When nested NPT is enabled and KVM_SET_NESTED_STATE is used to restore an old checkpoint (without a valid gPAT), the current IA32_PAT value must be used as L2's gPAT.
The current IA32_PAT value may be restored by KVM_SET_MSRS after KVM_SET_NESTED_STATE. Furthermore, there may be a KVM_GET_NESTED_STATE before the first KVM_RUN. Introduce a new boolean, svm->nested.legacy_gpat_semantics. When set, hPAT updates are also applied to gPAT, preserving the old behavior where L2 shared L1's PAT. svm_vcpu_pre_run() clears this boolean at the first KVM_RUN. Signed-off-by: Jim Mattson <[email protected]> --- arch/x86/kvm/svm/nested.c | 11 ++++++++--- arch/x86/kvm/svm/svm.c | 2 ++ arch/x86/kvm/svm/svm.h | 9 +++++++++ 3 files changed, 19 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 3f512fb630db..a7d6fc1382a7 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -1936,9 +1936,14 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu, if (ret) goto out_free; - if (nested_npt_enabled(svm) && - (kvm_state->hdr.svm.flags & KVM_STATE_SVM_VALID_GPAT)) - svm_set_gpat(svm, kvm_state->hdr.svm.gpat); + if (nested_npt_enabled(svm)) { + if (kvm_state->hdr.svm.flags & KVM_STATE_SVM_VALID_GPAT) { + svm_set_gpat(svm, kvm_state->hdr.svm.gpat); + } else { + svm_set_gpat(svm, vcpu->arch.pat); + svm->nested.legacy_gpat_semantics = true; + } + } svm->nested.force_msr_bitmap_recalc = true; diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index b62c32c3942d..a6a44deec82b 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4239,6 +4239,8 @@ static int svm_vcpu_pre_run(struct kvm_vcpu *vcpu) if (to_kvm_sev_info(vcpu->kvm)->need_init) return -EINVAL; + to_svm(vcpu)->nested.legacy_gpat_semantics = false; + return 1; } diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index a0e94a2c51a1..a559cd45c8a9 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -221,6 +221,13 @@ struct svm_nested_state { * on its side. */ bool force_msr_bitmap_recalc; + + /* + * Indicates that a legacy nested state was restored (without a + * valid gPAT). In this mode, updates to hPAT are also applied to + * gPAT, preserving the old behavior where L2 shared L1's PAT. + */ + bool legacy_gpat_semantics; }; struct vcpu_sev_es_state { @@ -604,6 +611,8 @@ static inline void svm_set_hpat(struct vcpu_svm *svm, u64 data) if (is_guest_mode(&svm->vcpu) && !nested_npt_enabled(svm)) svm_set_vmcb_gpat(svm->nested.vmcb02.ptr, data); } + if (svm->nested.legacy_gpat_semantics) + svm_set_gpat(svm, data); } static inline bool nested_vnmi_enabled(struct vcpu_svm *svm) -- 2.53.0.rc2.204.g2597b5adb4-goog
