linux-kernel - [PATCH v2 00/10] KVM: x86: Clean up RESET "emulation"

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Date:   Mon, 20 Sep 2021 17:02:53 -0700
From:   Sean Christopherson <seanjc@...gle.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Reiji Watanabe <reijiw@...gle.com>
Subject: [PATCH v2 00/10] KVM: x86: Clean up RESET "emulation"

Add dedicated helpers to emulate RESET (or at least, the parts of RESET
that KVM actually emulates) instead of having the relevant code scattered
throughout vcpu_create() and vcpu_reset().

Vitaly's innocuous suggestion to WARN on non-zero CR0 led to a wonderful
bit of git archaeology after, to my complete surprise, it fired on RESET
due to fx_init() setting CR0.ET (and XCR0.FP).

v2:
 - Add patches to drop defunct fx_init() code.
 - Add patch to zero CR3 at RESET/INIT. 
 - Add patch to mark all regs avail/dirty at creation, not at RESET/INIT.
 - Add patch to WARN if CRs are non-zero at RESET. [Vitaly]

v1: https://lkml.kernel.org/r/20210914230840.3030620-1-seanjc@google.com

Sean Christopherson (10):
  KVM: x86: Mark all registers as avail/dirty at vCPU creation
  KVM: x86: Clear KVM's cached guest CR3 at RESET/INIT
  KVM: x86: Do not mark all registers as avail/dirty during RESET/INIT
  KVM: x86: Remove defunct setting of CR0.ET for guests during vCPU
    create
  KVM: x86: Remove defunct setting of XCR0 for guest during vCPU create
  KVM: x86: Fold fx_init() into kvm_arch_vcpu_create()
  KVM: VMX: Drop explicit zeroing of MSR guest values at vCPU creation
  KVM: VMX: Move RESET emulation to vmx_vcpu_reset()
  KVM: SVM: Move RESET emulation to svm_vcpu_reset()
  KVM: x86: WARN on non-zero CRs at RESET to detect improper
    initalization

 arch/x86/kvm/svm/sev.c |  6 ++--
 arch/x86/kvm/svm/svm.c | 29 ++++++++++--------
 arch/x86/kvm/svm/svm.h |  2 +-
 arch/x86/kvm/vmx/vmx.c | 68 ++++++++++++++++++++----------------------
 arch/x86/kvm/x86.c     | 44 +++++++++++++--------------
 5 files changed, 76 insertions(+), 73 deletions(-)

-- 
2.33.0.464.g1972c5931b-goog