diff options
Diffstat (limited to 'arch/x86/kvm/smm.c')
| -rw-r--r-- | arch/x86/kvm/smm.c | 640 |
1 files changed, 640 insertions, 0 deletions
diff --git a/arch/x86/kvm/smm.c b/arch/x86/kvm/smm.c new file mode 100644 index 000000000000..d06d43d8d2aa --- /dev/null +++ b/arch/x86/kvm/smm.c @@ -0,0 +1,640 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kvm_host.h> +#include "x86.h" +#include "kvm_cache_regs.h" +#include "kvm_emulate.h" +#include "smm.h" +#include "cpuid.h" +#include "trace.h" + +#define CHECK_SMRAM32_OFFSET(field, offset) \ + ASSERT_STRUCT_OFFSET(struct kvm_smram_state_32, field, offset - 0xFE00) + +#define CHECK_SMRAM64_OFFSET(field, offset) \ + ASSERT_STRUCT_OFFSET(struct kvm_smram_state_64, field, offset - 0xFE00) + +static void check_smram_offsets(void) +{ + /* 32 bit SMRAM image */ + CHECK_SMRAM32_OFFSET(reserved1, 0xFE00); + CHECK_SMRAM32_OFFSET(smbase, 0xFEF8); + CHECK_SMRAM32_OFFSET(smm_revision, 0xFEFC); + CHECK_SMRAM32_OFFSET(io_inst_restart, 0xFF00); + CHECK_SMRAM32_OFFSET(auto_hlt_restart, 0xFF02); + CHECK_SMRAM32_OFFSET(io_restart_rdi, 0xFF04); + CHECK_SMRAM32_OFFSET(io_restart_rcx, 0xFF08); + CHECK_SMRAM32_OFFSET(io_restart_rsi, 0xFF0C); + CHECK_SMRAM32_OFFSET(io_restart_rip, 0xFF10); + CHECK_SMRAM32_OFFSET(cr4, 0xFF14); + CHECK_SMRAM32_OFFSET(reserved2, 0xFF18); + CHECK_SMRAM32_OFFSET(int_shadow, 0xFF1A); + CHECK_SMRAM32_OFFSET(reserved3, 0xFF1B); + CHECK_SMRAM32_OFFSET(ds, 0xFF2C); + CHECK_SMRAM32_OFFSET(fs, 0xFF38); + CHECK_SMRAM32_OFFSET(gs, 0xFF44); + CHECK_SMRAM32_OFFSET(idtr, 0xFF50); + CHECK_SMRAM32_OFFSET(tr, 0xFF5C); + CHECK_SMRAM32_OFFSET(gdtr, 0xFF6C); + CHECK_SMRAM32_OFFSET(ldtr, 0xFF78); + CHECK_SMRAM32_OFFSET(es, 0xFF84); + CHECK_SMRAM32_OFFSET(cs, 0xFF90); + CHECK_SMRAM32_OFFSET(ss, 0xFF9C); + CHECK_SMRAM32_OFFSET(es_sel, 0xFFA8); + CHECK_SMRAM32_OFFSET(cs_sel, 0xFFAC); + CHECK_SMRAM32_OFFSET(ss_sel, 0xFFB0); + CHECK_SMRAM32_OFFSET(ds_sel, 0xFFB4); + CHECK_SMRAM32_OFFSET(fs_sel, 0xFFB8); + CHECK_SMRAM32_OFFSET(gs_sel, 0xFFBC); + CHECK_SMRAM32_OFFSET(ldtr_sel, 0xFFC0); + CHECK_SMRAM32_OFFSET(tr_sel, 0xFFC4); + CHECK_SMRAM32_OFFSET(dr7, 0xFFC8); + CHECK_SMRAM32_OFFSET(dr6, 0xFFCC); + CHECK_SMRAM32_OFFSET(gprs, 0xFFD0); + CHECK_SMRAM32_OFFSET(eip, 0xFFF0); + CHECK_SMRAM32_OFFSET(eflags, 0xFFF4); + CHECK_SMRAM32_OFFSET(cr3, 0xFFF8); + CHECK_SMRAM32_OFFSET(cr0, 0xFFFC); + + /* 64 bit SMRAM image */ + CHECK_SMRAM64_OFFSET(es, 0xFE00); + CHECK_SMRAM64_OFFSET(cs, 0xFE10); + CHECK_SMRAM64_OFFSET(ss, 0xFE20); + CHECK_SMRAM64_OFFSET(ds, 0xFE30); + CHECK_SMRAM64_OFFSET(fs, 0xFE40); + CHECK_SMRAM64_OFFSET(gs, 0xFE50); + CHECK_SMRAM64_OFFSET(gdtr, 0xFE60); + CHECK_SMRAM64_OFFSET(ldtr, 