Received-SPF: pass (google.com: domain of linux-kernel+bounces-196580-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Message-ID: <ac8d6cca-0f59-4d03-8c11-d1b0f2fd3c08@amd.com>
Date: Fri, 31 May 2024 14:57:09 +0530
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH 1/4] KVM: x86: Expose per-vCPU APICv status
To: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>, kvm@vger.kernel.org
Cc: seanjc@google.com, pbonzini@redhat.com, linux-kernel@vger.kernel.org,
 suravee.suthikulpanit@amd.com, vashegde@amd.com, mlevitsk@redhat.com,
 joao.m.martins@oracle.com, boris.ostrovsky@oracle.com, mark.kanda@oracle.com
References: <20240429155738.990025-1-alejandro.j.jimenez@oracle.com>
 <20240429155738.990025-2-alejandro.j.jimenez@oracle.com>
Content-Language: en-US
From: Vasant Hegde <vasant.hegde@amd.com>
In-Reply-To: <20240429155738.990025-2-alejandro.j.jimenez@oracle.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0:
	=?utf-8?B?ekRPM0FKQnhZNzFUcVJPakNSM3NnOHE5eDNlWmhsTk0rOHJLRy9SQVkyT1hu?=
 =?utf-8?B?OUVPSnpPVTYzNk5pRS9CU0FvRXBSclE1anJKOElwbEMxeS9mWXhDbElpZmJa?=
 =?utf-8?B?Sm83V0JQcDZ0bzBCVGpDNEJ6RnVQZ2plTHNtL04zNE9LUTV5Wk5LTFdnQzM0?=
 =?utf-8?B?RzBaOEgwaXZBc3FxK3EzUXJSWldQc2RBdzN1QVl2bmVSaSt2Rm5LTEtIQTl4?=
 =?utf-8?B?MURFQjFaTWdLNHM1MjFIV0MwNFBuUlJlTTY4T21DL1B3TkkxTmxFNVJsRkFZ?=
 =?utf-8?B?cVpJMzFXMlV5RE4rOEhVd3pieXh0V2ZTcks1Y0JiZE9SdURYTEJBOVB6aXp0?=
 =?utf-8?B?b2ZCY2RCUFVhZFpoNzlPS0Y4eFdobldUQWRvM2Mvejl2SWFxdWZ0WVlwV3Bo?=
 =?utf-8?B?bENzd1dYZTkzWlZ0V0t6SHpSSDBSZm9mRHhMRXhUUkdySjFQWS9NR0RwZ1Bk?=
 =?utf-8?B?V0VGS25Nbit2SXA0RkxTNHM0RnZneGdWdGV5cWY3L0paMU1KaHJBTDBQYVVP?=
 =?utf-8?B?dnIzdUc3NVlDNGJzTUFvZW9sV3VGL1ZGOWd0ckswa3cvdDNBRFRBV3NvNVpR?=
 =?utf-8?B?SnBBNVFhTWlGZmVsY0ExYjhzbTBaZnhST2tIRkF5SlUwak0xYWxsd3V4SW1a?=
 =?utf-8?B?ei9SWFgvM1dOMEE4Q2FlVE1CYy9MYTUwYmFJT3JkeEtTNlFoODh4MkUraGYy?=
 =?utf-8?B?Yi9nMHlLMk1UcTBKSGZLRkZ3RE9ZQzRNTk84ZnBoS2d4SzBEbDhQalllSlJK?=
 =?utf-8?B?Z0NzOHZqNzhSSDFtczFtYUV2S0U2c0N2V0VIMHplVW1TeS9mSzJ0ZDNEeUVq?=
 =?utf-8?B?c0lxZHpmVnhZVWxXYW54akFVZXVGQ0FZOVZrNkg2UDhNZno1aHpRdWNQdzdF?=
 =?utf-8?B?MlBiMjArZnJtNFUwR1QzUFp6UFB2b1F1YUhpb2hXTUI5S2VaSWZzQVlCM2NL?=
 =?utf-8?B?cnhVV0FUQXBISGdHVEFEUDQvbloxWWY1YWVtRDNpeGYrTVlXZ0kzYVFaSXMr?=
 =?utf-8?B?N1RtQ2gvcW5OQVgvMlhHYnpUTjREa3J6eUoyWGlicWUzMk9VNzBJMEVIdEJq?=
 =?utf-8?B?YjgzbUtDaWhYQVJlM00zREpnc05KOG13WFhzNFJzMkk2VVF6Nm8yZmNFemdw?=
 =?utf-8?B?N0QxakFTenYzU0RiNFgwQW5lRnhDTE9SU3I0eU4zL3dhMDdJZWs4cGd0am1p?=
 =?utf-8?B?SVhUdkxOYWVRbG1NVDlSOGJhaktoRENlOFUvMVVrcS9TNXBVL3NUdG5ucWdy?=
 =?utf-8?B?ZEpJN25TY1VrNzFPV3l3bktBNUJYSDhIZGpBZE1tVFFDbDdhZzJjUi9rV1VZ?=
 =?utf-8?B?bHd1aXE0Syt0L2Jqa055WEt6VC81aWMrZnBCeFpNNjlTbndSdGJ4Z1FQZGZt?=
 =?utf-8?B?MzNtYVNzMUNsbGs5eVVsa3kwb29BL2tOUXFZck1HcStNV05Cb3I4NlQvMHcr?=
 =?utf-8?B?Q3cyT3RkRHJzRkFlcWxHL3luUGJNdzJSb1Jab2llZXVhcHBTeUtYRzRPbk1U?=
 =?utf-8?B?aGVBMHhXS1hmMGJEMEJFdVBxUjVMTVJXdVRCOEZ4blhZZUZ4T2FBVjRrbjhu?=
 =?utf-8?B?UTBIdXJycFJNZVlxVnpjdzA3MmE5WE9YQ0kyS1dJNVlueFB4UXNLSi91QS84?=
 =?utf-8?B?MzFiWUh4KzZ3a1IxaEM5N1pkZkJQQ1FrcHV3eUV2aTlzZGtlaGd6ZWwvYkNZ?=
 =?utf-8?B?Um81cllqelAyOThSZTRpMmxqK0xzcjdUWEJXSlFwTyt5NWtDSlVEWmdCbmhX?=
 =?utf-8?B?U0ZGMU1ENmJOVi9Yc2pxUXRBZWM4M2E0RngvYmxhMERnK3lBVHJtdjU3SVo5?=
 =?utf-8?B?YnYrQlA3dEU2ckFMbnZwV0VkRStXRE1YdU5aVy96WGt3TDhWNnlDYkZGQnJs?=
 =?utf-8?B?UnFvSzl5cFEzT29adUJMc0FCSWcxc0JBMFh2WEVXdisvL1lxTzdPZnplSnNY?=
 =?utf-8?B?K3FCNVBLWHRWMENhTWxVTFZKNDBLbG9CNmxMTGRFbk9jYTVwaVlMZkVaZHpx?=
 =?utf-8?B?YkMySnV3Y3JJSmp3cUdJTlNiQWdOV0pjQ2lBaDFHd1B6andFeHhVdUNGZS9l?=
 =?utf-8?B?V3hIS3ZFS1llT1lzMzJjMUEvQ3E3TVFHNWNYZU5xWWorQXV6TXg2WFhGMEhD?=
 =?utf-8?Q?qJGz+3rWKNNPkJIAq1md4Nc3N?=
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-Network-Message-Id: d28898b3-66f5-4a49-6f87-08dc8153de1c
X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB6048.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 31 May 2024 09:27:19.1624
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: 3AcmsmghOv67vTDIkQmvXUTJZoxhJGGuJq365aCbHfjUqlVD8PD8OhMZXGlFiwZ2LOb9I5Kz8wcSKiddJEtLqw==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM4PR12MB6303


