<div dir="ltr">Hello, <div><br></div><div>I was posting a couple weeks back here, asking questions about getting DomUs working in Xen when installing Xen from source. </div><div><br></div><div>Well, I have managed to get things working. Currently my setup is like this now.</div>
<div>Xen 4.2.2, installed from source, </div><div>Fedora 18 Dom0 x86_64, Debian 6 PV DomU x86_64, and Ubuntu 12.04 HVM DomU x86_64. </div><div>My processor has Intel VT-X enabled.</div><div><br></div><div>I used xl/xm to create DomUs. I was unable to get virt-manager working to create guests.</div>
<div>I faced a similar problem with Xen 4.1 and Fedora 17 earlier. </div><div><br></div><div>As the next step in my project, I want to log some system call information. </div><div><br></div><div>Basically, every time a system call is made in my PV DomU, I just want to print a line like "System call made from DomU, systemcall id = xx". That is all I need for now. </div>
<div><br></div><div>I have some questions regarding the same. </div><div>1. This might be a stupid question, but here goes.</div><div>After I modify source code, should I do the whole compilation/install process to see my changes. </div>
<div>ie. should i do "make and install xen, tools and stubdom" or will "make and install xen" suffice ?</div><div><br></div><div>2. How is the system call flow happening in Xen?</div><div> Where in the code is the system call being intercepted by the hypervisor for a PV DomU. ?</div>
<div><br></div><div>I found some information from this paper, <a href="http://hal.archives-ouvertes.fr/docs/00/43/10/31/PDF/Technical_Report_Syscall_Interception.pdf">http://hal.archives-ouvertes.fr/docs/00/43/10/31/PDF/Technical_Report_Syscall_Interception.pdf</a></div>
<div><br></div><div>but still am not clear about the whole picture.<br clear="all"><div><br></div><div>Is there documentation available explaining for how system calls are handled in Xen ?<br></div><div>The Xen code is quite large, and I am sorry to say I get lost reading it without some kind of knowledge.</div>
<div><br></div><div>3. How to log data?</div><div>I see printk statements in the code. Are printk statements tied to a certain logging level ? Should I add "loglvl=all guest_loglvl=all" to my Dom0 grub to see the output from printk statements ?</div>
<div>Also, which output file should I be seeing for my scenario?</div><div>/var/log/xen/xend.log ?</div><div><br></div><div>I apologize for the long email. <br>Please take some time out and kindly reply. </div><div><br></div>
<div><br></div>-- <br>Ranjith krishnan
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