We are currently duplicating the mmu memory cache functionality quite
heavily between the architectures that support KVM. As a first step,
move the x86 implementation (which seems to have the most recently
maintained version of the mmu memory cache) to common code.
We introduce an arch-specific kvm_types.h which can be used to specify
how many objects are required in the memory cache, an aspect which
diverges across architectures. Since kvm_host.h defines structures with
fields of the memcache object, we define the memcache structure in
kvm_types.h, and we include the architecture-specific kvm_types.h to
know the size of object in kvm_host.h.
We only define the functions and data types if
KVM_ARCH_WANT_MMU_MEMORY_CACHE is defined, because not all architectures
require the mmu memory cache.
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxx>
---
arch/arm/include/asm/kvm_types.h | 5 +++
arch/arm64/include/asm/kvm_types.h | 6 +++
arch/mips/include/asm/kvm_types.h | 5 +++
arch/powerpc/include/asm/kvm_types.h | 5 +++
arch/s390/include/asm/kvm_types.h | 5 +++
arch/x86/include/asm/kvm_host.h | 11 -----
arch/x86/include/asm/kvm_types.h | 9 ++++
arch/x86/kvm/mmu.c | 60 ---------------------------
include/linux/kvm_host.h | 11 +++++
include/linux/kvm_types.h | 13 ++++++
virt/kvm/kvm_main.c | 61 ++++++++++++++++++++++++++++
11 files changed, 120 insertions(+), 71 deletions(-)
create mode 100644 arch/arm/include/asm/kvm_types.h
create mode 100644 arch/arm64/include/asm/kvm_types.h
create mode 100644 arch/mips/include/asm/kvm_types.h
create mode 100644 arch/powerpc/include/asm/kvm_types.h
create mode 100644 arch/s390/include/asm/kvm_types.h
create mode 100644 arch/x86/include/asm/kvm_types.h
diff --git a/arch/arm/include/asm/kvm_types.h b/arch/arm/include/asm/kvm_types.h
new file mode 100644
index 000000000000..bc389f82e88d
--- /dev/null
+++ b/arch/arm/include/asm/kvm_types.h
@@ -0,0 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_ARM_KVM_TYPES_H
+#define _ASM_ARM_KVM_TYPES_H
+
+#endif /* _ASM_ARM_KVM_TYPES_H */
diff --git a/arch/arm64/include/asm/kvm_types.h b/arch/arm64/include/asm/kvm_types.h
new file mode 100644
index 000000000000..d0987007d581
--- /dev/null
+++ b/arch/arm64/include/asm/kvm_types.h
@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_ARM64_KVM_TYPES_H
+#define _ASM_ARM64_KVM_TYPES_H
+
+#endif /* _ASM_ARM64_KVM_TYPES_H */
+
diff --git a/arch/mips/include/asm/kvm_types.h b/arch/mips/include/asm/kvm_types.h
new file mode 100644
index 000000000000..5efeb32a5926
--- /dev/null
+++ b/arch/mips/include/asm/kvm_types.h
@@ -0,0 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_MIPS_KVM_TYPES_H
+#define _ASM_MIPS_KVM_TYPES_H
+
+#endif /* _ASM_MIPS_KVM_TYPES_H */
diff --git a/arch/powerpc/include/asm/kvm_types.h b/arch/powerpc/include/asm/kvm_types.h
new file mode 100644
index 000000000000..f627eceaa314
--- /dev/null
+++ b/arch/powerpc/include/asm/kvm_types.h
@@ -0,0 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_KVM_TYPES_H
+#define _ASM_POWERPC_KVM_TYPES_H
+
+#endif /* _ASM_POWERPC_KVM_TYPES_H */
diff --git a/arch/s390/include/asm/kvm_types.h b/arch/s390/include/asm/kvm_types.h
new file mode 100644
index 000000000000..b66a81f8a354
--- /dev/null
+++ b/arch/s390/include/asm/kvm_types.h
@@ -0,0 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_S390_KVM_TYPES_H
+#define _ASM_S390_KVM_TYPES_H
+
+#endif /* _ASM_S390_KVM_TYPES_H */
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 50eb430b0ad8..e5080b618f3c 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -179,8 +179,6 @@ enum {
#include <asm/kvm_emulate.h>
-#define KVM_NR_MEM_OBJS 40
-
#define KVM_NR_DB_REGS 4
#define DR6_BD (1 << 13)
@@ -231,15 +229,6 @@ enum {
struct kvm_kernel_irq_routing_entry;
-/*
- * 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];
-};
-
/*
* the pages used as guest page table on soft mmu are tracked by
* kvm_memory_slot.arch.gfn_track which is 16 bits, so the role bits used
diff --git a/arch/x86/include/asm/kvm_types.h b/arch/x86/include/asm/kvm_types.h
new file mode 100644
index 000000000000..40428651dc7a
--- /dev/null
+++ b/arch/x86/include/asm/kvm_types.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_KVM_TYPES_H
+#define _ASM_X86_KVM_TYPES_H
+
+#define KVM_ARCH_WANT_MMU_MEMORY_CACHE
+
+#define KVM_NR_MEM_OBJS 40
+
+#endif /* _ASM_X86_KVM_TYPES_H */
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 540190cee3cb..abcdb47b0ac7 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -40,7 +40,6 @@
#include <asm/page.h>
#include <asm/pat.h>
-#include <asm/pgalloc.h>
#include <asm/cmpxchg.h>
#include <asm/e820/api.h>
#include <asm/io.h>
