Make KVM compile on split source/object kernel configurations

KVM as is assumes that the kernel obj dir and the kernel source dir are at the same location. This is true for most self-built vanilla kernels, but some distributions split these up (e.g. SUSE). To keep compatible and have users have a good experience on building KVM on any distribution, this patch attempts to rebuild the logic from the kernel Makefile as closely as possible. With it I successfully built KVM on a current SUSE system.

Signed-off-by Alexander Graf <[email protected]>

Please check and see if it breaks the build process for anyone else. Building with IA64 on SUSE-kernels is still broken due to similar but separate problems.

Quoted 10 lines · Alexander Graf

KVM as is assumes that the kernel obj dir and the kernel source dir are at the same location. This is true for most self-built vanilla kernels, but some distributions split these up (e.g. SUSE). To keep compatible and have users have a good experience on building KVM on any distribution, this patch attempts to rebuild the logic from the kernel Makefile as closely as possible. With it I successfully built KVM on a current SUSE system.

Signed-off-by Alexander Graf <[email protected]>

Quoted 3 lines

Please check and see if it breaks the build process for anyone else. Building with IA64 on SUSE-kernels is still broken due to similar but separate problems.

Hi, Graf
what problems did you meet when building kvm/ia64 ?
Xiantao

Quoted 11 lines · Xiantao

Quoted 10 lines · Alexander Graf

KVM as is assumes that the kernel obj dir and the kernel source dir are at the same location. This is true for most self-built vanilla kernels, but some distributions split these up (e.g. SUSE). To keep compatible and have users have a good experience on building KVM on any distribution, this patch attempts to rebuild the logic from the kernel Makefile as closely as possible. With it I successfully built KVM on a current SUSE system.

Signed-off-by Alexander Graf <[email protected]>

Quoted 7 lines

Quoted 3 lines

Please check and see if it breaks the build process for anyone else. Building with IA64 on SUSE-kernels is still broken due to similar but separate problems.

Hi, Graf
what problems did you meet when building kvm/ia64 ?
Xiantao

This is the list of stuff I had to modify to get kvm-74 to run. I haven't tried anything more recent yet.

1) -mno-sdata does not work. Qemu CFLAGS need to be -msdata

2) In qemu/ia64.ld SEARCH_DIR is invalid for SUSE. It shouldn't search in /usr/ia64-linux but in /usr/ia64-suse-linux.

3) TARGET_PAGE_BITS is wrong

4) kernel/ia64/Makefile.pre assumes to find .S files in $KERNELDIR. They are in $SOURCEDIR.

5) kernel/ia64/Makefile.pre suffers from the same problem my original fix for x86 addressed.

6) The IA64 kernel build system is broken. The file asm-ia64/nr-irqs.h gets generated during the kernel build, but is not exported as obj, so it won't be in the split obj directory. Since the source-dir is clean though, the file simply does not exist on SUSE rpms.

I will attach the patch I use in our local buildsystem to make KVM compile on IA64. Please do not take this as fixes, most of them are simple workarounds and should rather be fixed properly. We were just hitting deadlines internally.

Alex

Quoted 24 lines · Alexander Graf

Quoted 20 lines · Xiantao

Quoted 9 lines · Alexander Graf

KVM as is assumes that the kernel obj dir and the kernel source dir are at the same location. This is true for most self-built vanilla kernels, but some distributions split these up (e.g. SUSE). To keep compatible and have users have a good experience on building
KVM on any distribution, this patch attempts to rebuild the logic from the kernel Makefile as closely as possible. With it I successfully built KVM on a current SUSE system.

Quoted 6 lines

Signed-off-by Alexander Graf <[email protected]>

Please check and see if it breaks the build process for anyone else.
Building with IA64 on SUSE-kernels is still broken due to similar but separate problems.

Hi, Graf
what problems did you meet when building kvm/ia64 ?
Xiantao

Quoted 4 lines

This is the list of stuff I had to modify to get kvm-74 to run. I haven't tried anything more recent yet.

1) -mno-sdata does not work. Qemu CFLAGS need to be -msdata

Which version of GCC are you using ?

Quoted 5 lines

2) In qemu/ia64.ld SEARCH_DIR is invalid for SUSE. It shouldn't search
in /usr/ia64-linux but in /usr/ia64-suse-linux.

