- /* NULL selector is not valid for CS and SS */
- if (seg == VCPU_SREG_CS || seg == VCPU_SREG_SS)
- if (!selector)
- kvm_queue_exception_e(vcpu, TS_VECTOR, selector >> 3);
-}
-
-int kvm_load_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
- int type_bits, int seg)
-{
- struct kvm_segment kvm_seg;
- struct desc_struct seg_desc;
-
- if (is_vm86_segment(vcpu, seg) || !is_protmode(vcpu))
- return kvm_load_realmode_segment(vcpu, selector, seg);
-
- if (load_guest_segment_descriptor(vcpu, selector, &seg_desc))
- return 1;
- seg_desct_to_kvm_desct(&seg_desc, selector, &kvm_seg);
-
- kvm_check_segment_descriptor(vcpu, seg, selector);
- kvm_seg.type |= type_bits;
-
- if (seg != VCPU_SREG_SS && seg != VCPU_SREG_CS &&
- seg != VCPU_SREG_LDTR)
- if (!kvm_seg.s)
- kvm_seg.unusable = 1;
-
- kvm_set_segment(vcpu, &kvm_seg, seg);
- if (selector && !kvm_seg.unusable && kvm_seg.s) {
- /* mark segment as accessed */
- seg_desc.type |= 1;
- save_guest_segment_descriptor(vcpu, selector, &seg_desc);
- }
- return 0;
-}
-
-static void save_state_to_tss32(struct kvm_vcpu *vcpu,
- struct tss_segment_32 *tss)
-{
- tss->cr3 = vcpu->arch.cr3;
- tss->eip = kvm_rip_read(vcpu);
- tss->eflags = kvm_get_rflags(vcpu);
- tss->eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
- tss->ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
- tss->edx = kvm_register_read(vcpu, VCPU_REGS_RDX);
- tss->ebx = kvm_register_read(vcpu, VCPU_REGS_RBX);
- tss->esp = kvm_register_read(vcpu, VCPU_REGS_RSP);
- tss->ebp = kvm_register_read(vcpu, VCPU_REGS_RBP);
- tss->esi = kvm_register_read(vcpu, VCPU_REGS_RSI);
- tss->edi = kvm_register_read(vcpu, VCPU_REGS_RDI);
- tss->es = get_segment_selector(vcpu, VCPU_SREG_ES);
- tss->cs = get_segment_selector(vcpu, VCPU_SREG_CS);
- tss->ss = get_segment_selector(vcpu, VCPU_SREG_SS);
- tss->ds = get_segment_selector(vcpu, VCPU_SREG_DS);
- tss->fs = get_segment_selector(vcpu, VCPU_SREG_FS);
- tss->gs = get_segment_selector(vcpu, VCPU_SREG_GS);
- tss->ldt_selector = get_segment_selector(vcpu, VCPU_SREG_LDTR);
-}
-
-static int load_state_from_tss32(struct kvm_vcpu *vcpu,
- struct tss_segment_32 *tss)
-{
- kvm_set_cr3(vcpu, tss->cr3);
-
- kvm_rip_write(vcpu, tss->eip);
- kvm_set_rflags(vcpu, tss->eflags | 2);
-
- kvm_register_write(vcpu, VCPU_REGS_RAX, tss->eax);
- kvm_register_write(vcpu, VCPU_REGS_RCX, tss->ecx);
- kvm_register_write(vcpu, VCPU_REGS_RDX, tss->edx);
- kvm_register_write(vcpu, VCPU_REGS_RBX, tss->ebx);
- kvm_register_write(vcpu, VCPU_REGS_RSP, tss->esp);
- kvm_register_write(vcpu, VCPU_REGS_RBP, tss->ebp);
- kvm_register_write(vcpu, VCPU_REGS_RSI, tss->esi);
- kvm_register_write(vcpu, VCPU_REGS_RDI, tss->edi);
-
- if (kvm_load_segment_descriptor(vcpu, tss->ldt_selector, 0, VCPU_SREG_LDTR))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->es, 1, VCPU_SREG_ES))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->cs, 9, VCPU_SREG_CS))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->ss, 1, VCPU_SREG_SS))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->ds, 1, VCPU_SREG_DS))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->fs, 1, VCPU_SREG_FS))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->gs, 1, VCPU_SREG_GS))
- return 1;
- return 0;
-}
-
-static void save_state_to_tss16(struct kvm_vcpu *vcpu,
- struct tss_segment_16 *tss)
-{
- tss->ip = kvm_rip_read(vcpu);
- tss->flag = kvm_get_rflags(vcpu);
- tss->ax = kvm_register_read(vcpu, VCPU_REGS_RAX);
- tss->cx = kvm_register_read(vcpu, VCPU_REGS_RCX);
- tss->dx = kvm_register_read(vcpu, VCPU_REGS_RDX);
- tss->bx = kvm_register_read(vcpu, VCPU_REGS_RBX);
- tss->sp = kvm_register_read(vcpu, VCPU_REGS_RSP);
- tss->bp = kvm_register_read(vcpu, VCPU_REGS_RBP);
- tss->si = kvm_register_read(vcpu, VCPU_REGS_RSI);
- tss->di = kvm_register_read(vcpu, VCPU_REGS_RDI);
-
- tss->es = get_segment_selector(vcpu, VCPU_SREG_ES);
- tss->cs = get_segment_selector(vcpu, VCPU_SREG_CS);
- tss->ss = get_segment_selector(vcpu, VCPU_SREG_SS);
- tss->ds = get_segment_selector(vcpu, VCPU_SREG_DS);
- tss->ldt = get_segment_selector(vcpu, VCPU_SREG_LDTR);
-}
-
-static int load_state_from_tss16(struct kvm_vcpu *vcpu,
