Mailing List Archive

ChangeSet 1.1459, 2005/05/19 09:20:21+01:00, arun.sharma@intel.com

[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>



arch/x86/domain.c | 6 ++++++
arch/x86/vmx.c | 17 ++++++++++++++++-
arch/x86/vmx_platform.c | 2 +-
include/asm-x86/vmx.h | 32 ++++++++++++++++++++++++++++++--
4 files changed, 53 insertions(+), 4 deletions(-)


diff -Nru a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
--- a/xen/arch/x86/domain.c 2005-05-19 05:04:44 -04:00
+++ b/xen/arch/x86/domain.c 2005-05-19 05:04:44 -04:00
@@ -425,6 +425,12 @@

/* 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 -Nru a/xen/arch/x86/vmx.c b/xen/arch/x86/vmx.c
--- a/xen/arch/x86/vmx.c 2005-05-19 05:04:44 -04:00
+++ b/xen/arch/x86/vmx.c 2005-05-19 05:04:44 -04:00
@@ -166,7 +166,7 @@
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 @@
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 -Nru a/xen/arch/x86/vmx_platform.c b/xen/arch/x86/vmx_platform.c
--- a/xen/arch/x86/vmx_platform.c 2005-05-19 05:04:44 -04:00
+++ b/xen/arch/x86/vmx_platform.c 2005-05-19 05:04:44 -04:00
@@ -49,7 +49,7 @@
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 -Nru a/xen/include/asm-x86/vmx.h b/xen/include/asm-x86/vmx.h
--- a/xen/include/asm-x86/vmx.h 2005-05-19 05:04:44 -04:00
+++ b/xen/include/asm-x86/vmx.h 2005-05-19 05:04:44 -04:00
@@ -131,6 +131,11 @@
#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 @@
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 @@

__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__ */

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