From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 07194CE8D6B for ; Mon, 17 Nov 2025 16:52:42 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.1164204.1491207 (Exim 4.92) (envelope-from ) id 1vL2Sj-0005Jj-42; Mon, 17 Nov 2025 16:52:21 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 1164204.1491207; Mon, 17 Nov 2025 16:52:21 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1vL2Sj-0005Jc-0U; Mon, 17 Nov 2025 16:52:21 +0000 Received: by outflank-mailman (input) for mailman id 1164204; Mon, 17 Nov 2025 16:52:19 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1vL2Sh-0005JW-9r for xen-devel@lists.xenproject.org; Mon, 17 Nov 2025 16:52:19 +0000 Received: from mail-ed1-x532.google.com (mail-ed1-x532.google.com [2a00:1450:4864:20::532]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id c447744c-c3d5-11f0-980a-7dc792cee155; Mon, 17 Nov 2025 17:52:13 +0100 (CET) Received: by mail-ed1-x532.google.com with SMTP id 4fb4d7f45d1cf-640aaa89697so5937873a12.3 for ; Mon, 17 Nov 2025 08:52:13 -0800 (PST) Received: from [10.156.60.236] (ip-037-024-206-209.um08.pools.vodafone-ip.de. [37.24.206.209]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-b734fad41f1sm1133864166b.23.2025.11.17.08.52.12 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 17 Nov 2025 08:52:12 -0800 (PST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: c447744c-c3d5-11f0-980a-7dc792cee155 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1763398333; x=1764003133; darn=lists.xenproject.org; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to; bh=weznmtnipny7ujYDz+XHFQiEruW9WJeEiY+a1pjZB7c=; b=PCiU/rYYE3XFghF97noy01SnJdkOoFCuOFVdk99wBvYMz3EED7UeubkSDL/uvZ2Id5 g5P+D51ASrceEKTd0gbRyhxQqwYVUb4eLnnsevJ2W2F1/OYZ6ayTVeCDbueiXlwg/+dY U68ninPLv4JcYCYbfWHnKadPPUDOk9ktjx2ZfZjA6A3cjCiBMkLpX5vf2XRQnc6fsuUM TuprzJLLD3Usvg53/6ZOCX15VpdClrSRpC6b+TMiZl90e00C8x8FmqBcyzy7jvpnumbt gj25juvcLzQ6l1KxhdzlNWiMIF4ifReWGfrI3EEkP3veLtsVNclZiZvkJGcdnsPKtcMP bsiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1763398333; x=1764003133; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=weznmtnipny7ujYDz+XHFQiEruW9WJeEiY+a1pjZB7c=; b=VnMJY/tsQyrWagntM3vqE6xPWWT4pb13Js3it8+sv6f33P/uBScrUNklpGmHrBGDjk PJhqBv5k1LgamZSr5dGEmtW9CXmyv8eh/xQTCvIVo4FD+f5HnqfQb+xD+mxEnrG+aDDt TCvoIhdJXe18GVhj5nIvnfEJHzubQFpBmbKcid+muc8wL2kDMEbXiOcUpzffYzEXQBQy Aopl09y+561WmLBbm+6dAQXWbl8qfwE4GgXBCQyTvHfHn3BqIlVWIjHd9ye9jIGTcRJo EJuiRyFiA1u7W2FDp+xUjHu/ix7QVI0X5FDrUv2s6rT9mtzPF5jOYokWeZ1d2GYDfVSu rWmw== X-Forwarded-Encrypted: i=1; AJvYcCWEWk0Jnm5wG+xGMIq3pxZiJTlyGYnwo1tzyNisXMweZMUy2S/xsiK6VhRz8pmQ28lavaGzbKtqz9c=@lists.xenproject.org X-Gm-Message-State: AOJu0YwXoTrhbQcBhn2LamAd5kho2ER1egQUSZyEAXNj7Us4VEJ51tv0 t1yb5xmysrCaQNVGo9NpuFU/vwzt3h+vKggmHT/uX6RGDMhroUBnbLUMoAmzGs8DHg== X-Gm-Gg: