x86/HVM: handle_{mmio*,pio}() return value adjustments

Don't ignore their return values. Don't indicate success to callers of
handle_pio() when in fact the domain has been crashed.

Make all three functions return bool. Adjust formatting of switch()
statements being touched anyway.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/x86/hvm/io.c
+++ b/xen/arch/x86/hvm/io.c
@@ -78,7 +78,7 @@ void send_invalidate_req(void)
         gprintk(XENLOG_ERR, "Unsuccessful map-cache invalidate\n");
 }
 
-int handle_mmio(void)
+bool handle_mmio(void)
 {
     struct hvm_emulate_ctxt ctxt;
     struct vcpu *curr = current;
@@ -100,22 +100,21 @@ int handle_mmio(void)
     {
     case X86EMUL_UNHANDLEABLE:
         hvm_dump_emulation_state(XENLOG_G_WARNING "MMIO", &ctxt);
-        return 0;
+        return false;
+
     case X86EMUL_EXCEPTION:
         if ( ctxt.ctxt.event_pending )
             hvm_inject_event(&ctxt.ctxt.event);
         break;
-    default:
-        break;
     }
 
     hvm_emulate_writeback(&ctxt);
 
-    return 1;
+    return true;
 }
 
-int handle_mmio_with_translation(unsigned long gla, unsigned long gpfn,
-                                 struct npfec access)
+bool handle_mmio_with_translation(unsigned long gla, unsigned long gpfn,
+                                  struct npfec access)
 {
     struct hvm_vcpu_io *vio = &current->arch.hvm_vcpu.hvm_io;
 
@@ -127,7 +126,7 @@ int handle_mmio_with_translation(unsigne
     return handle_mmio();
 }
 
-int handle_pio(uint16_t port, unsigned int size, int dir)
+bool handle_pio(uint16_t port, unsigned int size, int dir)
 {
     struct vcpu *curr = current;
     struct hvm_vcpu_io *vio = &curr->arch.hvm_vcpu.hvm_io;
@@ -155,19 +154,20 @@ int handle_pio(uint16_t port, unsigned i
                 memcpy(&guest_cpu_user_regs()->rax, &data, size);
         }
         break;
+
     case X86EMUL_RETRY:
         /* We should not advance RIP/EIP if the domain is shutting down */
         if ( curr->domain->is_shutting_down )
-            return 0;
-
+            return false;
         break;
+
     default:
         gdprintk(XENLOG_ERR, "Weird HVM ioemulation status %d.\n", rc);
         domain_crash(curr->domain);
-        break;
+        return false;
     }
 
-    return 1;
+    return true;
 }
 
 static bool_t dpci_portio_accept(const struct hvm_io_handler *handler,
--- a/xen/arch/x86/hvm/ioreq.c
+++ b/xen/arch/x86/hvm/ioreq.c
@@ -156,13 +156,14 @@ bool_t handle_hvm_io_completion(struct v
     {
     case HVMIO_no_completion:
         break;
+
     case HVMIO_mmio_completion:
-        handle_mmio();
-        break;
+        return handle_mmio();
+
     case HVMIO_pio_completion:
-        (void)handle_pio(vio->io_req.addr, vio->io_req.size,
-                         vio->io_req.dir);
-        break;
+        return handle_pio(vio->io_req.addr, vio->io_req.size,
+                          vio->io_req.dir);
+
     case HVMIO_realmode_completion:
     {
         struct hvm_emulate_ctxt ctxt;
--- a/xen/include/asm-x86/hvm/io.h
+++ b/xen/include/asm-x86/hvm/io.h
@@ -118,10 +118,10 @@ void relocate_portio_handler(
 
 void send_timeoffset_req(unsigned long timeoff);
 void send_invalidate_req(void);
-int handle_mmio(void);
-int handle_mmio_with_translation(unsigned long gla, unsigned long gpfn,
-                                 struct npfec);
-int handle_pio(uint16_t port, unsigned int size, int dir);
+bool handle_mmio(void);
+bool handle_mmio_with_translation(unsigned long gla, unsigned long gpfn,
+                                  struct npfec);
+bool handle_pio(uint16_t port, unsigned int size, int dir);
 void hvm_interrupt_post(struct vcpu *v, int vector, int type);
 void hvm_dpci_eoi(struct domain *d, unsigned int guest_irq,
                   const union vioapic_redir_entry *ent);