[PATCH 00/21] KVM: Cleanup and unify kvm_mmu_memory_cache usage

Sean Christopherson
2020-06-05T21:44:23Z

This series resurrects Christoffer Dall's series[1] to provide a common
MMU memory cache implementation that can be shared by x86, arm64 and MIPS.

It also picks up a suggested change from Ben Gardon[2] to clear shadow
page tables during initial allocation so as to avoid clearing entire
pages while holding mmu_lock.

The front half of the patches do house cleaning on x86's memory cache
implementation in preparation for moving it to common code, along with a
fair bit of cleanup on the usage. The middle chunk moves the patches to
common KVM, and the last two chunks convert arm64 and MIPS to the common
implementation.

Cleanup aside, the notable difference from Christoffer and Ben's proposed
patches is to make __GFP_ZERO optional, e.g. to allow x86 to skip zeroing
for its gfns array and to provide line of sight for my
cannot-yet-be-discussed-in-detail use case for non-zero initialized shadow
page tables[3].

Tested on x86 only, no testing whatsoever on arm64 or MIPS.

[1] https://lkml.kernel.org/r/20191105110357.8607-1-christoffer.dall@arm.com
[2] https://lkml.kernel.org/r/20190926231824.149014-4-bgardon@google.com
[3] https://lkml.kernel.org/r/20191127180731.GC16845@linux.intel.com

Sean Christopherson (21):
KVM: x86/mmu: Track the associated kmem_cache in the MMU caches
KVM: x86/mmu: Consolidate "page" variant of memory cache helpers
KVM: x86/mmu: Use consistent "mc" name for kvm_mmu_memory_cache locals
KVM: x86/mmu: Remove superfluous gotos from mmu_topup_memory_caches()
KVM: x86/mmu: Try to avoid crashing KVM if a MMU memory cache is empty
KVM: x86/mmu: Move fast_page_fault() call above
mmu_topup_memory_caches()
KVM: x86/mmu: Topup memory caches after walking GVA->GPA
KVM: x86/mmu: Clean up the gorilla math in mmu_topup_memory_caches()
KVM: x86/mmu: Separate the memory caches for shadow pages and gfn
arrays
KVM: x86/mmu: Make __GFP_ZERO a property of the memory cache
KVM: x86/mmu: Zero allocate shadow pages (outside of mmu_lock)
KVM: x86/mmu: Skip filling the gfn cache for guaranteed direct MMU
topups
KVM: x86/mmu: Prepend "kvm_" to memory cache helpers that will be
global
KVM: Move x86's version of struct kvm_mmu_memory_cache to common code
KVM: Move x86's MMU memory cache helpers to common KVM code
KVM: arm64: Drop @max param from mmu_topup_memory_cache()
KVM: arm64: Use common code's approach for __GFP_ZERO with memory
caches
KVM: arm64: Use common KVM implementation of MMU memory caches
KVM: MIPS: Drop @max param from mmu_topup_memory_cache()
KVM: MIPS: Account pages used for GPA page tables
KVM: MIPS: Use common KVM implementation of MMU memory caches

arch/arm64/include/asm/kvm_host.h | 11 ---
arch/arm64/include/asm/kvm_types.h | 8 ++
arch/arm64/kvm/arm.c | 2 +
arch/arm64/kvm/mmu.c | 54 +++--------
arch/mips/include/asm/kvm_host.h | 11 ---
arch/mips/include/asm/kvm_types.h | 7 ++
arch/mips/kvm/mmu.c | 44 ++-------
arch/powerpc/include/asm/kvm_types.h | 5 ++
arch/s390/include/asm/kvm_types.h | 5 ++
arch/x86/include/asm/kvm_host.h | 14 +--
arch/x86/include/asm/kvm_types.h | 7 ++
arch/x86/kvm/mmu/mmu.c | 129 +++++++++------------------
arch/x86/kvm/mmu/paging_tmpl.h | 10 +--
include/linux/kvm_host.h | 7 ++
include/linux/kvm_types.h | 19 ++++
virt/kvm/kvm_main.c | 55 ++++++++++++
16 files changed, 178 insertions(+), 210 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

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2.26.0