On Thu, 10/22 01:13, QuQ Edsel wrote: > Hi, > My friends and I were assigned a task to find out a point to insert a > callback function to intercept Disk IO activities such as read/write a .txt > file. Our final goal is to generate a report for target process/file 's > Disk IO activities. We have QEMU 2.3 with KVM enabled. We have been looking > for such a point for long...but not so capable of such a task. > People who had this project last year done so with TEMU 1.0 (probably QEMU > 0.9), and the implementation point they had is dma_buf_rw(). The > information in their report shows pid, timestamps, disk sector, buffer size > and write/read for a target file (I am not even sure if such information is > meaningful or useful) > Currently I have tried to printf in functions such as dma_buf_rw / > dma_blk_io / bdrv_aio_readv...etc. to see if they print out message when I > open/edit/save a .txt or .jpeg file. The first one just don't print at all, > and the second and third one print a lot after booting up the guest.... > I can see that the dma_blk_io function call in ide_dma_cb (core.c) may be > related because it prints as I have activities on files. However it also > prints sometime when I am not doing any thing... so I not that certain > about it. (and I don't know if write/read activities invoke such > function..)
Yes, dma_buf_rw should handle all your I/O unless you're doing PIO. I think the other activities you see when you're not doing anything is from guest system's background tasks. Thanks, Fam > > Is there a correct /better point to intercept disk IO information > ?(especially for activities such as read/write a .file) > Or what should I do to clearly get the needed information from Disk IO > functions? > I would be so grateful to have the information. > Thank you. > > The guest environment I have is 64bit Windows 7 with qcow2 image (not sure > if relative) >