[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] RE: Xen-devel digest, Vol 1 #716 - 11 msgs
Hi, Dan: I am talking about the "real hypercall" like IA32/XEN did for the para-virtualization. For the EFI/SAL/PAL calls, maybe it is better to be implemented in guest BIOS. Eddie > Re hypercalls. Actually there are hypercalls already in Xen/ia64 > and they do use the break instruction. It's just that the domain > calls them indirectly so perhaps they are better called "hyperthunks" > ("Thunk" is a rarely used compiler term which originated in Algol 60 > that means: "code that is used to convert calls to one interface > into calls to another"): > > When a domain is created, fake EFI/SAL/PAL (firmware) calls are > created > that contain the hypercalls. Thus when domain0 invokes an EFI/SAL/PAL > call, it calls a "stub" routine that invokes a break instruction/fault > that is recognized in Xen/ia64 as a hypercall, with arguments passed > in general registers (unlike Xen/x86 which passes hypercall arguments > in memory). > > You may want to step through a domain0 firmware call to see this work. > If I recall correctly, the code that creates the hyperthunks is > in arch/ia64/dom_fw.c > > While my intent is to use the same mechanism (breaks) for "real" > hypercalls, > I also want to explore the use of fast system calls (recently added > in Linux/ia64 by David Mosberger) using the epc instruction in certain > cases. > > Dan > ------------------------------------------------------- The SF.Net email is sponsored by: Beat the post-holiday blues Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek. It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |