diff options
| -rw-r--r-- | arch/x86/include/asm/kvm-x86-ops.h | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 3 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 6 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 28 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 34 |
5 files changed, 52 insertions, 20 deletions
diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index 13bc212cd4bc..e3054e3e46d5 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -37,6 +37,7 @@ KVM_X86_OP(get_segment) KVM_X86_OP(get_cpl) KVM_X86_OP(set_segment) KVM_X86_OP(get_cs_db_l_bits) +KVM_X86_OP(is_valid_cr0) KVM_X86_OP(set_cr0) KVM_X86_OP_OPTIONAL(post_set_cr3) KVM_X86_OP(is_valid_cr4) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 28bd38303d70..3bc146dfd38d 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1566,9 +1566,10 @@ struct kvm_x86_ops { void (*set_segment)(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg); void (*get_cs_db_l_bits)(struct kvm_vcpu *vcpu, int *db, int *l); + bool (*is_valid_cr0)(struct kvm_vcpu *vcpu, unsigned long cr0); void (*set_cr0)(struct kvm_vcpu *vcpu, unsigned long cr0); void (*post_set_cr3)(struct kvm_vcpu *vcpu, unsigned long cr3); - bool (*is_valid_cr4)(struct kvm_vcpu *vcpu, unsigned long cr0); + bool (*is_valid_cr4)(struct kvm_vcpu *vcpu, unsigned long cr4); void (*set_cr4)(struct kvm_vcpu *vcpu, unsigned long cr4); int (*set_efer)(struct kvm_vcpu *vcpu, u64 efer); void (*get_idt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index cea08e5fa69b..956726d867aa 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1786,6 +1786,11 @@ static void sev_post_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) } } +static bool svm_is_valid_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) +{ + return true; +} + void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) { struct vcpu_svm *svm = to_svm(vcpu); @@ -4809,6 +4814,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = { .set_segment = svm_set_segment, .get_cpl = svm_get_cpl, .get_cs_db_l_bits = svm_get_cs_db_l_bits, + .is_valid_cr0 = svm_is_valid_cr0, .set_cr0 = svm_set_cr0, .post_set_cr3 = sev_post_set_cr3, .is_valid_cr4 = svm_is_valid_cr4, diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 0dd4612b0ca2..3d011d62d969 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -3047,6 +3047,15 @@ static void enter_rmode(struct kvm_vcpu *vcpu) struct vcpu_vmx *vmx = to_vmx(vcpu); struct kvm_vmx *kvm_vmx = to_kvm_vmx(vcpu->kvm); + /* + * KVM should never use VM86 to virtualize Real Mode when L2 is active, + * as using VM86 is unnecessary if unrestricted guest is enabled, and + * if unrestricted guest is disabled, VM-Enter (from L1) with CR0.PG=0 + * should VM-Fail and KVM should reject userspace attempts to stuff + * CR0.PG=0 when L2 is active. + */ + WARN_ON_ONCE(is_guest_mode(vcpu)); + vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_TR], VCPU_SREG_TR); vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_ES], VCPU_SREG_ES); vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_DS], VCPU_SREG_DS); @@ -3236,6 +3245,17 @@ void ept_save_pdptrs(struct kvm_vcpu *vcpu) #define CR3_EXITING_BITS (CPU_BASED_CR3_LOAD_EXITING | \ CPU_BASED_CR3_STORE_EXITING) +static bool vmx_is_valid_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) +{ + if (is_guest_mode(vcpu)) + return nested_guest_cr0_valid(vcpu, cr0); + + if (to_vmx(vcpu)->nested.vmxon) + return nested_host_cr0_valid(vcpu, cr0); + + return true; +} + void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) { struct vcpu_vmx *vmx = to_vmx(vcpu); @@ -5375,18 +5395,11 @@ static int handle_set_cr0(struct kvm_vcpu *vcpu, unsigned long val) val = (val & ~vmcs12->cr0_guest_host_mask) | (vmcs12->guest_cr0 & vmcs12->cr0_guest_host_mask); - if (!nested_guest_cr0_valid(vcpu, val)) - return 1; - if (kvm_set_cr0(vcpu, val)) return 1; vmcs_writel(CR0_READ_SHADOW, orig_val); return 0; } else { - if (to_vmx(vcpu)->nested.vmxon && - !nested_host_cr0_valid(vcpu, val)) - return 1; - return kvm_set_cr0(vcpu, val); } } @@ -8214,6 +8227,7 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = { .set_segment = vmx_set_segment, .get_cpl = vmx_get_cpl, .get_cs_db_l_bits = vmx_get_cs_db_l_bits, + .is_valid_cr0 = vmx_is_valid_cr0, .set_cr0 = vmx_set_cr0, .is_valid_cr4 = vmx_is_valid_cr4, .set_cr4 = vmx_set_cr4, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 27080bd986b5..278dbd37dab2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -906,6 +906,22 @@ int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3) } EXPORT_SYMBOL_GPL(load_pdptrs); +static bool kvm_is_valid_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) +{ +#ifdef CONFIG_X86_64 + if (cr0 & 0xffffffff00000000UL) + return false; +#endif + + if ((cr0 & X86_CR0_NW) && !(cr0 & X86_CR0_CD)) + return false; + + if ((cr0 & X86_CR0_PG) && !(cr0 & X86_CR0_PE)) + return false; + + return static_call(kvm_x86_is_valid_cr0)(vcpu, cr0); +} + void kvm_post_set_cr0(struct kvm_vcpu *vcpu, unsigned long old_cr0, unsigned long cr0) { /* @@ -952,20 +968,13 @@ int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) { unsigned long old_cr0 = kvm_read_cr0(vcpu); - cr0 |= X86_CR0_ET; - -#ifdef CONFIG_X86_64 - if (cr0 & 0xffffffff00000000UL) + if (!kvm_is_valid_cr0(vcpu, cr0)) return 1; -#endif - - cr0 &= ~CR0_RESERVED_BITS; - if ((cr0 & X86_CR0_NW) && !(cr0 & X86_CR0_CD)) - return 1; + cr0 |= X86_CR0_ET; - if ((cr0 & X86_CR0_PG) && !(cr0 & X86_CR0_PE)) - return 1; + /* Write to CR0 reserved bits are ignored, even on Intel. */ + cr0 &= ~CR0_RESERVED_BITS; #ifdef CONFIG_X86_64 if ((vcpu->arch.efer & EFER_LME) && !is_paging(vcpu) && @@ -11468,7 +11477,8 @@ static bool kvm_is_valid_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs) return false; } - return kvm_is_valid_cr4(vcpu, sregs->cr4); + return kvm_is_valid_cr4(vcpu, sregs->cr4) && + kvm_is_valid_cr0(vcpu, sregs->cr0); } static int __set_sregs_common(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs, |