Two bug fixes to handle KVM_SET_SREGS without a preceding KVM_SET_CPUID2.
The overarching issue is that kvm_x86_ops.set_cr4() can fail, but its
invocation from __set_sregs(), a.k.a. KVM_SET_SREGS, ignores the result.
Fix the issue by moving all validity checks out of .set_cr4() in one way
or another.
I intentionally omitted a Cc to stable. The first bug fix in particular
may break stable trees as it simply removes a check, and I don't know that
stable trees have the generic CR4 reserved bit check that is needed to
prevent the guest from setting VMXE when nVMX is not allowed.
Sean Christopherson (6):
KVM: VMX: Drop guest CPUID check for VMXE in vmx_set_cr4()
KVM: VMX: Drop explicit 'nested' check from vmx_set_cr4()
KVM: SVM: Drop VMXE check from svm_set_cr4()
KVM: x86: Move vendor CR4 validity check to dedicated kvm_x86_ops hook
KVM: x86: Return bool instead of int for CR4 and SREGS validity checks
KVM: selftests: Verify supported CR4 bits can be set before
KVM_SET_CPUID2
arch/x86/include/asm/kvm_host.h | 3 +-
arch/x86/kvm/svm/nested.c | 2 +-
arch/x86/kvm/svm/svm.c | 12 ++-
arch/x86/kvm/svm/svm.h | 2 +-
arch/x86/kvm/vmx/nested.c | 2 +-
arch/x86/kvm/vmx/vmx.c | 35 +++----
arch/x86/kvm/vmx/vmx.h | 2 +-
arch/x86/kvm/x86.c | 28 +++---
arch/x86/kvm/x86.h | 2 +-
.../selftests/kvm/include/x86_64/processor.h | 17 ++++
.../selftests/kvm/include/x86_64/vmx.h | 4 -
.../selftests/kvm/x86_64/set_sregs_test.c | 92 ++++++++++++++++++-
12 files changed, 153 insertions(+), 48 deletions(-)
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2.28.0
