Patchwork target-i386: honor CR0_PG_MASK in cpu_get_phys_page_debug

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Submitter Max Filippov
Date Nov. 17, 2012, 8:52 p.m.
Message ID <1353185531-17042-1-git-send-email-jcmvbkbc@gmail.com>
Download mbox | patch
Permalink /patch/199873/
State New
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Comments

Max Filippov - Nov. 17, 2012, 8:52 p.m.
cpu_get_phys_page_debug is not in sync with cpu_x86_handle_mmu_fault:
the latter first checks CR0_PG_MASK and only after CR4_PAE_MASK.

This fixes odd gdb code display with PAE enabled.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 target-i386/helper.c |   37 ++++++++++++++++++++-----------------
 1 files changed, 20 insertions(+), 17 deletions(-)
Max Filippov - Dec. 4, 2012, 7:36 p.m.
On Sun, Nov 18, 2012 at 12:52 AM, Max Filippov <jcmvbkbc@gmail.com> wrote:
> cpu_get_phys_page_debug is not in sync with cpu_x86_handle_mmu_fault:
> the latter first checks CR0_PG_MASK and only after CR4_PAE_MASK.
>
> This fixes odd gdb code display with PAE enabled.
>
> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
> ---
>  target-i386/helper.c |   37 ++++++++++++++++++++-----------------
>  1 files changed, 20 insertions(+), 17 deletions(-)

Ping?
Andreas Färber - Dec. 5, 2012, 11:15 a.m.
Am 17.11.2012 21:52, schrieb Max Filippov:
> cpu_get_phys_page_debug is not in sync with cpu_x86_handle_mmu_fault:
> the latter first checks CR0_PG_MASK and only after CR4_PAE_MASK.
> 
> This fixes odd gdb code display with PAE enabled.
> 
> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

You write, they are "not in sync". Would it be possible to share code to
assure this, e.g., by calling a helper function from both?

Regards,
Andreas
Max Filippov - Dec. 5, 2012, 11:36 a.m.
On Wed, Dec 5, 2012 at 3:15 PM, Andreas Färber <afaerber@suse.de> wrote:
> Am 17.11.2012 21:52, schrieb Max Filippov:
>> cpu_get_phys_page_debug is not in sync with cpu_x86_handle_mmu_fault:
>> the latter first checks CR0_PG_MASK and only after CR4_PAE_MASK.
>>
>> This fixes odd gdb code display with PAE enabled.
>>
>> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
>
> You write, they are "not in sync". Would it be possible to share code to
> assure this, e.g., by calling a helper function from both?

I'd say yes though that'd be a bigger change. I'll try to do it.

Patch

diff --git a/target-i386/helper.c b/target-i386/helper.c
index bf206cf..7f5e8e3 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -877,7 +877,11 @@  hwaddr cpu_get_phys_page_debug(CPUX86State *env, target_ulong addr)
     uint32_t page_offset;
     int page_size;
 
-    if (env->cr[4] & CR4_PAE_MASK) {
+    if (!(env->cr[0] & CR0_PG_MASK)) {
+        pte = addr;
+        page_size = 4096;
+        pte = pte & env->a20_mask;
+    } else if (env->cr[4] & CR4_PAE_MASK) {
         target_ulong pdpe_addr;
         uint64_t pde, pdpe;
 
@@ -935,26 +939,25 @@  hwaddr cpu_get_phys_page_debug(CPUX86State *env, target_ulong addr)
     } else {
         uint32_t pde;
 
-        if (!(env->cr[0] & CR0_PG_MASK)) {
-            pte = addr;
-            page_size = 4096;
+        /* page directory entry */
+        pde_addr = ((env->cr[3] & ~0xfff) + ((addr >> 20) & 0xffc)) &
+                env->a20_mask;
+        pde = ldl_phys(pde_addr);
+        if (!(pde & PG_PRESENT_MASK)) {
+            return -1;
+        }
+        if ((pde & PG_PSE_MASK) && (env->cr[4] & CR4_PSE_MASK)) {
+            pte = pde & ~0x003ff000; /* align to 4MB */
+            page_size = 4096 * 1024;
         } else {
             /* page directory entry */
-            pde_addr = ((env->cr[3] & ~0xfff) + ((addr >> 20) & 0xffc)) & env->a20_mask;
-            pde = ldl_phys(pde_addr);
-            if (!(pde & PG_PRESENT_MASK))
+            pte_addr = ((pde & ~0xfff) + ((addr >> 10) & 0xffc)) &
+                    env->a20_mask;
+            pte = ldl_phys(pte_addr);
+            if (!(pte & PG_PRESENT_MASK)) {
                 return -1;
-            if ((pde & PG_PSE_MASK) && (env->cr[4] & CR4_PSE_MASK)) {
-                pte = pde & ~0x003ff000; /* align to 4MB */
-                page_size = 4096 * 1024;
-            } else {
-                /* page directory entry */
-                pte_addr = ((pde & ~0xfff) + ((addr >> 10) & 0xffc)) & env->a20_mask;
-                pte = ldl_phys(pte_addr);
-                if (!(pte & PG_PRESENT_MASK))
-                    return -1;
-                page_size = 4096;
             }
+            page_size = 4096;
         }
         pte = pte & env->a20_mask;
     }