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[PATCH] gdbstub: Update x86 control register bits

Mathias Krause posted 1 patch 5 days, 23 hours ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20260327143413.254227-1-minipli@grsecurity.net
gdbstub/gdb-xml/i386-32bit.xml | 47 +++++++++++++++++++---------------
gdbstub/gdb-xml/i386-64bit.xml |  7 +++++
2 files changed, 34 insertions(+), 20 deletions(-)
[PATCH] gdbstub: Update x86 control register bits
Posted by Mathias Krause 5 days, 23 hours ago 
The control register bits haven't been updated in a few years, making
them lack behind features QEMU ganied in these years.

Update them to the current version of the SDM and sort the 32bit version
to be in line with all the other definitions (descending order).

This should remove confusion when debugging, for example, CET-enabled
guests:

- before the change:
  (gdb) info registers cr4
  cr4            0x8000f0            [ PGE MCE PAE PSE ]

- after the change:
  (gdb) info registers cr4
  cr4            0x8000f0            [ CET PGE MCE PAE PSE ]

Signed-off-by: Mathias Krause <minipli@grsecurity.net>
---
 gdbstub/gdb-xml/i386-32bit.xml | 47 +++++++++++++++++++---------------
 gdbstub/gdb-xml/i386-64bit.xml |  7 +++++
 2 files changed, 34 insertions(+), 20 deletions(-)

diff --git a/gdbstub/gdb-xml/i386-32bit.xml b/gdbstub/gdb-xml/i386-32bit.xml
index 7a66a02b67e3..1dec40e1d2c1 100644
--- a/gdbstub/gdb-xml/i386-32bit.xml
+++ b/gdbstub/gdb-xml/i386-32bit.xml
@@ -87,27 +87,34 @@
   </flags>
 
   <flags id="i386_cr4" size="4">
-	<field name="VME" start="0" end="0"/>
-	<field name="PVI" start="1" end="1"/>
-	<field name="TSD" start="2" end="2"/>
-	<field name="DE" start="3" end="3"/>
-	<field name="PSE" start="4" end="4"/>
-	<field name="PAE" start="5" end="5"/>
-	<field name="MCE" start="6" end="6"/>
-	<field name="PGE" start="7" end="7"/>
-	<field name="PCE" start="8" end="8"/>
-	<field name="OSFXSR" start="9" end="9"/>
-	<field name="OSXMMEXCPT" start="10" end="10"/>
-	<field name="UMIP" start="11" end="11"/>
-	<field name="LA57" start="12" end="12"/>
-	<field name="VMXE" start="13" end="13"/>
-	<field name="SMXE" start="14" end="14"/>
-	<field name="FSGSBASE" start="16" end="16"/>
-	<field name="PCIDE" start="17" end="17"/>
-	<field name="OSXSAVE" start="18" end="18"/>
-	<field name="SMEP" start="20" end="20"/>
+	<field name="LAM_SUP" start="28" end="28"/>
+	<field name="LASS" start="27" end="27"/>
+	<field name="UINTR" start="25" end="25"/>
+	<field name="PKS" start="24" end="24"/>
+	<field name="CET" start="23" end="23"/>
+	<field name="PKE" start="22" end="22"/>
+	<field name="PKE" start="22" end="22"/>
 	<field name="SMAP" start="21" end="21"/>
-	<field name="PKE" start="22" end="22"/>
+	<field name="SMEP" start="20" end="20"/>
+	<field name="KL" start="19" end="19"/>
+	<field name="OSXSAVE" start="18" end="18"/>
+	<field name="PCIDE" start="17" end="17"/>
+	<field name="FSGSBASE" start="16" end="16"/>
+	<field name="SMXE" start="14" end="14"/>
+	<field name="VMXE" start="13" end="13"/>
+	<field name="LA57" start="12" end="12"/>
+	<field name="UMIP" start="11" end="11"/>
+	<field name="OSXMMEXCPT" start="10" end="10"/>
+	<field name="OSFXSR" start="9" end="9"/>
+	<field name="PCE" start="8" end="8"/>
+	<field name="PGE" start="7" end="7"/>
+	<field name="MCE" start="6" end="6"/>
+	<field name="PAE" start="5" end="5"/>
+	<field name="PSE" start="4" end="4"/>
+	<field name="DE" start="3" end="3"/>
+	<field name="TSD" start="2" end="2"/>
+	<field name="PVI" start="1" end="1"/>
+	<field name="VME" start="0" end="0"/>
   </flags>
 
