From b2467e744f89fcb2e723143c2b78bcbaf391828a Mon Sep 17 00:00:00 2001 From: Haozhong Zhang Date: Wed, 25 Nov 2015 17:21:39 +0800 Subject: KVM: nVMX: remove incorrect vpid check in nested invvpid emulation This patch removes the vpid check when emulating nested invvpid instruction of type all-contexts invalidation. The existing code is incorrect because: (1) According to Intel SDM Vol 3, Section "INVVPID - Invalidate Translations Based on VPID", invvpid instruction does not check vpid in the invvpid descriptor when its type is all-contexts invalidation. (2) According to the same document, invvpid of type all-contexts invalidation does not require there is an active VMCS, so/and get_vmcs12() in the existing code may result in a NULL-pointer dereference. In practice, it can crash both KVM itself and L1 hypervisors that use invvpid (e.g. Xen). Signed-off-by: Haozhong Zhang Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'arch/x86/kvm/vmx.c') diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 87acc5221740..af823a388c19 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -7394,11 +7394,6 @@ static int handle_invvpid(struct kvm_vcpu *vcpu) switch (type) { case VMX_VPID_EXTENT_ALL_CONTEXT: - if (get_vmcs12(vcpu)->virtual_processor_id == 0) { - nested_vmx_failValid(vcpu, - VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID); - return 1; - } __vmx_flush_tlb(vcpu, to_vmx(vcpu)->nested.vpid02); nested_vmx_succeed(vcpu); break; -- cgit v1.2.3 From 8b89fe1f6c430589122542f228a802d34995bebd Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 10 Dec 2015 18:37:32 +0100 Subject: kvm: x86: move tracepoints outside extended quiescent state Invoking tracepoints within kvm_guest_enter/kvm_guest_exit causes a lockdep splat. Reported-by: Borislav Petkov Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm.c | 4 ++-- arch/x86/kvm/vmx.c | 3 ++- arch/x86/kvm/x86.c | 4 ++-- 3 files changed, 6 insertions(+), 5 deletions(-) (limited to 'arch/x86/kvm/vmx.c') diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 83a1c643f9a5..899c40f826dd 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3422,6 +3422,8 @@ static int handle_exit(struct kvm_vcpu *vcpu) struct kvm_run *kvm_run = vcpu->run; u32 exit_code = svm->vmcb->control.exit_code; + trace_kvm_exit(exit_code, vcpu, KVM_ISA_SVM); + if (!is_cr_intercept(svm, INTERCEPT_CR0_WRITE)) vcpu->arch.cr0 = svm->vmcb->save.cr0; if (npt_enabled) @@ -3892,8 +3894,6 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu) vcpu->arch.regs[VCPU_REGS_RSP] = svm->vmcb->save.rsp; vcpu->arch.regs[VCPU_REGS_RIP] = svm->vmcb->save.rip; - trace_kvm_exit(svm->vmcb->control.exit_code, vcpu, KVM_ISA_SVM); - if (unlikely(svm->vmcb->control.exit_code == SVM_EXIT_NMI)) kvm_before_handle_nmi(&svm->vcpu); diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index af823a388c19..6b5605607849 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -8042,6 +8042,8 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu) u32 exit_reason = vmx->exit_reason; u32 vectoring_info = vmx->idt_vectoring_info; + trace_kvm_exit(exit_reason, vcpu, KVM_ISA_VMX); + /* * Flush logged GPAs PML buffer, this will make dirty_bitmap more * updated. Another good is, in kvm_vm_ioctl_get_dirty_log, before @@ -8668,7 +8670,6 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu) vmx->loaded_vmcs->launched = 1; vmx->exit_reason = vmcs_read32(VM_EXIT_REASON); - trace_kvm_exit(vmx->exit_reason, vcpu, KVM_ISA_VMX); /* * the KVM_REQ_EVENT optimization bit is only on for one entry, and if diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index eed32283d22c..b84ba4b17757 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6515,6 +6515,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) if (req_immediate_exit) smp_send_reschedule(vcpu->cpu); + trace_kvm_entry(vcpu->vcpu_id); + wait_lapic_expire(vcpu); __kvm_guest_enter(); if (unlikely(vcpu->arch.switch_db_regs)) { @@ -6527,8 +6529,6 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_RELOAD; } - trace_kvm_entry(vcpu->vcpu_id); - wait_lapic_expire(vcpu); kvm_x86_ops->run(vcpu); /* -- cgit v1.2.3 From 81b1b9ca6d5ca5f3ce91c0095402def657cf5db3 Mon Sep 17 00:00:00 2001 From: Haozhong Zhang Date: Mon, 14 Dec 2015 23:13:38 +0800 Subject: KVM: VMX: Fix host initiated access to guest MSR_TSC_AUX The current handling of accesses to guest MSR_TSC_AUX returns error if vcpu does not support rdtscp, though those accesses are initiated by host. This can result in the reboot failure of some versions of QEMU. This patch fixes this issue by passing those host initiated accesses for further handling instead. Signed-off-by: Haozhong Zhang Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/kvm/vmx.c') diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 6b5605607849..44976a596fa6 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2803,7 +2803,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) msr_info->data = vcpu->arch.ia32_xss; break; case MSR_TSC_AUX: - if (!guest_cpuid_has_rdtscp(vcpu)) + if (!guest_cpuid_has_rdtscp(vcpu) && !msr_info->host_initiated) return 1; /* Otherwise falls through */ default: @@ -2909,7 +2909,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) clear_atomic_switch_msr(vmx, MSR_IA32_XSS); break; case MSR_TSC_AUX: - if (!guest_cpuid_has_rdtscp(vcpu)) + if (!guest_cpuid_has_rdtscp(vcpu) && !msr_info->host_initiated) return 1; /* Check reserved bit, higher 32 bits should be zero */ if ((data >> 32) != 0) -- cgit v1.2.3