From nobody Sun Dec 14 23:37:32 2025 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 583862FE575; Sun, 26 Oct 2025 20:20:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761510034; cv=none; b=bUzHZNX24qzo5QX2n5xf00AOmqNSs7QhRv3xZDMID+G9mYfmN4/+5ZAeozhAMLuzRp5tvVD7/RVCzaa3Sl9Dcebk0Z6n+R0ae8XS+biJp4ZS0G6dMQtuIvLQlwAwqMFL456yNdFqHkkmiCTweF9jvIzgiW6UZwJcf9HAMErqTlc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761510034; c=relaxed/simple; bh=rjPIDpskL20C6Oj2hkpZTYAYILmVjXEFKy3avzX/sas=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Z5IbgvXYJhKIxx2uQ741S4NXmyHfuFdhgEbxrXWpa2vIpH2CmkzJjXQDW5jCK912aPSk9pn316JALzFo5Gah49eohRSi9HYaUx/v5oW3uZ/MQOxHMG0uhjzmVxEsxq4dFM51/lCjzEYM2JEsGeQb12l7lQ75HtrOPqnzx9E9DGY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=sTmDqB/p; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="sTmDqB/p" Received: from terminus.zytor.com (terminus.zytor.com [IPv6:2607:7c80:54:3:0:0:0:136]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 59QKJBkZ505258 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Sun, 26 Oct 2025 13:19:36 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 59QKJBkZ505258 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2025102301; t=1761509977; bh=duNLsHBm51GvJBU+6jcFsAlYUlA8d78MBWF3noqReXE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sTmDqB/pfpUCL9N7MPydev6Ez0qvKD2TI66rbrz5wK3+i/eyvVF9MMfLIJaY42r3K 34XpI3b/bvNOCn7QoMsnBkFORzNrQGF/9BVb9UdEKn52Lw208AgHrIe6XVS8ld1m8a sOh7KQFALg9h0A6TEaoMvFAp9zV8LKroHeOafCEyU5/1VijV5lZQcFphPO7uLrr1K6 Z34hW4vVfuNaCykfosSFTKWD3uMxgy+mWBL+7+DlfCBPjHPksoaJNwXsleVrRS/lGt aIJ/iqssI4VGBEocbbZbobwSyRM0Z0Ea6pelUdQwoYd1OHK8MAlfQlZhbE8DJRlbhz sRDdk7uOdL7yw== From: "Xin Li (Intel)" To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org Cc: pbonzini@redhat.com, seanjc@google.com, corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, xin@zytor.com, luto@kernel.org, peterz@infradead.org, andrew.cooper3@citrix.com, chao.gao@intel.com, hch@infradead.org, sohil.mehta@intel.com Subject: [PATCH v9 18/22] KVM: nVMX: Enable support for secondary VM exit controls Date: Sun, 26 Oct 2025 13:19:06 -0700 Message-ID: <20251026201911.505204-19-xin@zytor.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251026201911.505204-1-xin@zytor.com> References: <20251026201911.505204-1-xin@zytor.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Xin Li Add support for secondary VM exit controls in nested VMX to facilitate future FRED integration. Signed-off-by: Xin Li Signed-off-by: Xin Li (Intel) Tested-by: Shan Kang Tested-by: Xuelian Guo --- Changes in v8: * Relocate secondary_vm_exit_controls to the last u64 padding field. * Remove the change to Documentation/virt/kvm/x86/nested-vmx.rst. Changes in v5: * Allow writing MSR_IA32_VMX_EXIT_CTLS2 (Sean). * Add TB from Xuelian Guo. Change in v3: * Read secondary VM exit controls from vmcs_conf insteasd of the hardware MSR MSR_IA32_VMX_EXIT_CTLS2 to avoid advertising features to L1 that KVM itself doesn't support, e.g. because the expected entry+exit pairs aren't supported. (Sean Christopherson) --- arch/x86/kvm/vmx/capabilities.h | 1 + arch/x86/kvm/vmx/nested.c | 26 +++++++++++++++++++++++++- arch/x86/kvm/vmx/vmcs12.c | 1 + arch/x86/kvm/vmx/vmcs12.h | 3 ++- arch/x86/kvm/x86.h | 2 +- 5 files changed, 30 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilitie= s.h index 651507627ef3..f390f9f883c3 100644 --- a/arch/x86/kvm/vmx/capabilities.h +++ b/arch/x86/kvm/vmx/capabilities.h @@ -34,6 +34,7 @@ struct nested_vmx_msrs { u32 pinbased_ctls_high; u32 exit_ctls_low; u32 exit_ctls_high; + u64 secondary_exit_ctls; u32 entry_ctls_low; u32 entry_ctls_high; u32 misc_low; diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index b0cd745518b4..cbb682424a5b 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -1534,6 +1534,11 @@ int vmx_set_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_i= ndex, u64 data) return -EINVAL; vmx->nested.msrs.vmfunc_controls =3D data; return 0; + case MSR_IA32_VMX_EXIT_CTLS2: + if (data & ~vmcs_config.nested.secondary_exit_ctls) + return -EINVAL; + vmx->nested.msrs.secondary_exit_ctls =3D data; + return 0; default: /* * The rest of the VMX capability MSRs do not support restore. @@ -1573,6 +1578,9 @@ int vmx_get_vmx_msr(struct nested_vmx_msrs *msrs, u32= msr_index, u64 *pdata) if (msr_index =3D=3D MSR_IA32_VMX_EXIT_CTLS) *pdata |=3D VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR; break; + case MSR_IA32_VMX_EXIT_CTLS2: + *pdata =3D msrs->secondary_exit_ctls; + break; case MSR_IA32_VMX_TRUE_ENTRY_CTLS: case MSR_IA32_VMX_ENTRY_CTLS: *pdata =3D vmx_control_msr( @@ -2514,6 +2522,11 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vm= x, struct loaded_vmcs *vmcs0 exec_control &=3D ~VM_EXIT_LOAD_IA32_EFER; vm_exit_controls_set(vmx, exec_control); =20 + if (exec_control & VM_EXIT_ACTIVATE_SECONDARY_CONTROLS) { + exec_control =3D __secondary_vm_exit_controls_get(vmcs01); + secondary_vm_exit_controls_set(vmx, exec_control); + } + /* * Interrupt/Exception Fields */ @@ -7128,7 +7141,8 @@ static void nested_vmx_setup_exit_ctls(struct vmcs_co= nfig *vmcs_conf, VM_EXIT_HOST_ADDR_SPACE_SIZE | #endif VM_EXIT_LOAD_IA32_PAT | VM_EXIT_SAVE_IA32_PAT | - VM_EXIT_CLEAR_BNDCFGS | VM_EXIT_LOAD_CET_STATE; + VM_EXIT_CLEAR_BNDCFGS | VM_EXIT_LOAD_CET_STATE | + VM_EXIT_ACTIVATE_SECONDARY_CONTROLS; msrs->exit_ctls_high |=3D VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR | VM_EXIT_LOAD_IA32_EFER | VM_EXIT_SAVE_IA32_EFER | @@ -7141,6 +7155,16 @@ static void nested_vmx_setup_exit_ctls(struct vmcs_c= onfig *vmcs_conf, =20 /* We support free control of debug control saving. */ msrs->exit_ctls_low &=3D ~VM_EXIT_SAVE_DEBUG_CONTROLS; + + if (msrs->exit_ctls_high & VM_EXIT_ACTIVATE_SECONDARY_CONTROLS) { + msrs->secondary_exit_ctls =3D vmcs_conf->vmexit_2nd_ctrl; + /* + * As the secondary VM exit control is always loaded, do not + * advertise any feature in it to nVMX until its nVMX support + * is ready. + */ + msrs->secondary_exit_ctls &=3D 0; + } } =20 static void nested_vmx_setup_entry_ctls(struct vmcs_config *vmcs_conf, diff --git a/arch/x86/kvm/vmx/vmcs12.c b/arch/x86/kvm/vmx/vmcs12.c index 4233b5ca9461..3b01175f392a 100644 --- a/arch/x86/kvm/vmx/vmcs12.c +++ b/arch/x86/kvm/vmx/vmcs12.c @@ -66,6 +66,7 @@ const unsigned short vmcs12_field_offsets[] =3D { FIELD64(HOST_IA32_PAT, host_ia32_pat), FIELD64(HOST_IA32_EFER, host_ia32_efer), FIELD64(HOST_IA32_PERF_GLOBAL_CTRL, host_ia32_perf_global_ctrl), + FIELD64(SECONDARY_VM_EXIT_CONTROLS, secondary_vm_exit_controls), FIELD(PIN_BASED_VM_EXEC_CONTROL, pin_based_vm_exec_control), FIELD(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control), FIELD(EXCEPTION_BITMAP, exception_bitmap), diff --git a/arch/x86/kvm/vmx/vmcs12.h b/arch/x86/kvm/vmx/vmcs12.h index 4ad6b16525b9..fa5306dc0311 100644 --- a/arch/x86/kvm/vmx/vmcs12.h +++ b/arch/x86/kvm/vmx/vmcs12.h @@ -71,7 +71,7 @@ struct __packed vmcs12 { u64 pml_address; u64 encls_exiting_bitmap; u64 tsc_multiplier; - u64 padding64[1]; /* room for future expansion */ + u64 secondary_vm_exit_controls; /* * To allow migration of L1 (complete with its L2 guests) between * machines of different natural widths (32 or 64 bit), we cannot have @@ -261,6 +261,7 @@ static inline void vmx_check_vmcs12_offsets(void) CHECK_OFFSET(pml_address, 312); CHECK_OFFSET(encls_exiting_bitmap, 320); CHECK_OFFSET(tsc_multiplier, 328); + CHECK_OFFSET(secondary_vm_exit_controls, 336); CHECK_OFFSET(cr0_guest_host_mask, 344); CHECK_OFFSET(cr4_guest_host_mask, 352); CHECK_OFFSET(cr0_read_shadow, 360); diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index e9c6f304b02e..1576f192a647 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -95,7 +95,7 @@ do { \ * associated feature that KVM supports for nested virtualization. */ #define KVM_FIRST_EMULATED_VMX_MSR MSR_IA32_VMX_BASIC -#define KVM_LAST_EMULATED_VMX_MSR MSR_IA32_VMX_VMFUNC +#define KVM_LAST_EMULATED_VMX_MSR MSR_IA32_VMX_EXIT_CTLS2 =20 #define KVM_DEFAULT_PLE_GAP 128 #define KVM_VMX_DEFAULT_PLE_WINDOW 4096 --=20 2.51.0