[resending to Andre's actual e-mail address] On Thu, Nov 13, 2014 at 12:20 PM, Christoffer Dall <christoffer.dall@xxxxxxxxxx> wrote: > On Thu, Nov 13, 2014 at 12:45:42PM +0200, Nikolay Nikolaev wrote: > > [...] > >> >> >> >> Going through the vgic_handle_mmio we see that it will require large >> >> refactoring: >> >> - there are 15 MMIO ranges for the vgic now - each should be >> >> registered as a separate device >> >> - the handler of each range should be split into read and write >> >> - all handlers take 'struct kvm_exit_mmio', and pass it to >> >> 'vgic_reg_access', 'mmio_data_read' and 'mmio_data_read' >> >> >> >> To sum up - if we do this refactoring of vgic's MMIO handling + >> >> kvm_io_bus_ API getting 'vcpu" argument we'll get a 'much' cleaner >> >> vgic code and as a bonus we'll get 'ioeventfd' capabilities. >> >> >> >> We have 3 questions: >> >> - is the kvm_io_bus_ getting 'vcpu' argument acceptable for the other >> >> architectures too? >> >> - is this huge vgic MMIO handling redesign acceptable/desired (it >> >> touches a lot of code)? >> >> - is there a way that ioeventfd is accepted leaving vgic.c in it's >> >> current state? >> >> >> > Not sure how the latter question is relevant to this, but check with >> > Andre who recently looked at this as well and decided that for GICv3 the >> > only sane thing was to remove that comment for the gic. >> @Andre - what's your experience with the GICv3 and MMIO handling, >> anything specific? >> > >> > I don't recall the details of what you were trying to accomplish here >> > (it's been 8 months or so) but the surely the vgic handling code should >> > *somehow* be integrated into the handle_kernel_mmio (like Paolo >> > suggested), unless you come back and tell me that that would involve a >> > complete rewrite of the vgic code. >> I'm experimenting now - it's not exactly rewrite of whole vgic code, >> but it will touch a lot of it - all MMIO access handlers and the >> supporting functions. >> We're ready to spend the effort. My question is - is this acceptable? >> > I certainly appreciate the offer to do this work, but it's hard to say > at this point if it is worth it. > > What I was trying to say above is that Andre looked at this, and came to > the conclusion that it is not worth it. > > Marc, what are your thoughts? > > -Christoffer -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
