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| author |   Nicholas Piggin <npiggin@gmail.com> | 2021-11-23 19:52:11 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2021-11-24 21:09:00 +1100 |
| commit | 3e7b3379023dad2e78c3200373a6368f5d0ee599 (patch) | |
| tree | 6ee4abd9ea5dcacfa3b89688a4b8f98b4cf18257 /arch/powerpc/kvm/book3s_hv.c | |
| parent | KVM: PPC: Book3S HV P9: Implement TM fastpath for guest entry/exit (diff) | |
| download | linux-dev-3e7b3379023dad2e78c3200373a6368f5d0ee599.tar.xz linux-dev-3e7b3379023dad2e78c3200373a6368f5d0ee599.zip | |
KVM: PPC: Book3S HV P9: Switch PMU to guest as late as possible
This moves PMU switch to guest as late as possible in entry, and switch
back to host as early as possible at exit. This helps the host get the
most perf coverage of KVM entry/exit code as possible.
This is slightly suboptimal for SPR scheduling point of view when the
PMU is enabled, but when perf is disabled there is no real difference.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211123095231.1036501-34-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kvm/book3s_hv.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 40bee0d61482..c14467cf23d3 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -3833,8 +3833,6 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns s64 dec; int trap; - switch_pmu_to_guest(vcpu, &host_os_sprs); - save_p9_host_os_sprs(&host_os_sprs); /* @@ -3897,9 +3895,11 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns mtspr(SPRN_DAR, vcpu->arch.shregs.dar); mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr); + switch_pmu_to_guest(vcpu, &host_os_sprs); trap = plpar_hcall_norets(H_ENTER_NESTED, __pa(&hvregs), __pa(&vcpu->arch.regs)); kvmhv_restore_hv_return_state(vcpu, &hvregs); + switch_pmu_to_host(vcpu, &host_os_sprs); vcpu->arch.shregs.msr = vcpu->arch.regs.msr; vcpu->arch.shregs.dar = mfspr(SPRN_DAR); vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR); @@ -3918,8 +3918,6 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns restore_p9_host_os_sprs(vcpu, &host_os_sprs); - switch_pmu_to_host(vcpu, &host_os_sprs); - return trap; } |