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* [PATCH 00/45] KVM: Refactor vCPU creation
@ 2019-10-22  1:58 Sean Christopherson
  2019-10-22  1:58 ` [PATCH 01/45] KVM: PPC: Book3S HV: Uninit vCPU if vcore creation fails Sean Christopherson
                   ` (45 more replies)
  0 siblings, 46 replies; 51+ messages in thread
From: Sean Christopherson @ 2019-10-22  1:58 UTC (permalink / raw)
  To: Marc Zyngier, James Hogan, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, Paolo Bonzini, Radim Krčmář
  Cc: kvm-ppc, Wanpeng Li, kvm, David Hildenbrand, Joerg Roedel,
	Cornelia Huck, linux-mips, Sean Christopherson, linux-kernel,
	linux-arm-kernel, Vitaly Kuznetsov, kvmarm, Jim Mattson

*************************** DISCLAIMER **********************************
The non-x86 arch specific patches are completely untested.  Although the
changes are conceptually straightforward, I'm not remotely confident that
the patches are bug free, e.g. checkpatch caught several blatant typos
that would break compilation.
*************************************************************************

The end goal of this series is to strip down the interface between common
KVM code and arch specific code so that there is precisely one arch hook
for creating a vCPU and one hook for destroying a vCPU.  In addition to
cleaning up the code base, simplifying the interface gives architectures
more freedom to organize their vCPU creation code.

KVM's vCPU creation code is comically messy.  kvm_vm_ioctl_create_vcpu()
calls three separate arch hooks: init(), create() and setup().  The init()
call is especially nasty as it's hidden away in a common KVM function,
kvm_init_vcpu(), that for all intents and purposes must be immediately
invoked after the vcpu object is allocated.

Not to be outdone, vCPU destruction also has three arch hooks: uninit(),
destroy() and free(), the latter of which isn't actually invoked by common
KVM code, but the hook declaration still exists because architectures are
relying on its forward declaration.

Eliminating the extra arch hooks is relatively straightforward, just
tedious.  For the most part, there is no fundamental constraint that
necessitated the proliferation of arch hooks, rather they crept in over
time, usually when x86-centric code was moved out of generic KVM and into
x86 code.

E.g. kvm_arch_vcpu_setup() was added to allow x86 to do vcpu_load(), which
can only be done after preempt_notifier initialization, but adding setup()
overlooked the fact that the preempt_notifier was only initialized after
kvm_arch_vcpu_create() because preemption support was added when x86's MMU
setup (the vcpu_load() user) was called from common KVM code.

For all intents and purposes, there is no true functional change in this
series.  The order of some allocations will change, and a few memory leaks
are fixed, but the actual functionality of a guest should be unaffected.

Patches 01-03 are bug fixes in error handling paths that were found by
inspection when refactoring the associated code.

Patches 04-43 refactor each arch implementation so that the unwanted arch
hooks can be dropped without a functional change, e.g. move code out of
kvm_arch_vcpu_setup() so that all implementations are empty, then drop the
functions and caller.

Patches 44-45 are minor clean up to eliminate kvm_vcpu_uninit().


The net result is to go from this:

        vcpu = kvm_arch_vcpu_create(kvm, id);
               |
               |-> kvm_vcpu_init()
                   |
                   |-> kvm_arch_vcpu_init()

        if (IS_ERR(vcpu)) {
                r = PTR_ERR(vcpu);
                goto vcpu_decrement;
        }

        preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);

        r = kvm_arch_vcpu_setup(vcpu);
        if (r)
                goto vcpu_destroy;

to this:

        r = kvm_arch_vcpu_precreate(kvm, id);
        if (r)
                goto vcpu_decrement;

        vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
        if (!vcpu) {
                r = -ENOMEM;
                goto vcpu_decrement;
        }

        page = alloc_page(GFP_KERNEL | __GFP_ZERO);
        if (!page) {
                r = -ENOMEM;
                goto vcpu_free;
        }
        vcpu->run = page_address(page);

        kvm_vcpu_init(vcpu, kvm, id);

        r = kvm_arch_vcpu_create(vcpu);
        if (r)
                goto vcpu_free_run_page;


