From 2aa9c199cf8151c190c7e7ca3ddfcfbb2d85ac36 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 2 Jul 2020 19:35:38 -0700 Subject: [PATCH] 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. Suggested-by: Christoffer Dall Reviewed-by: Ben Gardon Signed-off-by: Sean Christopherson Message-Id: <20200703023545.8771-15-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini --- arch/arm64/include/asm/Kbuild | 1 + arch/mips/include/asm/Kbuild | 1 + arch/powerpc/include/asm/Kbuild | 1 + arch/s390/include/asm/Kbuild | 1 + arch/x86/include/asm/kvm_host.h | 13 ------------- arch/x86/include/asm/kvm_types.h | 7 +++++++ include/asm-generic/kvm_types.h | 5 +++++ include/linux/kvm_types.h | 19 +++++++++++++++++++ 8 files changed, 35 insertions(+), 13 deletions(-) create mode 100644 arch/x86/include/asm/kvm_types.h create mode 100644 include/asm-generic/kvm_types.h diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild index ff9cbb631212..35a68155cd0e 100644 --- a/arch/arm64/include/asm/Kbuild +++ b/arch/arm64/include/asm/Kbuild @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 generic-y += early_ioremap.h +generic-y += kvm_types.h generic-y += local64.h generic-y += mcs_spinlock.h generic-y += qrwlock.h diff --git a/arch/mips/include/asm/Kbuild b/arch/mips/include/asm/Kbuild index 8643d313890e..397e6d24d2ab 100644 --- a/arch/mips/include/asm/Kbuild +++ b/arch/mips/include/asm/Kbuild @@ -5,6 +5,7 @@ generated-y += syscall_table_64_n32.h generated-y += syscall_table_64_n64.h generated-y += syscall_table_64_o32.h generic-y += export.h +generic-y += kvm_types.h generic-y += local64.h generic-y += mcs_spinlock.h generic-y += parport.h diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild index dadbcf3a0b1e..2d444d09b553 100644 --- a/arch/powerpc/include/asm/Kbuild +++ b/arch/powerpc/include/asm/Kbuild @@ -4,6 +4,7 @@ generated-y += syscall_table_64.h generated-y += syscall_table_c32.h generated-y += syscall_table_spu.h generic-y += export.h +generic-y += kvm_types.h generic-y += local64.h generic-y += mcs_spinlock.h generic-y += vtime.h diff --git a/arch/s390/include/asm/Kbuild b/arch/s390/include/asm/Kbuild index 83f6e85de7bc..319efa0e6d02 100644 --- a/arch/s390/include/asm/Kbuild +++ b/arch/s390/include/asm/Kbuild @@ -6,5 +6,6 @@ generated-y += unistd_nr.h generic-y += asm-offsets.h generic-y += export.h +generic-y += kvm_types.h generic-y += local64.h generic-y += mcs_spinlock.h diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 9d41eb5a8453..5aaef036627f 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -193,8 +193,6 @@ struct x86_exception; enum x86_intercept; enum x86_intercept_stage; -#define KVM_NR_MEM_OBJS 40 - #define KVM_NR_DB_REGS 4 #define DR6_BD (1 << 13) @@ -245,17 +243,6 @@ enum x86_intercept_stage; 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; - gfp_t gfp_zero; - struct kmem_cache *kmem_cache; - 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..08f1b57d3b62 --- /dev/null +++ b/arch/x86/include/asm/kvm_types.h @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_KVM_TYPES_H +#define _ASM_X86_KVM_TYPES_H + +#define KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE 40 + +#endif /* _ASM_X86_KVM_TYPES_H */ diff --git a/include/asm-generic/kvm_types.h b/include/asm-generic/kvm_types.h new file mode 100644 index 000000000000..2a82daf110f1 --- /dev/null +++ b/include/asm-generic/kvm_types.h @@ -0,0 +1,5 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_KVM_TYPES_H +#define _ASM_GENERIC_KVM_TYPES_H + +#endif diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h index 68e84cf42a3f..a7580f69dda0 100644 --- a/include/linux/kvm_types.h +++ b/include/linux/kvm_types.h @@ -20,6 +20,8 @@ enum kvm_mr_change; #include +#include + /* * Address types: * @@ -58,4 +60,21 @@ struct gfn_to_pfn_cache { bool dirty; }; +#ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE +/* + * Memory caches are used to preallocate memory ahead of various MMU flows, + * e.g. page fault handlers. Gracefully handling allocation failures deep in + * MMU flows is problematic, as is triggering reclaim, I/O, etc... while + * holding MMU locks. Note, these caches act more like prefetch buffers than + * classical caches, i.e. objects are not returned to the cache on being freed. + */ +struct kvm_mmu_memory_cache { + int nobjs; + gfp_t gfp_zero; + struct kmem_cache *kmem_cache; + void *objects[KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE]; +}; +#endif + + #endif /* __KVM_TYPES_H__ */