From: Nicholas Piggin <npiggin@gmail.com>
To: kvm-ppc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org, Nicholas Piggin <npiggin@gmail.com>
Subject: [RFC PATCH 39/43] KVM: PPC: Book3S HV P9: Don't restore PSSCR if not needed
Date: Tue, 22 Jun 2021 20:57:32 +1000 [thread overview]
Message-ID: <20210622105736.633352-40-npiggin@gmail.com> (raw)
In-Reply-To: <20210622105736.633352-1-npiggin@gmail.com>
This also moves the PSSCR update in nested entry to avoid a SPR
scoreboard stall.
-45 cycles (6276) POWER9 virt-mode NULL hcall
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kvm/book3s_hv.c | 7 +++++--
arch/powerpc/kvm/book3s_hv_p9_entry.c | 26 +++++++++++++++++++-------
2 files changed, 24 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index c7cf771d3351..91bbd0a8f6b6 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3756,7 +3756,9 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
load_vcpu_state(vcpu, &host_os_sprs);
- mtspr(SPRN_PSSCR_PR, vcpu->arch.psscr);
+ if (vcpu->arch.psscr != host_psscr)
+ mtspr(SPRN_PSSCR_PR, vcpu->arch.psscr);
+
kvmhv_save_hv_regs(vcpu, &hvregs);
hvregs.lpcr = lpcr;
vcpu->arch.regs.msr = vcpu->arch.shregs.msr;
@@ -3797,7 +3799,6 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
vcpu->arch.psscr = mfspr(SPRN_PSSCR_PR);
- mtspr(SPRN_PSSCR_PR, host_psscr);
store_vcpu_state(vcpu);
@@ -3810,6 +3811,8 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
timer_rearm_host_dec(*tb);
restore_p9_host_os_sprs(vcpu, &host_os_sprs);
+ if (vcpu->arch.psscr != host_psscr)
+ mtspr(SPRN_PSSCR_PR, host_psscr);
return trap;
}
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
index f305d1d6445c..4bab56c10254 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -621,6 +621,7 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
unsigned long host_dawr0;
unsigned long host_dawrx0;
unsigned long host_psscr;
+ unsigned long host_hpsscr;
unsigned long host_pidr;
unsigned long host_dawr1;
unsigned long host_dawrx1;
@@ -638,7 +639,9 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
host_hfscr = mfspr(SPRN_HFSCR);
host_ciabr = mfspr(SPRN_CIABR);
- host_psscr = mfspr(SPRN_PSSCR);
+ host_psscr = mfspr(SPRN_PSSCR_PR);
+ if (cpu_has_feature(CPU_FTRS_POWER9_DD2_2))
+ host_hpsscr = mfspr(SPRN_PSSCR);
host_pidr = mfspr(SPRN_PID);
if (dawr_enabled()) {
@@ -719,8 +722,14 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
if (vcpu->arch.ciabr != host_ciabr)
mtspr(SPRN_CIABR, vcpu->arch.ciabr);
- mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
- (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
+
+ if (cpu_has_feature(CPU_FTRS_POWER9_DD2_2)) {
+ mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
+ (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
+ } else {
+ if (vcpu->arch.psscr != host_psscr)
+ mtspr(SPRN_PSSCR_PR, vcpu->arch.psscr);
+ }
mtspr(SPRN_HFSCR, vcpu->arch.hfscr);
@@ -905,7 +914,7 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
vcpu->arch.ic = mfspr(SPRN_IC);
vcpu->arch.pid = mfspr(SPRN_PID);
- vcpu->arch.psscr = mfspr(SPRN_PSSCR) & PSSCR_GUEST_VIS;
+ vcpu->arch.psscr = mfspr(SPRN_PSSCR_PR);
vcpu->arch.shregs.sprg0 = mfspr(SPRN_SPRG0);
vcpu->arch.shregs.sprg1 = mfspr(SPRN_SPRG1);
@@ -948,9 +957,12 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
mtspr(SPRN_PURR, local_paca->kvm_hstate.host_purr);
mtspr(SPRN_SPURR, local_paca->kvm_hstate.host_spurr);
- /* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
- mtspr(SPRN_PSSCR, host_psscr |
- (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
+ if (cpu_has_feature(CPU_FTRS_POWER9_DD2_2)) {
+ /* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
+ mtspr(SPRN_PSSCR, host_hpsscr |
+ (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
+ }
+
mtspr(SPRN_HFSCR, host_hfscr);
if (vcpu->arch.ciabr != host_ciabr)
mtspr(SPRN_CIABR, host_ciabr);
--
2.23.0
next prev parent reply other threads:[~2021-06-22 11:15 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-22 10:56 [RFC PATCH 00/43] KVM: PPC: Book3S HV P9: entry/exit optimisations round 1 Nicholas Piggin
2021-06-22 10:56 ` [RFC PATCH 01/43] powerpc/64s: Remove WORT SPR from POWER9/10 Nicholas Piggin
2021-06-30 17:29 ` Fabiano Rosas
2021-06-22 10:56 ` [RFC PATCH 02/43] KMV: PPC: Book3S HV P9: Use set_dec to set decrementer to host Nicholas Piggin
2021-06-22 10:56 ` [RFC PATCH 03/43] KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer read Nicholas Piggin
2021-06-22 10:56 ` [RFC PATCH 04/43] KVM: PPC: Book3S HV P9: Use large decrementer for HDEC Nicholas Piggin
2021-06-22 10:56 ` [RFC PATCH 05/43] KVM: PPC: Book3S HV P9: Reduce mftb per guest entry/exit Nicholas Piggin
2021-06-22 10:56 ` [RFC PATCH 06/43] powerpc/time: add API for KVM to re-arm the host timer/decrementer Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 07/43] KVM: PPC: Book3S HV: POWER10 enable HAIL when running radix guests Nicholas Piggin
2021-06-30 19:41 ` Fabiano Rosas
2021-06-22 10:57 ` [RFC PATCH 08/43] powerpc/64s: Keep AMOR SPR a constant ~0 at runtime Nicholas Piggin