Sean Christopherson (45):
  KVM: PPC: Book3S HV: Uninit vCPU if vcore creation fails
  KVM: PPC: Book3S PR: Free shared page if mmu initialization fails
  KVM: x86: Free wbinvd_dirty_mask if vCPU creation fails
  KVM: VMX: Allocate VPID after initializing VCPU
  KVM: VMX: Use direct vcpu pointer during vCPU create/free
  KVM: SVM: Use direct vcpu pointer during vCPU create/free
  KVM: x86: Allocate vcpu struct in common x86 code
  KVM: x86: Move FPU allocation to common x86 code
  KVM: x86: Move allocation of pio_data page down a few lines
  KVM: x86: Move kvm_vcpu_init() invocation to common code
  KVM: PPC: e500mc: Add build-time assert that vcpu is at offset 0
  KVM: PPC: Allocate vcpu struct in common PPC code
  KVM: PPC: Book3S PR: Allocate book3s and shadow vcpu after common init
  KVM: PPC: e500mc: Move reset of oldpir below call to kvm_vcpu_init()
  KVM: PPC: Move kvm_vcpu_init() invocation to common code
  KVM: MIPS: Use kvm_vcpu_cache to allocate vCPUs
  KVM: MIPS: Drop kvm_arch_vcpu_free()
  KVM: PPC: Drop kvm_arch_vcpu_free()
  KVM: arm: Drop kvm_arch_vcpu_free()
  KVM: x86: Remove spurious kvm_mmu_unload() from vcpu destruction path
  KVM: x86: Remove spurious clearing of async #PF MSR
  KVM: x86: Drop kvm_arch_vcpu_free()
  KVM: Remove kvm_arch_vcpu_free() declaration
  KVM: Add kvm_arch_vcpu_precreate() to handle pre-allocation issues
  KVM: s390: Move guts of kvm_arch_vcpu_init() into
    kvm_arch_vcpu_create()
  KVM: s390: Invoke kvm_vcpu_init() before allocating sie_page
  KVM: MIPS: Invoke kvm_vcpu_uninit() immediately prior to freeing vcpu
  KVM: x86: Invoke kvm_vcpu_uninit() immediately prior to freeing vcpu
  KVM: Introduce kvm_vcpu_destroy()
  KVM: Move vcpu alloc and init invocation to common code
  KVM: Unexport kvm_vcpu_cache and kvm_{un}init_vcpu()
  KVM: Move initialization of preempt notifier to kvm_vcpu_init()
  KVM: x86: Move guts of kvm_arch_vcpu_setup() into
    kvm_arch_vcpu_create()
  KVM: MIPS: Move .vcpu_setup() call to kvm_arch_vcpu_create()
  KVM: s390: Manually invoke vcpu setup during kvm_arch_vcpu_create()
  KVM: PPC: BookE: Setup vcpu during kvmppc_core_vcpu_create()
  KVM: Drop kvm_arch_vcpu_setup()
  KVM: x86: Move all vcpu init code into kvm_arch_vcpu_create()
  KVM: MIPS: Move all vcpu init code into kvm_arch_vcpu_create()
  KVM: ARM: Move all vcpu init code into kvm_arch_vcpu_create()
  KVM: PPC: Move all vcpu init code into kvm_arch_vcpu_create()
  KVM: arm64: Free sve_state via arm specific hook
  KVM: Drop kvm_arch_vcpu_init() and kvm_arch_vcpu_uninit()
  KVM: Move putting of vcpu->pid to kvm_vcpu_destroy()
  KVM: Move vcpu->run page allocation out of kvm_vcpu_init()