- struct tss_segment_16 *tss)
-{
- kvm_rip_write(vcpu, tss->ip);
- kvm_set_rflags(vcpu, tss->flag | 2);
- kvm_register_write(vcpu, VCPU_REGS_RAX, tss->ax);
- kvm_register_write(vcpu, VCPU_REGS_RCX, tss->cx);
- kvm_register_write(vcpu, VCPU_REGS_RDX, tss->dx);
- kvm_register_write(vcpu, VCPU_REGS_RBX, tss->bx);
- kvm_register_write(vcpu, VCPU_REGS_RSP, tss->sp);
- kvm_register_write(vcpu, VCPU_REGS_RBP, tss->bp);
- kvm_register_write(vcpu, VCPU_REGS_RSI, tss->si);
- kvm_register_write(vcpu, VCPU_REGS_RDI, tss->di);
-
- if (kvm_load_segment_descriptor(vcpu, tss->ldt, 0, VCPU_SREG_LDTR))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->es, 1, VCPU_SREG_ES))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->cs, 9, VCPU_SREG_CS))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->ss, 1, VCPU_SREG_SS))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->ds, 1, VCPU_SREG_DS))
- return 1;
- return 0;
-}
-
-static int kvm_task_switch_16(struct kvm_vcpu *vcpu, u16 tss_selector,
- u16 old_tss_sel, u32 old_tss_base,
- struct desc_struct *nseg_desc)
-{
- struct tss_segment_16 tss_segment_16;
- int ret = 0;
-
- if (kvm_read_guest(vcpu->kvm, old_tss_base, &tss_segment_16,
- sizeof tss_segment_16))
- goto out;
-
- save_state_to_tss16(vcpu, &tss_segment_16);
-
- if (kvm_write_guest(vcpu->kvm, old_tss_base, &tss_segment_16,
- sizeof tss_segment_16))
- goto out;
-
- if (kvm_read_guest(vcpu->kvm, get_tss_base_addr(vcpu, nseg_desc),
- &tss_segment_16, sizeof tss_segment_16))
- goto out;
-
- if (old_tss_sel != 0xffff) {
- tss_segment_16.prev_task_link = old_tss_sel;
-
- if (kvm_write_guest(vcpu->kvm,
- get_tss_base_addr(vcpu, nseg_desc),
- &tss_segment_16.prev_task_link,
- sizeof tss_segment_16.prev_task_link))
- goto out;
- }
-
- if (load_state_from_tss16(vcpu, &tss_segment_16))
- goto out;
-
- ret = 1;
-out:
- return ret;
-}
-
-static int kvm_task_switch_32(struct kvm_vcpu *vcpu, u16 tss_selector,
- u16 old_tss_sel, u32 old_tss_base,
- struct desc_struct *nseg_desc)
-{
- struct tss_segment_32 tss_segment_32;
- int ret = 0;
-
- if (kvm_read_guest(vcpu->kvm, old_tss_base, &tss_segment_32,
- sizeof tss_segment_32))
- goto out;
-
- save_state_to_tss32(vcpu, &tss_segment_32);
-
- if (kvm_write_guest(vcpu->kvm, old_tss_base, &tss_segment_32,
- sizeof tss_segment_32))
- goto out;
-
- if (kvm_read_guest(vcpu->kvm, get_tss_base_addr(vcpu, nseg_desc),
- &tss_segment_32, sizeof tss_segment_32))
- goto out;
-
- if (old_tss_sel != 0xffff) {
- tss_segment_32.prev_task_link = old_tss_sel;
-
- if (kvm_write_guest(vcpu->kvm,
- get_tss_base_addr(vcpu, nseg_desc),
- &tss_segment_32.prev_task_link,
- sizeof tss_segment_32.prev_task_link))
- goto out;
- }
-
- if (load_state_from_tss32(vcpu, &tss_segment_32))
- goto out;
-
- ret = 1;
-out:
- return ret;
-}
-
-int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason)
-{
- struct kvm_segment tr_seg;
- struct desc_struct cseg_desc;
- struct desc_struct nseg_desc;
- int ret = 0;
- u32 old_tss_base = get_segment_base(vcpu, VCPU_SREG_TR);
- u16 old_tss_sel = get_segment_selector(vcpu, VCPU_SREG_TR);
-
- old_tss_base = vcpu->arch.mmu.gva_to_gpa(vcpu, old_tss_base);
-
- /* FIXME: Handle errors. Failure to read either TSS or their
- * descriptors should generate a pagefault.
- */
- if (load_guest_segment_descriptor(vcpu, tss_selector, &nseg_desc))
- goto out;
-
- if (load_guest_segment_descriptor(vcpu, old_tss_sel, &cseg_desc))
- goto out;
-
- if (reason != TASK_SWITCH_IRET) {
- int cpl;
-
- cpl = kvm_x86_ops->get_cpl(vcpu);
- if ((tss_selector & 3) > nseg_desc.dpl || cpl > nseg_desc.dpl) {
- kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
- return 1;
- }
- }
-
- if (!nseg_desc.p || get_desc_limit(&nseg_desc) < 0x67) {
- kvm_queue_exception_e(vcpu, TS_VECTOR, tss_selector & 0xfffc);
- return 1;
- }
-
- if (reason == TASK_SWITCH_IRET || reason == TASK_SWITCH_JMP) {
- cseg_desc.type &= ~(1 << 1); //clear the B flag
- save_guest_segment_descriptor(vcpu, old_tss_sel, &cseg_desc);
- }
-
- if (reason == TASK_SWITCH_IRET) {
- u32 eflags = kvm_get_rflags(vcpu);
- kvm_set_rflags(vcpu, eflags & ~X86_EFLAGS_NT);
- }