2021-06-30 19:17 ` Fabiano Rosas
2021-06-22 10:57 ` [RFC PATCH 09/43] KVM: PPC: Book3S HV: Don't always save PMU for guest capable of nesting Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 10/43] powerpc/64s: Always set PMU control registers to frozen/disabled when not in use Nicholas Piggin
2021-07-01 13:17 ` Madhavan Srinivasan
2021-07-02 0:27 ` Nicholas Piggin
2021-07-08 12:45 ` Nicholas Piggin
2021-07-12 3:42 ` Madhavan Srinivasan
2021-07-10 2:50 ` Athira Rajeev
2021-07-12 2:41 ` Nicholas Piggin
2021-07-12 3:17 ` Athira Rajeev
2021-07-14 12:39 ` Nicholas Piggin
2021-07-16 3:43 ` Madhavan Srinivasan
2021-06-22 10:57 ` [RFC PATCH 11/43] KVM: PPC: Book3S HV P9: Implement PMU save/restore in C Nicholas Piggin
2021-07-10 2:47 ` Athira Rajeev
2021-07-12 2:49 ` Nicholas Piggin
2021-07-12 14:07 ` Athira Rajeev
2021-06-22 10:57 ` [RFC PATCH 12/43] KVM: PPC: Book3S HV P9: Factor out yield_count increment Nicholas Piggin
2021-07-08 17:56 ` Fabiano Rosas
2021-06-22 10:57 ` [RFC PATCH 13/43] KVM: PPC: Book3S HV P9: Factor PMU save/load into context switch functions Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 14/43] KVM: PPC: Book3S HV P9: Demand fault PMU SPRs when marked not inuse Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 15/43] KVM: PPC: Book3S HV: CTRL SPR does not require read-modify-write Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 16/43] KVM: PPC: Book3S HV P9: Move SPRG restore to restore_p9_host_os_sprs Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 17/43] KVM: PPC: Book3S HV P9: Reduce mtmsrd instructions required to save host SPRs Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 18/43] KVM: PPC: Book3S HV P9: Improve mtmsrd scheduling by delaying MSR[EE] disable Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 19/43] KVM: PPC: Book3S HV P9: Add kvmppc_stop_thread to match kvmppc_start_thread Nicholas Piggin
2021-06-30 20:18 ` Fabiano Rosas
2021-06-22 10:57 ` [RFC PATCH 20/43] KVM: PPC: Book3S HV: Change dec_expires to be relative to guest timebase Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 21/43] KVM: PPC: Book3S HV P9: Move TB updates Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 22/43] KVM: PPC: Book3S HV P9: Optimise timebase reads Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 23/43] KVM: PPC: Book3S HV P9: Avoid SPR scoreboard stalls Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 24/43] KVM: PPC: Book3S HV P9: Only execute mtSPR if the value changed Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 25/43] KVM: PPC: Book3S HV P9: Juggle SPR switching around Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 26/43] KVM: PPC: Book3S HV P9: Move vcpu register save/restore into functions Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 27/43] KVM: PPC: Book3S HV P9: Move host OS save/restore functions to built-in Nicholas Piggin
2021-07-08 5:32 ` Athira Rajeev
2021-07-12 2:50 ` Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 28/43] KVM: PPC: Book3S HV P9: Move nested guest entry into its own function Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 29/43] KVM: PPC: Book3S HV P9: Move remaining SPR and MSR access into low level entry Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 30/43] KVM: PPC: Book3S HV P9: Implement TM fastpath for guest entry/exit Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 31/43] KVM: PPC: Book3S HV P9: Switch PMU to guest as late as possible Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 32/43] KVM: PPC: Book3S HV P9: Restrict DSISR canary workaround to processors that require it Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 33/43] KVM: PPC: Book3S HV P9: More SPR speed improvements Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 34/43] KVM: PPC: Book3S HV P9: Demand fault EBB facility registers Nicholas Piggin
2021-07-08 17:46 ` Fabiano Rosas
2021-06-22 10:57 ` [RFC PATCH 35/43] KVM: PPC: Book3S HV P9: Demand fault TM " Nicholas Piggin
2021-07-08 17:46 ` Fabiano Rosas
2021-06-22 10:57 ` [RFC PATCH 36/43] KVM: PPC: Book3S HV P9: Use Linux SPR save/restore to manage some host SPRs Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 37/43] KVM: PPC: Book3S HV P9: Comment and fix MMU context switching code Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 38/43] KVM: PPC: Book3S HV P9: Test dawr_enabled() before saving host DAWR SPRs Nicholas Piggin
2021-06-30 17:51 ` Fabiano Rosas
2021-07-01 8:04 ` Nicholas Piggin
2021-06-22 10:57 ` Nicholas Piggin [this message]
2021-06-22 10:57 ` [RFC PATCH 40/43] KVM: PPC: Book3S HV P9: Avoid tlbsync sequence on radix guest exit Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 41/43] KVM: PPC: Book3S HV Nested: Avoid extra mftb() in nested entry Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 42/43] KVM: PPC: Book3S HV P9: Improve mfmsr performance on entry Nicholas Piggin
2021-06-22 10:57 ` [RFC PATCH 43/43] KVM: PPC: Book3S HV P9: Optimise hash guest SLB saving Nicholas Piggin
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