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

commit dad1613e0533b380318281c1519e1a3477c2d0d2 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index e3c2acc1adc735748ff3a2b83b0d39b3fc12d722..c19b9b96143d8256aa3956bb1aebd0e3829131e1 100644 (file)
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2869,6 +2869,12 @@ 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;
@@ -3090,6 +3096,12 @@ 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;