Received-SPF: pass (google.com: domain of linux-kernel+bounces-131517-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
Message-ID: <9734e080-96e4-4119-8ae6-28abb7877a3c@gmail.com>
Date: Thu, 4 Apr 2024 21:38:34 +0800
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH 05/15] x86/irq: Reserve a per CPU IDT vector for posted
 MSIs
Content-Language: en-US
To: Jacob Pan <jacob.jun.pan@linux.intel.com>,
 LKML <linux-kernel@vger.kernel.org>, X86 Kernel <x86@kernel.org>,
 Peter Zijlstra <peterz@infradead.org>, iommu@lists.linux.dev,
 Thomas Gleixner <tglx@linutronix.de>, Lu Baolu <baolu.lu@linux.intel.com>,
 kvm@vger.kernel.org, Dave Hansen <dave.hansen@intel.com>,
 Joerg Roedel <joro@8bytes.org>, "H. Peter Anvin" <hpa@zytor.com>,
 Borislav Petkov <bp@alien8.de>, Ingo Molnar <mingo@redhat.com>
Cc: Paul Luse <paul.e.luse@intel.com>, Dan Williams
 <dan.j.williams@intel.com>, Jens Axboe <axboe@kernel.dk>,
 Raj Ashok <ashok.raj@intel.com>, "Tian, Kevin" <kevin.tian@intel.com>,
 maz@kernel.org, seanjc@google.com, Robin Murphy <robin.murphy@arm.com>
References: <20240126234237.547278-1-jacob.jun.pan@linux.intel.com>
 <20240126234237.547278-6-jacob.jun.pan@linux.intel.com>
From: Robert Hoo <robert.hoo.linux@gmail.com>
In-Reply-To: <20240126234237.547278-6-jacob.jun.pan@linux.intel.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit

On 1/27/2024 7:42 AM, Jacob Pan wrote:
> When posted MSI is enabled, all device MSIs are multiplexed into a single
> notification vector. MSI handlers will be de-multiplexed at run-time by
> system software without IDT delivery.
> 
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> ---
>   arch/x86/include/asm/irq_vectors.h | 9 ++++++++-
>   1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
> index 3a19904c2db6..08329bef5b1d 100644
> --- a/arch/x86/include/asm/irq_vectors.h
> +++ b/arch/x86/include/asm/irq_vectors.h
> @@ -99,9 +99,16 @@
>   
>   #define LOCAL_TIMER_VECTOR		0xec
>   
> +/*
> + * Posted interrupt notification vector for all device MSIs delivered to
> + * the host kernel.
> + */
> +#define POSTED_MSI_NOTIFICATION_VECTOR	0xeb
>   #define NR_VECTORS			 256
>   
> -#ifdef CONFIG_X86_LOCAL_APIC
> +#ifdef X86_POSTED_MSI

X86_POSTED_MSI --> CONFIG_X86_POSTED_MSI?

> +#define FIRST_SYSTEM_VECTOR		POSTED_MSI_NOTIFICATION_VECTOR
> +#elif defined(CONFIG_X86_LOCAL_APIC)
>   #define FIRST_SYSTEM_VECTOR		LOCAL_TIMER_VECTOR
>   #else
>   #define FIRST_SYSTEM_VECTOR		NR_VECTORS