You can make a patch to fix it.

Quoted 1 line

3) TARGET_PAGE_BITS is wrong

Currently, we just set TARGET_PAGE_BITS to 16 by hardcoding in Qemu. In
the future, we should add the logic to make it equal to kernel's PAGE_SHIFT.

Quoted 2 lines

4) kernel/ia64/Makefile.pre assumes to find .S files in $KERNELDIR. They are in $SOURCEDIR.

There is no issue here, I think. You have to set corrent $KERNELDIR through ./configure --kerneldir=xxxx once target machine and build machine is not same.

Quoted 2 lines

5) kernel/ia64/Makefile.pre suffers from the same problem my original fix for x86 addressed.

Ditto.

Quoted 6 lines

6) The IA64 kernel build system is broken. The file asm-ia64/nr- irqs.h
gets generated during the kernel build, but is not exported as obj, so
it won't be in the split obj directory. Since the source-dir is clean though, the file simply does not exist on SUSE rpms.

You mean the source-dir is clean ? So the generated header files including (linux/autoconf.h, asm-offsets.h...)should be removed wholely?
I don't think they can be built with a clean source for most modules.

Quoted 24 lines · Xiantao

Quoted 23 lines · Alexander Graf

Quoted 19 lines · Xiantao

Quoted 9 lines · Alexander Graf

KVM as is assumes that the kernel obj dir and the kernel source dir are at the same location. This is true for most self-built vanilla kernels, but some distributions split these up (e.g. SUSE).
To keep compatible and have users have a good experience on building KVM on any distribution, this patch attempts to rebuild the logic from the kernel Makefile as closely as possible. With it I successfully built KVM on a current SUSE system.

Quoted 5 lines

Signed-off-by Alexander Graf <[email protected]>

Please check and see if it breaks the build process for anyone else. Building with IA64 on SUSE-kernels is still broken due to similar but separate problems.

Hi, Graf
what problems did you meet when building kvm/ia64 ?
Xiantao

Quoted 6 lines

Quoted 4 lines

This is the list of stuff I had to modify to get kvm-74 to run. I haven't tried anything more recent yet.

1) -mno-sdata does not work. Qemu CFLAGS need to be -msdata

Which version of GCC are you using ?

# gcc --version
gcc (SUSE Linux) 4.3.2 20080815 (prerelease) [gcc-4_3-branch revision
139129]

Quoted 5 lines

Quoted 4 lines

2) In qemu/ia64.ld SEARCH_DIR is invalid for SUSE. It shouldn't search in /usr/ia64-linux but in /usr/ia64-suse-linux.

You can make a patch to fix it.

Right, this one should be really easy to fix.

Quoted 4 lines

Quoted 1 line

3) TARGET_PAGE_BITS is wrong

Currently, we just set TARGET_PAGE_BITS to 16 by hardcoding in Qemu. In the future, we should add the logic to make it equal to kernel's PAGE_SHIFT.

From what I read on the KVM IA64 ML, this is not the first time
someone ran into this issue. Sounds like a really good idea to add the logic ;-).

Quoted 6 lines

Quoted 2 lines

4) kernel/ia64/Makefile.pre assumes to find .S files in $KERNELDIR. They are in $SOURCEDIR.

There is no issue here, I think. You have to set corrent $KERNELDIR through ./configure --kerneldir=xxxx once target machine and build machine is not same.

No, since $KERNELDIR is the build dir, as that one contains all the configurations. The source dir only contains the sources.

Quoted 11 lines

Quoted 2 lines

5) kernel/ia64/Makefile.pre suffers from the same problem my original fix for x86 addressed.

Ditto.

Quoted 5 lines

6) The IA64 kernel build system is broken. The file asm-ia64/nr- irqs.h gets generated during the kernel build, but is not exported as obj, so it won't be in the split obj directory. Since the source-dir is clean though, the file simply does not exist on SUSE rpms.

Quoted 4 lines

You mean the source-dir is clean ? So the generated header files including (linux/autoconf.h, asm-offsets.h...)should be removed wholely? I don't think they can be built with a clean source for most modules.

