return 0;
}
-static void seg_desct_to_kvm_desct(struct desc_struct *seg_desc, u16 selector,
- struct kvm_segment *kvm_desct)
-{
- kvm_desct->base = get_desc_base(seg_desc);
- kvm_desct->limit = get_desc_limit(seg_desc);
- if (seg_desc->g) {
- kvm_desct->limit <<= 12;
- kvm_desct->limit |= 0xfff;
- }
- kvm_desct->selector = selector;
- kvm_desct->type = seg_desc->type;
- kvm_desct->present = seg_desc->p;
- kvm_desct->dpl = seg_desc->dpl;
- kvm_desct->db = seg_desc->d;
- kvm_desct->s = seg_desc->s;
- kvm_desct->l = seg_desc->l;
- kvm_desct->g = seg_desc->g;
- kvm_desct->avl = seg_desc->avl;
- if (!selector)
- kvm_desct->unusable = 1;
- else
- kvm_desct->unusable = 0;
- kvm_desct->padding = 0;
-}
-
-static void get_segment_descriptor_dtable(struct kvm_vcpu *vcpu,
- u16 selector,
- struct desc_ptr *dtable)
-{
- if (selector & 1 << 2) {
- struct kvm_segment kvm_seg;
-
- kvm_get_segment(vcpu, &kvm_seg, VCPU_SREG_LDTR);
-
- if (kvm_seg.unusable)
- dtable->size = 0;
- else
- dtable->size = kvm_seg.limit;
- dtable->address = kvm_seg.base;
- }
- else
- kvm_x86_ops->get_gdt(vcpu, dtable);
-}
-
-/* allowed just for 8 bytes segments */
-static int load_guest_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
- struct desc_struct *seg_desc)
-{
- struct desc_ptr dtable;
- u16 index = selector >> 3;
- int ret;
- u32 err;
- gva_t addr;
-
- get_segment_descriptor_dtable(vcpu, selector, &dtable);
-
- if (dtable.size < index * 8 + 7) {
- kvm_queue_exception_e(vcpu, GP_VECTOR, selector & 0xfffc);
- return X86EMUL_PROPAGATE_FAULT;
- }
- addr = dtable.base + index * 8;
- ret = kvm_read_guest_virt_system(addr, seg_desc, sizeof(*seg_desc),
- vcpu, &err);
- if (ret == X86EMUL_PROPAGATE_FAULT)
- kvm_inject_page_fault(vcpu, addr, err);
-
- return ret;
-}
-
-/* allowed just for 8 bytes segments */
-static int save_guest_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
- struct desc_struct *seg_desc)
-{
- struct desc_ptr dtable;
- u16 index = selector >> 3;
-
- get_segment_descriptor_dtable(vcpu, selector, &dtable);
-
- if (dtable.size < index * 8 + 7)
- return 1;
- return kvm_write_guest_virt(dtable.address + index*8, seg_desc, sizeof(*seg_desc), vcpu, NULL);
-}
-
-static gpa_t get_tss_base_addr_write(struct kvm_vcpu *vcpu,
- struct desc_struct *seg_desc)
-{
- u32 base_addr = get_desc_base(seg_desc);
-
- return kvm_mmu_gva_to_gpa_write(vcpu, base_addr, NULL);
-}
-
-static gpa_t get_tss_base_addr_read(struct kvm_vcpu *vcpu,
- struct desc_struct *seg_desc)
-{
- u32 base_addr = get_desc_base(seg_desc);
-
- return kvm_mmu_gva_to_gpa_read(vcpu, base_addr, NULL);
-}
-
-static u16 get_segment_selector(struct kvm_vcpu *vcpu, int seg)
-{
- struct kvm_segment kvm_seg;
-
- kvm_get_segment(vcpu, &kvm_seg, seg);
- return kvm_seg.selector;
-}
-
-static int kvm_load_realmode_segment(struct kvm_vcpu *vcpu, u16 selector, int seg)
-{
- struct kvm_segment segvar = {
- .base = selector << 4,
- .limit = 0xffff,
- .selector = selector,
- .type = 3,
- .present = 1,
- .dpl = 3,
- .db = 0,
- .s = 1,
- .l = 0,
- .g = 0,
- .avl = 0,
- .unusable = 0,
- };
- kvm_x86_ops->set_segment(vcpu, &segvar, seg);
- return X86EMUL_CONTINUE;
-}
-
-static int is_vm86_segment(struct kvm_vcpu *vcpu, int seg)
-{
- return (seg != VCPU_SREG_LDTR) &&
- (seg != VCPU_SREG_TR) &&
- (kvm_get_rflags(vcpu) & X86_EFLAGS_VM);
-}
-
-int kvm_load_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector, int seg)
-{
- struct kvm_segment kvm_seg;
- struct desc_struct seg_desc;
- u8 dpl, rpl, cpl;
- unsigned err_vec = GP_VECTOR;
- u32 err_code = 0;
- bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */
- int ret;
