[PATCH 15/21] KVM: Move x86's MMU memory cache helpers to common KVM code

Sean Christopherson
2020-06-05T21:44:11Z

Move x86's memory cache helpers to common KVM code so that they can be
reused by arm64 and MIPS in future patches.

Suggested-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/mmu/mmu.c | 53 --------------------------------------
include/linux/kvm_host.h | 7 +++++
virt/kvm/kvm_main.c | 55 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 62 insertions(+), 53 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index b85d3e8e8403..a627437f73fd 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1060,47 +1060,6 @@ static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu)
local_irq_enable();
}

-static inline void *mmu_memory_cache_alloc_obj(struct kvm_mmu_memory_cache *mc,
- gfp_t gfp_flags)
-{
- gfp_flags |= mc->gfp_zero;
-
- if (mc->kmem_cache)
- return kmem_cache_alloc(mc->kmem_cache, gfp_flags);
- else
- return (void *)__get_free_page(gfp_flags);
-}
-
-static int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min)
-{
- void *obj;
-
- if (mc->nobjs >= min)
- return 0;
- while (mc->nobjs < ARRAY_SIZE(mc->objects)) {
- obj = mmu_memory_cache_alloc_obj(mc, GFP_KERNEL_ACCOUNT);
- if (!obj)
- return mc->nobjs >= min ? 0 : -ENOMEM;
- mc->objects[mc->nobjs++] = obj;
- }
- return 0;
-}
-
-static int kvm_mmu_memory_cache_nr_free_objects(struct kvm_mmu_memory_cache *mc)
-{
- return mc->nobjs;
-}
-
-static void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
-{
- while (mc->nobjs) {
- if (mc->kmem_cache)
- kmem_cache_free(mc->kmem_cache, mc->objects[--mc->nobjs]);
- else
- free_page((unsigned long)mc->objects[--mc->nobjs]);
- }
-}
-
static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu, bool maybe_indirect)
{
int r;
@@ -1132,18 +1091,6 @@ static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache);
}

-static void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
-{
- void *p;
-
- if (WARN_ON(!mc->nobjs))
- p = mmu_memory_cache_alloc_obj(mc, GFP_ATOMIC | __GFP_ACCOUNT);
- else
- p = mc->objects[--mc->nobjs];
- BUG_ON(!p);
- return p;
-}
-
static struct pte_list_desc *mmu_alloc_pte_list_desc(struct kvm_vcpu *vcpu)
{
return kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_list_desc_cache);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d38d6b9c24be..802b9e2306f0 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -815,6 +815,13 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu, bool usermode_vcpu_not_eligible);
void kvm_flush_remote_tlbs(struct kvm *kvm);
void kvm_reload_remote_mmus(struct kvm *kvm);

+#ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE
+int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min);
+int kvm_mmu_memory_cache_nr_free_objects(struct kvm_mmu_memory_cache *mc);
+void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc);
+void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc);
+#endif
+
bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req,
struct kvm_vcpu *except,
unsigned long *vcpu_bitmap, cpumask_var_t tmp);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4db151f6101e..fead5f1d5594 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -342,6 +342,61 @@ void kvm_reload_remote_mmus(struct kvm *kvm)
kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_RELOAD);
}

+#ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE
+static inline void *mmu_memory_cache_alloc_obj(struct kvm_mmu_memory_cache *mc,
+ gfp_t gfp_flags)
+{
+ gfp_flags |= mc->gfp_zero;
+
+ if (mc->kmem_cache)
+ return kmem_cache_alloc(mc->kmem_cache, gfp_flags);
+ else
+ return (void *)__get_free_page(gfp_flags);
+}
+
+int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min)
+{
+ void *obj;
+
+ if (mc->nobjs >= min)
+ return 0;
+ while (mc->nobjs < ARRAY_SIZE(mc->objects)) {
+ obj = mmu_memory_cache_alloc_obj(mc, GFP_KERNEL_ACCOUNT);
+ if (!obj)
+ return mc->nobjs >= min ? 0 : -ENOMEM;
+ mc->objects[mc->nobjs++] = obj;
+ }
+ return 0;
+}
+
+int kvm_mmu_memory_cache_nr_free_objects(struct kvm_mmu_memory_cache *mc)
+{
+ return mc->nobjs;
+}
+
+void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
+{
+ while (mc->nobjs) {
+ if (mc->kmem_cache)
+ kmem_cache_free(mc->kmem_cache, mc->objects[--mc->nobjs]);
+ else
+ free_page((unsigned long)mc->objects[--mc->nobjs]);
+ }
+}
+
+void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
+{
+ void *p;
+
+ if (WARN_ON(!mc->nobjs))
+ p = mmu_memory_cache_alloc_obj(mc, GFP_ATOMIC | __GFP_ACCOUNT);
+ else
+ p = mc->objects[--mc->nobjs];
+ BUG_ON(!p);
+ return p;
+}
+#endif
+
static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
{
mutex_init(&vcpu->mutex);
--
2.26.0