This is what I'm talking about all the time :-). For SUSE kernels there are two distinct directories:

# ls -l /usr/src
drwxr-xr-x 24 root root 4096 Aug 27 14:51 linux-2.6.27-rc4-
HEAD_20080825213702
drwxr-xr-x  3 root root 4096 Aug 25 23:28 linux-2.6.27-rc4-
HEAD_20080825213702-obj

whereas the normal directory contains the sources and the -obj directory contains all files that were generated during the build. Scratch that with the 2 rpm files - they are all in kernel-sources.

# ls -l
/usr/src/linux-2.6.27-rc4-HEAD_20080825213702-obj/ia64/default/ total
568 

(quoted diff) +0 -3

-rw-r--r-- 1 root root  76287 Aug 25 23:27 .config
-rw-r--r-- 2 root root    554 Aug 25 23:28 Makefile
-rw-r--r-- 1 root root 468615 Aug 25 23:51 Module.symvers

drwxr-xr-x 3 root root   4096 Aug 26 18:01 arch
drwxr-xr-x 5 root root   4096 Aug 26 18:01 include
drwxr-xr-x 2 root root   4096 Aug 26 18:01 include2
drwxr-xr-x 2 root root   4096 Aug 25 23:28 kernel
drwxr-xr-x 6 root root   4096 Aug 26 18:01 scripts

The problem is now that a lot of people assume these two directories to be one. This is the default mode when you compile a kernel. SUSE does not take this route though, and hasn't for quite a while now. I don't know about other distributions, but I guess we're not the only ones ;-).

Quoted 106 lines · Alexander Graf

Quoted 24 lines · Xiantao

Quoted 23 lines · Alexander Graf

Quoted 19 lines · Xiantao

Quoted 9 lines · Alexander Graf

KVM as is assumes that the kernel obj dir and the kernel source dir are at the same location. This is true for most self-built vanilla kernels, but some distributions split these up (e.g. SUSE).
To keep compatible and have users have a good experience on building KVM on any distribution, this patch attempts to rebuild the logic from the kernel Makefile as closely as possible. With it I successfully built KVM on a current SUSE system.

Quoted 5 lines

Signed-off-by Alexander Graf <[email protected]>

Please check and see if it breaks the build process for anyone else. Building with IA64 on SUSE-kernels is still broken due to similar but separate problems.

Hi, Graf
what problems did you meet when building kvm/ia64 ?
Xiantao

Quoted 6 lines

Quoted 4 lines

This is the list of stuff I had to modify to get kvm-74 to run. I haven't tried anything more recent yet.

1) -mno-sdata does not work. Qemu CFLAGS need to be -msdata

Which version of GCC are you using ?

# gcc --version
gcc (SUSE Linux) 4.3.2 20080815 (prerelease) [gcc-4_3-branch revision
139129]

Quoted 5 lines

Quoted 4 lines

2) In qemu/ia64.ld SEARCH_DIR is invalid for SUSE. It shouldn't search in /usr/ia64-linux but in /usr/ia64-suse-linux.

You can make a patch to fix it.

Right, this one should be really easy to fix.

Quoted 4 lines

Quoted 1 line

3) TARGET_PAGE_BITS is wrong

Currently, we just set TARGET_PAGE_BITS to 16 by hardcoding in Qemu. In the future, we should add the logic to make it equal to kernel's PAGE_SHIFT.

From what I read on the KVM IA64 ML, this is not the first time someone ran into this issue. Sounds like a really good idea to add the
logic ;-).

Quoted 6 lines

Quoted 2 lines

4) kernel/ia64/Makefile.pre assumes to find .S files in $KERNELDIR. They are in $SOURCEDIR.

There is no issue here, I think. You have to set corrent $KERNELDIR through ./configure --kerneldir=xxxx once target machine and build machine is not same.

No, since $KERNELDIR is the build dir, as that one contains all the configurations. The source dir only contains the sources.

Quoted 11 lines

Quoted 2 lines

5) kernel/ia64/Makefile.pre suffers from the same problem my original fix for x86 addressed.

Ditto.

Quoted 5 lines

6) The IA64 kernel build system is broken. The file asm-ia64/nr- irqs.h gets generated during the kernel build, but is not exported as obj, so it won't be in the split obj directory. Since the source-dir is clean though, the file simply does not exist on SUSE rpms.

