From mboxrd@z Thu Jan 1 00:00:00 1970 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 325D821A452; Thu, 19 Jun 2025 05:02:51 +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=1750309374; cv=none; b=kOlNdhEzV7orx1V/TVOgdpdeAHG3/UsCReBJMvlYTusANW+oPz2/mvkvOhtVsnVGd4bRf+WoVBzabtXCwan3wVe1mQ8qMIAa4dh1QU2ptxWbwCSKOyzrmcJLhPBWu6KuAiiwrVGbMdUmdf2r/wXBqYUpeuh13+I3IU5KtQ6H9Ng= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750309374; c=relaxed/simple; bh=cC1gNkglobCCgQWoLRRzm+tji0YRzCCMskKW7Rup5es=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=GWvMkHKNOe1w9mTA/SOxeEWIySM2JmMWyTl7CkNOj87yBRIk4jNMh9+Xw9g3yaBOrpw6DY1C439j3QbgsONWQxGzx5H4FmgVfzeABUjwqfbgBGHV1WFcHsj4JChudcZhTePhMywneyByZhLa0dhzmBIUyeMZkbTC6tuL5RgjzQI= 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=nJlMFyh+; 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="nJlMFyh+" Received: from [192.168.7.202] ([71.202.166.45]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 55J529FG1854570 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Wed, 18 Jun 2025 22:02:10 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 55J529FG1854570 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2025052101; t=1750309332; bh=nz8+KCii5aZfAsUnyh008znZgZhwquPROyRzQoxFqeU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=nJlMFyh+ggWVGqIlASPvwYh5Mktn0GpAWRc4Ez52VsMr9JJFOsr68py3bAlMqCyVa iPTFNYYN9v3AZnZMbNUzpMZrF5c5KPFwyH2FOvTO/JiF4XLBMbXxRdolhMLtWb3GQ4 g6U5VKe+4x9fa3SvV3nyYsYgYselIur7BeF1j8HsmaYBDzk0IiHaYi591QoRNziaPP phFigHu1V45uCzhqSqmglaZrWJNDAdwpN7T+4/+WAoRKpwykXs/PrZ5TlpJ0/bEWs8 MaGPZRCuIqr7QzmC0G9Buu4oLjgHl6Xs4ww37cGZ9QI6ps7VibWf6LNW/2QiAqLtra /X+rG0AtsNaNw== Message-ID: <7525af7f-a817-47d5-91f7-d7702380c85f@zytor.com> Date: Wed, 18 Jun 2025 22:02:08 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7 02/10] x86/fred: Pass event data to the NMI entry point from KVM To: Sohil Mehta , x86@kernel.org, linux-kernel@vger.kernel.org Cc: "H . Peter Anvin" , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Peter Zijlstra , Sean Christopherson , Adrian Hunter , Kan Liang , Tony Luck , Zhang Rui , Steven Rostedt , Andrew Cooper , "Kirill A . Shutemov" , Jacob Pan , Andi Kleen , Kai Huang , Sandipan Das , linux-perf-users@vger.kernel.org, linux-edac@vger.kernel.org, kvm@vger.kernel.org, linux-pm@vger.kernel.org, linux-trace-kernel@vger.kernel.org References: <20250612214849.3950094-1-sohil.mehta@intel.com> <20250612214849.3950094-3-sohil.mehta@intel.com> Content-Language: en-US From: Xin Li Autocrypt: addr=xin@zytor.com; keydata= xsDNBGUPz1cBDACS/9yOJGojBFPxFt0OfTWuMl0uSgpwk37uRrFPTTLw4BaxhlFL0bjs6q+0 2OfG34R+a0ZCuj5c9vggUMoOLdDyA7yPVAJU0OX6lqpg6z/kyQg3t4jvajG6aCgwSDx5Kzg5 