Re: [Xen-devel] Infiniband support
Thanks a lot for the response. I am not sure if I asked it right: I already have Infiniband installed on my kernel and it is working fine in the user space. However, I would like to use the RDMA Verbs API inside the Xen code, like calling RDMA functions to send/receive data. That requires Infiniband headers to be included in the Xen code, but I'm have difficulty with that. So is there any sample code of someone already calling Infiniband/RDMA functions within Xen code or any guide on how to recompile Xen with custom headers? Thanks a lot! On Thu, Jan 7, 2016 at 2:34 PM Ian Campbell wrote: > On Wed, 2016-01-06 at 06:54 +0000, Gohar Irfan wrote: > > Hi, > > > > Can anyone guide me on how to compile Xen with Infiniband support? > > (Particularly Mellanox) > > I want to perform some RDMA read/write functionality from within the Xen > > code (it is for a course project) using the Verbs API. > > Xen itself doesn't typically contain I/O drivers at all, that is delegated > to the domain 0 or driver domain kernel(s). > > IOW you need to be looking at how to compile Infiniband support into your > dom0 kernel, i.e. in Linux or BSD or whatever, I would presume there are > plenty of resources on that subject on the web. > > Ian. > > > > > > Thanks, > > Gohar > > > > ___ > > Xen-devel mailing list > > Xen-devel@lists.xen.org > > http://lists.xen.org/xen-devel > ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
[Xen-devel] Infiniband support
Hi, Can anyone guide me on how to compile Xen with Infiniband support? (Particularly Mellanox) I want to perform some RDMA read/write functionality from within the Xen code (it is for a course project) using the Verbs API. Thanks, Gohar ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
[Xen-devel] subscribe
___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
[Xen-devel] sh_page_fault
In case of HVM guests, where is the sh_page_fault function called? ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
[Xen-devel] HVM guest creation
Where in the code base is the initialization of a new domain (to run unmodified guests) done? Where is it given the details about the memory it has access to? ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
[Xen-devel] nr_pages increase
Is it possible to increase the number of pages (or memory size) visible to the guest OS (domU)? Perhaps at boot-time? Can this be achieved by increasing the value of nr_pages in the start_info struct when it is initialized? Where exactly in the code is this happening? Thanks ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Re: [Xen-devel] Page Fault
Sorry, my apologies. I got it now, thanks! On Mon, Nov 30, 2015 at 3:32 PM Jan Beulich wrote: > >>> On 29.11.15 at 19:19, wrote: > > Inside the page fault handler for shadow page tables (sh_page_fault > > function in multi.c) where is the code for swapping in a page from disk? > > There is no swapping in from disk in that code. You probably think > of memory-paging, which has nothing to do with shadow code. > > Jan > > ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
[Xen-devel] Page Fault
Inside the page fault handler for shadow page tables (sh_page_fault function in multi.c) where is the code for swapping in a page from disk? ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
[Xen-devel] Page Table
Where does Xen maintain the page table for each VM? The mapping of page number to frame numbers, basically. ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Re: [Xen-devel] help for snapshot
I'm also working on a similar thing - can you please tell me how you copy the memory pages from one part of the memory to another? On Tue, Oct 13, 2015 at 10:04 AM 高强 wrote: > Hi,alls > > I'm modifying the source code of xen-4.4.1. Specifically, I'm modifying > the memory copy part of snapshot. I first put all memory pages to write > protection, and then rewrite the write protection exception part of the > code. After capture the exception then save the memory page , and all > memory page copy is complete, call the function xenaccess_teardown(xch, > xenaccess), but there is a mistake: > > libxl: error: libxl_utils.c:396:libxl_read_exactly: file/stream truncated > reading ipc msg header from domain 3 save/restore helper stdout pipe > libxl: error: libxl_exec.c:129:libxl_report_child_exitstatus: domain 3 > save/restore helper [-1] died due to fatal signal Segmentation fault (core > dumped) > Failed to save domain, resuming domain > > Has anyone ever meet this kind of problem, and who can tell me the cause > of the error. > > Thanks > ___ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel > ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
[Xen-devel] Malloc
What is the alternate of doing a malloc in Xen? I have a data structure (containing a list from the list.h implementation) and I want to initialize a pointer and allocate space for my struct. But since malloc doesn’t work in Xen, what should I do? Thanks ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Re: [Xen-devel] Page Table Entry Modifications
A clarification: I also want to COPY the contents of the frames, so there will be no memory corruption. In essence, only the frame numbers will be changed. My other question, which is sort of a follow up to this, may be relevant: "Given two GMFN in shadow paging (HVM) is there a way to swap their contents? Let's say I have GMFN x and GMFN y, I want to put the contents of x in y and the contents of y in x. " Thanks a lot! On Sun, Sep 27, 2015 at 9:04 PM Gohar Irfan wrote: > This might not seem useful or anything, but this is a part of an > experiment so I will describe what I'm trying to do: > > Divide the memory into two equal halves and call them A and B. > Let's say region A has 10 pages, from page numbers 1 to 10. Region B has > 10 pages from page numbers 11 to 20 (hypothetical, of course.) > When a page from region B (page number 11 to 20) is being accessed, say > page 15, then swap