exit() sends a signal that writes
+         * kvm->run->immediate_exit.  The signal is already happening after the
+         * write to cpu->exit_request so, if KVM read kvm->run->immediate_exit
+         * as true, cpu->exit_request will always read as true.
+         */
+
         attrs = kvm_arch_post_run(cpu, run);
 
 #ifdef KVM_HAVE_MCE_INJECTION
@@ -3346,7 +3345,6 @@ int kvm_cpu_exec(CPUState *cpu)
         vm_stop(RUN_STATE_INTERNAL_ERROR);
     }
 
-    qatomic_set(&cpu->exit_request, 0);
     return ret;
 }
 
@@ -3731,7 +3729,7 @@ int kvm_on_sigbus_vcpu(CPUState *cpu, int code, void *addr)
     have_sigbus_pending = true;
     pending_sigbus_addr = addr;
     pending_sigbus_code = code;
-    qatomic_set(&cpu->exit_request, 1);
+    qatomic_set(&cpu->exit_request, true);
     return 0;
 #else
     return 1;