| 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
| ||
|
Date: Wed, 18 Jul 2007 10:09:37 -0700 From: "Dor Laor" <dor.laor@...ranet.com> To: "Avi Kivity" <avi@...ranet.com>, "Alan Cox" <alan@...rguk.ukuu.org.uk> Cc: <kvm-devel@...ts.sourceforge.net>, <linux-kernel@...r.kernel.org> Subject: RE: [kvm-devel] [RFC] Deferred interrupt handling. >Alan Cox wrote: >>> What if we will force the specific device to the end of the list. >Once >>> IRQ_NONE was returned by the other devices, we will mask the irq, >>> forward the irq to the guest, issue a timer for 1msec. Motivation: >>> 1msec is long enough for the guest to ack the irq + host unmask the >irq >>> >> >> It makes no difference. The deadlock isn't fixable by timing hacks. >> Consider the following sequence >> >> >> Guest0 - blocked on I/O >> >> IRQ14 from your hardware >> Block IRQ14 >> Sent to guest (guest is blocked) >> >> IRQ14 from hard disk >> Ignored (as blocked) >> But now the timer will pop and the hard disk will get its irq. The guest will be released right after. >> Deadlock >> > >IMO the only reasonable solution is to disallow interrupt forwarding >with shared irqs. If someone later comes up with a bright idea, we can >implement it. Otherwise the problem will solve itself with hardware >moving to msi. > I though of that but the problem is that we'd like to use it with current hardware devices that are shared. :( - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists