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| author | Nicholas Piggin <npiggin@gmail.com> | 2021-11-23 10:51:42 +0100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-11-24 11:08:56 +0100 |
| commit | 4ebbd075bcde7884e078d4360510b989f559bfec (patch) | |
| tree | b4c0e43a6125510b84d4e7efcde674a527ff0ae5 /arch/powerpc/kvm/book3s_hv.c | |
| parent | KMV: PPC: Book3S HV P9: Use set_dec to set decrementer to host (diff) | |
| download | linux-4ebbd075bcde7884e078d4360510b989f559bfec.tar.xz linux-4ebbd075bcde7884e078d4360510b989f559bfec.zip | |
KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer read
There is no need to save away the host DEC value, as it is derived
from the host timer subsystem which maintains the next timer time,
so it can be restored from there.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211123095231.1036501-5-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kvm/book3s_hv.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index c7dbdec183b9..3322edbafc64 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -3873,18 +3873,17 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit, struct kvmppc_vcore *vc = vcpu->arch.vcore; struct p9_host_os_sprs host_os_sprs; s64 dec; - u64 tb; + u64 tb, next_timer; int trap, save_pmu; WARN_ON_ONCE(vcpu->arch.ceded); - dec = mfspr(SPRN_DEC); tb = mftb(); - if (dec < 0) + next_timer = timer_get_next_tb(); + if (tb >= next_timer) return BOOK3S_INTERRUPT_HV_DECREMENTER; - local_paca->kvm_hstate.dec_expires = dec + tb; - if (local_paca->kvm_hstate.dec_expires < time_limit) - time_limit = local_paca->kvm_hstate.dec_expires; + if (next_timer < time_limit) + time_limit = next_timer; save_p9_host_os_sprs(&host_os_sprs); @@ -4063,7 +4062,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit, vc->entry_exit_map = 0x101; vc->in_guest = 0; - set_dec(local_paca->kvm_hstate.dec_expires - mftb()); + next_timer = timer_get_next_tb(); + set_dec(next_timer - mftb()); /* We may have raced with new irq work */ if (test_irq_work_pending()) set_dec(1); |