0xFE70); + CHECK_SMRAM64_OFFSET(idtr, 0xFE80); + CHECK_SMRAM64_OFFSET(tr, 0xFE90); + CHECK_SMRAM64_OFFSET(io_restart_rip, 0xFEA0); + CHECK_SMRAM64_OFFSET(io_restart_rcx, 0xFEA8); + CHECK_SMRAM64_OFFSET(io_restart_rsi, 0xFEB0); + CHECK_SMRAM64_OFFSET(io_restart_rdi, 0xFEB8); + CHECK_SMRAM64_OFFSET(io_restart_dword, 0xFEC0); + CHECK_SMRAM64_OFFSET(reserved1, 0xFEC4); + CHECK_SMRAM64_OFFSET(io_inst_restart, 0xFEC8); + CHECK_SMRAM64_OFFSET(auto_hlt_restart, 0xFEC9); + CHECK_SMRAM64_OFFSET(amd_nmi_mask, 0xFECA); + CHECK_SMRAM64_OFFSET(int_shadow, 0xFECB); + CHECK_SMRAM64_OFFSET(reserved2, 0xFECC); + CHECK_SMRAM64_OFFSET(efer, 0xFED0); + CHECK_SMRAM64_OFFSET(svm_guest_flag, 0xFED8); + CHECK_SMRAM64_OFFSET(svm_guest_vmcb_gpa, 0xFEE0); + CHECK_SMRAM64_OFFSET(svm_guest_virtual_int, 0xFEE8); + CHECK_SMRAM64_OFFSET(reserved3, 0xFEF0); + CHECK_SMRAM64_OFFSET(smm_revison, 0xFEFC); + CHECK_SMRAM64_OFFSET(smbase, 0xFF00); + CHECK_SMRAM64_OFFSET(reserved4, 0xFF04); + CHECK_SMRAM64_OFFSET(ssp, 0xFF18); + CHECK_SMRAM64_OFFSET(svm_guest_pat, 0xFF20); + CHECK_SMRAM64_OFFSET(svm_host_efer, 0xFF28); + CHECK_SMRAM64_OFFSET(svm_host_cr4, 0xFF30); + CHECK_SMRAM64_OFFSET(svm_host_cr3, 0xFF38); + CHECK_SMRAM64_OFFSET(svm_host_cr0, 0xFF40); + CHECK_SMRAM64_OFFSET(cr4, 0xFF48); + CHECK_SMRAM64_OFFSET(cr3, 0xFF50); + CHECK_SMRAM64_OFFSET(cr0, 0xFF58); + CHECK_SMRAM64_OFFSET(dr7, 0xFF60); + CHECK_SMRAM64_OFFSET(dr6, 0xFF68); + CHECK_SMRAM64_OFFSET(rflags, 0xFF70); + CHECK_SMRAM64_OFFSET(rip, 0xFF78); + CHECK_SMRAM64_OFFSET(gprs, 0xFF80); + + BUILD_BUG_ON(sizeof(union kvm_smram) != 512); +} + +#undef CHECK_SMRAM64_OFFSET +#undef CHECK_SMRAM32_OFFSET + + +void kvm_smm_changed(struct kvm_vcpu *vcpu, bool entering_smm) +{ + trace_kvm_smm_transition(vcpu->vcpu_id, vcpu->arch.smbase, entering_smm); + + if (entering_smm) { + vcpu->arch.hflags |= HF_SMM_MASK; + } else { + vcpu->arch.hflags &= ~(HF_SMM_MASK | HF_SMM_INSIDE_NMI_MASK); + + /* Process a latched INIT or SMI, if any. */ + kvm_make_request(KVM_REQ_EVENT, vcpu); + + /* + * Even if KVM_SET_SREGS2 loaded PDPTRs out of band, + * on SMM exit we still need to reload them from + * guest memory + */ + vcpu->arch.pdptrs_from_userspace = false; + } + + kvm_mmu_reset_context(vcpu); +} + +void process_smi(struct kvm_vcpu *vcpu) +{ + vcpu->arch.smi_pending = true; + kvm_make_request(KVM_REQ_EVENT, vcpu); +} + +static u32 enter_smm_get_segment_flags(struct kvm_segment *seg) +{ + u32 flags = 0; + flags |= seg->g << 23; + flags |= seg->db << 22; + flags |= seg->l << 21; + flags |= seg->avl << 20; + flags |= seg->present << 15; + flags |= seg->dpl << 13; + flags |= seg->s << 12; + flags |= seg->type << 8; + return flags; +} + +static void enter_smm_save_seg_32(struct kvm_vcpu *vcpu, + struct kvm_smm_seg_state_32 *state, + u32 *selector, int n) +{ + struct kvm_segment seg; + + kvm_get_segment(vcpu, &seg, n); + *selector = seg.selector; + state->base = seg.base; + state->limit = seg.limit; + state->flags = enter_smm_get_segment_flags(&seg); +} + +#ifdef CONFIG_X86_64 +static void enter_smm_save_seg_64(struct kvm_vcpu *vcpu, + struct kvm_smm_seg_state_64 *state, + int n) +{ + struct kvm_segment seg; + + kvm_get_segment(vcpu, &seg, n); + state->selector = seg.selector; + state->attributes = enter_smm_get_segment_flags(&seg) >> 8; + state->limit = seg.limit; + state->base = seg.base; +} +#endif + +static void enter_smm_save_state_32(struct kvm_vcpu *vcpu, + struct kvm_smram_state_32 *smram) +{ + struct desc_ptr dt; + int i; + + smram->cr0 = kvm_read_cr0(vcpu); + smram->cr3 = kvm_read_cr3(vcpu); + smram->eflags = kvm_get_rflags(vcpu); + smram->eip = kvm_rip_read(vcpu); + + for (i = 0; i < 8; i++) + smram->gprs[i] = kvm_register_read_raw(vcpu, i); + + smram->dr6 = (u32)vcpu->arch.dr6; + smram->dr7 = (u32)vcpu->arch.dr7; + + enter_smm_save_seg_32(vcpu, &smram->tr, &smram->tr_sel, VCPU_SREG_TR); + enter_smm_save_seg_32(vcpu, &smram->ldtr, &smram->ldtr_sel, VCPU_SREG_LDTR); + + static_call(kvm_x86_get_gdt)(vcpu, &dt); + smram->gdtr.base = dt.address; + smram->gdtr.limit = dt.size; + + static_call(kvm_x86_get_idt)(vcpu, &dt); + smram->idtr.base = dt.address; + smram->idtr.limit = dt.size; + + enter_smm_save_seg_32(vcpu, &smram->es, &smram->es_sel, VCPU_SREG_ES); + enter_smm_save_seg_32(vcpu, &smram->cs, &smram->cs_sel, VCPU_SREG_CS); + enter_smm_save_seg_32(vcpu, &smram->ss, &smram->ss_sel, VCPU_SREG_SS); + + enter_smm_save_seg_32(vcpu, &smram->ds, &smram->ds_sel, VCPU_SREG_DS); + enter_smm_save_seg_32(vcpu, &smram->fs, &smram->fs_sel, VCPU_SREG_FS); + enter_smm_save_seg_32(vcpu, &smram->gs, &smram->gs_sel, VCPU_SREG_GS); + + smram->cr4 = kvm_read_cr4(vcpu); + smram->smm_revision = 0x00020000; + smram->smbase = vcpu->arch.smbase; + + smram->int_shadow = static_call(kvm_x86_get_interrupt_shadow)(vcpu); +} + +#ifdef CONFIG_X86_64 +static void enter_smm_save_state_64(struct kvm_vcpu *vcpu, + struct kvm_smram_state_64 *smram) +{ + struct desc_ptr dt; + int i; + + for (i = 0; i < 16; i++) + smram->gprs[15 - i] = kvm_register_read_raw(vcpu, i); + + smram->rip = kvm_rip_read(vcpu); + smram->rflags = kvm_get_rflags(vcpu); + + smram->dr6 = vcpu->arch.dr6; + smram->dr7 = vcpu->arch.dr7; + + smram->cr0 = kvm_read_cr0(vcpu); + smram->cr3 = kvm_read_cr3(vcpu); + smram->cr4 = kvm_read_cr4(vcpu); + + smram->smbase = vcpu->arch.smbase; + smram->smm_revison = 0x00020064; + + smram->efer = vcpu->arch.efer; + + enter_smm_save_seg_64(vcpu, &smram->tr, VCPU_SREG_TR); + + static_call(kvm_x86_get_idt)(vcpu, &dt); + smram->idtr.limit = dt.size; + smram->idtr.base = dt.address; + + enter_smm_save_seg_64(vcpu, &smram->ldtr, VCPU_SREG_LDTR); + + static_call(kvm_x86_get_gdt)(vcpu, &dt); + smram->gdtr.limit = dt.size; + smram->gdtr.base = dt.address; + + enter_smm_save_seg_64(vcpu, &smram->es, VCPU_SREG_ES); + enter_smm_save_seg_64(vcpu, &smram->cs, VCPU_SREG_CS); + enter_smm_save_seg_64(vcpu, &smram->ss, VCPU_SREG_SS); + enter_smm_save_seg_64(vcpu, &smram->ds, VCPU_SREG_DS); + enter_smm_save_seg_64(vcpu, &smram->fs, VCPU_SREG_FS); + enter_smm_save_seg_64(vcpu, &smram->gs, VCPU_SREG_GS); + + smram->int_shadow = static_call(kvm_x86_get_interrupt_shadow)(vcpu); +} +#endif + +void enter_smm(struct kvm_vcpu *vcpu) +{ + struct kvm_segment cs, ds; + struct desc_ptr dt; + unsigned long cr0; + union kvm_smram smram; + + check_smram_offsets(); + + memset(smram.bytes, 0, sizeof(smram.bytes)); + +#ifdef CONFIG_X86_64 + if (guest_cpuid_has(vcpu, X86_FEATURE_LM)) + enter_smm_save_state_64(vcpu, &smram.smram64); + else +#endif + enter_smm_save_state_32(vcpu, &smram.smram32); + + /* + * Give enter_smm() a chance to make ISA-specific changes to the vCPU + * state (e.g. leave guest mode) after we've saved the state into the + * SMM state-save area. + * + * Kill the VM in the unlikely case of failure, because the VM + * can be in undefined state in this case. + */ + if (static_call(kvm_x86_enter_smm)(vcpu, &smram)) + goto error; + + kvm_smm_changed(vcpu, true); + + if (kvm_vcpu_write_guest(vcpu, vcpu->arch.smbase + 0xfe00, &smram, sizeof(smram))) + goto error; + + if (static_call(kvm_x86_get_nmi_mask)(vcpu)) + vcpu->arch.hflags |= HF_SMM_INSIDE_NMI_MASK; + else + static_call(kvm_x86_set_nmi_mask)(vcpu, true); + + kvm_set_rflags(vcpu, X86_EFLAGS_FIXED); + kvm_rip_write(vcpu, 0x8000); + + static_call(kvm_x86_set_interrupt_shadow)(vcpu, 0); + + cr0 = vcpu->arch.cr0 & ~(X86_CR0_PE | X86_CR0_EM | X86_CR0_TS | X86_CR0_PG); + static_call(kvm_x86_set_cr0)(vcpu, cr0); + + static_call(kvm_x86_set_cr4)(vcpu, 0); + + /* Undocumented: IDT limit is set to zero on entry to SMM. */ + dt.address = dt.size = 0; + static_call(kvm_x86_set_idt)(vcpu, &dt); + + if (WARN_ON_ONCE(kvm_set_dr(vcpu, 7, DR7_FIXED_1))) + goto error; + + cs.selector = (vcpu->arch.smbase >> 4) & 0xffff; + cs.base = vcpu->arch.smbase; + + ds.selector = 0; + ds.base = 0; + + cs.limit = ds.limit = 0xffffffff; + cs.type = ds.type = 0x3; + cs.dpl = ds.dpl = 0; + cs.db = ds.db = 0; + cs.s = ds.s = 1; + cs.l = ds.l = 0; + cs.g = ds.g = 1; + cs.avl = ds.avl = 0; + cs.present = ds.present = 1; + cs.unusable = ds.unusable = 0; + cs.padding = ds.padding = 0; + + kvm_set_segment(vcpu, &cs, VCPU_SREG_CS); + kvm_set_segment(vcpu, &ds, VCPU_SREG_DS); + kvm_set_segment(vcpu, &ds, VCPU_SREG_ES); + kvm_set_segment(vcpu, &ds, VCPU_SREG_FS); + kvm_set_segment(vcpu, &ds, VCPU_SREG_GS); + kvm_set_segment(vcpu, &ds, VCPU_SREG_SS); + +#ifdef CONFIG_X86_64 + if (guest_cpuid_has(vcpu, X86_FEATURE_LM)) + if (static_call(kvm_x86_set_efer)(vcpu, 0)) + goto error; +#endif + + kvm_update_cpuid_runtime(vcpu); + kvm_mmu_reset_context(vcpu); + return; +error: + kvm_vm_dead(vcpu->kvm); +} + +static void rsm_set_desc_flags(struct kvm_segment *desc, u32 flags) +{ + desc->g = (flags >> 23) & 1; + desc->db = (flags >> 22) & 1; + desc->l = (flags >> 21) & 1; + desc->avl = (flags >> 20) & 1; + desc->present = (flags >> 15) & 1; + desc->dpl = (flags >> 13) & 3; + desc->s = (flags >> 12) & 1; + desc->type = (flags >> 8) & 15; + + desc->unusable = !desc->present; + desc->padding = 0; +} + +static int rsm_load_seg_32(struct kvm_vcpu *vcpu, + const struct kvm_smm_seg_state_32 *state, + u16 selector, int n) +{ + struct kvm_segment desc; + + desc.selector = selector; + desc.base = state->base; + desc.limit = state->limit; + rsm_set_desc_flags(&desc, state->flags); + kvm_set_segment(vcpu, &desc, n); + return X86EMUL_CONTINUE; +} + +#ifdef CONFIG_X86_64 + +static int rsm_load_seg_64(struct kvm_vcpu *vcpu, + const struct kvm_smm_seg_state_64 *state, + int n) +{ + struct kvm_segment desc; + + desc.selector = state->selector; + rsm_set_desc_flags(&desc, state->attributes << 8); + desc.limit = state->limit; + desc.base = state->base; + kvm_set_segment(vcpu, &desc, n); + return X86EMUL_CONTINUE; +} +#endif + +static int rsm_enter_protected_mode(struct kvm_vcpu *vcpu, + u64 cr0, u64 cr3, u64 cr4) +{ + int bad; + u64 pcid; + + /* In order to later set CR4.PCIDE, CR3[11:0] must be zero. */ + pcid = 0; + if (cr4 & X86_CR4_PCIDE) { + pcid = cr3 & 0xfff; + cr3 &= ~0xfff; + } + + bad = kvm_set_cr3(vcpu, cr3); + if (bad) + return X86EMUL_UNHANDLEABLE; + + /* + * First enable PAE, long mode needs it before CR0.PG = 1 is set. + * Then enable protected mode. However, PCID cannot be enabled + * if EFER.LMA=0, so set it separately. + */ + bad = kvm_set_cr4(vcpu, cr4 & ~X86_CR4_PCIDE); + if (bad) + return X86EMUL_UNHANDLEABLE; + + bad = kvm_set_cr0(vcpu, cr0); + if (bad) + return X86EMUL_UNHANDLEABLE; + + if (cr4 & X86_CR4_PCIDE) { + bad = kvm_set_cr4(vcpu, cr4); + if (bad) + return X86EMUL_UNHANDLEABLE; + if (pcid) { + bad = kvm_set_cr3(vcpu, cr3 | pcid); + if (bad) + return