   <flags id="i386_efer" size="4">
diff --git a/gdbstub/gdb-xml/i386-64bit.xml b/gdbstub/gdb-xml/i386-64bit.xml
index 6d889692114d..9ac9164e6a99 100644
--- a/gdbstub/gdb-xml/i386-64bit.xml
+++ b/gdbstub/gdb-xml/i386-64bit.xml
@@ -102,9 +102,16 @@
   </flags>
 
   <flags id="x64_cr4" size="8">
+	<field name="FRED" start="32" end="32"/>
+	<field name="LAM_SUP" start="28" end="28"/>
+	<field name="LASS" start="27" end="27"/>
+	<field name="UINTR" start="25" end="25"/>
+	<field name="PKS" start="24" end="24"/>
+	<field name="CET" start="23" end="23"/>
 	<field name="PKE" start="22" end="22"/>
 	<field name="SMAP" start="21" end="21"/>
 	<field name="SMEP" start="20" end="20"/>
+	<field name="KL" start="19" end="19"/>
 	<field name="OSXSAVE" start="18" end="18"/>
 	<field name="PCIDE" start="17" end="17"/>
 	<field name="FSGSBASE" start="16" end="16"/>
-- 
2.53.0
Re: [PATCH] gdbstub: Update x86 control register bits
Posted by Paolo Bonzini 5 days, 20 hours ago 
Queued, thanks.

Paolo
Re: [PATCH] gdbstub: Update x86 control register bits
Posted by Alex Bennée 5 days, 22 hours ago 
Mathias Krause <minipli@grsecurity.net> writes:

> The control register bits haven't been updated in a few years, making
> them lack behind features QEMU ganied in these years.
>
> Update them to the current version of the SDM and sort the 32bit version
> to be in line with all the other definitions (descending order).

Do these changes come from the gdb upstream (which is where all the XML
originally comes from).

