Re: QEMU dies on any attempt to load a Linux kernel module when using a 9P rootfs

2013-11-26 Thread Christopher Covington
Hi Richard, On 11/25/2013 04:50 PM, Richard Yao wrote: I figured out the problem. There is zerocopy IO is being done via DMA to a buffer allocated with valloc(). Right now, I am running a hack-fix locally so I can get some other stuff done first. I will propose a proper fix to the list in a

Re: QEMU dies on any attempt to load a Linux kernel module when using a 9P rootfs

2013-11-26 Thread Richard Yao
Christopher, It sounds like you disabled zero-copy entirely, which is not necessary. As far as I recall, loading kernel modules is the only case in which valloc() allocated buffers are used. In the worst case, we only need to disable zero-copy on such buffers. I have been using a small patch to

Re: QEMU dies on any attempt to load a Linux kernel module when using a 9P rootfs

2013-11-26 Thread Richard Yao
I have this bad habit of not reviewing emails until after I send them. Anyway, Chris, thanks for your offer of help, but I can handle this on my own. The previous email was mostly to give you an early version of the patch and let you know what I plan to do to improve upon it before I propose some

Re: [PATCH char-misc-linus 4/5] misc: mic: Fix sparse warnings and other endianness issues.

2013-11-26 Thread Greg Kroah-Hartman
On Tue, Nov 26, 2013 at 10:14:21AM -0800, Ashutosh Dixit wrote: Endianness issues are now consistent as per the documentation in host/mic_virtio.h. Note that the host can be both BE or LE whereas the card is always LE. Memory space sparse warnings are fixed for now by using __force. This is

Re: Re: [PATCH -tip v3 13/23] x86/trap: Use NOKPROBE_SYMBOL macro in trap.c

2013-11-26 Thread Masami Hiramatsu
(2013/11/23 6:21), Andi Kleen wrote: On Wed, Nov 20, 2013 at 04:22:21AM +, Masami Hiramatsu wrote: Use NOKPROBE_SYMBOL macro to protect functions from kprobes instead of __kprobes annotation in trap.c. This also applies __always_inline annotation for some cases, because NOKPROBE_SYMBOL()