From 0f12244fe70e8a94a491f6cd7ed70a352ab6c26c Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Wed, 28 Apr 2010 19:15:31 +0300 Subject: [PATCH] KVM: x86 emulator: make set_cr() callback return error if it fails Make set_cr() callback return error if it fails instead of injecting #GP behind emulator's back. Signed-off-by: Gleb Natapov Signed-off-by: Avi Kivity --- arch/x86/include/asm/kvm_emulate.h | 2 +- arch/x86/kvm/emulate.c | 10 +- arch/x86/kvm/x86.c | 148 +++++++++++++++-------------- 3 files changed, 84 insertions(+), 76 deletions(-) diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index df53ba2294b6..6c4f4918db5e 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -135,7 +135,7 @@ struct x86_emulate_ops { unsigned long (*get_cached_segment_base)(int seg, struct kvm_vcpu *vcpu); void (*get_gdt)(struct desc_ptr *dt, struct kvm_vcpu *vcpu); ulong (*get_cr)(int cr, struct kvm_vcpu *vcpu); - void (*set_cr)(int cr, ulong val, struct kvm_vcpu *vcpu); + int (*set_cr)(int cr, ulong val, struct kvm_vcpu *vcpu); int (*cpl)(struct kvm_vcpu *vcpu); void (*set_rflags)(struct kvm_vcpu *vcpu, unsigned long rflags); int (*get_dr)(int dr, unsigned long *dest, struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index f56ec486393e..061f7d37c9f7 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2272,7 +2272,10 @@ static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt, struct decode_cache *c = &ctxt->decode; int ret; - ops->set_cr(3, tss->cr3, ctxt->vcpu); + if (ops->set_cr(3, tss->cr3, ctxt->vcpu)) { + kvm_inject_gp(ctxt->vcpu, 0); + return X86EMUL_PROPAGATE_FAULT; + } c->eip = tss->eip; ctxt->eflags = tss->eflags | 2; c->regs[VCPU_REGS_RAX] = tss->eax; @@ -3135,7 +3138,10 @@ twobyte_insn: c->dst.type = OP_NONE; /* no writeback */ break; case 0x22: /* mov reg, cr */ - ops->set_cr(c->modrm_reg, c->modrm_val, ctxt->vcpu); + if (ops->set_cr(c->modrm_reg, c->modrm_val, ctxt->vcpu)) { + kvm_inject_gp(ctxt->vcpu, 0); + goto done; + } c->dst.type = OP_NONE; break; case 0x23: /* mov from reg to dr */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 9a469df6011c..64c6e7a31411 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -414,57 +414,49 @@ out: return changed; } -void kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) +static int __kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) { cr0 |= X86_CR0_ET; #ifdef CONFIG_X86_64 - if (cr0 & 0xffffffff00000000UL) { - kvm_inject_gp(vcpu, 0); - return; - } + if (cr0 & 0xffffffff00000000UL) + return 1; #endif cr0 &= ~CR0_RESERVED_BITS; - if ((cr0 & X86_CR0_NW) && !(cr0 & X86_CR0_CD)) { - kvm_inject_gp(vcpu, 0); - return; - } + if ((cr0 & X86_CR0_NW) && !(cr0 & X86_CR0_CD)) + return 1; - if ((cr0 & X86_CR0_PG) && !(cr0 & X86_CR0_PE)) { - kvm_inject_gp(vcpu, 0); - return; - } + if ((cr0 & X86_CR0_PG) && !(cr0 & X86_CR0_PE)) + return 1; if (!is_paging(vcpu) && (cr0 & X86_CR0_PG)) { #ifdef CONFIG_X86_64 if ((vcpu->arch.efer & EFER_LME)) { int cs_db, cs_l; - if (!is_pae(vcpu)) { - kvm_inject_gp(vcpu, 0); - return; - } + if (!is_pae(vcpu)) + return 1; kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l); - if (cs_l) { - kvm_inject_gp(vcpu, 0); - return; - - } + if (cs_l) + return 1; } else #endif - if (is_pae(vcpu) && !load_pdptrs(vcpu, vcpu->arch.cr3)) { - kvm_inject_gp(vcpu, 0); - return; - } - + if (is_pae(vcpu) && !load_pdptrs(vcpu, vcpu->arch.cr3)) + return 1; } kvm_x86_ops->set_cr0(vcpu, cr0); kvm_mmu_reset_context(vcpu); - return; + return 0; +} + +void kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) +{ + if (__kvm_set_cr0(vcpu, cr0)) + kvm_inject_gp(vcpu, 0); } EXPORT_SYMBOL_GPL(kvm_set_cr0); @@ -474,61 +466,56 @@ void kvm_lmsw(struct kvm_vcpu *vcpu, unsigned long msw) } EXPORT_SYMBOL_GPL(kvm_lmsw); -void kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) +int __kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) { unsigned long old_cr4 = kvm_read_cr4(vcpu); unsigned long pdptr_bits = X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE; - if (cr4 & CR4_RESERVED_BITS) { - kvm_inject_gp(vcpu, 0); - return; - } + if (cr4 & CR4_RESERVED_BITS) + return 1; if (is_long_mode(vcpu)) { - if (!