-
- if (is_vm86_segment(vcpu, seg) || !is_protmode(vcpu))
- return kvm_load_realmode_segment(vcpu, selector, seg);
-
- /* NULL selector is not valid for TR, CS and SS */
- if ((seg == VCPU_SREG_CS || seg == VCPU_SREG_SS || seg == VCPU_SREG_TR)
- && null_selector)
- goto exception;
-
- /* TR should be in GDT only */
- if (seg == VCPU_SREG_TR && (selector & (1 << 2)))
- goto exception;
-
- ret = load_guest_segment_descriptor(vcpu, selector, &seg_desc);
- if (ret)
- return ret;
-
- seg_desct_to_kvm_desct(&seg_desc, selector, &kvm_seg);
-
- if (null_selector) { /* for NULL selector skip all following checks */
- kvm_seg.unusable = 1;
- goto load;
- }
-
- err_code = selector & 0xfffc;
- err_vec = GP_VECTOR;
-
- /* can't load system descriptor into segment selecor */
- if (seg <= VCPU_SREG_GS && !kvm_seg.s)
- goto exception;
-
- if (!kvm_seg.present) {
- err_vec = (seg == VCPU_SREG_SS) ? SS_VECTOR : NP_VECTOR;
- goto exception;
- }
-
- rpl = selector & 3;
- dpl = kvm_seg.dpl;
- cpl = kvm_x86_ops->get_cpl(vcpu);
-
- switch (seg) {
- case VCPU_SREG_SS:
- /*
- * segment is not a writable data segment or segment
- * selector's RPL != CPL or segment selector's RPL != CPL
- */
- if (rpl != cpl || (kvm_seg.type & 0xa) != 0x2 || dpl != cpl)
- goto exception;
- break;
- case VCPU_SREG_CS:
- if (!(kvm_seg.type & 8))
- goto exception;
-
- if (kvm_seg.type & 4) {
- /* conforming */
- if (dpl > cpl)
- goto exception;
- } else {
- /* nonconforming */
- if (rpl > cpl || dpl != cpl)
- goto exception;
- }
- /* CS(RPL) <- CPL */
- selector = (selector & 0xfffc) | cpl;
- break;
- case VCPU_SREG_TR:
- if (kvm_seg.s || (kvm_seg.type != 1 && kvm_seg.type != 9))
- goto exception;
- break;
- case VCPU_SREG_LDTR:
- if (kvm_seg.s || kvm_seg.type != 2)
- goto exception;
- break;
- default: /* DS, ES, FS, or GS */
- /*
- * segment is not a data or readable code segment or
- * ((segment is a data or nonconforming code segment)
- * and (both RPL and CPL > DPL))
- */
- if ((kvm_seg.type & 0xa) == 0x8 ||
- (((kvm_seg.type & 0xc) != 0xc) && (rpl > dpl && cpl > dpl)))
- goto exception;
- break;
- }
-
- if (!kvm_seg.unusable && kvm_seg.s) {
- /* mark segment as accessed */
- kvm_seg.type |= 1;
- seg_desc.type |= 1;
- save_guest_segment_descriptor(vcpu, selector, &seg_desc);
- }
-load:
- kvm_set_segment(vcpu, &kvm_seg, seg);
- return X86EMUL_CONTINUE;
-exception:
- kvm_queue_exception_e(vcpu, err_vec, err_code);
- return X86EMUL_PROPAGATE_FAULT;
-}
-
-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 void kvm_load_segment_selector(struct kvm_vcpu *vcpu, u16 sel, int seg)
-{
- struct kvm_segment kvm_seg;
- kvm_get_segment(vcpu, &kvm_seg, seg);
- kvm_seg.selector = sel;
- kvm_set_segment(vcpu, &kvm_seg, seg);
-}
-
-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);
-
- /*
- * SDM says that segment selectors are loaded before segment
- * descriptors
- */
- kvm_load_segment_selector(vcpu, tss->ldt_selector, VCPU_SREG_LDTR);
- kvm_load_segment_selector(vcpu, tss->es, VCPU_SREG_ES);
- kvm_load_segment_selector(vcpu, tss->cs, VCPU_SREG_CS);
- kvm_load_segment_selector(vcpu, tss->ss, VCPU_SREG_SS);
- kvm_load_segment_selector(vcpu, tss->ds, VCPU_SREG_DS);
- kvm_load_segment_selector(vcpu, tss->fs, VCPU_SREG_FS);
- kvm_load_segment_selector(vcpu, tss->gs, VCPU_SREG_GS);
-
- /*
- * Now load segment descriptors. If fault happenes at this stage
- * it is handled in a context of new task
- */
