KVM: SVM: fix emulation of msr reads/writes of MSR_FS_BASE and MSR_GS_BASE

If these msrs are read by the emulator (e.g due to 'force emulation' prefix),
SVM code currently fails to extract the corresponding segment bases,
and return them to the emulator.

Fix that.

Cc: stable@vger.kernel.org
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20240802151608.72896-3-mlevitsk@redhat.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index d6f252555ab3ff0c68ead0ab03013ec8782364ab..b11454151f252f1acc3efc15f7bfcbdf2e402a4a 100644 (file)
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2876,6 +2876,12 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
        case MSR_CSTAR:
                msr_info->data = svm->vmcb01.ptr->save.cstar;
                break;
+       case MSR_GS_BASE:
+               msr_info->data = svm->vmcb01.ptr->save.gs.base;
+               break;
+       case MSR_FS_BASE:
+               msr_info->data = svm->vmcb01.ptr->save.fs.base;
+               break;
        case MSR_KERNEL_GS_BASE:
                msr_info->data = svm->vmcb01.ptr->save.kernel_gs_base;
                break;
@@ -3101,6 +3107,12 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
        case MSR_CSTAR:
                svm->vmcb01.ptr->save.cstar = data;
                break;
+       case MSR_GS_BASE:
+               svm->vmcb01.ptr->save.gs.base = data;
+               break;
+       case MSR_FS_BASE:
+               svm->vmcb01.ptr->save.fs.base = data;
+               break;
        case MSR_KERNEL_GS_BASE:
                svm->vmcb01.ptr->save.kernel_gs_base = data;
                break;