On Wed, Apr 27, 2016 at 8:38 PM, Martin Cerveny <mar...@c-home.cz> wrote: > Hello. > > I have problem with multiple ioreq_servers > server 1 (emulates VGA) and server 2 (qemu). > > Emulation VGA server maps VGA PIO registers (3c0-3cf, 3b4-3b5 ...) > Qemu maps "all" PIO space (0-ffff) > (ref: > http://xenbits.xen.org/gitweb/?p=qemu-xen.git;a=blob;f=exec.c;h=46fe70ed49f85d0638061aa5b09f1f9d521b0bd3;hb=18f2ce4bfe67f9b38143d9d96207e49c92b6881c#l2007 > ) > Xen does not check overlap errors between ioreq_servers > (ref: > http://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=xen/arch/x86/hvm/hvm.c;h=186e01e3b05a0264e8f4538b226da2feed50d11a;hb=d77bac5c064ffb9dbb5b89b55b89853f1b784ebf#l1252 > ) > Xen choose "first match" > (ref: > http://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=xen/arch/x86/hvm/hvm.c;h=186e01e3b05a0264e8f4538b226da2feed50d11a;hb=d77bac5c064ffb9dbb5b89b55b89853f1b784ebf#l2594 > ) > > In my case all requests to VGA PIO are sent to qemu (qemu VGA is disabled > with parameter "-display none"/"-vga none") and dropped. > Emulation VGA server receives only memory updates (eg. a0000-bffff). > > Is this problem resolved in updates (actual code looks the same (ioreq.c)) ? > Is there any prioritization between ioreq_servers (but it is probably bad > idea) ? > Should the IO mapping check overlap between ioreq_servers (but it is > probably bad idea) ? > Should the qemu IO map only emulated areas (why it needs all ?) ?
I think the idea was that devicemodels should only request IO ports for devices they actually intend to emulate. It sounds like this is an unfinished implementation inside of qemu. -George _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
