Re: [Qemu-devel] Functions to intercept Disk IO information?
On Thu, 10/22 14:18, QuQ Edsel wrote: > Thank you for reply！ > But as I insert a printf message in dma_buf_rw, compile and boot up the VM, > there are no messages printed even when I open/create/edit a .txt or .jpeg > file ? > If dma_buf_rw is called it is supposed to print messages in the monitor... > On the other hand, > the dma_blk_io called in ide_dma_ cb did happen when files are > manipulated Yes, it was a mistake, I meant dma_blk_io, sorry for confusion. :) dma_buf_rw only works for some device types, while dma_blk_io works more commonly. > Would it be point to determine Disk IO and to intercept the information I > need? > Sorry I really lack knowledge in this field... > Does the PIO you mentioned means NIC IO? PIO is port I/O which doesn't use DMA. Fam > > Edsel > > 2015-10-22 9:22 GMT+08:00 Fam Zheng : > > > 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) > > > > >
Re: [Qemu-devel] Functions to intercept Disk IO information?
Thank you for reply！ But as I insert a printf message in dma_buf_rw, compile and boot up the VM, there are no messages printed even when I open/create/edit a .txt or .jpeg file ? If dma_buf_rw is called it is supposed to print messages in the monitor... On the other hand, the dma_blk_io called in ide_dma_ cb did happen when files are manipulated Would it be point to determine Disk IO and to intercept the information I need? Sorry I really lack knowledge in this field... Does the PIO you mentioned means NIC IO? Edsel 2015-10-22 9:22 GMT+08:00 Fam Zheng : > 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) > > >
Re: [Qemu-devel] Functions to intercept Disk IO information?
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) >
[Qemu-devel] Functions to intercept Disk IO information?
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..) 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) Edsel
