linux-kernel - Re: [RFC 09/14] vfio/nvgrace-egm: Add chardev ops for EGM management

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250905133624.GF616306@nvidia.com>
Date: Fri, 5 Sep 2025 10:36:24 -0300
From: Jason Gunthorpe <jgg@...dia.com>
To: ankita@...dia.com
Cc: alex.williamson@...hat.com, yishaih@...dia.com, skolothumtho@...dia.com,
	kevin.tian@...el.com, yi.l.liu@...el.com, zhiw@...dia.com,
	aniketa@...dia.com, cjia@...dia.com, kwankhede@...dia.com,
	targupta@...dia.com, vsethi@...dia.com, acurrid@...dia.com,
	apopple@...dia.com, jhubbard@...dia.com, danw@...dia.com,
	anuaggarwal@...dia.com, mochs@...dia.com, kjaju@...dia.com,
	dnigam@...dia.com, kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [RFC 09/14] vfio/nvgrace-egm: Add chardev ops for EGM management

On Thu, Sep 04, 2025 at 04:08:23AM +0000, ankita@...dia.com wrote:
>  static int nvgrace_egm_mmap(struct file *file, struct vm_area_struct *vma)
>  {
> -	return 0;
> +	struct chardev *egm_chardev = file->private_data;
> +	struct nvgrace_egm_dev *egm_dev =
> +		egm_chardev_to_nvgrace_egm_dev(egm_chardev);
> +
> +	/*
> +	 * EGM memory is invisible to the host kernel and is not managed
> +	 * by it. Map the usermode VMA to the EGM region.
> +	 */
> +	return remap_pfn_range(vma, vma->vm_start,
> +			       PHYS_PFN(egm_dev->egmphys),
> +			       (vma->vm_end - vma->vm_start),
> +			       vma->vm_page_prot);

This needs to handle vm_pgoff and sanity check end - start!!

It should also reject !MAP_SHARED

Jason