 arch/arm/include/asm/kvm_host.h    |   2 +-
 arch/arm/kvm/guest.c               |   5 -
 arch/arm64/include/asm/kvm_host.h  |   2 +-
 arch/arm64/kvm/guest.c             |   5 -
 arch/arm64/kvm/reset.c             |   2 +-
 arch/mips/kvm/mips.c               |  84 ++++-------
 arch/powerpc/include/asm/kvm_ppc.h |   6 +-
 arch/powerpc/kvm/book3s.c          |   9 +-
 arch/powerpc/kvm/book3s_hv.c       |  27 +---
 arch/powerpc/kvm/book3s_pr.c       |  33 ++---
 arch/powerpc/kvm/booke.c           |  65 ++++----
 arch/powerpc/kvm/e500.c            |  34 +----
 arch/powerpc/kvm/e500mc.c          |  32 ++--
 arch/powerpc/kvm/powerpc.c         |  70 ++++-----
 arch/s390/include/asm/kvm_host.h   |   1 -
 arch/s390/kvm/kvm-s390.c           | 110 +++++++-------
 arch/x86/include/asm/kvm_host.h    |   2 +-
 arch/x86/kvm/svm.c                 |  52 +------
 arch/x86/kvm/vmx/vmx.c             |  72 +++------
 arch/x86/kvm/x86.c                 | 230 ++++++++++++++---------------
 include/linux/kvm_host.h           |  13 +-
 virt/kvm/arm/arm.c                 |  76 ++++------
 virt/kvm/kvm_main.c                |  71 +++++----
 23 files changed, 387 insertions(+), 616 deletions(-)

-- 
2.22.0

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^ permalink raw reply	[flat|nested] 51+ messages in thread

end of thread, other threads:[~2019-10-24  8:08 UTC | newest]

