Re: [PATCH 2/2] Drivers: hv: Move add_interrupt_randomness() to hypervisor callback sysvec

[Thomas Gleixner]

On Thu, Apr 02 2026 at 13:24, Michael Kelley wrote:
> From: Michael Kelley <mhklinux@xxxxxxxxxxx>
>
> The Hyper-V ISRs, for normal guests and when running in the
> hypervisor root patition, are calling add_interrupt_randomness() as a
> primary source of entropy. The call is currently in the ISRs as a common
> place to handle both x86/x64 and arm64. On x86/x64, hypervisor interrupts
> come through a custom sysvec entry, and do not go through a generic
> interrupt handler. On arm64, hypervisor interrupts come through an
> emulated GICv3. GICv3 uses the generic handler handle_percpu_devid_irq(),
> which does not do add_interrupt_randomness() -- unlike its counterpart
> handle_percpu_irq(). But handle_percpu_devid_irq() is now updated to do
> the add_interrupt_randomness(). So add_interrupt_randomness() is now
> needed only in Hyper-V's x86/x64 custom sysvec path.
>
> Move add_interrupt_randomness() from the Hyper-V ISRs into the Hyper-V
> x86/x64 custom sysvec path, matching the existing STIMER0 sysvec path.
> With this change, add_interrupt_randomness() is no longer called from any
> device drivers, which is appropriate.
>
> Signed-off-by: Michael Kelley <mhklinux@xxxxxxxxxxx>

Acked-by: Thomas Gleixner <tglx@xxxxxxxxxx>