- if (kvm_load_segment_descriptor(vcpu, tss->ldt_selector, VCPU_SREG_LDTR))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->es, VCPU_SREG_ES))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->cs, VCPU_SREG_CS))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->ss, VCPU_SREG_SS))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->ds, VCPU_SREG_DS))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->fs, VCPU_SREG_FS))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->gs, 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);
-
- /*
- * SDM says that segment selectors are loaded before segment
- * descriptors
- */
- kvm_load_segment_selector(vcpu, tss->ldt, VCPU_SREG_LDTR);
- kvm_load_segment_selector(vcpu, tss->es, VCPU_SREG_ES);
- kvm_load_segment_selector(vcpu, tss->cs, VCPU_SREG_CS);
- kvm_load_segment_selector(vcpu, tss->ss, VCPU_SREG_SS);
- kvm_load_segment_selector(vcpu, tss->ds, VCPU_SREG_DS);
-
- /*
- * Now load segment descriptors. If fault happenes at this stage
- * it is handled in a context of new task
- */
- if (kvm_load_segment_descriptor(vcpu, tss->ldt, VCPU_SREG_LDTR))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->es, VCPU_SREG_ES))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->cs, VCPU_SREG_CS))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->ss, VCPU_SREG_SS))
- return 1;
-
- if (kvm_load_segment_descriptor(vcpu, tss->ds, 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_read(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_write(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_read(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_write(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);
- u32 desc_limit;
-
- old_tss_base = kvm_mmu_gva_to_gpa_write(vcpu, old_tss_base, NULL);
-
- /* 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;
- }
- }
-
- desc_limit = get_desc_limit(&nseg_desc);
- if (!nseg_desc.p ||
- ((desc_limit < 0x67 && (nseg_desc.type & 8)) ||
- desc_limit < 0x2b)) {
- 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);
- }
+ int cs_db, cs_l, ret;
+ cache_all_regs(vcpu);
- /* set back link to prev task only if NT bit is set in eflags
- note that old_tss_sel is not used afetr this point */
- if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE)
- old_tss_sel = 0xffff;
+ kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
- if (nseg_desc.type & 8)
- ret = kvm_task_switch_32(vcpu, tss_selector, old_tss_sel,
- old_tss_base, &nseg_desc);
- else
- ret = kvm_task_switch_16(vcpu, tss_selector, old_tss_sel,
- old_tss_base, &nseg_desc);
+ vcpu->arch.emulate_ctxt.vcpu = vcpu;
+ vcpu->arch.emulate_ctxt.eflags = kvm_x86_ops->get_rflags(vcpu);
+ vcpu->arch.emulate_ctxt.eip = kvm_rip_read(vcpu);
+ vcpu->arch.emulate_ctxt.mode =
+ (!is_protmode(vcpu)) ? X86EMUL_MODE_REAL :
+ (vcpu->arch.emulate_ctxt.eflags & X86_EFLAGS_VM)
+ ? X86EMUL_MODE_VM86 : cs_l
+ ? X86EMUL_MODE_PROT64 : cs_db
+ ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16;
- if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE) {
- u32 eflags = kvm_get_rflags(vcpu);
- kvm_set_rflags(vcpu, eflags | X86_EFLAGS_NT);
- }
+ ret = emulator_task_switch(&vcpu->arch.emulate_ctxt, &emulate_ops,
+ tss_selector, reason);
- if (reason != TASK_SWITCH_IRET) {
- nseg_desc.type |= (1 << 1);
- save_guest_segment_descriptor(vcpu, tss_selector,
- &nseg_desc);
- }
+ if (ret == X86EMUL_CONTINUE)
+ kvm_x86_ops->set_rflags(vcpu, vcpu->arch.emulate_ctxt.eflags);
- kvm_x86_ops->set_cr0(vcpu, kvm_read_cr0(vcpu) | X86_CR0_TS);
- seg_desct_to_kvm_desct(&nseg_desc, tss_selector, &tr_seg);
- tr_seg.type = 11;
- kvm_set_segment(vcpu, &tr_seg, VCPU_SREG_TR);
-out:
- return ret;
+ return (ret != X86EMUL_CONTINUE);
}
EXPORT_SYMBOL_GPL(kvm_task_switch);
projects / linux-beck.git / commitdiff