On 06/11/2014 00:05, Mario Smarduch wrote: > On 11/05/2014 08:09 AM, Paolo Bonzini wrote: >> >> >> On 01/11/2014 11:12, James Hogan wrote: >>> AFAICT all of the arch implementations of kvm_vm_ioctl_get_dirty_log() >>> except x86 and ppc hv (i.e. ia60, mips, ppc pv, s390) already make use >>> of the existing generic function kvm_get_dirty_log() to help implement >>> their kvm_vm_ioctl_get_dirty_log functions, which all look pretty >>> similar now except for TLB flushing. >>> >>> Would they not be a better base for a generic >>> kvm_vm_ioctl_get_dirty_log()? >>> >>> It feels a bit wrong to add a generic higher level function which >>> doesn't make use of the existing generic lower level abstraction. >>> >>> (Appologies if this has already been brought up in previous versions of >>> the patchset, I haven't been tracking them). >> >> I agree that we should make the interface look more like >> kvm_get_dirty_log(). Here the steps are: >> >> + * 1. Take a snapshot of the bit and clear it if needed. >> + * 2. Write protect the corresponding page. >> + * 3. Flush TLB's if needed. >> + * 4. Copy the snapshot to the userspace. > > Hi Paolo, > thanks for breaking it down between generic/architecture layers, > helps a lot. Initially I thought we could get TLB flushing to > generic layer, previous x86 version worked for ARM. But looking > deeper other architectures either use non-generic flush or none > at all. Right now we would have x86, ARM, IA64 using generic TLB flush. > I'll restructure for another version. I'll test the swap between 3 and 4 above, and send it to the list. Feel free to include it in v13, so that it gets back to me via Christoffer and Marc. Paolo -- 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
