[Xen-devel] [PATCH] vmx-gdbserver-paging.patch

[Arun Sharma <arun.sharma@xxxxxxxxx>]

gdbserver should not try to convert guest physical to machine physical if
paging is not enabled.

Signed-off-by: Arun Sharma <arun.sharma@xxxxxxxxx>

--- a/xen/include/public/arch-x86_32.h  Thu Jun 16 22:46:01 2005
+++ b/xen/include/public/arch-x86_32.h  Thu Jun 16 23:49:22 2005
@@ -134,6 +134,8 @@
     unsigned long gdt_frames[16], gdt_ents; /* GDT (machine frames, # ents) */
     unsigned long kernel_ss, kernel_sp;     /* Virtual TSS (only SS1/SP1)   */
     unsigned long pt_base;                  /* CR3 (pagetable base)         */
+    unsigned long cr0;                      /* CR0                          */
+    unsigned long cr4;                      /* CR4                          */
     unsigned long debugreg[8];              /* DB0-DB7 (debug registers)    */
     unsigned long event_callback_cs;        /* CS:EIP of event callback     */
     unsigned long event_callback_eip;
--- a/tools/libxc/xc_ptrace.c   Thu Jun 16 22:46:01 2005
+++ b/tools/libxc/xc_ptrace.c   Thu Jun 16 23:49:22 2005
@@ -3,6 +3,8 @@
 #include "xc_private.h"
 #include <time.h>
 
+#define X86_CR0_PE              0x00000001 /* Enable Protected Mode    (RW) */
+#define X86_CR0_PG              0x80000000 /* Paging                   (RW) */
 
 #define BSD_PAGE_MASK  (PAGE_SIZE-1)
 #define        PG_FRAME        (~((unsigned long)BSD_PAGE_MASK)
@@ -132,6 +134,13 @@
 static unsigned long            cr3[MAX_VIRT_CPUS];
 static vcpu_guest_context_t ctxt[MAX_VIRT_CPUS];
 
+static inline int paging_enabled(vcpu_guest_context_t *v)
+{
+    unsigned long cr0 = v->cr0;
+
+    return (cr0 & X86_CR0_PE) && (cr0 & X86_CR0_PG);
+}
+
 /* --------------------- */
 
 static void *
@@ -179,7 +188,7 @@
     } 
     if ((pde = cr3_virt[cpu][vtopdi(va)]) == 0) /* logical address */
        goto error_out;
-    if (ctxt[cpu].flags & VGCF_VMX_GUEST)
+    if ((ctxt[cpu].flags & VGCF_VMX_GUEST) && paging_enabled(&ctxt[cpu]))
         pde = page_array[pde >> PAGE_SHIFT] << PAGE_SHIFT;
     if (pde != pde_phys[cpu]) 
     {
--- a/xen/arch/x86/dom0_ops.c   Thu Jun 16 22:46:01 2005
+++ b/xen/arch/x86/dom0_ops.c   Thu Jun 16 23:49:22 2005
@@ -393,8 +393,11 @@
 
 #ifdef __i386__
 #ifdef CONFIG_VMX
-    if ( VMX_DOMAIN(v) )
+    if ( VMX_DOMAIN(v) ) {
         save_vmx_cpu_user_regs(&c->user_regs);
+        __vmread(CR0_READ_SHADOW, &c->cr0);
+        __vmread(CR4_READ_SHADOW, &c->cr4);
+    }
 #endif
 #endif
 

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