[0/5] KVM: VMX: Add caching of EXIT_QUAL and INTR_INFO
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Message ID 20200415203454.8296-1-sean.j.christopherson@intel.com
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  • KVM: VMX: Add caching of EXIT_QUAL and INTR_INFO
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Sean Christopherson April 15, 2020, 8:34 p.m. UTC
Patches 4-5 are the focus of this series, adding caching of
vmcs.EXIT_QUALIFICATION and proper caching of vmcs.INTR_INFO (instead of
caching it with ad hoc rules about when it's available).  Patches 1-3
are prep work to clean up the register caching to ensure correctness when
switching between vmcs01 and vmcs02.

The idea for this came about when working on the "unionize exit_reason"
series.  The nested VM-Exit logic looks at both fields multiple times,
which is ok-ish when everything is crammed into one or two functions, but
incurs multiple VMREADs when split up.  I really didn't want to solve that
issue by piling on more cases where vmx->exit_intr_info would be valid, or
by duplicating that fragile pattern for exit_qualification.

Paolo, this will conflict with the "unionize exit_reason" series, though
the conflict resolution is all mechnical in nature.  Let me know if you
want me to respin one on top of the other, send a single series, etc...

Sean Christopherson (5):
  KVM: nVMX: Invoke ept_save_pdptrs() if and only if PAE paging is
    enabled
  KVM: nVMX: Reset register cache (available and dirty masks) on VMCS
    switch
  KVM: nVMX: Drop manual clearing of segment cache on nested VMCS switch
  KVM: VMX: Cache vmcs.EXIT_QUALIFICATION using arch avail_reg flags
  KVM: VMX: Cache vmcs.EXIT_INTR_INFO using arch avail_reg flags

 arch/x86/include/asm/kvm_host.h |  2 +
 arch/x86/kvm/vmx/nested.c       | 29 +++++++------
 arch/x86/kvm/vmx/nested.h       |  4 +-
 arch/x86/kvm/vmx/vmx.c          | 73 ++++++++++++++++-----------------
 arch/x86/kvm/vmx/vmx.h          | 35 +++++++++++++++-
 5 files changed, 86 insertions(+), 57 deletions(-)

Comments

Paolo Bonzini April 16, 2020, 1:42 p.m. UTC | #1
On 15/04/20 22:34, Sean Christopherson wrote:
> Patches 4-5 are the focus of this series, adding caching of
> vmcs.EXIT_QUALIFICATION and proper caching of vmcs.INTR_INFO (instead of
> caching it with ad hoc rules about when it's available).  Patches 1-3
> are prep work to clean up the register caching to ensure correctness when
> switching between vmcs01 and vmcs02.
> 
> The idea for this came about when working on the "unionize exit_reason"
> series.  The nested VM-Exit logic looks at both fields multiple times,
> which is ok-ish when everything is crammed into one or two functions, but
> incurs multiple VMREADs when split up.  I really didn't want to solve that
> issue by piling on more cases where vmx->exit_intr_info would be valid, or
> by duplicating that fragile pattern for exit_qualification.
> 
> Paolo, this will conflict with the "unionize exit_reason" series, though
> the conflict resolution is all mechnical in nature.  Let me know if you
> want me to respin one on top of the other, send a single series, etc...

Queued, I think I fixed the conflicts right.  We'll see if anything
explodes when I test it. :)

Paolo

> 
> Sean Christopherson (5):
>   KVM: nVMX: Invoke ept_save_pdptrs() if and only if PAE paging is
>     enabled
>   KVM: nVMX: Reset register cache (available and dirty masks) on VMCS
>     switch
>   KVM: nVMX: Drop manual clearing of segment cache on nested VMCS switch
>   KVM: VMX: Cache vmcs.EXIT_QUALIFICATION using arch avail_reg flags
>   KVM: VMX: Cache vmcs.EXIT_INTR_INFO using arch avail_reg flags
> 
>  arch/x86/include/asm/kvm_host.h |  2 +
>  arch/x86/kvm/vmx/nested.c       | 29 +++++++------
>  arch/x86/kvm/vmx/nested.h       |  4 +-
>  arch/x86/kvm/vmx/vmx.c          | 73 ++++++++++++++++-----------------
>  arch/x86/kvm/vmx/vmx.h          | 35 +++++++++++++++-
>  5 files changed, 86 insertions(+), 57 deletions(-)
>