Re: [PATCH v2 28/37] KVM: PPC: Book3S HV P9: Add helpers for OS SPR handling
From: Fabiano Rosas <hidden>
Date: 2021-03-02 15:05:26
Nicholas Piggin [off-list ref] writes:
This is a first step to wrapping supervisor and user SPR saving and loading up into helpers, which will then be called independently in bare metal and nested HV cases in order to optimise SPR access. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> ---
<snip>
+/* vcpu guest regs must already be saved */
+static void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
+ struct p9_host_os_sprs *host_os_sprs)
+{
+ mtspr(SPRN_PSPB, 0);
+ mtspr(SPRN_WORT, 0);
+ mtspr(SPRN_UAMOR, 0);
+ mtspr(SPRN_PSPB, 0);Not your fault, but PSPB is set twice here.
+ + mtspr(SPRN_DSCR, host_os_sprs->dscr); + mtspr(SPRN_TIDR, host_os_sprs->tidr); + mtspr(SPRN_IAMR, host_os_sprs->iamr); + + if (host_os_sprs->amr != vcpu->arch.amr) + mtspr(SPRN_AMR, host_os_sprs->amr); + + if (host_os_sprs->fscr != vcpu->arch.fscr) + mtspr(SPRN_FSCR, host_os_sprs->fscr); +} +
<snip>
quoted hunk ↗ jump to hunk
@@ -3605,34 +3666,10 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit, vcpu->arch.dec_expires = dec + tb; vcpu->cpu = -1; vcpu->arch.thread_cpu = -1; - vcpu->arch.ctrl = mfspr(SPRN_CTRLF); - - vcpu->arch.iamr = mfspr(SPRN_IAMR); - vcpu->arch.pspb = mfspr(SPRN_PSPB); - vcpu->arch.fscr = mfspr(SPRN_FSCR); - vcpu->arch.tar = mfspr(SPRN_TAR); - vcpu->arch.ebbhr = mfspr(SPRN_EBBHR); - vcpu->arch.ebbrr = mfspr(SPRN_EBBRR); - vcpu->arch.bescr = mfspr(SPRN_BESCR); - vcpu->arch.wort = mfspr(SPRN_WORT); - vcpu->arch.tid = mfspr(SPRN_TIDR); - vcpu->arch.amr = mfspr(SPRN_AMR); - vcpu->arch.uamor = mfspr(SPRN_UAMOR); - vcpu->arch.dscr = mfspr(SPRN_DSCR); - - mtspr(SPRN_PSPB, 0); - mtspr(SPRN_WORT, 0); - mtspr(SPRN_UAMOR, 0); - mtspr(SPRN_DSCR, host_dscr); - mtspr(SPRN_TIDR, host_tidr); - mtspr(SPRN_IAMR, host_iamr); - mtspr(SPRN_PSPB, 0); - if (host_amr != vcpu->arch.amr) - mtspr(SPRN_AMR, host_amr); + restore_p9_host_os_sprs(vcpu, &host_os_sprs); - if (host_fscr != vcpu->arch.fscr) - mtspr(SPRN_FSCR, host_fscr); + store_spr_state(vcpu);
store_spr_state should come first, right? We want to save the guest state before restoring the host state.
msr_check_and_set(MSR_FP | MSR_VEC | MSR_VSX); store_fp_state(&vcpu->arch.fp);