Hi, I've been reading the xen source code recently, and I have got 2 questions about hypercall. 1. I find 2 header files named hypercall.h in the directory linux/arch/x86/include. One is in the sub-directory /mach-xen/asm/hypercall.h, and the other is /asm/xen/hypercall.h. After comparing these two, I find their contents are similar but different, and I can't figure out what's the difference between them, what their purposes are , and when kernel want to trap into xen hypervisor, which one will kernel choose？ 2. I find that the xen tools also used hypercall. My question is how does tools used it ? is the process the same as the kernel, or xen tools use hypercall in a different way? -- View this message in context: http://xen.1045712.n5.nabble.com/2-questions-about-hypercall-tp5024421p5024421.html Sent from the Xen - Dev mailing list archive at Nabble.com. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On Sat, 2011-11-26 at 06:33 +0000, anita wrote:> Hi, I've been reading the xen source code recently, and I have got 2 > questions about hypercall. > > 1. I find 2 header files named hypercall.h in the directory > linux/arch/x86/include. One is in the sub-directory > /mach-xen/asm/hypercall.h, and the other is /asm/xen/hypercall.h. After > comparing these two, I find their contents are similar but different, and I > can't figure out what's the difference between them, what their purposes are > , and when kernel want to trap into xen hypervisor, which one will kernel > choose？This is not the Xen source code. You appear to be looking at a linux source tree but you haven't said which.> 2. I find that the xen tools also used hypercall. My question is how does > tools used it ? is the process the same as the kernel, or xen tools use > hypercall in a different way?They use libxenctrl which in turn uses a special ioctl on /proc/xen/privcmd to make hypercalls. Ian.> > -- > View this message in context: http://xen.1045712.n5.nabble.com/2-questions-about-hypercall-tp5024421p5024421.html > Sent from the Xen - Dev mailing list archive at Nabble.com. > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Thanks very much for your reply!
1. I''m using kernel 2.6.32.13
2. Do you mean that when the tools want to use hypercall, it doesn''t
need to do
--->HYPERVISOR_XX ---> __hypercalln ----> int 0x82 as the
dom0 or domU do.
It simply executes the assembly-code in the privcmd_ioctl to do
the int0x82 ???
--
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