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[142.68.80.239]) by smtp.gmail.com with ESMTPSA id af79cd13be357-795015bed64sm346687985a.8.2024.06.05.09.22.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Jun 2024 09:22:50 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.95) (envelope-from ) id 1sEtPV-007TNB-Pb; Wed, 05 Jun 2024 13:22:49 -0300 Date: Wed, 5 Jun 2024 13:22:49 -0300 From: Jason Gunthorpe To: Fred Griffoul Cc: griffoul@gmail.com, Alex Williamson , Yi Liu , Kevin Tian , Eric Auger , Stefan Hajnoczi , Christian Brauner , Ankit Agrawal , Reinette Chatre , Ye Bin , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] vfio/pci: add msi interrupt affinity support Message-ID: <20240605162249.GE791043@ziepe.ca> References: <20240605155509.53536-1-fgriffo@amazon.co.uk> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240605155509.53536-1-fgriffo@amazon.co.uk> On Wed, Jun 05, 2024 at 03:55:05PM +0000, Fred Griffoul wrote: > The usual way to configure a device interrupt from userland is to write > the /proc/irq//smp_affinity or smp_affinity_list files. When using > vfio to implement a device driver or a virtual machine monitor, this may > not be ideal: the process managing the vfio device interrupts may not be > granted root privilege, for security reasons. Thus it cannot directly > control the interrupt affinity and has to rely on an external command. For a long time I've been beating a drum that people need to stop using /proc/irq/../smp_affinity, so I like this idea :) Jason