Re: [PATCH 2/2 V2] kvm tools: Fix virt_queue__set_used_elem

[Sasha Levin <levinsasha928@gmail.com>]

On Thu, 2011-05-05 at 07:47 +0800, Asias He wrote:
> On 05/04/2011 12:41 PM, Sasha Levin wrote:
> > On Tue, 2011-05-03 at 22:47 +0200, Ingo Molnar wrote:
> >> * Sasha Levin <levinsasha928@gmail.com> wrote:
> >>
> >>> Increase idx only after updating the used element.
> >>> Not doing so may mark a buffer as used without having
> >>> it's head and length updated.
> >>>
> >>> Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
> >>> ---
> >>>  tools/kvm/virtio.c |   19 ++++++++++++++++++-
> >>>  1 files changed, 18 insertions(+), 1 deletions(-)
> >>>
> >>> diff --git a/tools/kvm/virtio.c b/tools/kvm/virtio.c
> >>> index 6249521..266a1b6 100644
> >>> --- a/tools/kvm/virtio.c
> >>> +++ b/tools/kvm/virtio.c
> >>> @@ -1,15 +1,32 @@
> >>>  #include <linux/virtio_ring.h>
> >>>  #include <stdint.h>
> >>>  #include <sys/uio.h>
> >>> +#include <asm/system.h>
> >>
> >> If this system.h is included from the current kernel (and not from the 
> >> system's) then:
> >>
> >> Acked-by: Ingo Molnar <mingo@elte.hu>
> >>
> > 
> > The system.h that'll get picked up is
> > '../../arch/$(ARCH)/include/asm/system.h' within the current kernel tree
> > and not the system one.
> >> Thanks,
> >>
> >> 	Ingo
> > 
> 
> Hi,
> 
> With commit d7f0c07afeefa2d20739437306e4b8bb2853cf83 in master
> (kvm tools: Fix virt_queue__set_used_elem)
> 
> I see this:
> 
> asias@hj:~/qemu-stuff/pekka.git/tools/kvm$ make
>   GEN      include/common-cmds.h
> ../../include/asm-generic/bitops/fls64.h:33:2: error: #error
> BITS_PER_LONG not 32 or 64
> ../../include/linux/bitops.h:133:2: error: #error BITS_PER_LONG not 32 or 64
> ../../include/asm-generic/bitops/fls64.h:33:2: error: #error
> BITS_PER_LONG not 32 or 64
> ../../include/linux/bitops.h:133:2: error: #error BITS_PER_LONG not 32 or 64
> make: *** No rule to make target `virtio.d', needed by `kvm'.  Stop.
> 
> 
> With 'make V=1', I found this one triggered the error:
> 
> cc -M -MT virtio.o  -DCONFIG_X86_32 -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE
> -Iinclude -I../../include -I../../arch/x86/include/ -Os -g -Werror -Wall
> -Wcast-align -Wformat=2 -Winit-self -Wmissing-declarations
> -Wmissing-prototypes -Wnested-externs -Wno-system-headers
> -Wold-style-definition -Wredundant-decls -Wsign-compare
> -Wstrict-prototypes -Wundef -Wvolatile-register-var -Wwrite-strings
> virtio.c -o virtio.d
> 
> 

It looks like gcc is trying to pull kernel headers instead the headers
we have in include/linux. I'm not really sure why it happens though,
I've tried building again with a clean kvm dir (in case I forgot to add
a file to the commit) but it worked fine.

Can you compare your include/linux dir to the one located on the master
git tree?

-- 

Sasha.