[21/21] KVM: MIPS: Use common KVM implementation of MMU memory caches

Move to the common MMU memory cache implementation now that the common
code and MIPS's existing code are semantically compatible.

No functional change intended.

Suggested-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/mips/include/asm/kvm_host.h  | 11 ---------
 arch/mips/include/asm/kvm_types.h |  2 ++
 arch/mips/kvm/mmu.c               | 40 ++++---------------------------
 3 files changed, 7 insertions(+), 46 deletions(-)

Reviewed-by: Huacai Chen <chenhc@lemote.com>

On Sat, Jun 6, 2020 at 5:41 AM Sean Christopherson
<sean.j.christopherson@intel.com> wrote:
>
> Move to the common MMU memory cache implementation now that the common
> code and MIPS's existing code are semantically compatible.
>
> No functional change intended.
>
> Suggested-by: Christoffer Dall <christoffer.dall@arm.com>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> ---
>  arch/mips/include/asm/kvm_host.h  | 11 ---------
>  arch/mips/include/asm/kvm_types.h |  2 ++
>  arch/mips/kvm/mmu.c               | 40 ++++---------------------------
>  3 files changed, 7 insertions(+), 46 deletions(-)
>
> diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
> index 363e7a89d173..f49617175f60 100644
> --- a/arch/mips/include/asm/kvm_host.h
> +++ b/arch/mips/include/asm/kvm_host.h
> @@ -335,17 +335,6 @@ struct kvm_mips_tlb {
>         long tlb_lo[2];
>  };
>
> -#define KVM_NR_MEM_OBJS     4
> -
> -/*
> - * We don't want allocation failures within the mmu code, so we preallocate
> - * enough memory for a single page fault in a cache.
> - */
> -struct kvm_mmu_memory_cache {
> -       int nobjs;
> -       void *objects[KVM_NR_MEM_OBJS];
> -};
> -
>  #define KVM_MIPS_AUX_FPU       0x1
>  #define KVM_MIPS_AUX_MSA       0x2
>
> diff --git a/arch/mips/include/asm/kvm_types.h b/arch/mips/include/asm/kvm_types.h
> index 5efeb32a5926..213754d9ef6b 100644
> --- a/arch/mips/include/asm/kvm_types.h
> +++ b/arch/mips/include/asm/kvm_types.h
> @@ -2,4 +2,6 @@
>  #ifndef _ASM_MIPS_KVM_TYPES_H
>  #define _ASM_MIPS_KVM_TYPES_H
>
> +#define KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE     4
> +
>  #endif /* _ASM_MIPS_KVM_TYPES_H */
> diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
> index 41a4a063a730..d6acd88c0c46 100644
> --- a/arch/mips/kvm/mmu.c
> +++ b/arch/mips/kvm/mmu.c
> @@ -25,39 +25,9 @@
>  #define KVM_MMU_CACHE_MIN_PAGES 2
>  #endif
>
> -static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache, int min)
> -{
> -       void *page;
> -
> -       if (cache->nobjs >= min)
> -               return 0;
> -       while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
> -               page = (void *)__get_free_page(GFP_KERNEL_ACCOUNT);
> -               if (!page)
> -                       return -ENOMEM;
> -               cache->objects[cache->nobjs++] = page;
> -       }
> -       return 0;
> -}
> -
> -static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
> -{
> -       while (mc->nobjs)
> -               free_page((unsigned long)mc->objects[--mc->nobjs]);
> -}
> -
> -static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
> -{
> -       void *p;
> -
> -       BUG_ON(!mc || !mc->nobjs);
> -       p = mc->objects[--mc->nobjs];
> -       return p;
> -}
> -
>  void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu)
>  {
> -       mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
> +       kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
>  }
>
>  /**
> @@ -151,7 +121,7 @@ static pte_t *kvm_mips_walk_pgd(pgd_t *pgd, struct kvm_mmu_memory_cache *cache,
>
>                 if (!cache)
>                         return NULL;
> -               new_pmd = mmu_memory_cache_alloc(cache);
> +               new_pmd = kvm_mmu_memory_cache_alloc(cache);
>                 pmd_init((unsigned long)new_pmd,
>                          (unsigned long)invalid_pte_table);
>                 pud_populate(NULL, pud, new_pmd);
> @@ -162,7 +132,7 @@ static pte_t *kvm_mips_walk_pgd(pgd_t *pgd, struct kvm_mmu_memory_cache *cache,
>
>                 if (!cache)
>                         return NULL;
> -               new_pte = mmu_memory_cache_alloc(cache);
> +               new_pte = kvm_mmu_memory_cache_alloc(cache);
>                 clear_page(new_pte);
>                 pmd_populate_kernel(NULL, pmd, new_pte);
>         }
> @@ -709,7 +679,7 @@ static int kvm_mips_map_page(struct kvm_vcpu *vcpu, unsigned long gpa,
>                 goto out;
>
>         /* We need a minimum of cached pages ready for page table creation */
> -       err = mmu_topup_memory_cache(memcache, KVM_MMU_CACHE_MIN_PAGES);
> +       err = kvm_mmu_topup_memory_cache(memcache, KVM_MMU_CACHE_MIN_PAGES);
>         if (err)
>                 goto out;
>
> @@ -793,7 +763,7 @@ static pte_t *kvm_trap_emul_pte_for_gva(struct kvm_vcpu *vcpu,
>         int ret;
>
>         /* We need a minimum of cached pages ready for page table creation */
> -       ret = mmu_topup_memory_cache(memcache, KVM_MMU_CACHE_MIN_PAGES);
> +       ret = kvm_mmu_topup_memory_cache(memcache, KVM_MMU_CACHE_MIN_PAGES);
>         if (ret)
>                 return NULL;
>
> --
> 2.26.0
>