Rj3AXl8k2wb0jdqRB4RvaOPFiHNGgXCs5Pkux/qr0laeFIpzMKMootGa4kfURgPhRzUaM1vy bsMsL8vpJtGUmitrSqe5dVNBH00whLtPFM7IbzKURPUOkRRiusFAsw0a1ztCgoFczq6VfAVu raTye0L/VXwZd+aGi401V2tLsAHxxckRi9p3mc0jExPc60joK+aZPy6amwSCy5kAJ/AboYtY VmKIGKx1yx8POy6m+1lZ8C0q9b8eJ8kWPAR78PgT37FQWKYS1uAroG2wLdK7FiIEpPhCD+zH wlslo2ETbdKjrLIPNehQCOWrT32k8vFNEMLP5G/mmjfNj5sEf3IOKgMTMVl9AFjsINLHcxEQ 6T8nGbX/n3msP6A36FDfdSEAEQEAAc0WWGluIExpIDx4aW5Aenl0b3IuY29tPsLBDQQTAQgA NxYhBIUq/WFSDTiOvUIqv2u9DlcdrjdRBQJlD89XBQkFo5qAAhsDBAsJCAcFFQgJCgsFFgID AQAACgkQa70OVx2uN1HUpgv/cM2fsFCQodLArMTX5nt9yqAWgA5t1srri6EgS8W3F+3Kitge tYTBKu6j5BXuXaX3vyfCm+zajDJN77JHuYnpcKKr13VcZi1Swv6Jx1u0II8DOmoDYLb1Q2ZW v83W55fOWJ2g72x/UjVJBQ0sVjAngazU3ckc0TeNQlkcpSVGa/qBIHLfZraWtdrNAQT4A1fa sWGuJrChBFhtKbYXbUCu9AoYmmbQnsx2EWoJy3h7OjtfFapJbPZql+no5AJ3Mk9eE5oWyLH+ QWqtOeJM7kKvn/dBudokFSNhDUw06e7EoVPSJyUIMbYtUO7g2+Atu44G/EPP0yV0J4lRO6EA wYRXff7+I1jIWEHpj5EFVYO6SmBg7zF2illHEW31JAPtdDLDHYcZDfS41caEKOQIPsdzQkaQ oW2hchcjcMPAfyhhRzUpVHLPxLCetP8vrVhTvnaZUo0xaVYb3+wjP+D5j/3+hwblu2agPsaE vgVbZ8Fx3TUxUPCAdr/p73DGg57oHjgezsDNBGUPz1gBDAD4Mg7hMFRQqlzotcNSxatlAQNL MadLfUTFz8wUUa21LPLrHBkUwm8RujehJrzcVbPYwPXIO0uyL/F///CogMNx7Iwo6by43KOy g89wVFhyy237EY76j1lVfLzcMYmjBoTH95fJC/lVb5Whxil6KjSN/R/y3jfG1dPXfwAuZ/4N cMoOslWkfZKJeEut5aZTRepKKF54T5r49H9F7OFLyxrC/uI9UDttWqMxcWyCkHh0v1Di8176 jjYRNTrGEfYfGxSp+3jYL3PoNceIMkqM9haXjjGl0W1B4BidK1LVYBNov0rTEzyr0a1riUrp Qk+6z/LHxCM9lFFXnqH7KWeToTOPQebD2B/Ah5CZlft41i8L6LOF/LCuDBuYlu/fI2nuCc8d m4wwtkou1Y/kIwbEsE/6RQwRXUZhzO6llfoN96Fczr/RwvPIK5SVMixqWq4QGFAyK0m/1ap4 bhIRrdCLVQcgU4glo17vqfEaRcTW5SgX+pGs4KIPPBE5J/ABD6pBnUUAEQEAAcLA/AQYAQgA JhYhBIUq/WFSDTiOvUIqv2u9DlcdrjdRBQJlD89ZBQkFo5qAAhsMAAoJEGu9DlcdrjdR4C0L /RcjolEjoZW8VsyxWtXazQPnaRvzZ4vhmGOsCPr2BPtMlSwDzTlri8BBG1/3t/DNK4JLuwEj OAIE3fkkm+UG4Kjud6aNeraDI52DRVCSx6xff3bjmJsJJMb12mWglN6LjdF6K+PE+OTJUh2F dOhslN5C2kgl0dvUuevwMgQF3IljLmi/6APKYJHjkJpu1E6luZec/lRbetHuNFtbh3xgFIJx 2RpgVDP4xB3f8r0I+y6ua+p7fgOjDLyoFjubRGed0Be45JJQEn7A3CSb6Xu7NYobnxfkwAGZ Q81a2XtvNS7Aj6NWVoOQB5KbM4yosO5+Me1V1SkX2jlnn26JPEvbV3KRFcwV5RnDxm4OQTSk PYbAkjBbm+tuJ/Sm+5Yp5T/BnKz21FoCS8uvTiziHj2H7Cuekn6F8EYhegONm+RVg3vikOpn gao85i4HwQTK9/D1wgJIQkdwWXVMZ6q/OALaBp82vQ2U9sjTyFXgDjglgh00VRAHP7u1Rcu4 l75w1xInsg== In-Reply-To: <20250612214849.3950094-3-sohil.mehta@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 6/12/2025 2:48 PM, Sohil Mehta wrote: > Extend the FRED NMI entry point from KVM to take an extra argument to > allow KVM to invoke the FRED event dispatch framework with event data. > > This API is used to pass the NMI-source bitmap for NMI-induced VM exits. > Read the VMCS exit qualification field to get the NMI-source information > and store it as event data precisely in the format expected by the FRED > event framework. > > Read the VMCS exit qualification unconditionally since almost all > upcoming CPUs are expected to enable FRED and NMI-source together. In > the rare case that NMI-source isn't enabled, the extra VMREAD would be > harmless since the exit qualification is expected to be zero. > > Suggested-by: Sean Christopherson > Originally-by: Zeng Guang > Signed-off-by: Sohil Mehta A couple of nits below, otherwise: Reviewed-by: Xin Li (Intel) > --- > v7: Pass the event data from KVM only for NMI. (Sean) > > v6: No change > > v5: Read the VMCS exit qualification unconditionally. (Sean) > Combine related patches into one. > --- > arch/x86/entry/entry_64_fred.S | 2 +- > arch/x86/include/asm/fred.h | 11 ++++++----- > arch/x86/kvm/vmx/vmx.c | 2 +- > 3 files changed, 8 insertions(+), 7 deletions(-) > > diff --git a/arch/x86/entry/entry_64_fred.S b/arch/x86/entry/entry_64_fred.S > index 29c5c32c16c3..1c9c6e036233 100644 > --- a/arch/x86/entry/entry_64_fred.S > +++ b/arch/x86/entry/entry_64_fred.S > @@ -93,7 +93,7 @@ SYM_FUNC_START(asm_fred_entry_from_kvm) > * +--------+-----------------+ > */ > push $0 /* Reserved, must be 0 */ > - push $0 /* Event data, 0 for IRQ/NMI */ > + push %rsi /* Event data for NMI */ Maybe a bit more accurate? /* Event data, NMI-source bitmap only so far */ > push %rdi /* fred_ss handed in by the caller */ > push %rbp > pushf > diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h > index 552332ca060c..bccf4a3c06b8 100644 > --- a/arch/x86/include/asm/fred.h > +++ b/arch/x86/include/asm/fred.h > @@ -66,14 +66,14 @@ static __always_inline unsigned long fred_event_data(struct pt_regs *regs) > > void asm_fred_entrypoint_user(void); > void asm_fred_entrypoint_kernel(void); > -void asm_fred_entry_from_kvm(struct fred_ss); > +void asm_fred_entry_from_kvm(struct fred_ss ss, unsigned long edata); > > __visible void fred_entry_from_user(struct pt_regs *regs); > __visible void fred_entry_from_kernel(struct pt_regs *regs); > __visible void __fred_entry_from_kvm(struct pt_regs *regs); > > /* Must be called from noinstr code, thus __always_inline */ > -static __always_inline void fred_nmi_from_kvm(void) > +static __always_inline void fred_nmi_from_kvm(unsigned long edata) > { > struct fred_ss ss = { > .ss = __KERNEL_DS, > @@ -83,7 +83,7 @@ static __always_inline void fred_nmi_from_kvm(void) > .lm = 1, > }; > > - asm_fred_entry_from_kvm(ss); > + asm_fred_entry_from_kvm(ss, edata); > } > > static inline void fred_irq_from_kvm(unsigned int vector) > @@ -95,7 +95,8 @@ static inline void fred_irq_from_kvm(unsigned int vector) > .lm = 1, > }; > > - asm_fred_entry_from_kvm(ss); > + /* Event data is always zero for IRQ */ /* Event data not used for IRQ thus 0 */