From ea48731fbda09f9b853bf6d29315bed9362051ee Mon Sep 17 00:00:00 2001 From: David Gibson Date: Fri, 2 Feb 2018 14:29:08 +1100 Subject: [PATCH] KVM: PPC: Book3S HV: Make HPT resizing work on POWER9 This adds code to enable the HPT resizing code to work on POWER9, which uses a slightly modified HPT entry format compared to POWER8. On POWER9, we convert HPTEs read from the HPT from the new format to the old format so that the rest of the HPT resizing code can work as before. HPTEs written to the new HPT are converted to the new format as the last step before writing them into the new HPT. This takes out the checks added by commit 2c40007c4ae3 ("KVM: PPC: Book3S HV: Disable HPT resizing on POWER9 for now", 2017-02-18), now that HPT resizing works on POWER9. On POWER9, when we pivot to the new HPT, we now call kvmppc_setup_partition_table() to update the partition table in order to make the hardware use the new HPT. [paulus@ozlabs.org - added kvmppc_setup_partition_table() call, wrote commit message.] Tested-by: Laurent Vivier Signed-off-by: David Gibson Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_64_mmu_hv.c | 30 ++++++++++++++++++++++------- arch/powerpc/kvm/powerpc.c | 3 +-- 2 files changed, 24 insertions(+), 9 deletions(-) diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index d19649960bbf9..cb34be7d1a49f 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -1261,6 +1261,11 @@ static unsigned long resize_hpt_rehash_hpte(struct kvm_resize_hpt *resize, /* Nothing to do */ goto out; + if (cpu_has_feature(CPU_FTR_ARCH_300)) { + rpte = be64_to_cpu(hptep[1]); + vpte = hpte_new_to_old_v(vpte, rpte); + } + /* Unmap */ rev = &old->rev[idx]; guest_rpte = rev->guest_rpte; @@ -1290,7 +1295,6 @@ static unsigned long resize_hpt_rehash_hpte(struct kvm_resize_hpt *resize, /* Reload PTE after unmap */ vpte = be64_to_cpu(hptep[0]); - BUG_ON(vpte & HPTE_V_VALID); BUG_ON(!(vpte & HPTE_V_ABSENT)); @@ -1299,6 +1303,12 @@ static unsigned long resize_hpt_rehash_hpte(struct kvm_resize_hpt *resize, goto out; rpte = be64_to_cpu(hptep[1]); + + if (cpu_has_feature(CPU_FTR_ARCH_300)) { + vpte = hpte_new_to_old_v(vpte, rpte); + rpte = hpte_new_to_old_r(rpte); + } + pshift = kvmppc_hpte_base_page_shift(vpte, rpte); avpn = HPTE_V_AVPN_VAL(vpte) & ~(((1ul << pshift) - 1) >> 23); pteg = idx / HPTES_PER_GROUP; @@ -1336,6 +1346,10 @@ static unsigned long resize_hpt_rehash_hpte(struct kvm_resize_hpt *resize, new_hptep = (__be64 *)(new->virt + (new_idx << 4)); replace_vpte = be64_to_cpu(new_hptep[0]); + if (cpu_has_feature(CPU_FTR_ARCH_300)) { + unsigned long replace_rpte = be64_to_cpu(new_hptep[1]); + replace_vpte = hpte_new_to_old_v(replace_vpte, replace_rpte); + } if (replace_vpte & (HPTE_V_VALID | HPTE_V_ABSENT)) { BUG_ON(new->order >= old->order); @@ -1351,6 +1365,11 @@ static unsigned long resize_hpt_rehash_hpte(struct kvm_resize_hpt *resize, /* Discard the previous HPTE */ } + if (cpu_has_feature(CPU_FTR_ARCH_300)) { + rpte = hpte_old_to_new_r(vpte, rpte); + vpte = hpte_old_to_new_v(vpte); + } + new_hptep[1] = cpu_to_be64(rpte); new->rev[new_idx].guest_rpte = guest_rpte; /* No need for a barrier, since new HPT isn't active */ @@ -1368,12 +1387,6 @@ static int resize_hpt_rehash(struct kvm_resize_hpt *resize) unsigned long i; int rc; - /* - * resize_hpt_rehash_hpte() doesn't handle the new-format HPTEs - * that POWER9 uses, and could well hit a BUG_ON on POWER9. - */ - if (cpu_has_feature(CPU_FTR_ARCH_300)) - return -EIO; for (i = 0; i < kvmppc_hpt_npte(&kvm->arch.hpt); i++) { rc = resize_hpt_rehash_hpte(resize, i); if (rc != 0) @@ -1404,6 +1417,9 @@ static void resize_hpt_pivot(struct kvm_resize_hpt *resize) synchronize_srcu_expedited(&kvm->srcu); + if (cpu_has_feature(CPU_FTR_ARCH_300)) + kvmppc_setup_partition_table(kvm); + resize_hpt_debug(resize, "resize_hpt_pivot() done\n"); } diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 77eb25abc6016..cf86aeb43fcfb 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -633,8 +633,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = 1; break; case KVM_CAP_SPAPR_RESIZE_HPT: - /* Disable this on POWER9 until code handles new HPTE format */ - r = !!hv_enabled && !cpu_has_feature(CPU_FTR_ARCH_300); + r = !!hv_enabled; break; #endif #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE -- 2.39.5