(cr4 & X86_CR4_PAE)) { - kvm_inject_gp(vcpu, 0); - return; - } + if (!(cr4 & X86_CR4_PAE)) + return 1; } else if (is_paging(vcpu) && (cr4 & X86_CR4_PAE) && ((cr4 ^ old_cr4) & pdptr_bits) - && !load_pdptrs(vcpu, vcpu->arch.cr3)) { - kvm_inject_gp(vcpu, 0); - return; - } + && !load_pdptrs(vcpu, vcpu->arch.cr3)) + return 1; + + if (cr4 & X86_CR4_VMXE) + return 1; - if (cr4 & X86_CR4_VMXE) { - kvm_inject_gp(vcpu, 0); - return; - } kvm_x86_ops->set_cr4(vcpu, cr4); vcpu->arch.cr4 = cr4; kvm_mmu_reset_context(vcpu); + + return 0; +} + +void kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) +{ + if (__kvm_set_cr4(vcpu, cr4)) + kvm_inject_gp(vcpu, 0); } EXPORT_SYMBOL_GPL(kvm_set_cr4); -void kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) +static int __kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) { if (cr3 == vcpu->arch.cr3 && !pdptrs_changed(vcpu)) { kvm_mmu_sync_roots(vcpu); kvm_mmu_flush_tlb(vcpu); - return; + return 0; } if (is_long_mode(vcpu)) { - if (cr3 & CR3_L_MODE_RESERVED_BITS) { - kvm_inject_gp(vcpu, 0); - return; - } + if (cr3 & CR3_L_MODE_RESERVED_BITS) + return 1; } else { if (is_pae(vcpu)) { - if (cr3 & CR3_PAE_RESERVED_BITS) { - kvm_inject_gp(vcpu, 0); - return; - } - if (is_paging(vcpu) && !load_pdptrs(vcpu, cr3)) { - kvm_inject_gp(vcpu, 0); - return; - } + if (cr3 & CR3_PAE_RESERVED_BITS) + return 1; + if (is_paging(vcpu) && !load_pdptrs(vcpu, cr3)) + return 1; } /* * We don't check reserved bits in nonpae mode, because @@ -546,24 +533,34 @@ void kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) * to debug) behavior on the guest side. */ if (unlikely(!gfn_to_memslot(vcpu->kvm, cr3 >> PAGE_SHIFT))) + return 1; + vcpu->arch.cr3 = cr3; + vcpu->arch.mmu.new_cr3(vcpu); + return 0; +} + +void kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) +{ + if (__kvm_set_cr3(vcpu, cr3)) kvm_inject_gp(vcpu, 0); - else { - vcpu->arch.cr3 = cr3; - vcpu->arch.mmu.new_cr3(vcpu); - } } EXPORT_SYMBOL_GPL(kvm_set_cr3); -void kvm_set_cr8(struct kvm_vcpu *vcpu, unsigned long cr8) +int __kvm_set_cr8(struct kvm_vcpu *vcpu, unsigned long cr8) { - if (cr8 & CR8_RESERVED_BITS) { - kvm_inject_gp(vcpu, 0); - return; - } + if (cr8 & CR8_RESERVED_BITS) + return 1; if (irqchip_in_kernel(vcpu->kvm)) kvm_lapic_set_tpr(vcpu, cr8); else vcpu->arch.cr8 = cr8; + return 0; +} + +void kvm_set_cr8(struct kvm_vcpu *vcpu, unsigned long cr8) +{ + if (__kvm_set_cr8(vcpu, cr8)) + kvm_inject_gp(vcpu, 0); } EXPORT_SYMBOL_GPL(kvm_set_cr8); @@ -3681,27 +3678,32 @@ static unsigned long emulator_get_cr(int cr, struct kvm_vcpu *vcpu) return value; } -static void emulator_set_cr(int cr, unsigned long val, struct kvm_vcpu *vcpu) +static int emulator_set_cr(int cr, unsigned long val, struct kvm_vcpu *vcpu) { + int res = 0; + switch (cr) { case 0: - kvm_set_cr0(vcpu, mk_cr_64(kvm_read_cr0(vcpu), val)); + res = __kvm_set_cr0(vcpu, mk_cr_64(kvm_read_cr0(vcpu), val)); break; case 2: vcpu->arch.cr2 = val; break; case 3: - kvm_set_cr3(vcpu, val); + res = __kvm_set_cr3(vcpu, val); break; case 4: - kvm_set_cr4(vcpu, mk_cr_64(kvm_read_cr4(vcpu), val)); + res = __kvm_set_cr4(vcpu, mk_cr_64(kvm_read_cr4(vcpu), val)); break; case 8: - kvm_set_cr8(vcpu, val & 0xfUL); + res = __kvm_set_cr8(vcpu, val & 0xfUL); break; default: vcpu_printf(vcpu, "%s: unexpected cr %u\n", __func__, cr); + res = -1; } + + return res; } static int emulator_get_cpl(struct kvm_vcpu *vcpu) -- 2.34.1