Marcelo Tosatti 63b5cf04f4 Lazy storage key handling ... ------------------------- Linux does not use the ACC and F bits of the storage key. Newer Linux versions also do not use the storage keys for dirty and reference tracking. We can optimize the guest handling for those guests for faults as well as page-in and page-out by simply not caring about the guest visible storage key. We trap guest storage key instruction to enable those keys only on demand. Migration bitmap Until now s390 never provided a proper dirty bitmap. Let's provide a proper migration bitmap for s390. We also change the user dirty tracking to a fault based mechanism. This makes the host completely independent from the storage keys. Long term this will allow us to back guest memory with large pages. per-VM device attributes ------------------------ To avoid the introduction of new ioctls, let's provide the attribute semanantic also on the VM-"device". Userspace controlled CMMA ------------------------- The CMMA assist is changed from "always on" to "on if requested" via per-VM device attributes. In addition a callback to reset all usage states is provided. Proper guest DAT handling for intercepts ---------------------------------------- While instructions handled by SIE take care of all addressing aspects, KVM/s390 currently does not care about guest address translation of intercepts. This worked out fine, because - the s390 Linux kernel has a 1:1 mapping between kernel virtual<->real for all pages up to memory size - intercepts happen only for a small amount of cases - all of these intercepts happen to be in the kernel text for current distros Of course we need to be better for other intercepts, kernel modules etc. We provide the infrastructure and rework all in-kernel intercepts to work on logical addresses (paging etc) instead of real ones. The code has been running internally for several months now, so it is time for going public. GDB support ----------- We provide breakpoints, single stepping and watchpoints. Fixes/Cleanups -------------- - Improve program check delivery - Factor out the handling of transactional memory on program checks - Use the existing define __LC_PGM_TDB - Several cleanups in the lowcore structure - Documentation NOTES ----- - All patches touching base s390 are either ACKed or written by the s390 maintainers - One base KVM patch "KVM: add kvm_is_error_gpa() helper" - One patch introduces the notion of VM device attributes -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIcBAABAgAGBQJTVlHZAAoJEBF7vIC1phx8REgP/1P0EUzfBpoS53z1v60n2uLT lW79LY9Op4/ZacEgHtU9LzmGa88X0arDsIpBZQsTNLF77AGFcMCCV3X2il/lQrRG KSE+ycKLoFjCcES442DwF4gHoGldD+KL/+5LPWSQZtvb9dDpHDft9aeMRBbpUL0Q M2kKQDlmJ2XqQu3D5PwSHgVRByHiHOzmTe2ejSSbdppkwBpaiqSBBBk0jVYDW9Jh eqUnBcrrYW2p+QS37ELM6hOkfDXN/vXoHBQeyca19TuZVCPNA7HeJaPc2mJ/GZk9 wrNWEmY3f/lY0lk0zMwBwsDOS5K7jbtvXzcex6m+NsIqQuOvKsmPBy1BWb/axcK5 uZq/JGFC0fxsFU+7ImtvQrJ/DMHnVuvSKF4WUVle2GdMlDIqkguwX27WwHSiH4/r Au02KlVIMUZdLAEUrw/W/S4MPLeZYoGfetHGCOmSaP2qGc97BVFedZaqekDlUgMw 3gIoQmSIBcfrgF4k9N4nLjdhAX2S4gkviwF3pTlIkecNfa7RcI3Xk7U9mVPmIhL4 IquVqjdXZH4m0e4gViBMtQ0IPwGt1qFlV6Wv3O9MExhfi7VQ8M8TMYNhEvtGpY75 cuZwZYGM4FqszDAy9hbk0avTLqCxqlTiBKi3tHoQMappQmsJPrIdxIpev3MZPHCp vZMkbzhM9l3eefNJVw66 =jxBp -----END PGP SIGNATURE----- Merge tag 'kvm-s390-20140422' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into queue Lazy storage key handling ------------------------- Linux does not use the ACC and F bits of the storage key. Newer Linux versions also do not use the storage keys for dirty and reference tracking. We can optimize the guest handling for those guests for faults as well as page-in and page-out by simply not caring about the guest visible storage key. We trap guest storage key instruction to enable those keys only on demand. Migration bitmap Until now s390 never provided a proper dirty bitmap. Let's provide a proper migration bitmap for s390. We also change the user dirty tracking to a fault based mechanism. This makes the host completely independent from the storage keys. Long term this will allow us to back guest memory with large pages. per-VM device attributes ------------------------ To avoid the introduction of new ioctls, let's provide the attribute semanantic also on the VM-"device". Userspace controlled CMMA ------------------------- The CMMA assist is changed from "always on" to "on if requested" via per-VM device attributes. In addition a callback to reset all usage states is provided. Proper guest DAT handling for intercepts ---------------------------------------- While instructions handled by SIE take care of all addressing aspects, KVM/s390 currently does not care about guest address translation of intercepts. This worked out fine, because - the s390 Linux kernel has a 1:1 mapping between kernel virtual<->real for all pages up to memory size - intercepts happen only for a small amount of cases - all of these intercepts happen to be in the kernel text for current distros Of course we need to be better for other intercepts, kernel modules etc. We provide the infrastructure and rework all in-kernel intercepts to work on logical addresses (paging etc) instead of real ones. The code has been running internally for several months now, so it is time for going public. GDB support ----------- We provide breakpoints, single stepping and watchpoints. Fixes/Cleanups -------------- - Improve program check delivery - Factor out the handling of transactional memory on program checks - Use the existing define __LC_PGM_TDB - Several cleanups in the lowcore structure - Documentation NOTES ----- - All patches touching base s390 are either ACKed or written by the s390 maintainers - One base KVM patch "KVM: add kvm_is_error_gpa() helper" - One patch introduces the notion of VM device attributes Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Conflicts: include/uapi/linux/kvm.h		2014-04-22 10:51:06 -03:00
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kvm	Lazy storage key handling	2014-04-22 10:51:06 -03:00