Hi, For each domUs there is unique shared memory(2-way circular queue) and event-channel(one shared memory and event-channel per domU) or there is only one shared memory and interdomain event-channel(for every DomU)? regards: Amit _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
> For each domUs there is unique shared memory(2-way circular queue) and > event-channel(one shared memory and event-channel per domU) or there is > only one shared memory and interdomain event-channel(for every DomU)?Each domain has a separate shared memory page and event channel. Actually, in general, there are multiple shared memory areas and event channels per domU. Each virtual device (e.g. virtual network interface) may require its own separate shared memory page and event channel to talk to the backend. So if you have a domain with two vifs it''ll need two shared memory pages and two event channels. The block driver will also want a memory page and event channel for each virtual block device. And so on. Hope this helps, Cheers, Mark -- Dave: Just a question. What use is a unicyle with no seat? And no pedals! Mark: To answer a question with a question: What use is a skateboard? Dave: Skateboards have wheels. Mark: My wheel has a wheel! _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
hi I have a question about HVM and PV, in the HVM,xen is running in the root mode,and should vmentry or vmexit to HVM vm,and in the PV,xen is running in the ring0, am i right? and if some PV vm and some HVM vm are running on the physical node with VTsupport,then which mode does the xen run in? in ring0 or what about it ? Thanks in advance _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
> I have a question about HVM and PV, in the HVM,xen is running in the > root mode,and should vmentry or vmexit to HVM vm,and in the PV,xen is > running in the ring0, am i right? > and if some PV vm and some HVM vm are running on the physical node > with VTsupport,then which mode does the xen run in? in ring0 or what > about it ?On a machine which is not VT capable, there is no "root" or "non-root" mode, so Xen runs in ring 0 and guests ring in rings 1-3. On a machine which is VT capable you have "root mode" and "non-root mode". "root mode" is basically the same as the normal operation of a non-VT processor; it still has the rings 0-3, which fulfill the same purpose as they did on non-VT machines. They still work the same. "non-root mode" is a second set of CPU protection rings 0-3, which Xen uses for HVM guests and which operate independently of those rings in "root mode". If you''re running PV and HVM guests at once then you have: * Xen runs in ring 0 of "root mode" * dom0 runs in ring 1-3 of "root mode" * PV domUs run in ring 1-3 of "root mode" * HVM domUs run in rings 0-3 of "non-root mode" Note that when VT is available, "root mode" and "non-root" mode both have a set of their own rings. So it''s not a question of whether something runs in ring "n" anymore, it''s a question of whether it runs in ring n /of root mode/ or ring n /of non-root mode/. Cheers, Mark -- Dave: Just a question. What use is a unicyle with no seat? And no pedals! Mark: To answer a question with a question: What use is a skateboard? Dave: Skateboards have wheels. Mark: My wheel has a wheel! _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
hi I read the code of eventchannel,and I am confused by the viarable named as"consumer_is_xen"in the evtchn struct, what is the function of consumer_is_xen? and does dom use eventchannel to communicate with hypervisor? why not the hypercall? and in which condition is eventchannel used in this way,that is ,the dom issues an event to hypervisor or xen,and xen is a consumer? Thanks in advance Mark Williamson 写道:>> For each domUs there is unique shared memory(2-way circular queue) and >> event-channel(one shared memory and event-channel per domU) or there is >> only one shared memory and interdomain event-channel(for every DomU)? >> > > Each domain has a separate shared memory page and event channel. Actually, in > general, there are multiple shared memory areas and event channels per domU. > > Each virtual device (e.g. virtual network interface) may require its own > separate shared memory page and event channel to talk to the backend. So if > you have a domain with two vifs it''ll need two shared memory pages and two > event channels. > > The block driver will also want a memory page and event channel for each > virtual block device. > > And so on. > > Hope this helps, > > Cheers, > Mark > >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
It''s a special-case type of inter-domain event channel in which one end is connected to Xen itself rather than the guest. It''s actually only used for the per-vcpu ioemu event-channel that HVM guests require. -- Keir On 21/12/07 08:39, "tgh" <wwwwww4187@sina.com.cn> wrote:> hi > I read the code of eventchannel,and I am confused by the viarable > named as"consumer_is_xen"in the evtchn struct, what is the function of > consumer_is_xen? and does dom use eventchannel to communicate with > hypervisor? why not the hypercall? and in which condition is > eventchannel used in this way,that is ,the dom issues an event to > hypervisor or xen,and xen is a consumer? > > Thanks in advance > > > > > Mark Williamson 写道: >>> For each domUs there is unique shared memory(2-way circular queue) and >>> event-channel(one shared memory and event-channel per domU) or there is >>> only one shared memory and interdomain event-channel(for every DomU)? >>> >> >> Each domain has a separate shared memory page and event channel. Actually, >> in >> general, there are multiple shared memory areas and event channels per domU. >> >> Each virtual device (e.g. virtual network interface) may require its own >> separate shared memory page and event channel to talk to the backend. So if >> you have a domain with two vifs it''ll need two shared memory pages and two >> event channels. >> >> The block driver will also want a memory page and event channel for each >> virtual block device. >> >> And so on. >> >> Hope this helps, >> >> Cheers, >> Mark >> >> > > > _______________________________________________ > 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