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

From: Sean Christopherson
Date: Wed Apr 15 2020 - 16:35:03 EST


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(-)

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2.26.0