From: Ben Gardon <bgardon@google.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Marc Zyngier <maz@kernel.org>, Paul Mackerras <paulus@ozlabs.org>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Janosch Frank <frankja@linux.ibm.com>,
Paolo Bonzini <pbonzini@redhat.com>,
James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
David Hildenbrand <david@redhat.com>,
Cornelia Huck <cohuck@redhat.com>,
Claudio Imbrenda <imbrenda@linux.ibm.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org,
kvm@vger.kernel.org, kvm-ppc@vger.kernel.org,
linux-kernel@vger.kernel.org, Peter Feiner <pfeiner@google.com>,
Peter Shier <pshier@google.com>,
Junaid Shahid <junaids@google.com>,
Christoffer Dall <christoffer.dall@arm.com>
Subject: Re: [PATCH 14/21] KVM: Move x86's version of struct kvm_mmu_memory_cache to common code
Date: Wed, 10 Jun 2020 12:01:54 -0700 [thread overview]
Message-ID: <CANgfPd_v31zC5-mKsT14hd7W=X2Pvg3RBPjn2d4tFSChdbsr3A@mail.gmail.com> (raw)
In-Reply-To: <20200605213853.14959-15-sean.j.christopherson@intel.com>
On Fri, Jun 5, 2020 at 2:39 PM Sean Christopherson
<sean.j.christopherson@intel.com> wrote:
>
> 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.
>
> Suggested-by: Christoffer Dall <christoffer.dall@arm.com>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
> ---
> 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 | 13 -------------
> arch/x86/include/asm/kvm_types.h | 7 +++++++
> include/linux/kvm_types.h | 19 +++++++++++++++++++
> 7 files changed, 47 insertions(+), 13 deletions(-)
> 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/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 fb99e6776e27..8e8fea13b6c7 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/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
>
next prev parent reply other threads:[~2020-06-10 19:02 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-05 21:38 [PATCH 00/21] KVM: Cleanup and unify kvm_mmu_memory_cache usage Sean Christopherson
2020-06-05 21:38 ` [PATCH 01/21] KVM: x86/mmu: Track the associated kmem_cache in the MMU caches Sean Christopherson
2020-06-09 21:07 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 02/21] KVM: x86/mmu: Consolidate "page" variant of memory cache helpers Sean Christopherson
2020-06-09 22:54 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 03/21] KVM: x86/mmu: Use consistent "mc" name for kvm_mmu_memory_cache locals Sean Christopherson
2020-06-10 22:03 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 04/21] KVM: x86/mmu: Remove superfluous gotos from mmu_topup_memory_caches() Sean Christopherson
2020-06-09 22:57 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 05/21] KVM: x86/mmu: Try to avoid crashing KVM if a MMU memory cache is empty Sean Christopherson
2020-06-10 22:12 ` Ben Gardon
2020-06-17 0:53 ` Sean Christopherson
2020-06-17 16:36 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 06/21] KVM: x86/mmu: Move fast_page_fault() call above mmu_topup_memory_caches() Sean Christopherson
2020-06-09 23:03 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 07/21] KVM: x86/mmu: Topup memory caches after walking GVA->GPA Sean Christopherson
2020-06-10 22:34 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 08/21] KVM: x86/mmu: Clean up the gorilla math in mmu_topup_memory_caches() Sean Christopherson
2020-06-10 22:20 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 09/21] KVM: x86/mmu: Separate the memory caches for shadow pages and gfn arrays Sean Christopherson
2020-06-09 23:56 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 10/21] KVM: x86/mmu: Make __GFP_ZERO a property of the memory cache Sean Christopherson
2020-06-10 18:57 ` Ben Gardon
2020-06-22 19:40 ` Sean Christopherson
2020-06-05 21:38 ` [PATCH 11/21] KVM: x86/mmu: Zero allocate shadow pages (outside of mmu_lock) Sean Christopherson
2020-06-10 18:49 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 12/21] KVM: x86/mmu: Skip filling the gfn cache for guaranteed direct MMU topups Sean Christopherson
2020-06-10 18:52 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 13/21] KVM: x86/mmu: Prepend "kvm_" to memory cache helpers that will be global Sean Christopherson
2020-06-10 18:56 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 14/21] KVM: Move x86's version of struct kvm_mmu_memory_cache to common code Sean Christopherson
2020-06-10 19:01 ` Ben Gardon [this message]
2020-06-10 21:58 ` Ben Gardon
2020-06-22 16:57 ` Sean Christopherson
2020-06-11 7:42 ` Marc Zyngier
2020-06-05 21:38 ` [PATCH 15/21] KVM: Move x86's MMU memory cache helpers to common KVM code Sean Christopherson
2020-06-10 20:24 ` Ben Gardon
2020-06-05 21:38 ` [PATCH 16/21] KVM: arm64: Drop @max param from mmu_topup_memory_cache() Sean Christopherson
2020-06-10 22:00 ` Ben Gardon
2020-06-11 15:59 ` Sean Christopherson
2020-06-05 21:38 ` [PATCH 17/21] KVM: arm64: Use common code's approach for __GFP_ZERO with memory caches Sean Christopherson
2020-06-11 7:59 ` Marc Zyngier
2020-06-11 15:43 ` Sean Christopherson
2020-06-11 15:51 ` Marc Zyngier
2020-06-05 21:38 ` [PATCH 18/21] KVM: arm64: Use common KVM implementation of MMU " Sean Christopherson
2020-06-11 8:01 ` Marc Zyngier
2020-06-11 15:46 ` Sean Christopherson
2020-06-05 21:38 ` [PATCH 19/21] KVM: MIPS: Drop @max param from mmu_topup_memory_cache() Sean Christopherson
2020-06-08 8:56 ` Huacai Chen
2020-06-05 21:38 ` [PATCH 20/21] KVM: MIPS: Account pages used for GPA page tables Sean Christopherson
2020-06-08 8:56 ` Huacai Chen
2020-06-05 21:38 ` [PATCH 21/21] KVM: MIPS: Use common KVM implementation of MMU memory caches Sean Christopherson
2020-06-08 8:57 ` Huacai Chen
2020-06-11 8:06 ` [PATCH 00/21] KVM: Cleanup and unify kvm_mmu_memory_cache usage Marc Zyngier
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