KVM: SVM: Ensure SPEC_CTRL[63:32] is context switched between guest and host

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SPEC_CTRL is an MSR, i.e. a 64-bit value, but the VMRUN assembly code
assumes bits 63:32 are always zero.  The bug is _currently_ benign because
neither KVM nor the kernel support setting any of bits 63:32, but it's
still a bug that needs to be fixed.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Link: https://patch.msgid.link/20251106191230.182393-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

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Uros Bizjak 2025-11-06 11:12:30 -08:00 • committed by Sean Christopherson

parent 3d80f4c93d

commit c331b400e2

1 changed files with 37 additions and 10 deletions

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arch/x86/kvm/svm/vmenter.S

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