Hi, RFCv1 --> v2 - Dropped "pinned VMID" support for now. - Dropped RFC tag. Sanity tested on HiSilicon D06 board. Thanks, Shameer History: ------- Please find the RFC series here, https://lore.kernel.org/kvmarm/20210506165232.1969-1-shameerali.kolothum.thodi@xxxxxxxxxx/ >From RFCv1: This is based on a suggestion from Will [0] to try out the asid based kvm vmid solution as a separate VMID allocator instead of the shared lib approach attempted in v4[1]. The idea is to compare both the approaches and see whether the shared lib solution with callbacks make sense or not. Though we are not using the pinned vmids yet, patch #2 has code for pinned vmid support. This is just to help the comparison. Test Setup/Results ---------------- The measurement was made with maxcpus set to 8 and with the number of VMID limited to 4-bit. The test involves running concurrently 40 guests with 2 vCPUs. Each guest will then execute hackbench 5 times before exiting. The performance difference between the current algo and the new one are(avg. of 10 runs): - 1.9% less entry/exit from the guest - 0.5% faster This is more or less comparable to v4 numbers. For the complete series, please see, https://github.com/hisilicon/kernel-dev/tree/private-v5.12-rc7-vmid-2nd-rfc and for the shared asid lib v4 solution, https://github.com/hisilicon/kernel-dev/tree/private-v5.12-rc7-asid-v4 As you can see there are ofcourse code duplication with this approach but may be it is more easy to maintain considering the complexity involved. [0] https://lore.kernel.org/lkml/20210422160846.GB2214@willie-the-truck/ [1] https://lore.kernel.org/lkml/20210414112312.13704-1-shameerali.kolothum.thodi@xxxxxxxxxx/ Julien Grall (2): arch/arm64: Introduce a capability to tell whether 16-bit VMID is available kvm/arm: Align the VMID allocation with the arm64 ASID one Shameer Kolothum (1): kvm/arm: Introduce a new vmid allocator for KVM arch/arm64/include/asm/kvm_asm.h | 4 +- arch/arm64/include/asm/kvm_host.h | 10 +- arch/arm64/include/asm/kvm_mmu.h | 7 +- arch/arm64/kernel/cpufeature.c | 9 ++ arch/arm64/kvm/Makefile | 2 +- arch/arm64/kvm/arm.c | 115 ++++---------- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 6 +- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 3 +- arch/arm64/kvm/hyp/nvhe/tlb.c | 10 +- arch/arm64/kvm/hyp/vhe/tlb.c | 10 +- arch/arm64/kvm/mmu.c | 1 - arch/arm64/kvm/vmid.c | 206 ++++++++++++++++++++++++++ arch/arm64/tools/cpucaps | 1 + 13 files changed, 273 insertions(+), 111 deletions(-) create mode 100644 arch/arm64/kvm/vmid.c -- 2.17.1 _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