@@ -1018,56 +1017,6 @@ static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu)
local_irq_enable();
}
-static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
- struct kmem_cache *base_cache, int min)
-{
- void *obj;
-
- if (cache->nobjs >= min)
- return 0;
- while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
- obj = kmem_cache_alloc(base_cache, GFP_PGTABLE_USER);
- if (!obj)
- return cache->nobjs >= min ? 0 : -ENOMEM;
- cache->objects[cache->nobjs++] = obj;
- }
- return 0;
-}
-
-static int mmu_memory_cache_free_objects(struct kvm_mmu_memory_cache *cache)
-{
- return cache->nobjs;
-}
-
-static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc,
- struct kmem_cache *cache)
-{
- while (mc->nobjs)
- kmem_cache_free(cache, mc->objects[--mc->nobjs]);
-}
-
-static int mmu_topup_memory_cache_page(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_PGTABLE_USER);
- if (!page)
- return cache->nobjs >= min ? 0 : -ENOMEM;
- cache->objects[cache->nobjs++] = page;
- }
- return 0;
-}
-
-static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc)
-{
- while (mc->nobjs)
- free_page((unsigned long)mc->objects[--mc->nobjs]);
-}
-
static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
{
int r;
@@ -1094,15 +1043,6 @@ static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
mmu_page_header_cache);
}
-static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
-{
- void *p;
-
- BUG_ON(!mc->nobjs);
- p = mc->objects[--mc->nobjs];
- return p;
-}
-
static struct pte_list_desc *mmu_alloc_pte_list_desc(struct kvm_vcpu *vcpu)
{
return 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 719fc3e15ea4..612922d440cc 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -788,6 +788,17 @@ 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_WANT_MMU_MEMORY_CACHE
+int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
+ struct kmem_cache *base_cache, int min);
+int mmu_memory_cache_free_objects(struct kvm_mmu_memory_cache *cache);
+void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc,
+ struct kmem_cache *cache);
+int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache, int min);
+void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc);
+void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc);
+#endif
+
bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req,
unsigned long *vcpu_bitmap, cpumask_var_t tmp);
bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req);
diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
index bde5374ae021..ca7d3b3c8487 100644
--- a/include/linux/kvm_types.h
+++ b/include/linux/kvm_types.h
@@ -18,6 +18,7 @@ struct kvm_memslots;
enum kvm_mr_change;
+#include <asm/kvm_types.h>
#include <asm/types.h>
/*
@@ -49,4 +50,16 @@ struct gfn_to_hva_cache {
struct kvm_memory_slot *memslot;
};
+#ifdef KVM_ARCH_WANT_MMU_MEMORY_CACHE
+/*
+ * 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];
+};
+#endif
+
+
#endif /* __KVM_TYPES_H__ */
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index fd68fbe0a75d..a4e8297152e9 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -51,6 +51,7 @@
#include <linux/io.h>
#include <linux/lockdep.h>
+#include <asm/pgalloc.h>
#include <asm/processor.h>
#include <asm/ioctl.h>
#include <linux/uaccess.h>
@@ -288,6 +289,66 @@ void kvm_reload_remote_mmus(struct kvm *kvm)
kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_RELOAD);
}
+#ifdef KVM_ARCH_WANT_MMU_MEMORY_CACHE
+int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
+ struct kmem_cache *base_cache, int min)
+{
+ void *obj;
+
+ if (cache->nobjs >= min)
+ return 0;
+ while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
+ obj = kmem_cache_alloc(base_cache, GFP_PGTABLE_USER);
+ if (!obj)
+ return cache->nobjs >= min ? 0 : -ENOMEM;
+ cache->objects[cache->nobjs++] = obj;
+ }
+ return 0;
+}
+
+int mmu_memory_cache_free_objects(struct kvm_mmu_memory_cache *cache)
+{
+ return cache->nobjs;
+}
+
+void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc,
+ struct kmem_cache *cache)
+{
+ while (mc->nobjs)
+ kmem_cache_free(cache, mc->objects[--mc->nobjs]);
+}
+
+int mmu_topup_memory_cache_page(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_PGTABLE_USER);
+ if (!page)
+ return cache->nobjs >= min ? 0 : -ENOMEM;
+ cache->objects[cache->nobjs++] = page;
+ }
+ return 0;
+}
+
+void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc)
+{
+ while (mc->nobjs)
+ free_page((unsigned long)mc->objects[--mc->nobjs]);
+}
+
+void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
+{
+ void *p;
+
+ BUG_ON(!mc->nobjs);
+ p = mc->objects[--mc->nobjs];
+ return p;
+}
+#endif
+
int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
{
struct page *page;
--
2.18.0
