From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ladi Prosek Subject: [PATCH v3 2/4] KVM: nVMX: propagate errors from prepare_vmcs02 Date: Wed, 30 Nov 2016 16:03:09 +0100 Message-ID: <1480518191-4572-3-git-send-email-lprosek@redhat.com> References: <1480518191-4572-1-git-send-email-lprosek@redhat.com> Cc: pbonzini@redhat.com, rkrcmar@redhat.com, bsd@redhat.com To: kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:44248 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933390AbcK3PDV (ORCPT ); Wed, 30 Nov 2016 10:03:21 -0500 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 91884C00BB19 for ; Wed, 30 Nov 2016 15:03:21 +0000 (UTC) In-Reply-To: <1480518191-4572-1-git-send-email-lprosek@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: It is possible that prepare_vmcs02 fails to load the guest state. This patch adds the proper error handling for such a case. L1 will receive an INVALID_STATE vmexit with the appropriate exit qualification if it happens. A failure to set guest CR3 is the only error propagated from prepare_vmcs02 at the moment. Signed-off-by: Ladi Prosek --- arch/x86/kvm/vmx.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 034dc7a..70598a1 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -9803,8 +9803,11 @@ static int nested_vmx_store_msr(struct kvm_vcpu *vcpu, u64 gpa, u32 count) * needs. In addition to modifying the active vmcs (which is vmcs02), this * function also has additional necessary side-effects, like setting various * vcpu->arch fields. + * Returns 0 on success, 1 on failure. Invalid state exit qualification code + * is assigned to entry_failure_code on failure. */ -static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) +static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, + unsigned long *entry_failure_code) { struct vcpu_vmx *vmx = to_vmx(vcpu); u32 exec_control; @@ -10124,8 +10127,12 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) nested_ept_enabled) { vcpu->arch.cr3 = vmcs12->guest_cr3; __set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail); - } else - kvm_set_cr3(vcpu, vmcs12->guest_cr3); + } else { + if (kvm_set_cr3(vcpu, vmcs12->guest_cr3)) { + *entry_failure_code = ENTRY_FAIL_DEFAULT; + return 1; + } + } kvm_mmu_reset_context(vcpu); @@ -10144,6 +10151,7 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) kvm_register_write(vcpu, VCPU_REGS_RSP, vmcs12->guest_rsp); kvm_register_write(vcpu, VCPU_REGS_RIP, vmcs12->guest_rip); + return 0; } /* @@ -10158,6 +10166,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) struct loaded_vmcs *vmcs02; bool ia32e; u32 msr_entry_idx; + unsigned long exit_qualification; if (!nested_vmx_check_permission(vcpu) || !nested_vmx_check_vmcs12(vcpu)) @@ -10313,7 +10322,13 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) vmx_segment_cache_clear(vmx); - prepare_vmcs02(vcpu, vmcs12); + if (prepare_vmcs02(vcpu, vmcs12, &exit_qualification)) { + leave_guest_mode(vcpu); + vmx_load_vmcs01(vcpu); + nested_vmx_entry_failure(vcpu, vmcs12, + EXIT_REASON_INVALID_STATE, exit_qualification); + return 1; + } msr_entry_idx = nested_vmx_load_msr(vcpu, vmcs12->vm_entry_msr_load_addr, -- 2.7.4