| Message ID | 20210305150638.2675513-3-npiggin@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | KVM: PPC: Book3S: C-ify the P9 entry/exit code | expand |
Nicholas Piggin <npiggin@gmail.com> writes: > This bit only applies to hash partitions. > > Signed-off-by: Nicholas Piggin <npiggin@gmail.com> > --- > arch/powerpc/kvm/book3s_hv.c | 6 ++++-- > arch/powerpc/kvm/book3s_hv_nested.c | 2 +- > 2 files changed, 5 insertions(+), 3 deletions(-) > > diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c > index c40eeb20be39..2e29b96ef775 100644 > --- a/arch/powerpc/kvm/book3s_hv.c > +++ b/arch/powerpc/kvm/book3s_hv.c > @@ -1666,10 +1666,12 @@ static void kvmppc_set_lpcr(struct kvm_vcpu *vcpu, u64 new_lpcr, > > /* > * Userspace can only modify DPFD (default prefetch depth), > - * ILE (interrupt little-endian) and TC (translation control). > + * ILE (interrupt little-endian) and TC (translation control) if HPT. > * On POWER8 and POWER9 userspace can also modify AIL (alt. interrupt loc.). > */ > - mask = LPCR_DPFD | LPCR_ILE | LPCR_TC; > + mask = LPCR_DPFD | LPCR_ILE; > + if (!kvm_is_radix(kvm)) > + mask |= LPCR_TC; I think in theory there is a possibility that userspace sets the LPCR while we running Radix and then calls the KVM_PPC_CONFIGURE_V3_MMU ioctl right after to switch to HPT. I'm not sure if that would make sense but maybe it's something to consider... > if (cpu_has_feature(CPU_FTR_ARCH_207S)) { > mask |= LPCR_AIL; > /* LPCR[AIL]=1/2 is disallowed */ > diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c > index b496079e02f7..0e6cf650cbfe 100644 > --- a/arch/powerpc/kvm/book3s_hv_nested.c > +++ b/arch/powerpc/kvm/book3s_hv_nested.c > @@ -141,7 +141,7 @@ static void sanitise_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr) > * Don't let L1 change LPCR bits for the L2 except these: > * Keep this in sync with kvmppc_set_lpcr. > */ > - mask = LPCR_DPFD | LPCR_ILE | LPCR_TC | LPCR_LD | LPCR_LPES | LPCR_MER; > + mask = LPCR_DPFD | LPCR_ILE | LPCR_LD | LPCR_LPES | LPCR_MER; > /* LPCR[AIL]=1/2 is disallowed */ > if ((hr->lpcr & LPCR_AIL) && (hr->lpcr & LPCR_AIL) != LPCR_AIL_3) > hr->lpcr &= ~LPCR_AIL;
Excerpts from Fabiano Rosas's message of March 9, 2021 1:47 am: > Nicholas Piggin <npiggin@gmail.com> writes: > >> This bit only applies to hash partitions. >> >> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> >> --- >> arch/powerpc/kvm/book3s_hv.c | 6 ++++-- >> arch/powerpc/kvm/book3s_hv_nested.c | 2 +- >> 2 files changed, 5 insertions(+), 3 deletions(-) >> >> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c >> index c40eeb20be39..2e29b96ef775 100644 >> --- a/arch/powerpc/kvm/book3s_hv.c >> +++ b/arch/powerpc/kvm/book3s_hv.c >> @@ -1666,10 +1666,12 @@ static void kvmppc_set_lpcr(struct kvm_vcpu *vcpu, u64 new_lpcr, >> >> /* >> * Userspace can only modify DPFD (default prefetch depth), >> - * ILE (interrupt little-endian) and TC (translation control). >> + * ILE (interrupt little-endian) and TC (translation control) if HPT. >> * On POWER8 and POWER9 userspace can also modify AIL (alt. interrupt loc.). >> */ >> - mask = LPCR_DPFD | LPCR_ILE | LPCR_TC; >> + mask = LPCR_DPFD | LPCR_ILE; >> + if (!kvm_is_radix(kvm)) >> + mask |= LPCR_TC; > > I think in theory there is a possibility that userspace sets the LPCR > while we running Radix and then calls the KVM_PPC_CONFIGURE_V3_MMU ioctl > right after to switch to HPT. I'm not sure if that would make sense but > maybe it's something to consider... Oh actually it is an issue for the later AIL patch I think. So LPCR will have to be filtered again when switching MMU mode. Good catch, I'll add something for that. Thanks, Nick > >> if (cpu_has_feature(CPU_FTR_ARCH_207S)) { >> mask |= LPCR_AIL; >> /* LPCR[AIL]=1/2 is disallowed */ >> diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c >> index b496079e02f7..0e6cf650cbfe 100644 >> --- a/arch/powerpc/kvm/book3s_hv_nested.c >> +++ b/arch/powerpc/kvm/book3s_hv_nested.c >> @@ -141,7 +141,7 @@ static void sanitise_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr) >> * Don't let L1 change LPCR bits for the L2 except these: >> * Keep this in sync with kvmppc_set_lpcr. >> */ >> - mask = LPCR_DPFD | LPCR_ILE | LPCR_TC | LPCR_LD | LPCR_LPES | LPCR_MER; >> + mask = LPCR_DPFD | LPCR_ILE | LPCR_LD | LPCR_LPES | LPCR_MER; >> /* LPCR[AIL]=1/2 is disallowed */ >> if ((hr->lpcr & LPCR_AIL) && (hr->lpcr & LPCR_AIL) != LPCR_AIL_3) >> hr->lpcr &= ~LPCR_AIL; >
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index c40eeb20be39..2e29b96ef775 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -1666,10 +1666,12 @@ static void kvmppc_set_lpcr(struct kvm_vcpu *vcpu, u64 new_lpcr, /* * Userspace can only modify DPFD (default prefetch depth), - * ILE (interrupt little-endian) and TC (translation control). + * ILE (interrupt little-endian) and TC (translation control) if HPT. * On POWER8 and POWER9 userspace can also modify AIL (alt. interrupt loc.). */ - mask = LPCR_DPFD | LPCR_ILE | LPCR_TC; + mask = LPCR_DPFD | LPCR_ILE; + if (!kvm_is_radix(kvm)) + mask |= LPCR_TC; if (cpu_has_feature(CPU_FTR_ARCH_207S)) { mask |= LPCR_AIL; /* LPCR[AIL]=1/2 is disallowed */ diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c index b496079e02f7..0e6cf650cbfe 100644 --- a/arch/powerpc/kvm/book3s_hv_nested.c +++ b/arch/powerpc/kvm/book3s_hv_nested.c @@ -141,7 +141,7 @@ static void sanitise_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr) * Don't let L1 change LPCR bits for the L2 except these: * Keep this in sync with kvmppc_set_lpcr. */ - mask = LPCR_DPFD | LPCR_ILE | LPCR_TC | LPCR_LD | LPCR_LPES | LPCR_MER; + mask = LPCR_DPFD | LPCR_ILE | LPCR_LD | LPCR_LPES | LPCR_MER; /* LPCR[AIL]=1/2 is disallowed */ if ((hr->lpcr & LPCR_AIL) && (hr->lpcr & LPCR_AIL) != LPCR_AIL_3) hr->lpcr &= ~LPCR_AIL;
This bit only applies to hash partitions. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/kvm/book3s_hv.c | 6 ++++-- arch/powerpc/kvm/book3s_hv_nested.c | 2 +- 2 files changed, 5 insertions(+), 3 deletions(-)