ASbGncuVVNmRaGNm2O8PFghiHQ266NLYDIf9EvWEMMhpU+5H0WXSmgg+PNk2TSP+nBF Fu9XtffCRHHdC71fZuRHPjjS/HzT+TuosRm4AvbA/YmM2TNlhhx7oo+o/YxG37/15OibtTKMh14 YsUu7GS7g6uVUsbsYinFBra3LFtmvmoAy6Tr16UCuf0iviOUiKrTCau9+7I3qnbhIcs1eDq+oNV /pqwIbEiw01hBF+w8GOaq/kwADskhcVEmPnDyyqesqkllLQ6Rf6dKn8hhVe36rGsLcp8q1+DR6d M25fYGbV1AKuPIlT1x671b1+eSzQNEnhM7ufUN7kB77OBvI0BM0SQo9fyofha/zq/k9OSStcuzw +3LrS+396jIilDwmPGuvQZJRhupJF21wDNaYMDs8y34CucTRR5tkiJt0N8XInaxLCVED29whMoj NDtIxfp25aYyESZF4zndWWXfoS1GmNlkRRAszqPUktIP94Fjzn6JqjFrlfDub8l0nb/Ln1J7+L7 wfUyC2Oqn/lWQ== X-Google-Smtp-Source: AGHT+IGbCFREwi2uakdE5UYH/RbFRM5WzZpqBevojXwmpUyh8F6lcTxKbAcm2eGsKG5kTBfTi+N95g== X-Received: by 2002:a17:906:7304:b0:b72:a899:168d with SMTP id a640c23a62f3a-b73677edba0mr1349594766b.13.1763398333182; Mon, 17 Nov 2025 08:52:13 -0800 (PST) Message-ID: <225378f4-0ebd-4c77-ae77-807bbb03b0bb@suse.com> Date: Mon, 17 Nov 2025 17:52:13 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [XEN][PATCH v3] xen: make VMTRACE support optional To: Grygorii Strashko Cc: Andrew Cooper , =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= , Anthony PERARD , Michal Orzel , Julien Grall , Stefano Stabellini , Tamas K Lengyel , Alexandru Isaila , Petre Pircalabu , Teddy Astie , Penny Zheng , "xen-devel@lists.xenproject.org" References: <20251114142207.279834-1-grygorii_strashko@epam.com> Content-Language: en-US From: Jan Beulich Autocrypt: addr=jbeulich@suse.com; keydata= xsDiBFk3nEQRBADAEaSw6zC/EJkiwGPXbWtPxl2xCdSoeepS07jW8UgcHNurfHvUzogEq5xk hu507c3BarVjyWCJOylMNR98Yd8VqD9UfmX0Hb8/BrA+Hl6/DB/eqGptrf4BSRwcZQM32aZK 7Pj2XbGWIUrZrd70x1eAP9QE3P79Y2oLrsCgbZJfEwCgvz9JjGmQqQkRiTVzlZVCJYcyGGsD /0tbFCzD2h20ahe8rC1gbb3K3qk+LpBtvjBu1RY9drYk0NymiGbJWZgab6t1jM7sk2vuf0Py O9Hf9XBmK0uE9IgMaiCpc32XV9oASz6UJebwkX+zF2jG5I1BfnO9g7KlotcA/v5ClMjgo6Gl MDY4HxoSRu3i1cqqSDtVlt+AOVBJBACrZcnHAUSuCXBPy0jOlBhxPqRWv6ND4c9PH1xjQ3NP nxJuMBS8rnNg22uyfAgmBKNLpLgAGVRMZGaGoJObGf72s6TeIqKJo/LtggAS9qAUiuKVnygo 3wjfkS9A3DRO+SpU7JqWdsveeIQyeyEJ/8PTowmSQLakF+3fote9ybzd880fSmFuIEJldWxp Y2ggPGpiZXVsaWNoQHN1c2UuY29tPsJgBBMRAgAgBQJZN5xEAhsDBgsJCAcDAgQVAggDBBYC AwECHgECF4AACgkQoDSui/t3IH4J+wCfQ5jHdEjCRHj23O/5ttg9r9OIruwAn3103WUITZee e7Sbg12UgcQ5lv7SzsFNBFk3nEQQCACCuTjCjFOUdi5Nm244F+78kLghRcin/awv+IrTcIWF hUpSs1Y91iQQ7KItirz5uwCPlwejSJDQJLIS+QtJHaXDXeV6NI0Uef1hP20+y8qydDiVkv6l IreXjTb7DvksRgJNvCkWtYnlS3mYvQ9NzS9PhyALWbXnH6sIJd2O9lKS1Mrfq+y0IXCP10eS FFGg+Av3IQeFatkJAyju0PPthyTqxSI4lZYuJVPknzgaeuJv/2NccrPvmeDg6Coe7ZIeQ8Yj t0ARxu2xytAkkLCel1Lz1WLmwLstV30g80nkgZf/wr+/BXJW/oIvRlonUkxv+IbBM3dX2OV8 AmRv1ySWPTP7AAMFB/9PQK/VtlNUJvg8GXj9ootzrteGfVZVVT4XBJkfwBcpC/XcPzldjv+3 HYudvpdNK3lLujXeA5fLOH+Z/G9WBc5pFVSMocI71I8bT8lIAzreg0WvkWg5V2WZsUMlnDL9 mpwIGFhlbM3gfDMs7MPMu8YQRFVdUvtSpaAs8OFfGQ0ia3LGZcjA6Ik2+xcqscEJzNH+qh8V m5jjp28yZgaqTaRbg3M/+MTbMpicpZuqF4rnB0AQD12/3BNWDR6bmh+EkYSMcEIpQmBM51qM EKYTQGybRCjpnKHGOxG0rfFY1085mBDZCH5Kx0cl0HVJuQKC+dV2ZY5AqjcKwAxpE75MLFkr wkkEGBECAAkFAlk3nEQCGwwACgkQoDSui/t3IH7nnwCfcJWUDUFKdCsBH/E5d+0ZnMQi+G0A nAuWpQkjM1ASeQwSHEeAWPgskBQL In-Reply-To: <20251114142207.279834-1-grygorii_strashko@epam.