Re: [RFC PATCH 04/12] kvm-arm: Rename kvm_pmd_huge to huge_pmd

Christoffer Dall
2016-03-22T08:54:27Z

On Mon, Mar 14, 2016 at 04:53:03PM +0000, Suzuki K Poulose wrote:
> kvm_pmd_huge doesn't have any dependency on the page table
> where the pmd lives (i.e, hyp vs. stage2). So, rename it to
> huge_pmd() to make it explicit.
>
> kvm_p.d_* wrappers will be used for helpers which differ
> across hyp vs stage2.

I don't understand this commit message. Do you associate the kvm_
prefix specifically with one of hyp or stage2?

I remember reviewers in the past specifically asked to name anything
relating to pgtable macros in the kvm code with a kvm_ prefix to
distinguish them from logic used elsewhere in the kernel.

I specifically do not like having huge_pmd() be significantly different
in logic from pmd_huge(), so defining pmd_thp_or_huge() for arm64 is a
much better option.

Thanks,
-Christoffer

>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> ---
> arch/arm/kvm/mmu.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
> index a16631c..3b038bb 100644
> --- a/arch/arm/kvm/mmu.c
> +++ b/arch/arm/kvm/mmu.c
> @@ -44,7 +44,7 @@ static phys_addr_t hyp_idmap_vector;
>
> #define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t))
>
> -#define kvm_pmd_huge(_x) (pmd_huge(_x) || pmd_trans_huge(_x))
> +#define huge_pmd(_x) (pmd_huge(_x) || pmd_trans_huge(_x))
> #define kvm_pud_huge(_x) pud_huge(_x)
>
> #define KVM_S2PTE_FLAG_IS_IOMAP (1UL << 0)
> @@ -114,7 +114,7 @@ static bool kvm_is_device_pfn(unsigned long pfn)
> */
> static void stage2_dissolve_pmd(struct kvm *kvm, phys_addr_t addr, pmd_t *pmd)
> {
> - if (!kvm_pmd_huge(*pmd))
> + if (!huge_pmd(*pmd))
> return;
>
> pmd_clear(pmd);
> @@ -176,7 +176,7 @@ static void clear_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr)
> static void clear_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr)
> {
> pte_t *pte_table = pte_offset_kernel(pmd, 0);
> - VM_BUG_ON(kvm_pmd_huge(*pmd));
> + VM_BUG_ON(huge_pmd(*pmd));
> pmd_clear(pmd);
> kvm_tlb_flush_vmid_ipa(kvm, addr);
> pte_free_kernel(NULL, pte_table);
> @@ -239,7 +239,7 @@ static void unmap_pmds(struct kvm *kvm, pud_t *pud,
> do {
> next = kvm_pmd_addr_end(addr, end);
> if (!pmd_none(*pmd)) {
> - if (kvm_pmd_huge(*pmd)) {
> + if (huge_pmd(*pmd)) {
> pmd_t old_pmd = *pmd;
>
> pmd_clear(pmd);
> @@ -325,7 +325,7 @@ static void stage2_flush_pmds(struct kvm *kvm, pud_t *pud,
> do {
> next = kvm_pmd_addr_end(addr, end);
> if (!pmd_none(*pmd)) {
> - if (kvm_pmd_huge(*pmd))
> + if (huge_pmd(*pmd))
> kvm_flush_dcache_pmd(*pmd);
> else
> stage2_flush_ptes(kvm, pmd, addr, next);
> @@ -1043,7 +1043,7 @@ static void stage2_wp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end)
> do {
> next = kvm_pmd_addr_end(addr, end);
> if (!pmd_none(*pmd)) {
> - if (kvm_pmd_huge(*pmd)) {
> + if (huge_pmd(*pmd)) {
> if (!kvm_s2pmd_readonly(pmd))
> kvm_set_s2pmd_readonly(pmd);
> } else {
> @@ -1324,7 +1324,7 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
> if (!pmd || pmd_none(*pmd)) /* Nothing there */
> goto out;
>
> - if (kvm_pmd_huge(*pmd)) { /* THP, HugeTLB */
> + if (huge_pmd(*pmd)) { /* THP, HugeTLB */
> *pmd = pmd_mkyoung(*pmd);
> pfn = pmd_pfn(*pmd);
> pfn_valid = true;
> @@ -1532,7 +1532,7 @@ static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, void *data)
> if (!pmd || pmd_none(*pmd)) /* Nothing there */
> return 0;
>
> - if (kvm_pmd_huge(*pmd)) { /* THP, HugeTLB */
> + if (huge_pmd(*pmd)) { /* THP, HugeTLB */
> if (pmd_young(*pmd)) {
> *pmd = pmd_mkold(*pmd);
> return 1;
> @@ -1562,7 +1562,7 @@ static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, void *data)
> if (!pmd || pmd_none(*pmd)) /* Nothing there */
> return 0;
>
> - if (kvm_pmd_huge(*pmd)) /* THP, HugeTLB */
> + if (huge_pmd(*pmd)) /* THP, HugeTLB */
> return pmd_young(*pmd);
>
> pte = pte_offset_kernel(pmd, gpa);
> --
> 1.7.9.5
>