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]
Date:   Tue, 10 Aug 2021 01:10:40 +0000
From:   Sunil Muthuswamy <>
To:     Marc Zyngier <>
CC:     Robin Murphy <>,
        Thomas Gleixner <>,
        "" <>,
        "" <>,
        "" <>,
        Michael Kelley <>,
        Boqun Feng <>,
        KY Srinivasan <>,
        Arnd Bergmann <>,
        Lorenzo Pieralisi <>
Subject: RE: [EXTERNAL] Re: [RFC 1/1] irqchip/gic-v3-its: Add irq domain and
 chip for Direct LPI without ITS

On Monday, August 9, 2021 2:15 AM,
Marc Zyngier <> wrote:
> If you plug directly into the GICv3 layer, I'd rather you inject SPIs,
> just like any other non-architectural MSI controller. You can directly
> interface with the ACPI GSI layer for that, without any need to mess
> with the GICv3 internals. The SPI space isn't very large, but still
> much larger than the equivalent x86 space (close to 1000).
> If time is of the essence, I suggest you go the SPI way. For anything
> involving LPIs, I really want to see a firmware spec that works for
> everyone as opposed to a localised Hyper-V hack.
Ok, thanks. Before we commit to anything, I would like to make sure
that I am on the same page in terms of your description. With that in
mind, I have few questions. Hopefully, these should settle the matter.
1. If we go with the SPI route, then the way I envision it is that the 
    Hyper-V vPCI driver will implement an IRQ chip, which will take
    care of allocating & managing the SPI interrupt for Hyper-V vPCI.
    This IRQ chip will parent itself to the architectural GIC IRQ chip for
    general interrupt management. Does that match with your
    understanding/suggestion as well?

2. In the above, how will Hyper-V vPCI module discover the
    architectural GIC IRQ domain generically for virtual devices that
    are not firmware enumerated? Today, the GIC v3 IRQ domain is
    not exported and the general 'irq_find_xyz' APIs only work for
    firmware enumerated devices (i.e. something that has a fwnode

3. Longer term, if we implement LPIs (with an ITS or Direct LPI), to
    be able to support all scenarios such as Live Migration, the
    Hyper-V virtual PCI driver would like to be able to control the
    MSI address & data that gets programmed on the device
   (i.e. .irq_compose_msi_msg). We can use the architectural
   methods for everything else. Does that fit into the realm of
   what would be acceptable upstream?


Powered by blists - more mailing lists