diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 205b17eed93c..0dec502d20be 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2496,7 +2496,7 @@ static int task_switch_16(struct x86_emulate_ctxt *ctxt, static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt, struct tss_segment_32 *tss) { - tss->cr3 = ctxt->ops->get_cr(ctxt, 3); + /* CR3 and ldt selector are not saved intentionally */ tss->eip = ctxt->_eip; tss->eflags = ctxt->eflags; tss->eax = reg_read(ctxt, VCPU_REGS_RAX); @@ -2514,7 +2514,6 @@ static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt, tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS); tss->fs = get_segment_selector(ctxt, VCPU_SREG_FS); tss->gs = get_segment_selector(ctxt, VCPU_SREG_GS); - tss->ldt_selector = get_segment_selector(ctxt, VCPU_SREG_LDTR); } static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt, @@ -2604,6 +2603,8 @@ static int task_switch_32(struct x86_emulate_ctxt *ctxt, struct tss_segment_32 tss_seg; int ret; u32 new_tss_base = get_desc_base(new_desc); + u32 eip_offset = offsetof(struct tss_segment_32, eip); + u32 ldt_sel_offset = offsetof(struct tss_segment_32, ldt_selector); ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg, &ctxt->exception); @@ -2613,8 +2614,9 @@ static int task_switch_32(struct x86_emulate_ctxt *ctxt, save_state_to_tss32(ctxt, &tss_seg); - ret = ops->write_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg, - &ctxt->exception); + /* Only GP registers and segment selectors are saved */ + ret = ops->write_std(ctxt, old_tss_base + eip_offset, &tss_seg.eip, + ldt_sel_offset - eip_offset, &ctxt->exception); if (ret != X86EMUL_CONTINUE) /* FIXME: need to provide precise fault address */ return ret;