diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2021-11-23 12:52:03 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-11-24 13:08:59 +0300 |
| commit | 9a1e530bbbdaa2184993a7d7fc61d78871540ccd (patch) | |
| tree | 5833774a0d676fd979366875ff7d529521ecfb27 /arch/powerpc/kvm/book3s_hv_p9_entry.c | |
| parent | cb2553a093093ae46cfaee31321bcedcd0312c5d (diff) | |
| download | linux-9a1e530bbbdaa2184993a7d7fc61d78871540ccd.tar.xz | |
KVM: PPC: Book3S HV P9: Avoid SPR scoreboard stalls
Avoid interleaving mfSPR and mtSPR to reduce SPR scoreboard stalls.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211123095231.1036501-26-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kvm/book3s_hv_p9_entry.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_p9_entry.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c index 2bd96d8256d1..bd0021cd3a67 100644 --- a/arch/powerpc/kvm/book3s_hv_p9_entry.c +++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c @@ -228,6 +228,9 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc host_dawrx1 = mfspr(SPRN_DAWRX1); } + local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR); + local_paca->kvm_hstate.host_spurr = mfspr(SPRN_SPURR); + if (vc->tb_offset) { u64 new_tb = *tb + vc->tb_offset; mtspr(SPRN_TBU40, new_tb); @@ -244,8 +247,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc mtspr(SPRN_DPDES, vc->dpdes); mtspr(SPRN_VTB, vc->vtb); - local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR); - local_paca->kvm_hstate.host_spurr = mfspr(SPRN_SPURR); mtspr(SPRN_PURR, vcpu->arch.purr); mtspr(SPRN_SPURR, vcpu->arch.spurr); @@ -448,10 +449,8 @@ tm_return_to_guest: /* Advance host PURR/SPURR by the amount used by guest */ purr = mfspr(SPRN_PURR); spurr = mfspr(SPRN_SPURR); - mtspr(SPRN_PURR, local_paca->kvm_hstate.host_purr + - purr - vcpu->arch.purr); - mtspr(SPRN_SPURR, local_paca->kvm_hstate.host_spurr + - spurr - vcpu->arch.spurr); + local_paca->kvm_hstate.host_purr += purr - vcpu->arch.purr; + local_paca->kvm_hstate.host_spurr += spurr - vcpu->arch.spurr; vcpu->arch.purr = purr; vcpu->arch.spurr = spurr; @@ -464,6 +463,9 @@ tm_return_to_guest: vcpu->arch.shregs.sprg2 = mfspr(SPRN_SPRG2); vcpu->arch.shregs.sprg3 = mfspr(SPRN_SPRG3); + vc->dpdes = mfspr(SPRN_DPDES); + vc->vtb = mfspr(SPRN_VTB); + dec = mfspr(SPRN_DEC); if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */ dec = (s32) dec; @@ -481,6 +483,9 @@ tm_return_to_guest: vc->tb_offset_applied = 0; } + 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)); @@ -509,8 +514,6 @@ tm_return_to_guest: if (cpu_has_feature(CPU_FTR_ARCH_31)) asm volatile(PPC_CP_ABORT); - vc->dpdes = mfspr(SPRN_DPDES); - vc->vtb = mfspr(SPRN_VTB); mtspr(SPRN_DPDES, 0); if (vc->pcr) mtspr(SPRN_PCR, PCR_MASK); |