Quoted 4 lines

You mean the source-dir is clean ? So the generated header files including (linux/autoconf.h, asm-offsets.h...)should be removed wholely? I don't think they can be built with a clean source for most modules.

This is what I'm talking about all the time :-). For SUSE kernels there are two distinct directories:

# ls -l /usr/src
drwxr-xr-x 24 root root 4096 Aug 27 14:51 linux-2.6.27-rc4-
HEAD_20080825213702
drwxr-xr-x  3 root root 4096 Aug 25 23:28 linux-2.6.27-rc4-
HEAD_20080825213702-obj

whereas the normal directory contains the sources and the -obj directory contains all files that were generated during the build. Scratch that with the 2 rpm files - they are all in kernel-sources.

# ls -l
/usr/src/linux-2.6.27-rc4-HEAD_20080825213702-obj/ia64/default/ total
568

(quoted diff) +0 -3

-rw-r--r-- 1 root root  76287 Aug 25 23:27 .config
-rw-r--r-- 2 root root    554 Aug 25 23:28 Makefile
-rw-r--r-- 1 root root 468615 Aug 25 23:51 Module.symvers

drwxr-xr-x 3 root root   4096 Aug 26 18:01 arch
drwxr-xr-x 5 root root   4096 Aug 26 18:01 include
drwxr-xr-x 2 root root   4096 Aug 26 18:01 include2
drwxr-xr-x 2 root root   4096 Aug 25 23:28 kernel
drwxr-xr-x 6 root root   4096 Aug 26 18:01 scripts

Quoted 5 lines

The problem is now that a lot of people assume these two directories to be one. This is the default mode when you compile a kernel. SUSE does not take this route though, and hasn't for quite a while now. I don't know about other distributions, but I guess we're not the only ones ;-).

Okay, I see now. But due to shortage of Suse OS at hand, I can't try it
. Anyway once you found any issues related to the compability with Suse
OS, welcome to post patches to fix them. :)

KVM as is assumes that the kernel obj dir and the kernel source dir are at the same location. This is true for most self-built vanilla kernels, but some distributions split these up (e.g. SUSE). To keep compatible and have users have a good experience on building KVM on any distribution, this patch attempts to rebuild the logic from the kernel Makefile as closely as possible. With it I successfully built KVM on a current SUSE system.

Signed-off-by Alexander Graf <[email protected]>

Please check and see if it breaks the build process for anyone else. Building with IA64 on SUSE-kernels is still broken due to similar but separate problems.

Quoted 8 lines · Alexander Graf

KVM as is assumes that the kernel obj dir and the kernel source dir are at the same location. This is true for most self-built vanilla kernels, but some distributions split these up (e.g. SUSE). To keep compatible and have users have a good experience on building KVM on any distribution, this patch attempts to rebuild the logic from the kernel Makefile as closely as possible. With it I successfully built KVM on a current SUSE system.

Quoted 5 lines

Signed-off-by Alexander Graf <[email protected]>

Please check and see if it breaks the build process for anyone else. Building with IA64 on SUSE-kernels is still broken due to similar but separate problems.

Hi, Graf
I am confused by this patch. Why not use ./configure --kerneldir= your_kernel_source_directory ? It should be also workable for you. In the Makefile, KERNELDIR means the kernel source directory of target machine, and is set to /lib/modules/$(uname -r)/build of build machine by default. But you can change it at your will through configure or modifying config.mak.

KVM as is assumes that the kernel obj dir and the kernel source dir are at the same location. This is true for most self-built vanilla kernels, but some distributions split these up (e.g. SUSE).
To keep compatible and have users have a good experience on building KVM on any distribution, this patch attempts to rebuild the logic from the kernel Makefile as closely as possible. With it I successfully built KVM on a current SUSE system.

