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

Sean Christopherson
2020-06-05T21:40:09Z

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