[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PATCH] e1000: Delay LSC until mask is active

From: Peter Maydell
Subject: Re: [Qemu-devel] [PATCH] e1000: Delay LSC until mask is active
Date: Thu, 3 Jul 2014 18:57:20 +0100

On 3 July 2014 18:39, Alexander Graf <address@hidden> wrote:
> Mac OS X reads ICR on every interrupt. When the IRQ line is shared, this may
> result in a race where LSC is not interpreted yet, but already gets cleared.
> The guest already has a way of telling us that it can interpret LSC events
> though and that's via the interrupt mask register (IMS).
> So if we just leave the LSC interrupt bit pending, but invisible to the guest
> as long as it's not ready to receive LSC interrupts, we basically defer the
> interrupt to the earliest point in time when the guest would know how to
> handle it.

This would break any guests dealing with this in a polling
mode (ie "permanently leave interrupts masked and read
ICR periodically to find out whether anything interesting
has happened"), right?

-- PMM

reply via email to

[Prev in Thread] Current Thread [Next in Thread]