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 14.11.2025 15:22, Grygorii Strashko wrote: > --- a/xen/arch/x86/hvm/Kconfig > +++ b/xen/arch/x86/hvm/Kconfig > @@ -35,6 +35,18 @@ config INTEL_VMX > If your system includes a processor with Intel VT-x support, say Y. > If in doubt, say Y. > > +config VMTRACE > + bool "HW VM tracing support" > + depends on INTEL_VMX > + default y > + help > + Enables HW VM tracing support which allows to configure HW processor > + features (vmtrace_op) to enable capturing information about software > + execution using dedicated hardware facilities with minimal interference > + to the software being traced. The trace data can be retrieved using buffer > + shared between Xen and domain > + (see XENMEM_acquire_resource(XENMEM_resource_vmtrace_buf)). Please check adjacent options above or ... > config HVM_FEP > bool "HVM Forced Emulation Prefix support (UNSUPPORTED)" if UNSUPPORTED > default DEBUG ... below for how proper indentation would look like here. > --- a/xen/arch/x86/hvm/vmx/vmcs.c > +++ b/xen/arch/x86/hvm/vmx/vmcs.c > @@ -307,6 +307,7 @@ static int vmx_init_vmcs_config(bool bsp) > rdmsrl(MSR_IA32_VMX_MISC, _vmx_misc_cap); > > /* Check whether IPT is supported in VMX operation. */ > +#ifdef CONFIG_VMTRACE This imo wants to move ahead of the comment. (Feels a little like I may have said so already, but it may well have been in the context of a different recent patch.) > @@ -772,13 +775,24 @@ static inline int hvm_vmtrace_get_option( > > return -EOPNOTSUPP; > } > +#else > +/* > + * Function declaration(s) here are used without definition(s) to make compiler > + * happy when VMTRACE=n, compiler DCE will eliminate unused code. > + */ > +int hvm_vmtrace_output_position(struct vcpu *v, uint64_t *pos); > +#endif > > static inline int hvm_vmtrace_reset(struct vcpu *v) > { > +#ifdef CONFIG_VMTRACE > if ( hvm_funcs.vmtrace_reset ) > return alternative_call(hvm_funcs.vmtrace_reset, v); > > return -EOPNOTSUPP; > +#else > + return -EOPNOTSUPP; > +#endif No #else please and the #endif moved up. > --- a/xen/arch/x86/vm_event.c > +++ b/xen/arch/x86/vm_event.c > @@ -253,7 +253,8 @@ void vm_event_fill_regs(vm_event_request_t *req) > req->data.regs.x86.shadow_gs = ctxt.shadow_gs; > req->data.regs.x86.dr6 = ctxt.dr6; > > - if ( hvm_vmtrace_output_position(curr, &req->data.regs.x86.vmtrace_pos) != 1 ) > + if ( IS_ENABLED(CONFIG_VMTRACE) && > + hvm_vmtrace_output_position(curr, &req->data.regs.x86.vmtrace_pos) != 1 ) Would be nice if the too-long-line issue here was also address, when the line needs touching anyway. Jan