the contents of page 15 with the contents of one of the > pages from region A, say page 5. > To achieve this, I need some help. In the default scenario, page 15 points > to frame X and page 5 points to frame Y. I want to make page 15 point to > frame Y and page 5 to frame X of the memory. > > I want to run this experiment and find the degradation in performance for > a project. > If some portion of this seems vague, I can explain. But I urgently need > help on how to achieve this. > > My understanding is that it can be done in the page fault handler of > shadow page tables. I have mentioned the relevant file and function earlier > in this thread. > > Thanks a lot! > > On Sun, Sep 27, 2015 at 7:57 PM Meng Xu wrote: > >> 2015-09-23 4:42 GMT-04:00 Gohar Irfan : >> > >> > It is for a project, I'm trying to experiment with a couple of things. >> >> Well, this is too general... Everything can be a project. People tries >> to know what exact things you want to achieve so that they can figure >> out if you are heading the correct direction. >> >> Meng >> > ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
[Xen-devel] Swap Frame Contents
Given two GMFN in shadow paging (HVM) is there a way to swap their contents? Let's say I have GMFN x and GMFN y, I want to put the contents of x in y and the contents of y in x. Thanks. ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Re: [Xen-devel] Page Table Entry Modifications
This might not seem useful or anything, but this is a part of an experiment so I will describe what I'm trying to do: Divide the memory into two equal halves and call them A and B. Let's say region A has 10 pages, from page numbers 1 to 10. Region B has 10 pages from page numbers 11 to 20 (hypothetical, of course.) When a page from region B (page number 11 to 20) is being accessed, say page 15, then swap the contents of page 15 with the contents of one of the pages from region A, say page 5. To achieve this, I need some help. In the default scenario, page 15 points to frame X and page 5 points to frame Y. I want to make page 15 point to frame Y and page 5 to frame X of the memory. I want to run this experiment and find the degradation in performance for a project. If some portion of this seems vague, I can explain. But I urgently need help on how to achieve this. My understanding is that it can be done in the page fault handler of shadow page tables. I have mentioned the relevant file and function earlier in this thread. Thanks a lot! On Sun, Sep 27, 2015 at 7:57 PM Meng Xu wrote: > 2015-09-23 4:42 GMT-04:00 Gohar Irfan : > > > > It is for a project, I'm trying to experiment with a couple of things. > > Well, this is too general... Everything can be a project. People tries > to know what exact things you want to achieve so that they can figure > out if you are heading the correct direction. > > Meng > ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Re: [Xen-devel] Page Table Entry Modifications
Could someone please help me with this? It's really important and urgent. Thanks a lot! On Wed, Sep 23, 2015 at 1:42 PM Gohar Irfan wrote: > It is for a project, I'm trying to experiment with a couple of things. > > Could you please guide me how this could be achieved? Some relevant chunks > of code, perhaps? > > Thanks! > > On Wed, Sep 23, 2015 at 1:35 PM Andrew Cooper > wrote: > >> On 22/09/15 20:35, Gohar Irfan wrote: >> >> Hi All, >> >> I want to know if, in the case of HVM (shadow page tables), we can change >> the machine frame number pointed to by a page table entry? >> >> >> Yes - Xen is able to change the mfn in a pte. >> >> >> An overly simplified example would be: let's say I have page number 10 >> that is pointing to machine frame number 10, but I would like it to point >> to machine frame number 1? >> >> >> Yes - that is in theory possible. >> >> >> Can this be achieved inside the "sh_page_fault" function inside >> "xen/arch/x86/mm/shadow/multi.c" as this seems like a relevant place for >> this modification to me. >> >> >> What are you trying to achieve? Modifications such as what you request >> are possible, but you are exceedingly likely to end up with memory >> corruption as a result. >> >> >> ~Andrew >> > ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Re: [Xen-devel] Page Table Entry Modifications
It is for a project, I'm trying to experiment with a couple of things. Could you please guide me how this could be achieved? Some relevant chunks of code, perhaps? Thanks! On Wed, Sep 23, 2015 at 1:35 PM Andrew Cooper wrote: > On 22/09/15 20:35, Gohar Irfan wrote: > > Hi All, > > I want to know if, in the case of HVM (shadow page tables), we can change > the machine frame number pointed to by a page table entry? > > > Yes - Xen is able to change the mfn in a pte. > > > An overly simplified example would be: let's say I have page number 10 > that is pointing to machine frame number 10, but I would like it to point > to machine frame number 1? > > > Yes - that is in theory possible. > > > Can this be achieved inside the "sh_page_fault" function inside > "xen/arch/x86/mm/shadow/multi.c" as this seems like a relevant place for > this modification to me. > > > What are you trying to achieve? Modifications such as what you request > are possible, but you are exceedingly likely to end up with memory > corruption as a result. > > > ~Andrew > ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
[Xen-devel] Page Table Entry Modifications
Hi All, I want to know if, in the case of HVM (shadow page tables), we can change the machine frame number pointed to by a page table entry? An overly simplified example would be: let's say I have page number 10 that is pointing to machine frame number 10, but I would like it to point to machine frame number 1? Can this be achieved inside the "sh_page_fault" function inside "xen/arch/x86/mm/shadow/multi.c" as this seems like a relevant place for this modification to me. Thanks! ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
