This patch series adds support for passing TMEM commands between KVM guests and the host. This opens the possibility to use TMEM cross-guests and posibly across hosts with RAMster. Since frontswap was merged in the 3.4 cycle, the kernel now has all facilities required to work with TMEM. There is no longer a dependency on out of tree code. We can split this patch series into two: - The guest side, which is basically two shims that proxy mm/cleancache.c and mm/frontswap.c requests from the guest back to the host. This is done using a new KVM_HC_TMEM hypercall. - The host side, which is a rather small shim which connects KVM to zcache. It's worth noting that this patch series don't have any significant logic in it, and is mostly a collection of shims to pass TMEM commands across hypercalls. I ran benchmarks using both the "streaming test" proposed by Avi, and some general fio tests. Since the fio tests showed similar results to the streaming test, and no anomalies, here is the summary of the streaming tests: First, trying to stream a 26GB random file without KVM TMEM: real 7m36.046s user 0m17.113s sys 5m23.809s And with KVM TMEM: real 7m36.018s user 0m17.124s sys 5m28.391s - No significant difference. Now, trying to stream a 16gb file that compresses nicely, first without KVM TMEM: real 5m10.299s user 0m11.311s sys 3m40.139s And a second run without dropping cache: real 4m33.951s user 0m10.869s sys 3m13.789s Now, with KVM TMEM: real 4m55.528s user 0m11.119s sys 3m33.243s And a second run: real 2m53.713s user 0m7.971s sys 2m29.807s So KVM TMEM shows a nice performance increase once it can store pages on the host. Sasha Levin (10): KVM: reintroduce hc_gpa KVM: wire up the TMEM HC zcache: export zcache interface KVM: add KVM TMEM entries in the appropriate config menu entry KVM: bring in general tmem definitions zcache: move out client declaration and add a KVM client KVM: add KVM TMEM host side interface KVM: add KVM TMEM guest support KVM: support guest side cleancache KVM: support guest side frontswap arch/x86/kvm/Kconfig | 1 + arch/x86/kvm/Makefile | 2 + arch/x86/kvm/tmem/Kconfig | 43 +++++++++++ arch/x86/kvm/tmem/Makefile | 6 ++ arch/x86/kvm/tmem/cleancache.c | 120 +++++++++++++++++++++++++++++ arch/x86/kvm/tmem/frontswap.c | 139 ++++++++++++++++++++++++++++++++++ arch/x86/kvm/tmem/guest.c | 95 +++++++++++++++++++++++ arch/x86/kvm/tmem/guest.h | 11 +++ arch/x86/kvm/tmem/host.c | 78 +++++++++++++++++++ arch/x86/kvm/tmem/host.h | 20 +++++ arch/x86/kvm/tmem/tmem.h | 62 +++++++++++++++ arch/x86/kvm/x86.c | 13 +++ drivers/staging/zcache/zcache-main.c | 48 ++++++++++-- drivers/staging/zcache/zcache.h | 20 +++++ include/linux/kvm_para.h | 1 + 15 files changed, 652 insertions(+), 7 deletions(-) create mode 100644 arch/x86/kvm/tmem/Kconfig create mode 100644 arch/x86/kvm/tmem/Makefile create mode 100644 arch/x86/kvm/tmem/cleancache.c create mode 100644 arch/x86/kvm/tmem/frontswap.c create mode 100644 arch/x86/kvm/tmem/guest.c create mode 100644 arch/x86/kvm/tmem/guest.h create mode 100644 arch/x86/kvm/tmem/host.c create mode 100644 arch/x86/kvm/tmem/host.h create mode 100644 arch/x86/kvm/tmem/tmem.h create mode 100644 drivers/staging/zcache/zcache.h -- 1.7.8.6 -- 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
