From 9526b8037a76c973d1bac56ca6a00be92be9b131 Mon Sep 17 00:00:00 2001
From: "arun.sharma@intel.com[kaf24]" <arun.sharma@intel.com[kaf24]>
Date: Thu, 19 May 2005 08:20:21 +0000
Subject: [PATCH] bitkeeper revision 1.1459 (428c4c45ObcqPNCq2Ebb3M0y4qnxog)

[PATCH] vmx-gdbserver-sstep.patch

This patch enables single stepping a VMX domain using the gdbserver.

Signed-Off-By: Leendert van Doorn <leendert@watson.ibm.com>
Signed-off-by: Arun Sharma <arun.sharma@intel.com>
---
 xen/arch/x86/domain.c       |  6 ++++++
 xen/arch/x86/vmx.c          | 17 ++++++++++++++++-
 xen/arch/x86/vmx_platform.c |  2 +-
 xen/include/asm-x86/vmx.h   | 32 ++++++++++++++++++++++++++++++--
 4 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 0b93ed87a2..458257a492 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -425,6 +425,12 @@ int arch_set_info_guest(
 
         /* Ensure real hardware interrupts are enabled. */
         ed->arch.guest_context.user_regs.eflags |= EF_IE;
+    } else {
+        __vmwrite(GUEST_EFLAGS, ed->arch.guest_context.user_regs.eflags);
+        if (ed->arch.guest_context.user_regs.eflags & EF_TF)
+                __vm_set_bit(EXCEPTION_BITMAP, EXCEPTION_BITMAP_DB);
+        else 
+                __vm_clear_bit(EXCEPTION_BITMAP, EXCEPTION_BITMAP_DB);
     }
 
     if ( test_bit(_VCPUF_initialised, &ed->vcpu_flags) )
diff --git a/xen/arch/x86/vmx.c b/xen/arch/x86/vmx.c
index 52c976f51f..78572a132b 100644
--- a/xen/arch/x86/vmx.c
+++ b/xen/arch/x86/vmx.c
@@ -166,7 +166,7 @@ static void vmx_do_no_device_fault()
         cr0 &= ~X86_CR0_TS;
         __vmwrite(GUEST_CR0, cr0);
     }
-    __vmwrite(EXCEPTION_BITMAP, MONITOR_DEFAULT_EXCEPTION_BITMAP);
+    __vm_clear_bit(EXCEPTION_BITMAP, EXCEPTION_BITMAP_NM);
 }
 
 static void vmx_do_general_protection_fault(struct cpu_user_regs *regs) 
@@ -1108,6 +1108,21 @@ asmlinkage void vmx_vmexit_handler(struct cpu_user_regs regs)
             save_cpu_user_regs(&regs);
             pdb_handle_exception(3, &regs, 1);
             restore_cpu_user_regs(&regs);
+            break;
+        }
+#else
+        case TRAP_debug:
+        {
+            void store_cpu_user_regs(struct cpu_user_regs *regs);
+            long do_sched_op(unsigned long op);
+
+
+            store_cpu_user_regs(&regs);
+            __vm_clear_bit(GUEST_PENDING_DBG_EXCEPTIONS, PENDING_DEBUG_EXC_BS);
+
+            set_bit(_VCPUF_ctrl_pause, &current->vcpu_flags);
+            do_sched_op(SCHEDOP_yield);
+
             break;
         }
 #endif
diff --git a/xen/arch/x86/vmx_platform.c b/xen/arch/x86/vmx_platform.c
index 8de185c072..4ccafe7c2b 100644
--- a/xen/arch/x86/vmx_platform.c
+++ b/xen/arch/x86/vmx_platform.c
@@ -49,7 +49,7 @@ static long get_reg_value(int size, int index, int seg, struct cpu_user_regs *re
     return 0;
 }
 #elif defined (__i386__)
-static void store_cpu_user_regs(struct cpu_user_regs *regs)
+void store_cpu_user_regs(struct cpu_user_regs *regs)
 {
     __vmread(GUEST_SS_SELECTOR, &regs->ss);
     __vmread(GUEST_ESP, &regs->esp);
diff --git a/xen/include/asm-x86/vmx.h b/xen/include/asm-x86/vmx.h
index 3041a334f1..d9bed6621b 100644
--- a/xen/include/asm-x86/vmx.h
+++ b/xen/include/asm-x86/vmx.h
@@ -131,6 +131,11 @@ extern unsigned int cpu_rev;
 #define EXCEPTION_BITMAP_MC     (1 << 18)       /* Machine Check */
 #define EXCEPTION_BITMAP_XF     (1 << 19)       /* SIMD Floating-Point Exception */
 
+/* Pending Debug exceptions */
+
+#define PENDING_DEBUG_EXC_BP    (1 << 12)       /* break point */
+#define PENDING_DEBUG_EXC_BS    (1 << 14)       /* Single step */
+
 #ifdef XEN_DEBUGGER
 #define MONITOR_DEFAULT_EXCEPTION_BITMAP        \
     ( EXCEPTION_BITMAP_PG |                     \
@@ -231,6 +236,30 @@ static inline int __vmwrite (unsigned long field, unsigned long value)
     return 0;
 }
 
+static inline int __vm_set_bit(unsigned long field, unsigned long mask)
+{
+        unsigned long tmp;
+        int err = 0;
+
+        err |= __vmread(field, &tmp);
+        tmp |= mask;
+        err |= __vmwrite(field, tmp);
+
+        return err;
+}
+
+static inline int __vm_clear_bit(unsigned long field, unsigned long mask)
+{
+        unsigned long tmp;
+        int err = 0;
+
+        err |= __vmread(field, &tmp);
+        tmp &= ~mask;
+        err |= __vmwrite(field, tmp);
+
+        return err;
+}
+
 static inline void __vmxoff (void)
 {
     __asm__ __volatile__ ( VMXOFF_OPCODE 
@@ -263,8 +292,7 @@ static inline void vmx_stts()
 
     __vmread(CR0_READ_SHADOW, &cr0);
     if (!(cr0 & X86_CR0_TS))
-       __vmwrite(EXCEPTION_BITMAP, MONITOR_DEFAULT_EXCEPTION_BITMAP | 
-                                   EXCEPTION_BITMAP_NM);
+       __vm_set_bit(EXCEPTION_BITMAP, EXCEPTION_BITMAP_NM);
 }
  
 #endif /* __ASM_X86_VMX_H__ */
-- 
2.30.2