>
> This should remove confusion when debugging, for example, CET-enabled
> guests:
>
> - before the change:
>   (gdb) info registers cr4
>   cr4            0x8000f0            [ PGE MCE PAE PSE ]
>
> - after the change:
>   (gdb) info registers cr4
>   cr4            0x8000f0            [ CET PGE MCE PAE PSE ]
>
> Signed-off-by: Mathias Krause <minipli@grsecurity.net>
> ---
>  gdbstub/gdb-xml/i386-32bit.xml | 47 +++++++++++++++++++---------------
>  gdbstub/gdb-xml/i386-64bit.xml |  7 +++++
>  2 files changed, 34 insertions(+), 20 deletions(-)
>
> diff --git a/gdbstub/gdb-xml/i386-32bit.xml b/gdbstub/gdb-xml/i386-32bit.xml
> index 7a66a02b67e3..1dec40e1d2c1 100644
> --- a/gdbstub/gdb-xml/i386-32bit.xml
> +++ b/gdbstub/gdb-xml/i386-32bit.xml
> @@ -87,27 +87,34 @@
>    </flags>
>  
>    <flags id="i386_cr4" size="4">
> -	<field name="VME" start="0" end="0"/>
> -	<field name="PVI" start="1" end="1"/>
> -	<field name="TSD" start="2" end="2"/>
> -	<field name="DE" start="3" end="3"/>
> -	<field name="PSE" start="4" end="4"/>
> -	<field name="PAE" start="5" end="5"/>
> -	<field name="MCE" start="6" end="6"/>
> -	<field name="PGE" start="7" end="7"/>
> -	<field name="PCE" start="8" end="8"/>
> -	<field name="OSFXSR" start="9" end="9"/>
> -	<field name="OSXMMEXCPT" start="10" end="10"/>
> -	<field name="UMIP" start="11" end="11"/>
> -	<field name="LA57" start="12" end="12"/>
> -	<field name="VMXE" start="13" end="13"/>
> -	<field name="SMXE" start="14" end="14"/>
> -	<field name="FSGSBASE" start="16" end="16"/>
> -	<field name="PCIDE" start="17" end="17"/>
> -	<field name="OSXSAVE" start="18" end="18"/>
> -	<field name="SMEP" start="20" end="20"/>
> +	<field name="LAM_SUP" start="28" end="28"/>
> +	<field name="LASS" start="27" end="27"/>
> +	<field name="UINTR" start="25" end="25"/>
> +	<field name="PKS" start="24" end="24"/>
> +	<field name="CET" start="23" end="23"/>
> +	<field name="PKE" start="22" end="22"/>
> +	<field name="PKE" start="22" end="22"/>
>  	<field name="SMAP" start="21" end="21"/>
> -	<field name="PKE" start="22" end="22"/>
> +	<field name="SMEP" start="20" end="20"/>
> +	<field name="KL" start="19" end="19"/>
> +	<field name="OSXSAVE" start="18" end="18"/>
> +	<field name="PCIDE" start="17" end="17"/>
> +	<field name="FSGSBASE" start="16" end="16"/>
> +	<field name="SMXE" start="14" end="14"/>
> +	<field name="VMXE" start="13" end="13"/>
> +	<field name="LA57" start="12" end="12"/>
> +	<field name="UMIP" start="11" end="11"/>
> +	<field name="OSXMMEXCPT" start="10" end="10"/>
> +	<field name="OSFXSR" start="9" end="9"/>
> +	<field name="PCE" start="8" end="8"/>
> +	<field name="PGE" start="7" end="7"/>
> +	<field name="MCE" start="6" end="6"/>
> +	<field name="PAE" start="5" end="5"/>
> +	<field name="PSE" start="4" end="4"/>
> +	<field name="DE" start="3" end="3"/>
> +	<field name="TSD" start="2" end="2"/>
> +	<field name="PVI" start="1" end="1"/>
> +	<field name="VME" start="0" end="0"/>
>    </flags>
>  
>    <flags id="i386_efer" size="4">
> diff --git a/gdbstub/gdb-xml/i386-64bit.xml b/gdbstub/gdb-xml/i386-64bit.xml
> index 6d889692114d..9ac9164e6a99 100644
> --- a/gdbstub/gdb-xml/i386-64bit.xml
> +++ b/gdbstub/gdb-xml/i386-64bit.xml
> @@ -102,9 +102,16 @@
>    </flags>
>  
>    <flags id="x64_cr4" size="8">
> +	<field name="FRED" start="32" end="32"/>
> +	<field name="LAM_SUP" start="28" end="28"/>
> +	<field name="LASS" start="27" end="27"/>
> +	<field name="UINTR" start="25" end="25"/>
> +	<field name="PKS" start="24" end="24"/>
> +	<field name="CET" start="23" end="23"/>
>  	<field name="PKE" start="22" end="22"/>
>  	<field name="SMAP" start="21" end="21"/>
>  	<field name="SMEP" start="20" end="20"/>
> +	<field name="KL" start="19" end="19"/>
>  	<field name="OSXSAVE" start="18" end="18"/>
>  	<field name="PCIDE" start="17" end="17"/>
>  	<field name="FSGSBASE" start="16" end="16"/>

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro
Re: [PATCH] gdbstub: Update x86 control register bits
Posted by Mathias Krause 5 days, 21 hours ago 
On 27.03.26 17:06, Alex Bennée wrote:
> Mathias Krause <minipli@grsecurity.net> writes:
> 
>> The control register bits haven't been updated in a few years, making
>> them lack behind features QEMU ganied in these years.
>>
>> Update them to the current version of the SDM and sort the 32bit version
>> to be in line with all the other definitions (descending order).
> 
> Do these changes come from the gdb upstream (which is where all the XML
> originally comes from).

The upstream version has no control register coverage, that's QEMU
specific and came with 7b0f97bade8a ("gdbstub: Fix i386/x86_64 machine
description and add control registers").

Thanks,
Mathias

Patchew 2.1-devel-ea86937

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