[PATCH] KVM: IA64: Using CFLAGS_vcpu.o to compile vcpu.c

[PATCH] KVM: IA64: Using CFLAGS_vcpu.o to compile vcpu.c

[Zhang, Xiantao]

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Hi, Avi 
	Please apply the patch and queue it as 2.6.28 fix. Thanks!
Xiantao

>From d759572033e1bf0e4ca6b7d8f7be8e8387fb4bbb Mon Sep 17 00:00:00 2001
From: Xiantao Zhang <xiantao.zhang@intel.com>
Date: Thu, 20 Nov 2008 10:35:35 +0800
Subject: [PATCH] KVM: IA64: Using CFLAGS_vcpu.o to compile vcpu.c

EXTRA_CFLAGS doesn't work for this case.
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
---
 arch/ia64/kvm/Makefile |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/ia64/kvm/Makefile b/arch/ia64/kvm/Makefile
index 3ab4d6d..92cef66 100644
--- a/arch/ia64/kvm/Makefile
+++ b/arch/ia64/kvm/Makefile
@@ -58,7 +58,7 @@ endif
 kvm-objs := $(common-objs) kvm-ia64.o kvm_fw.o
 obj-$(CONFIG_KVM) += kvm.o
 
-EXTRA_CFLAGS_vcpu.o += -mfixed-range=f2-f5,f12-f127
+CFLAGS_vcpu.o += -mfixed-range=f2-f5,f12-f127
 kvm-intel-objs = vmm.o vmm_ivt.o trampoline.o vcpu.o optvfault.o mmio.o \
 	vtlb.o process.o
 #Add link memcpy and memset to avoid possible structure assignment error
-- 
1.6.0

[-- Attachment #2: 0001-KVM-IA64-Using-CFLAGS_vcpu.o-to-compile-vcpu.c.patch --]
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From d759572033e1bf0e4ca6b7d8f7be8e8387fb4bbb Mon Sep 17 00:00:00 2001
From: Xiantao Zhang <xiantao.zhang@intel.com>
Date: Thu, 20 Nov 2008 10:35:35 +0800
Subject: [PATCH] KVM: IA64: Using CFLAGS_vcpu.o to compile vcpu.c

EXTRA_CFLAGS doesn't work for this case.
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
---
 arch/ia64/kvm/Makefile |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/ia64/kvm/Makefile b/arch/ia64/kvm/Makefile
index 3ab4d6d..92cef66 100644
--- a/arch/ia64/kvm/Makefile
+++ b/arch/ia64/kvm/Makefile
@@ -58,7 +58,7 @@ endif
 kvm-objs := $(common-objs) kvm-ia64.o kvm_fw.o
 obj-$(CONFIG_KVM) += kvm.o
 
-EXTRA_CFLAGS_vcpu.o += -mfixed-range=f2-f5,f12-f127
+CFLAGS_vcpu.o += -mfixed-range=f2-f5,f12-f127
 kvm-intel-objs = vmm.o vmm_ivt.o trampoline.o vcpu.o optvfault.o mmio.o \
 	vtlb.o process.o
 #Add link memcpy and memset to avoid possible structure assignment error
-- 
1.6.0

Re: [PATCH] KVM: IA64: Using CFLAGS_vcpu.o to compile vcpu.c

[Avi Kivity]

Zhang, Xiantao wrote:
> Hi, Avi 
> 	Please apply the patch and queue it as 2.6.28 fix. Thanks!
> Xiantao
>
> From d759572033e1bf0e4ca6b7d8f7be8e8387fb4bbb Mon Sep 17 00:00:00 2001
> From: Xiantao Zhang <xiantao.zhang@intel.com>
> Date: Thu, 20 Nov 2008 10:35:35 +0800
> Subject: [PATCH] KVM: IA64: Using CFLAGS_vcpu.o to compile vcpu.c
>
> EXTRA_CFLAGS doesn't work for this case.
>   

Can you provide more information on how this was only discovered now?  
Was there a change in mainline that removed support for EXTRA_CFLAGS?


