On 15.12.2016 06:53, David Gibson wrote:
> Currently the kvm_hpt_info structure stores the hashed page table's order,
> and also the number of HPTEs it contains and a mask for its size. The
> last two can be easily derived from the order, so remove them and just
> calculate them as necessary with a couple of helper inlines.
>
> Signed-off-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
> ---
[...]
> diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
> index b5799d1..fe88132 100644
> --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
> +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
> @@ -83,15 +83,11 @@ long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp)
>
> kvm->arch.hpt.virt = hpt;
> kvm->arch.hpt.order = order;
> - /* HPTEs are 2**4 bytes long */
> - kvm->arch.hpt.npte = 1ul << (order - 4);
> - /* 128 (2**7) bytes in each HPTEG */
> - kvm->arch.hpt.mask = (1ul << (order - 7)) - 1;
>
> atomic64_set(&kvm->arch.mmio_update, 0);
>
> /* Allocate reverse map array */
> - rev = vmalloc(sizeof(struct revmap_entry) * kvm->arch.hpt.npte);
> + rev = vmalloc(sizeof(struct revmap_entry) * kvmppc_hpt_npte(&kvm->arch.hpt));
> if (!rev) {
> pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n");
> goto out_freehpt;
> @@ -194,8 +190,8 @@ void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
> if (npages > 1ul << (40 - porder))
> npages = 1ul << (40 - porder);
> /* Can't use more than 1 HPTE per HPTEG */
> - if (npages > kvm->arch.hpt.mask + 1)
> - npages = kvm->arch.hpt.mask + 1;
> + if (npages > kvmppc_hpt_mask(&kvm->arch.hpt) + 1)
> + npages = kvmppc_hpt_mask(&kvm->arch.hpt) + 1;
>
> hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
> HPTE_V_BOLTED | hpte0_pgsize_encoding(psize);
> @@ -205,7 +201,8 @@ void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
> for (i = 0; i < npages; ++i) {
> addr = i << porder;
> /* can't use hpt_hash since va > 64 bits */
> - hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & kvm->arch.hpt.mask;
> + hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25)))
> + & kvmppc_hpt_mask(&kvm->arch.hpt);
> /*
> * We assume that the hash table is empty and no
> * vcpus are using it at this stage. Since we create
kvmppc_hpt_mask() is now called three times in kvmppc_map_vrma() ... you
could use a local variable to store the value so that the calculation
has only be done once here.
> @@ -1306,7 +1303,7 @@ static ssize_t kvm_htab_read(struct file *file, char __user *buf,
>
> /* Skip uninteresting entries, i.e. clean on not-first pass */
> if (!first_pass) {
> - while (i < kvm->arch.hpt.npte &&
> + while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
> !hpte_dirty(revp, hptp)) {
> ++i;
> hptp += 2;
> @@ -1316,7 +1313,7 @@ static ssize_t kvm_htab_read(struct file *file, char __user *buf,
> hdr.index = i;
>
> /* Grab a series of valid entries */
> - while (i < kvm->arch.hpt.npte &&
> + while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
> hdr.n_valid < 0xffff &&
> nb + HPTE_SIZE < count &&
> record_hpte(flags, hptp, hpte, revp, 1, first_pass)) {
> @@ -1332,7 +1329,7 @@ static ssize_t kvm_htab_read(struct file *file, char __user *buf,
> ++revp;
> }
> /* Now skip invalid entries while we can */
> - while (i < kvm->arch.hpt.npte &&
> + while (i < kvmppc_hpt_npte(&kvm->arch.hpt) &&
> hdr.n_invalid < 0xffff &&
> record_hpte(flags, hptp, hpte, revp, 0, first_pass)) {
> /* found an invalid entry */
Dito, you could use a local variable to store the value from
kvmppc_hpt_npte()
Anyway, apart from these nits, patch looks fine to me, so:
Reviewed-by: Thomas Huth <thuth@xxxxxxxxxx>
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