Re: [PATCH 0/5] KVM: VMX: Add caching of EXIT_QUAL and INTR_INFO

From: Paolo Bonzini
Date: Thu Apr 16 2020 - 10:03:38 EST


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(-)
>