[PATCH v3 14/21] KVM: Move x86's version of struct kvm_mmu_memory_cache to common code
From: Sean Christopherson <hidden>
Date: 2020-07-03 02:37:43
Also in:
kvm, kvmarm, linux-arch, linux-mips, lkml
Subsystem:
arm64 port (aarch64 architecture), generic include/asm header files, kernel virtual machine (kvm), kernel virtual machine for x86 (kvm/x86), linux for powerpc (32-bit and 64-bit), mips, s390 architecture, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Catalin Marinas, Will Deacon, Arnd Bergmann, Paolo Bonzini, Sean Christopherson, Madhavan Srinivasan, Michael Ellerman, Thomas Bogendoerfer, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
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 <redacted> Reviewed-by: Ben Gardon <redacted> Signed-off-by: Sean Christopherson <redacted> --- 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 685fe5ac7124..c461710d621a 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 <linux/types.h> +#include <asm/kvm_types.h> + /* * 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__ */
--
2.26.0
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