diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2021-11-23 10:52:12 +0100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-11-24 11:09:00 +0100 |
| commit | d55b1eccc7aa14a1750aecf271806365478ca805 (patch) | |
| tree | 0c1ad8328b39c01b9e2561031765f183ca7249ad | |
| parent | KVM: PPC: Book3S HV P9: Switch PMU to guest as late as possible (diff) | |
| download | linux-d55b1eccc7aa14a1750aecf271806365478ca805.tar.xz linux-d55b1eccc7aa14a1750aecf271806365478ca805.zip | |
KVM: PPC: Book3S HV P9: Restrict DSISR canary workaround to processors that require it
Use CPU_FTR_P9_RADIX_PREFETCH_BUG to apply the workaround, to test for
DD2.1 and below processors. This saves a mtSPR in guest entry.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211123095231.1036501-35-npiggin@gmail.com
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 3 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_p9_entry.c | 6 |
2 files changed, 6 insertions, 3 deletions
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index c14467cf23d3..3795080d5403 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -1590,7 +1590,8 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu, unsigned long vsid; long err; - if (vcpu->arch.fault_dsisr == HDSISR_CANARY) { + if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG) && + unlikely(vcpu->arch.fault_dsisr == HDSISR_CANARY)) { r = RESUME_GUEST; /* Just retry if it's the canary */ break; } diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c index 619bbcd47b92..67f57b03a896 100644 --- a/arch/powerpc/kvm/book3s_hv_p9_entry.c +++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c @@ -683,9 +683,11 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc * HDSI which should correctly update the HDSISR the second time HDSI * entry. * - * Just do this on all p9 processors for now. + * The "radix prefetch bug" test can be used to test for this bug, as + * it also exists fo DD2.1 and below. */ - mtspr(SPRN_HDSISR, HDSISR_CANARY); + if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) + mtspr(SPRN_HDSISR, HDSISR_CANARY); mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0); mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1); |