[Xen-devel] [PATCH v2 2/7] xen/x86: merge 2 hvm_event_... functions into 1

[Corneliu ZUZU <czuzu@xxxxxxxxxxxxxxx>]

This patch merges almost identical functions hvm_event_int3 and
hvm_event_single_step into a single function called hvm_event_breakpoint.

Signed-off-by: Corneliu ZUZU <czuzu@xxxxxxxxxxxxxxx>
---
 xen/arch/x86/hvm/event.c        | 76 +++++++++++++++++++----------------------
 xen/arch/x86/hvm/vmx/vmx.c      | 15 ++++----
 xen/include/asm-x86/hvm/event.h | 11 ++++--
 3 files changed, 52 insertions(+), 50 deletions(-)

diff --git a/xen/arch/x86/hvm/event.c b/xen/arch/x86/hvm/event.c
index a3d4892..e3444db 100644
--- a/xen/arch/x86/hvm/event.c
+++ b/xen/arch/x86/hvm/event.c
@@ -1,9 +1,12 @@
 /*
-* event.c: Common hardware virtual machine event abstractions.
+* arch/x86/hvm/event.c
+*
+* Arch-specific hardware virtual machine event abstractions.
 *
 * Copyright (c) 2004, Intel Corporation.
 * Copyright (c) 2005, International Business Machines Corporation.
 * Copyright (c) 2008, Citrix Systems, Inc.
+* Copyright (c) 2016, Bitdefender S.R.L.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
@@ -151,61 +154,52 @@ void hvm_event_guest_request(void)
     }
 }
 
-int hvm_event_int3(unsigned long rip)
+static inline
+uint64_t gfn_of_rip(unsigned long rip)
 {
-    int rc = 0;
     struct vcpu *curr = current;
+    struct segment_register sreg;
+    uint32_t pfec = PFEC_page_present | PFEC_insn_fetch;
 
-    if ( curr->domain->arch.monitor.software_breakpoint_enabled )
-    {
-        struct segment_register sreg;
-        uint32_t pfec = PFEC_page_present | PFEC_insn_fetch;
-        vm_event_request_t req = {
-            .reason = VM_EVENT_REASON_SOFTWARE_BREAKPOINT,
-            .vcpu_id = curr->vcpu_id,
-        };
-
-        hvm_get_segment_register(curr, x86_seg_ss, &sreg);
-        if ( sreg.attr.fields.dpl == 3 )
-            pfec |= PFEC_user_mode;
+    hvm_get_segment_register(curr, x86_seg_ss, &sreg);
+    if ( sreg.attr.fields.dpl == 3 )
+        pfec |= PFEC_user_mode;
 
-        hvm_get_segment_register(curr, x86_seg_cs, &sreg);
-        req.u.software_breakpoint.gfn = paging_gva_to_gfn(curr,
-                                                          sreg.base + rip,
-                                                          &pfec);
-
-        rc = hvm_event_traps(1, &req);
-    }
+    hvm_get_segment_register(curr, x86_seg_cs, &sreg);
 
-    return rc;
+    return (uint64_t) paging_gva_to_gfn(curr, sreg.base + rip, &pfec);
 }
 
-int hvm_event_single_step(unsigned long rip)
+int hvm_event_breakpoint(unsigned long rip,
+                         enum hvm_event_breakpoint_type type)
 {
-    int rc = 0;
     struct vcpu *curr = current;
+    struct arch_domain *ad = &curr->domain->arch;
+    vm_event_request_t req;
 
-    if ( curr->domain->arch.monitor.singlestep_enabled )
+    switch ( type )
     {
-        struct segment_register sreg;
-        uint32_t pfec = PFEC_page_present | PFEC_insn_fetch;
-        vm_event_request_t req = {
-            .reason = VM_EVENT_REASON_SINGLESTEP,
-            .vcpu_id = curr->vcpu_id,
-        };
-
-        hvm_get_segment_register(curr, x86_seg_ss, &sreg);
-        if ( sreg.attr.fields.dpl == 3 )
-            pfec |= PFEC_user_mode;
+    case HVM_EVENT_SOFTWARE_BREAKPOINT:
+        if ( !ad->monitor.software_breakpoint_enabled )
+            return 0;
+        req.reason = VM_EVENT_REASON_SOFTWARE_BREAKPOINT;
+        req.u.software_breakpoint.gfn = gfn_of_rip(rip);
+        break;
 