Signed-off-by Alexander Graf <[email protected]>

Please check and see if it breaks the build process for anyone else. Building with IA64 on SUSE-kernels is still broken due to similar but separate problems.

configure +0 -0

index 3bb10ce..5e9cbab 100755
@@ -1,6 +1,7 @@
 #!/bin/bash
 

prefix=/usr/local
+kernelsourcedir=
kerneldir=/lib/modules/$(uname -r)/build
cc=gcc
ld=ld

configure +0 -0

@@ -102,6 +103,11 @@ if [ "$arch" = "powerpc" ]; then
    qemu_ldflags="$qemu_ldflags -L $PWD/libfdt"

fi

configure +5 -0

+# see if we have split build and source directories
+if [ -d "$kerneldir/include2" ]; then
+    kernelsourcedir=${kerneldir%/*}/source
+fi
+

#configure user dir

(cd user; ./configure --prefix="$prefix" --kerneldir="$libkvm_kerneldir" \
          --arch="$arch" \

configure +0 -0

@@ -124,6 +130,7 @@ cat <<EOF > config.mak

ARCH=$arch
PREFIX=$prefix
KERNELDIR=$kerneldir
+KERNELSOURCEDIR=$kernelsourcedir
LIBKVM_KERNELDIR=$libkvm_kerneldir
WANT_MODULE=$want_module
CROSS_COMPILE=$cross_prefix

kernel/Makefile +0 -0

index 3f5f6da..d2cf89c 100644
@@ -36,7 +36,9 @@ hack-files = $(hack-files-$(ARCH_DIR))

all:: header-link prerequisite
# include header priority 1) $LINUX 2) $KERNELDIR 3) include-compat

	$(MAKE) -C $(KERNELDIR) M=`pwd` \

kernel/Makefile +0 -1

-		LINUXINCLUDE="-I`pwd`/include -Iinclude -Iarch/${ARCH_DIR}/ 

include -Ipwd/include-compat \

kernel/Makefile +3 -0

+		LINUXINCLUDE="-I`pwd`/include -Iinclude \
+		$(if $(KERNELSOURCEDIR),-Iinclude2 -I$(KERNELSOURCEDIR)/include) \
+		-Iarch/${ARCH_DIR}/include -I`pwd`/include-compat \

		-include include/linux/autoconf.h \
		-include `pwd`/$(ARCH_DIR)/external-module-compat.h"
		"$$@"

Any further comments on this? I would really like to see KVM build out-of-the-box on SUSE kernels (and kernels built with O= at the same time).

Alex

Quoted 66 lines

KVM as is assumes that the kernel obj dir and the kernel source dir are at the same location. This is true for most self-built vanilla kernels, but some distributions split these up (e.g. SUSE). To keep compatible and have users have a good experience on building KVM on any distribution, this patch attempts to rebuild the logic from the kernel Makefile as closely as possible. With it I successfully built KVM on a current SUSE system.

Signed-off-by Alexander Graf <[email protected]>

Please check and see if it breaks the build process for anyone else. Building with IA64 on SUSE-kernels is still broken due to similar but separate problems.

configure +0 -0

index 3bb10ce..5e9cbab 100755
@@ -1,6 +1,7 @@
 #!/bin/bash
 

prefix=/usr/local
+kernelsourcedir=
kerneldir=/lib/modules/$(uname -r)/build
cc=gcc
ld=ld

configure +0 -0

@@ -102,6 +103,11 @@ if [ "$arch" = "powerpc" ]; then
    qemu_ldflags="$qemu_ldflags -L $PWD/libfdt"

fi

configure +5 -0

+# see if we have split build and source directories
+if [ -d "$kerneldir/include2" ]; then
+    kernelsourcedir=${kerneldir%/*}/source
+fi
+

#configure user dir
(cd user; ./configure --prefix="$prefix"

--kerneldir="$libkvm_kerneldir" \
          --arch="$arch" \

configure +0 -0

@@ -124,6 +130,7 @@ cat <<EOF > config.mak

ARCH=$arch
PREFIX=$prefix
KERNELDIR=$kerneldir
+KERNELSOURCEDIR=$kernelsourcedir
LIBKVM_KERNELDIR=$libkvm_kerneldir
WANT_MODULE=$want_module
CROSS_COMPILE=$cross_prefix

kernel/Makefile +0 -0

index 3f5f6da..d2cf89c 100644
@@ -36,7 +36,9 @@ hack-files = $(hack-files-$(ARCH_DIR))

all:: header-link prerequisite
# include header priority 1) $LINUX 2) $KERNELDIR 3) include-compat

