KVM: Move x86's version of struct kvm_mmu_memory_cache to common code

Move x86's 'struct kvm_mmu_memory_cache' to common code in anticipation of moving the entire x86 implementation code to common KVM and reusing it for arm64 and MIPS. Add a new architecture specific asm/kvm_types.h to control the existence and parameters of the struct. The new header is needed to avoid a chicken-and-egg problem with asm/kvm_host.h as all architectures define instances of the struct in their vCPU structs. Add an asm-generic version of kvm_types.h to avoid having empty files on PPC and s390 in the long term, and for arm64 and mips in the short term.

Sean Christopherson committed 6 years ago

Commit 2aa9c191 parent 94ce87e8 files · +35 −13Browse files

Showing the changes to include/linux (1 of 8 files). Show all

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include/linux/kvm_types.h+19−0

@@ -20,6 +20,8 @@ enum kvm_mr_change; · 19 unmodified lines
20	20
21	21	#include <linux/types.h>
22	22
	23	+#include <asm/kvm_types.h>
	24	+
23	25	/*
24	26	* Address types:
25	27	*
@@ -58,4 +60,21 @@ struct gfn_to_pfn_cache { · 32 unmodified lines
58	60	bool dirty;
59	61	};
60	62
	63	+#ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE
	64	+/*
	65	+ * Memory caches are used to preallocate memory ahead of various MMU flows,
	66	+ * e.g. page fault handlers. Gracefully handling allocation failures deep in
	67	+ * MMU flows is problematic, as is triggering reclaim, I/O, etc... while
	68	+ * holding MMU locks. Note, these caches act more like prefetch buffers than
	69	+ * classical caches, i.e. objects are not returned to the cache on being freed.
	70	+ */
	71	+struct kvm_mmu_memory_cache {
	72	+ int nobjs;
	73	+ gfp_t gfp_zero;
	74	+ struct kmem_cache *kmem_cache;
	75	+ void *objects[KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE];
	76	+};
	77	+#endif
	78	+
	79	+
61	80	#endif /* __KVM_TYPES_H__ */