-        hvm_get_segment_register(curr, x86_seg_cs, &sreg);
-        req.u.singlestep.gfn = paging_gva_to_gfn(curr, sreg.base + rip,
-                                                 &pfec);
+    case HVM_EVENT_SINGLESTEP_BREAKPOINT:
+        if ( !ad->monitor.singlestep_enabled )
+            return 0;
+        req.reason = VM_EVENT_REASON_SINGLESTEP;
+        req.u.singlestep.gfn = gfn_of_rip(rip);
+        break;
 
-        rc = hvm_event_traps(1, &req);
+    default:
+        return -EOPNOTSUPP;
     }
 
-    return rc;
+    req.vcpu_id = curr->vcpu_id;
+
+    return hvm_event_traps(1, &req);
 }
 
 /*
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index b9f340c..cf0e642 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -3192,8 +3192,10 @@ void vmx_vmexit_handler(struct cpu_user_regs *regs)
                 break;
             }
             else {
-                int handled = hvm_event_int3(regs->eip);
-                
+                int handled =
+                        hvm_event_breakpoint(regs->eip,
+                                             HVM_EVENT_SOFTWARE_BREAKPOINT);
+
                 if ( handled < 0 ) 
                 {
                     struct hvm_trap trap = {
@@ -3517,10 +3519,11 @@ void vmx_vmexit_handler(struct cpu_user_regs *regs)
     case EXIT_REASON_MONITOR_TRAP_FLAG:
         v->arch.hvm_vmx.exec_control &= ~CPU_BASED_MONITOR_TRAP_FLAG;
         vmx_update_cpu_exec_control(v);
-        if ( v->arch.hvm_vcpu.single_step ) {
-          hvm_event_single_step(regs->eip);
-          if ( v->domain->debugger_attached )
-              domain_pause_for_debugger();
+        if ( v->arch.hvm_vcpu.single_step )
+        {
+            hvm_event_breakpoint(regs->eip, HVM_EVENT_SINGLESTEP_BREAKPOINT);
+            if ( v->domain->debugger_attached )
+                domain_pause_for_debugger();
         }
 
         break;
diff --git a/xen/include/asm-x86/hvm/event.h b/xen/include/asm-x86/hvm/event.h
index 11eb1fe..7a83b45 100644
--- a/xen/include/asm-x86/hvm/event.h
+++ b/xen/include/asm-x86/hvm/event.h
@@ -17,6 +17,12 @@
 #ifndef __ASM_X86_HVM_EVENT_H__
 #define __ASM_X86_HVM_EVENT_H__
 
+enum hvm_event_breakpoint_type
+{
+    HVM_EVENT_SOFTWARE_BREAKPOINT,
+    HVM_EVENT_SINGLESTEP_BREAKPOINT,
+};
+
 /*
  * Called for current VCPU on crX/MSR changes by guest.
  * The event might not fire if the client has subscribed to it in onchangeonly
@@ -27,9 +33,8 @@ bool_t hvm_event_cr(unsigned int index, unsigned long value,
 #define hvm_event_crX(what, new, old) \
     hvm_event_cr(VM_EVENT_X86_##what, new, old)
 void hvm_event_msr(unsigned int msr, uint64_t value);
-/* Called for current VCPU: returns -1 if no listener */
-int hvm_event_int3(unsigned long rip);
-int hvm_event_single_step(unsigned long rip);
+int hvm_event_breakpoint(unsigned long rip,
+                         enum hvm_event_breakpoint_type type);
 void hvm_event_guest_request(void);
 
 #endif /* __ASM_X86_HVM_EVENT_H__ */
-- 
2.5.0


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