    $(MAKE) -C $(KERNELDIR) M=`pwd` \

kernel/Makefile +3 -3

-        LINUXINCLUDE="-I`pwd`/include -Iinclude
-Iarch/${ARCH_DIR}/include -I`pwd`/include-compat \
+        LINUXINCLUDE="-I`pwd`/include -Iinclude \
+        $(if $(KERNELSOURCEDIR),-Iinclude2
-I$(KERNELSOURCEDIR)/include) \
+        -Iarch/${ARCH_DIR}/include -I`pwd`/include-compat \
        -include include/linux/autoconf.h \
        -include `pwd`/$(ARCH_DIR)/external-module-compat.h"
        "$$@"

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Any further comments on this? I would really like to see KVM build out- of-the-box on SUSE kernels (and kernels built with O= at the same time).

Alex

Quoted 61 lines · Alexander Graf

KVM as is assumes that the kernel obj dir and the kernel source dir are at the same location. This is true for most self-built vanilla kernels, but some distributions split these up (e.g. SUSE). To keep compatible and have users have a good experience on building KVM on any distribution, this patch attempts to rebuild the logic from the kernel Makefile as closely as possible. With it I successfully built KVM on a current SUSE system.

Signed-off-by Alexander Graf <[email protected]>

Please check and see if it breaks the build process for anyone else. Building with IA64 on SUSE-kernels is still broken due to similar but separate problems.

configure +0 -0

index 3bb10ce..5e9cbab 100755
@@ -1,6 +1,7 @@
 #!/bin/bash
 

prefix=/usr/local
+kernelsourcedir=
kerneldir=/lib/modules/$(uname -r)/build
cc=gcc
ld=ld

configure +0 -0

@@ -102,6 +103,11 @@ if [ "$arch" = "powerpc" ]; then
    qemu_ldflags="$qemu_ldflags -L $PWD/libfdt"

fi

configure +5 -0

+# see if we have split build and source directories
+if [ -d "$kerneldir/include2" ]; then
+    kernelsourcedir=${kerneldir%/*}/source
+fi
+

#configure user dir
(cd user; ./configure --prefix="$prefix" --

kerneldir="$libkvm_kerneldir" \
          --arch="$arch" \

configure +0 -0

@@ -124,6 +130,7 @@ cat <<EOF > config.mak

ARCH=$arch
PREFIX=$prefix
KERNELDIR=$kerneldir
+KERNELSOURCEDIR=$kernelsourcedir
LIBKVM_KERNELDIR=$libkvm_kerneldir
WANT_MODULE=$want_module
CROSS_COMPILE=$cross_prefix

kernel/Makefile +0 -0

index 3f5f6da..d2cf89c 100644
@@ -36,7 +36,9 @@ hack-files = $(hack-files-$(ARCH_DIR))

all:: header-link prerequisite
# include header priority 1) $LINUX 2) $KERNELDIR 3) include-compat

	$(MAKE) -C $(KERNELDIR) M=`pwd` \

kernel/Makefile +0 -1

-		LINUXINCLUDE="-I`pwd`/include -Iinclude -Iarch/${ARCH_DIR}/

include -Ipwd/include-compat \

kernel/Makefile +3 -0

+		LINUXINCLUDE="-I`pwd`/include -Iinclude \
+		$(if $(KERNELSOURCEDIR),-Iinclude2 -I$(KERNELSOURCEDIR)/include) \
+		-Iarch/${ARCH_DIR}/include -I`pwd`/include-compat \

Quoted 3 lines

		-include include/linux/autoconf.h \
		-include `pwd`/$(ARCH_DIR)/external-module-compat.h"
		"$$@"

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With your patch, I still can't build with a split kernel source/object dir.

Don't know if it's a difference of configure options or what. Here's mine just in case:
./configure --disable-gfx-check --disable-sdl --with-patched-kernel --prefix=/usr

I needed the attached patch as well.

Quoted 10 lines · Brian Jackson

With your patch, I still can't build with a split kernel source/ object dir.

Don't know if it's a difference of configure options or what. Here's mine just
in case:
./configure --disable-gfx-check --disable-sdl --with-patched-kernel --prefix=/usr

I needed the attached patch as well.

Does --with-patched-kernel work again? I thought that's broken anyways.

Alex

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