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From:   "Tian, Kevin" <kevin.tian@intel.com>
To:     "Chatre, Reinette" <reinette.chatre@intel.com>,
        "jgg@nvidia.com" <jgg@nvidia.com>,
        "yishaih@nvidia.com" <yishaih@nvidia.com>,
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CC:     "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "Jiang, Dave" <dave.jiang@intel.com>,
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        "Yu, Fenghua" <fenghua.yu@intel.com>,
        "tom.zanussi@linux.intel.com" <tom.zanussi@linux.intel.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "patches@lists.linux.dev" <patches@lists.linux.dev>
Subject: RE: [RFC PATCH V2 14/18] vfio/pci: Add core IMS support
Thread-Topic: [RFC PATCH V2 14/18] vfio/pci: Add core IMS support
Thread-Index: AQHZ+HP7H8n8M1qsCESF8QGnzw9E4rBHZG0A
Date:   Fri, 13 Oct 2023 08:10:48 +0000
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> From: Chatre, Reinette <reinette.chatre@intel.com>
> Sent: Saturday, October 7, 2023 12:41 AM
>=20
> A virtual device driver starts by initializing the backend
> using new vfio_pci_ims_init_intr_ctx(), cleanup using new
> vfio_pci_ims_release_intr_ctx(). Once initialized the virtual
> device driver can call vfio_pci_set_irqs_ioctl() to handle the
> VFIO_DEVICE_SET_IRQS ioctl() after it has validated the parameters
> to be appropriate for the particular device.

I wonder whether the code sharing can go deeper from
vfio_pci_set_irqs_ioctl() all the way down to set_vector_signal()
with proper abstraction. Then handle emulated interrupt in the
common code instead of ims specific path. intel gvt also uses
emulated interrupt, which could be converted to use this library
too.

There is some subtle difference between pci/ims backends
regarding to how set_vector_signal() is coded in this series. But
it is not intuitive to me whether such a difference is conceptual
or simply from a coding preference.

Would you mind doing an exercise whether that is achievable?

Thanks
Kevin