-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

RE: [PATCH] KVM: IA64: Using CFLAGS_vcpu.o to compile vcpu.c

[Zhang, Xiantao]

Avi Kivity wrote:
> Zhang, Xiantao wrote:
>> Hi, Avi
>> 	Please apply the patch and queue it as 2.6.28 fix. Thanks!
>> Xiantao
>> 
>> From d759572033e1bf0e4ca6b7d8f7be8e8387fb4bbb Mon Sep 17 00:00:00
>> 2001 From: Xiantao Zhang <xiantao.zhang@intel.com>
>> Date: Thu, 20 Nov 2008 10:35:35 +0800
>> Subject: [PATCH] KVM: IA64: Using CFLAGS_vcpu.o to compile vcpu.c
>> 
>> EXTRA_CFLAGS doesn't work for this case.
>> 
> 
> Can you provide more information on how this was only discovered now?
> Was there a change in mainline that removed support for EXTRA_CFLAGS?]
It should be an old issue we didn't sense before.  To specify single object's compile option, only CFLAGS can work in this case. 
Xiantao

Re: [PATCH] KVM: IA64: Using CFLAGS_vcpu.o to compile vcpu.c

[Avi Kivity]

Zhang, Xiantao wrote:
>> Can you provide more information on how this was only discovered now?
>> Was there a change in mainline that removed support for EXTRA_CFLAGS?]
>>     
> It should be an old issue we didn't sense before.  To specify single object's compile option, only CFLAGS can work in this case. 

How did we not notice the issue?  What is the effect of the missing flags?

It seems like a critical problem that should prevent kvm from working at 
all, so I don't understand how it was discovered so late.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

RE: [PATCH] KVM: IA64: Using CFLAGS_vcpu.o to compile vcpu.c

[Zhang, Xiantao]

[-- Attachment #1: Type: text/plain, Size: 1947 bytes --]

Avi Kivity wrote:
> Zhang, Xiantao wrote:
>>> Can you provide more information on how this was only discovered
>>> now? Was there a change in mainline that removed support for
>>> EXTRA_CFLAGS?] 
>>> 
>> It should be an old issue we didn't sense before.  To specify single
>> object's compile option, only CFLAGS can work in this case. 
> 
> How did we not notice the issue?  What is the effect of the missing
> flags? 
> It seems like a critical problem that should prevent kvm from working
> at all, so I don't understand how it was discovered so late.

Once missing this flags, compiler can touch the fixed registers and leads to faults. But fortunately,current gcc didn't use them for optimizations, so we didn't find it before. But anyway it should be a potential issue. 
Updated one, remove kernel's default range. 

>From 451ce36037cb1075c572de42d9ad9c4c7ee863e4 Mon Sep 17 00:00:00 2001
From: Xiantao Zhang <xiantao.zhang@intel.com>
Date: Thu, 20 Nov 2008 19:49:00 +0800
Subject: [PATCH] KVM: ia64: Fix: Use CFLAGS_vcpu.o to compile vcpu.c

EXTRA_CFLAGS doesn't work for this case.Without this flag,
it may result in compiler touch fixed registers.

Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
---
 arch/ia64/kvm/Makefile |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/ia64/kvm/Makefile b/arch/ia64/kvm/Makefile
index 3ab4d6d..603e53c 100644
--- a/arch/ia64/kvm/Makefile
+++ b/arch/ia64/kvm/Makefile
@@ -58,7 +58,8 @@ endif
 kvm-objs := $(common-objs) kvm-ia64.o kvm_fw.o
 obj-$(CONFIG_KVM) += kvm.o
 
-EXTRA_CFLAGS_vcpu.o += -mfixed-range=f2-f5,f12-f127
+CFLAGS_REMOVE_vcpu.o += -mfixed-range=f12-f15,f32-f127
+CFLAGS_vcpu.o += -mfixed-range=f2-f5,f12-f127
 kvm-intel-objs = vmm.o vmm_ivt.o trampoline.o vcpu.o optvfault.o mmio.o \
 	vtlb.o process.o
 #Add link memcpy and memset to avoid possible structure assignment error
-- 
1.6.0


Xiantao

[-- Attachment #2: 0001-KVM-ia64-Fix-Use-CFLAGS_vcpu.o-to-compile-vcpu.c.patch --]
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From 451ce36037cb1075c572de42d9ad9c4c7ee863e4 Mon Sep 17 00:00:00 2001
From: Xiantao Zhang <xiantao.zhang@intel.com>
Date: Thu, 20 Nov 2008 19:49:00 +0800
Subject: [PATCH] KVM: ia64: Fix: Use CFLAGS_vcpu.o to compile vcpu.c

EXTRA_CFLAGS doesn't work for this case.Without this flag,
it may result in compiler touch fixed registers.

Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
---
 arch/ia64/kvm/Makefile |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/ia64/kvm/Makefile b/arch/ia64/kvm/Makefile
index 3ab4d6d..603e53c 100644
--- a/arch/ia64/kvm/Makefile
+++ b/arch/ia64/kvm/Makefile
@@ -58,7 +58,8 @@ endif
 kvm-objs := $(common-objs) kvm-ia64.o kvm_fw.o
 obj-$(CONFIG_KVM) += kvm.o
 
-EXTRA_CFLAGS_vcpu.o += -mfixed-range=f2-f5,f12-f127
+CFLAGS_REMOVE_vcpu.o += -mfixed-range=f12-f15,f32-f127
+CFLAGS_vcpu.o += -mfixed-range=f2-f5,f12-f127
 kvm-intel-objs = vmm.o vmm_ivt.o trampoline.o vcpu.o optvfault.o mmio.o \
 	vtlb.o process.o
 #Add link memcpy and memset to avoid possible structure assignment error
-- 
1.6.0

Re: [PATCH] KVM: IA64: Using CFLAGS_vcpu.o to compile vcpu.c

[Avi Kivity]

Zhang, Xiantao wrote:
> Avi Kivity wrote:
>   
>> Zhang, Xiantao wrote:
>>     
>>>> Can you provide more information on how this was only discovered
>>>> now? Was there a change in mainline that removed support for
>>>> EXTRA_CFLAGS?] 
>>>>
>>>>         
>>> It should be an old issue we didn't sense before.  To specify single
>>> object's compile option, only CFLAGS can work in this case. 
>>>       
>> How did we not notice the issue?  What is the effect of the missing
>> flags? 
>> It seems like a critical problem that should prevent kvm from working
>> at all, so I don't understand how it was discovered so late.
>>     
>
> Once missing this flags, compiler can touch the fixed registers and leads to faults. But fortunately,current gcc didn't use them for optimizations, so we didn't find it before. But anyway it should be a potential issue. 
> Updated one, remove kernel's default range. 
>
>   

Okay, so it worked by accident?

> Subject: [PATCH] KVM: ia64: Fix: Use CFLAGS_vcpu.o to compile vcpu.c
>
> EXTRA_CFLAGS doesn't work for this case.Without this flag,
> it may result in compiler touch fixed registers.
>   

Applied, thanks.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

RE: [PATCH] KVM: IA64: Using CFLAGS_vcpu.o to compile vcpu.c

[Zhang, Xiantao]

Avi Kivity wrote:
> Zhang, Xiantao wrote:
>> Avi Kivity wrote:
>> 
>>> Zhang, Xiantao wrote:
>>> 
>>>>> Can you provide more information on how this was only discovered
>>>>> now? Was there a change in mainline that removed support for
>>>>> EXTRA_CFLAGS?] 
>>>>> 
>>>>> 
>>>> It should be an old issue we didn't sense before.  To specify
>>>> single object's compile option, only CFLAGS can work in this case.
>>>> 
>>> How did we not notice the issue?  What is the effect of the missing
>>> flags? It seems like a critical problem that should prevent kvm
>>> from working at all, so I don't understand how it was discovered so
>>> late. 
>>> 
>> 
>> Once missing this flags, compiler can touch the fixed registers and
>> leads to faults. But fortunately,current gcc didn't use them for
>> optimizations, so we didn't find it before. But anyway it should be
>> a potential issue. Updated one, remove kernel's default range.  
>> 
>> 
> 
> Okay, so it worked by accident?

At least we didn't meet explict issue was caused by it. But anyway, it may bite us with the changes of compiler or compiler's configuration.  

>> Subject: [PATCH] KVM: ia64: Fix: Use CFLAGS_vcpu.o to compile vcpu.c
>> 
>> EXTRA_CFLAGS doesn't work for this case.Without this flag,
>> it may result in compiler touch fixed registers.
>> 
> 
> Applied, thanks.