diff options
Diffstat (limited to 'arch/x86/kvm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm.c | 78 |
1 files changed, 26 insertions, 52 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 5c6512dbac7c..779b09194f03 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -93,14 +93,6 @@ struct nested_state { /* A VMEXIT is required but not yet emulated */ bool exit_required; - /* - * If we vmexit during an instruction emulation we need this to restore - * the l1 guest rip after the emulation - */ - unsigned long vmexit_rip; - unsigned long vmexit_rsp; - unsigned long vmexit_rax; - /* cache for intercepts of the guest */ u32 intercept_cr; u32 intercept_dr; @@ -1362,31 +1354,6 @@ static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) { struct vcpu_svm *svm = to_svm(vcpu); - if (is_guest_mode(vcpu)) { - /* - * We are here because we run in nested mode, the host kvm - * intercepts cr0 writes but the l1 hypervisor does not. - * But the L1 hypervisor may intercept selective cr0 writes. - * This needs to be checked here. - */ - unsigned long old, new; - - /* Remove bits that would trigger a real cr0 write intercept */ - old = vcpu->arch.cr0 & SVM_CR0_SELECTIVE_MASK; - new = cr0 & SVM_CR0_SELECTIVE_MASK; - - if (old == new) { - /* cr0 write with ts and mp unchanged */ - svm->vmcb->control.exit_code = SVM_EXIT_CR0_SEL_WRITE; - if (nested_svm_exit_handled(svm) == NESTED_EXIT_DONE) { - svm->nested.vmexit_rip = kvm_rip_read(vcpu); - svm->nested.vmexit_rsp = kvm_register_read(vcpu, VCPU_REGS_RSP); - svm->nested.vmexit_rax = kvm_register_read(vcpu, VCPU_REGS_RAX); - return; - } - } - } - #ifdef CONFIG_X86_64 if (vcpu->arch.efer & EFER_LME) { if (!is_paging(vcpu) && (cr0 & X86_CR0_PG)) { @@ -2673,6 +2640,29 @@ static int emulate_on_interception(struct vcpu_svm *svm) return emulate_instruction(&svm->vcpu, 0) == EMULATE_DONE; } +bool check_selective_cr0_intercepted(struct vcpu_svm *svm, unsigned long val) +{ + unsigned long cr0 = svm->vcpu.arch.cr0; + bool ret = false; + u64 intercept; + + intercept = svm->nested.intercept; + + if (!is_guest_mode(&svm->vcpu) || + (!(intercept & (1ULL << INTERCEPT_SELECTIVE_CR0)))) + return false; + + cr0 &= ~SVM_CR0_SELECTIVE_MASK; + val &= ~SVM_CR0_SELECTIVE_MASK; + + if (cr0 ^ val) { + svm->vmcb->control.exit_code = SVM_EXIT_CR0_SEL_WRITE; + ret = (nested_svm_exit_handled(svm) == NESTED_EXIT_DONE); + } + + return ret; +} + #define CR_VALID (1ULL << 63) static int cr_interception(struct vcpu_svm *svm) @@ -2696,7 +2686,8 @@ static int cr_interception(struct vcpu_svm *svm) val = kvm_register_read(&svm->vcpu, reg); switch (cr) { case 0: - err = kvm_set_cr0(&svm->vcpu, val); + if (!check_selective_cr0_intercepted(svm, val)) + err = kvm_set_cr0(&svm->vcpu, val); break; case 3: err = kvm_set_cr3(&svm->vcpu, val); @@ -2741,23 +2732,6 @@ static int cr_interception(struct vcpu_svm *svm) return 1; } -static int cr0_write_interception(struct vcpu_svm *svm) -{ - struct kvm_vcpu *vcpu = &svm->vcpu; - int r; - - r = cr_interception(svm); - - if (svm->nested.vmexit_rip) { - kvm_register_write(vcpu, VCPU_REGS_RIP, svm->nested.vmexit_rip); - kvm_register_write(vcpu, VCPU_REGS_RSP, svm->nested.vmexit_rsp); - kvm_register_write(vcpu, VCPU_REGS_RAX, svm->nested.vmexit_rax); - svm->nested.vmexit_rip = 0; - } - - return r; -} - static int dr_interception(struct vcpu_svm *svm) { int reg, dr; @@ -3045,7 +3019,7 @@ static int (*svm_exit_handlers[])(struct vcpu_svm *svm) = { [SVM_EXIT_READ_CR4] = cr_interception, [SVM_EXIT_READ_CR8] = cr_interception, [SVM_EXIT_CR0_SEL_WRITE] = emulate_on_interception, - [SVM_EXIT_WRITE_CR0] = cr0_write_interception, + [SVM_EXIT_WRITE_CR0] = cr_interception, [SVM_EXIT_WRITE_CR3] = cr_interception, [SVM_EXIT_WRITE_CR4] = cr_interception, [SVM_EXIT_WRITE_CR8] = cr8_write_interception, |