On 4/29/2024 9:27 PM, Alejandro Jimenez wrote:
> Expose the APICv activation status of individual vCPUs via the stats
> subsystem. In special cases a vCPU's APICv can be deactivated/disabled
> even though there are no VM-wide inhibition reasons. The only current
> example of this is AVIC for a vCPU running in nested mode. This type of
> inhibition is not recorded in the VM inhibit reasons or visible in
> current tracepoints.
> 
> Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>


Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>

-Vasant

> ---
>  arch/x86/include/asm/kvm_host.h | 1 +
>  arch/x86/kvm/lapic.c            | 1 +
>  arch/x86/kvm/x86.c              | 2 ++
>  3 files changed, 4 insertions(+)
> 
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 1d13e3cd1dc5..12f30cb5c842 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1573,6 +1573,7 @@ struct kvm_vcpu_stat {
>  	u64 preemption_other;
>  	u64 guest_mode;
>  	u64 notify_window_exits;
> +	u64 apicv_active;
>  };
>  
>  struct x86_instruction_info;
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index cf37586f0466..37fe75a5db8c 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -2872,6 +2872,7 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu, int timer_advance_ns)
>  	 */
>  	if (enable_apicv) {
>  		apic->apicv_active = true;
> +		vcpu->stat.apicv_active = apic->apicv_active;
>  		kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu);
>  	}
>  
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index e9ef1fa4b90b..0451c4c8d731 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -304,6 +304,7 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
>  	STATS_DESC_COUNTER(VCPU, preemption_other),
>  	STATS_DESC_IBOOLEAN(VCPU, guest_mode),
>  	STATS_DESC_COUNTER(VCPU, notify_window_exits),
> +	STATS_DESC_IBOOLEAN(VCPU, apicv_active),
>  };
>  
>  const struct kvm_stats_header kvm_vcpu_stats_header = {
> @@ -10625,6 +10626,7 @@ void __kvm_vcpu_update_apicv(struct kvm_vcpu *vcpu)
>  		goto out;
>  
>  	apic->apicv_active = activate;
> +	vcpu->stat.apicv_active = apic->apicv_active;
>  	kvm_apic_update_apicv(vcpu);
>  	static_call(kvm_x86_refresh_apicv_exec_ctrl)(vcpu);
>