Thread overview: 51+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-10-22  1:58 [PATCH 00/45] KVM: Refactor vCPU creation Sean Christopherson
2019-10-22  1:58 ` [PATCH 01/45] KVM: PPC: Book3S HV: Uninit vCPU if vcore creation fails Sean Christopherson
2019-10-24  7:04   ` Greg Kurz
2019-10-22  1:58 ` [PATCH 02/45] KVM: PPC: Book3S PR: Free shared page if mmu initialization fails Sean Christopherson
2019-10-24  7:05   ` Greg Kurz
2019-10-22  1:58 ` [PATCH 03/45] KVM: x86: Free wbinvd_dirty_mask if vCPU creation fails Sean Christopherson
2019-10-22  1:58 ` [PATCH 04/45] KVM: VMX: Allocate VPID after initializing VCPU Sean Christopherson
2019-10-22  1:58 ` [PATCH 05/45] KVM: VMX: Use direct vcpu pointer during vCPU create/free Sean Christopherson
2019-10-22  1:58 ` [PATCH 06/45] KVM: SVM: " Sean Christopherson
2019-10-22  1:58 ` [PATCH 07/45] KVM: x86: Allocate vcpu struct in common x86 code Sean Christopherson
2019-10-22  1:58 ` [PATCH 08/45] KVM: x86: Move FPU allocation to " Sean Christopherson
2019-10-22  1:58 ` [PATCH 09/45] KVM: x86: Move allocation of pio_data page down a few lines Sean Christopherson
2019-10-22  1:58 ` [PATCH 10/45] KVM: x86: Move kvm_vcpu_init() invocation to common code Sean Christopherson
2019-10-22  1:58 ` [PATCH 11/45] KVM: PPC: e500mc: Add build-time assert that vcpu is at offset 0 Sean Christopherson
2019-10-22  1:58 ` [PATCH 12/45] KVM: PPC: Allocate vcpu struct in common PPC code Sean Christopherson
2019-10-22  1:58 ` [PATCH 13/45] KVM: PPC: Book3S PR: Allocate book3s and shadow vcpu after common init Sean Christopherson
2019-10-22  1:58 ` [PATCH 14/45] KVM: PPC: e500mc: Move reset of oldpir below call to kvm_vcpu_init() Sean Christopherson
2019-10-22  1:58 ` [PATCH 15/45] KVM: PPC: Move kvm_vcpu_init() invocation to common code Sean Christopherson
2019-10-22  1:58 ` [PATCH 16/45] KVM: MIPS: Use kvm_vcpu_cache to allocate vCPUs Sean Christopherson
2019-10-22  1:58 ` [PATCH 17/45] KVM: MIPS: Drop kvm_arch_vcpu_free() Sean Christopherson
2019-10-22  1:58 ` [PATCH 18/45] KVM: PPC: " Sean Christopherson
2019-10-22  1:58 ` [PATCH 19/45] KVM: arm: " Sean Christopherson
2019-10-22  1:59 ` [PATCH 20/45] KVM: x86: Remove spurious kvm_mmu_unload() from vcpu destruction path Sean Christopherson
2019-10-22  1:59 ` [PATCH 21/45] KVM: x86: Remove spurious clearing of async #PF MSR Sean Christopherson
2019-10-22  1:59 ` [PATCH 22/45] KVM: x86: Drop kvm_arch_vcpu_free() Sean Christopherson
2019-10-22  1:59 ` [PATCH 23/45] KVM: Remove kvm_arch_vcpu_free() declaration Sean Christopherson
2019-10-22  1:59 ` [PATCH 24/45] KVM: Add kvm_arch_vcpu_precreate() to handle pre-allocation issues Sean Christopherson
2019-10-22  1:59 ` [PATCH 25/45] KVM: s390: Move guts of kvm_arch_vcpu_init() into kvm_arch_vcpu_create() Sean Christopherson
2019-10-22  1:59 ` [PATCH 26/45] KVM: s390: Invoke kvm_vcpu_init() before allocating sie_page Sean Christopherson
2019-10-22  1:59 ` [PATCH 27/45] KVM: MIPS: Invoke kvm_vcpu_uninit() immediately prior to freeing vcpu Sean Christopherson
2019-10-22  1:59 ` [PATCH 28/45] KVM: x86: " Sean Christopherson
2019-10-22  1:59 ` [PATCH 29/45] KVM: Introduce kvm_vcpu_destroy() Sean Christopherson
2019-10-22  1:59 ` [PATCH 30/45] KVM: Move vcpu alloc and init invocation to common code Sean Christopherson
2019-10-22  1:59 ` [PATCH 31/45] KVM: Unexport kvm_vcpu_cache and kvm_{un}init_vcpu() Sean Christopherson
2019-10-22  1:59 ` [PATCH 32/45] KVM: Move initialization of preempt notifier to kvm_vcpu_init() Sean Christopherson
2019-10-22  1:59 ` [PATCH 33/45] KVM: x86: Move guts of kvm_arch_vcpu_setup() into kvm_arch_vcpu_create() Sean Christopherson
2019-10-22  1:59 ` [PATCH 34/45] KVM: MIPS: Move .vcpu_setup() call to kvm_arch_vcpu_create() Sean Christopherson
2019-10-22  1:59 ` [PATCH 35/45] KVM: s390: Manually invoke vcpu setup during kvm_arch_vcpu_create() Sean Christopherson
2019-10-22  1:59 ` [PATCH 36/45] KVM: PPC: BookE: Setup vcpu during kvmppc_core_vcpu_create() Sean Christopherson
2019-10-22  1:59 ` [PATCH 37/45] KVM: Drop kvm_arch_vcpu_setup() Sean Christopherson
2019-10-22  1:59 ` [PATCH 38/45] KVM: x86: Move all vcpu init code into kvm_arch_vcpu_create() Sean Christopherson
2019-10-22  1:59 ` [PATCH 39/45] KVM: MIPS: " Sean Christopherson
2019-10-22  1:59 ` [PATCH 40/45] KVM: ARM: " Sean Christopherson
2019-10-22  1:59 ` [PATCH 41/45] KVM: PPC: " Sean Christopherson
2019-10-22  1:59 ` [PATCH 42/45] KVM: arm64: Free sve_state via arm specific hook Sean Christopherson
2019-10-22 11:43   ` Christoffer Dall
2019-10-22 18:41     ` Sean Christopherson
2019-10-22  1:59 ` [PATCH 43/45] KVM: Drop kvm_arch_vcpu_init() and kvm_arch_vcpu_uninit() Sean Christopherson
2019-10-22  1:59 ` [PATCH 44/45] KVM: Move putting of vcpu->pid to kvm_vcpu_destroy() Sean Christopherson
2019-10-22  1:59 ` [PATCH 45/45] KVM: Move vcpu->run page allocation out of kvm_vcpu_init() Sean Christopherson
2019-10-22 11:51 ` [PATCH 00/45] KVM: Refactor vCPU creation Christoffer Dall

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