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[Qemu-devel] Re: [RESEND #3][PATCH] i386: Catch all non-present ptes in
From: |
Jan Kiszka |
Subject: |
[Qemu-devel] Re: [RESEND #3][PATCH] i386: Catch all non-present ptes in cpu_get_phys_page_debug |
Date: |
Mon, 18 Aug 2008 17:50:08 +0200 |
User-agent: |
Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 |
Anthony Liguori wrote:
> Jan Kiszka wrote:
>> It helps debugging guests when yet unmapped pages are correctly reported
>> as, well, unmapped.
>>
>> Signed-off-by: Jan Kiszka <address@hidden>
>> ---
>> target-i386/helper.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> Index: b/target-i386/helper.c
>> ===================================================================
>> --- a/target-i386/helper.c
>> +++ b/target-i386/helper.c
>> @@ -1192,6 +1192,8 @@ target_phys_addr_t cpu_get_phys_page_deb
>> page_size = 4096;
>> pte = ldq_phys(pte_addr);
>> }
>> + if (!(pte & PG_PRESENT_MASK))
>> + return -1;
>> } else {
>> uint32_t pde;
>>
>> @@ -1211,10 +1213,10 @@ target_phys_addr_t cpu_get_phys_page_deb
>> /* 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;
>> }
>> + if (!(pte & PG_PRESENT_MASK))
>> + return -1;
>> }
>>
>
> This looks redundant. In the PSE=1 case, the check for pde &
> PG_PRESENT_MASK takes care of it. In the PSE=0 clause, there is already
> a check for pte & PG_PRESENT_MASK.
True.
>
> The first chunk looks like a genuine fix though.
Here is the stripped-down version:
-----------
It helps debugging guests when yet unmapped pages are correctly reported
as, well, unmapped.
Signed-off-by: Jan Kiszka <address@hidden>
---
target-i386/helper.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
Index: b/target-i386/helper.c
===================================================================
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -1192,6 +1192,8 @@ target_phys_addr_t cpu_get_phys_page_deb
page_size = 4096;
pte = ldq_phys(pte_addr);
}
+ if (!(pte & PG_PRESENT_MASK))
+ return -1;
} else {
uint32_t pde;