X86EMUL_UNHANDLEABLE; + } + + } + + return X86EMUL_CONTINUE; +} + +static int rsm_load_state_32(struct x86_emulate_ctxt *ctxt, + const struct kvm_smram_state_32 *smstate) +{ + struct kvm_vcpu *vcpu = ctxt->vcpu; + struct desc_ptr dt; + int i, r; + + ctxt->eflags = smstate->eflags | X86_EFLAGS_FIXED; + ctxt->_eip = smstate->eip; + + for (i = 0; i < 8; i++) + *reg_write(ctxt, i) = smstate->gprs[i]; + + if (kvm_set_dr(vcpu, 6, smstate->dr6)) + return X86EMUL_UNHANDLEABLE; + if (kvm_set_dr(vcpu, 7, smstate->dr7)) + return X86EMUL_UNHANDLEABLE; + + rsm_load_seg_32(vcpu, &smstate->tr, smstate->tr_sel, VCPU_SREG_TR); + rsm_load_seg_32(vcpu, &smstate->ldtr, smstate->ldtr_sel, VCPU_SREG_LDTR); + + dt.address = smstate->gdtr.base; + dt.size = smstate->gdtr.limit; + static_call(kvm_x86_set_gdt)(vcpu, &dt); + + dt.address = smstate->idtr.base; + dt.size = smstate->idtr.limit; + static_call(kvm_x86_set_idt)(vcpu, &dt); + + rsm_load_seg_32(vcpu, &smstate->es, smstate->es_sel, VCPU_SREG_ES); + rsm_load_seg_32(vcpu, &smstate->cs, smstate->cs_sel, VCPU_SREG_CS); + rsm_load_seg_32(vcpu, &smstate->ss, smstate->ss_sel, VCPU_SREG_SS); + + rsm_load_seg_32(vcpu, &smstate->ds, smstate->ds_sel, VCPU_SREG_DS); + rsm_load_seg_32(vcpu, &smstate->fs, smstate->fs_sel, VCPU_SREG_FS); + rsm_load_seg_32(vcpu, &smstate->gs, smstate->gs_sel, VCPU_SREG_GS); + + vcpu->arch.smbase = smstate->smbase; + + r = rsm_enter_protected_mode(vcpu, smstate->cr0, + smstate->cr3, smstate->cr4); + + if (r != X86EMUL_CONTINUE) + return r; + + static_call(kvm_x86_set_interrupt_shadow)(vcpu, 0); + ctxt->interruptibility = (u8)smstate->int_shadow; + + return r; +} + +#ifdef CONFIG_X86_64 +static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt, + const struct kvm_smram_state_64 *smstate) +{ + struct kvm_vcpu *vcpu = ctxt->vcpu; + struct desc_ptr dt; + int i, r; + + for (i = 0; i < 16; i++) + *reg_write(ctxt, i) = smstate->gprs[15 - i]; + + ctxt->_eip = smstate->rip; + ctxt->eflags = smstate->rflags | X86_EFLAGS_FIXED; + + if (kvm_set_dr(vcpu, 6, smstate->dr6)) + return X86EMUL_UNHANDLEABLE; + if (kvm_set_dr(vcpu, 7, smstate->dr7)) + return X86EMUL_UNHANDLEABLE; + + vcpu->arch.smbase = smstate->smbase; + + if (kvm_set_msr(vcpu, MSR_EFER, smstate->efer & ~EFER_LMA)) + return X86EMUL_UNHANDLEABLE; + + rsm_load_seg_64(vcpu, &smstate->tr, VCPU_SREG_TR); + + dt.size = smstate->idtr.limit; + dt.address = smstate->idtr.base; + static_call(kvm_x86_set_idt)(vcpu, &dt); + + rsm_load_seg_64(vcpu, &smstate->ldtr, VCPU_SREG_LDTR); + + dt.size = smstate->gdtr.limit; + dt.address = smstate->gdtr.base; + static_call(kvm_x86_set_gdt)(vcpu, &dt); + + r = rsm_enter_protected_mode(vcpu, smstate->cr0, smstate->cr3, smstate->cr4); + if (r != X86EMUL_CONTINUE) + return r; + + rsm_load_seg_64(vcpu, &smstate->es, VCPU_SREG_ES); + rsm_load_seg_64(vcpu, &smstate->cs, VCPU_SREG_CS); + rsm_load_seg_64(vcpu, &smstate->ss, VCPU_SREG_SS); + rsm_load_seg_64(vcpu, &smstate->ds, VCPU_SREG_DS); + rsm_load_seg_64(vcpu, &smstate->fs, VCPU_SREG_FS); + rsm_load_seg_64(vcpu, &smstate->gs, VCPU_SREG_GS); + + static_call(kvm_x86_set_interrupt_shadow)(vcpu, 0); + ctxt->interruptibility = (u8)smstate->int_shadow; + + return X86EMUL_CONTINUE; +} +#endif + +int emulator_leave_smm(struct x86_emulate_ctxt *ctxt) +{ + struct kvm_vcpu *vcpu = ctxt->vcpu; + unsigned long cr0; + union kvm_smram smram; + u64 smbase; + int ret; + + smbase = vcpu->arch.smbase; + + ret = kvm_vcpu_read_guest(vcpu, smbase + 0xfe00, smram.bytes, sizeof(smram)); + if (ret < 0) + return X86EMUL_UNHANDLEABLE; + + if ((vcpu->arch.hflags & HF_SMM_INSIDE_NMI_MASK) == 0) + static_call(kvm_x86_set_nmi_mask)(vcpu, false); + + kvm_smm_changed(vcpu, false); + + /* + * Get back to real mode, to prepare a safe state in which to load + * CR0/CR3/CR4/EFER. It's all a bit more complicated if the vCPU + * supports long mode. + */ +#ifdef CONFIG_X86_64 + if (guest_cpuid_has(vcpu, X86_FEATURE_LM)) { + struct kvm_segment cs_desc; + unsigned long cr4; + + /* Zero CR4.PCIDE before CR0.PG. */ + cr4 = kvm_read_cr4(vcpu); + if (cr4 & X86_CR4_PCIDE) + kvm_set_cr4(vcpu, cr4 & ~X86_CR4_PCIDE); + + /* A 32-bit code segment is required to clear EFER.LMA. */ + memset(&cs_desc, 0, sizeof(cs_desc)); + cs_desc.type = 0xb; + cs_desc.s = cs_desc.g = cs_desc.present = 1; + kvm_set_segment(vcpu, &cs_desc, VCPU_SREG_CS); + } +#endif + + /* For the 64-bit case, this will clear EFER.LMA. */ + cr0 = kvm_read_cr0(vcpu); + if (cr0 & X86_CR0_PE) + kvm_set_cr0(vcpu, cr0 & ~(X86_CR0_PG | X86_CR0_PE)); + +#ifdef CONFIG_X86_64 + if (guest_cpuid_has(vcpu, X86_FEATURE_LM)) { + unsigned long cr4, efer; + + /* Clear CR4.PAE before clearing EFER.LME. */ + cr4 = kvm_read_cr4(vcpu); + if (cr4 & X86_CR4_PAE) + kvm_set_cr4(vcpu, cr4 & ~X86_CR4_PAE); + + /* And finally go back to 32-bit mode. */ + efer = 0; + kvm_set_msr(vcpu, MSR_EFER, efer); + } +#endif + + /* + * Give leave_smm() a chance to make ISA-specific changes to the vCPU + * state (e.g. enter guest mode) before loading state from the SMM + * state-save area. + */ + if (static_call(kvm_x86_leave_smm)(vcpu, &smram)) + return X86EMUL_UNHANDLEABLE; + +#ifdef CONFIG_X86_64 + if (guest_cpuid_has(vcpu, X86_FEATURE_LM)) + return rsm_load_state_64(ctxt, &smram.smram64); + else +#endif + return rsm_load_state_32(ctxt, &smram.smram32); +} |