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@xxxxxxxxx>
---
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 c0a04ce39e00..a37ab798eb7c 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3856,7 +3856,9 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns
if (unlikely(load_vcpu_state(vcpu, &host_os_sprs)))
msr = mfmsr(); /* TM restore can update msr */
- 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;
@@ -3897,7 +3899,6 @@ 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);
@@ -3910,6 +3911,8 @@ 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 976687c3709a..52690af66ca9 100644
--- a/arch/powerpc/kvm/book3s_hv_p9_entry.c
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -639,6 +639,7 @@ 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;
@@ -656,7 +657,9 @@ 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()) {
@@ -740,8 +743,14 @@ 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);
@@ -947,7 +956,7 @@ 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);
@@ -993,9 +1002,12 @@ 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
