Christoffer Dall <christoffer.dall@xxxxxxxxxx> writes: > On Thu, Nov 20, 2014 at 04:55:14PM +0000, Alex Bennée wrote: >> Hi, >> >> I've almost finished the ARMv8 guest debug support but I have one >> problem left to solve. userspace needs to know how many hardware debug >> registers are available for GDB to use. >> * KVM ioctl KVM_GET_DEBUGREGS >> >> This is currently x86 only and looks like it's more aimed at debug >> registers than capability stuff. Also I'm not sure what the state of >> this ioctl is compared to KVM_SET_GUEST_DEBUG. Do these APIs overlap or >> is one an older deprecated x86 only API? > > The API text and a brief glance of the x86 code seems to indicate that > this is also the vcpu state... Yeah I was getting confused as to the difference between the two API calls. Is this just an x86 version of what GET/SET_ONE_REG replaced? >> * Add another KVM ioctl? >> >> This would have the downside of being specific to KVM and of course >> proliferating the API space again. >> > This may not be that bad, for example, could we ever imaging that we'd > only want to export a few of the debug registers for host gdbstub > usage? However it is general information which might be useful to the whole system (although I suspect KVM and PTRACE are the only two). It would be a shame to have an informational API wrapped up in the extra boiler-plate of a specific API. -- Alex Bennée -- 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
