From: Alex Williamson <alex.williamson@hp.com>
To: kvm@vger.kernel.org
Subject: Re: [PATCH] kvm: device-assignment: Catch GSI overflow
Date: Thu, 07 May 2009 11:16:53 -0600 [thread overview]
Message-ID: <1241716613.23680.31.camel@bling> (raw)
In-Reply-To: <20090507170834.26367.91907.stgit@dl380g6-3.ned.telco.ned.telco>
On Thu, 2009-05-07 at 11:09 -0600, Alex Williamson wrote:
> Fix the index at which we return -ENOSPC since the kernel side will
> reject a GSI >= KVM_MAX_IRQ_ROUTES. Also, mask as a signed int before
> testing for error.
Even with this, there still seems to be a fundamental problem with our
consumption of GSIs in kvm. For example, every time a guest writes to
the MSI capabilities area and enables MSI support, we call
kvm_get_irq_route_gsi() to get a new max_used_gsi + 1 value, then call
kvm_add_routing_entry(), which updates max_used_gsi. It doesn't take
too long before we exhaust the GSI space and the device no longer works.
This seems to happen within a minute or two of booting a guest with an
e1000e device sitting idle on a busy network. Do we need to keep a
bitmap of used GSIs or maybe just attempt to reuse the GSI we've gotten
previously for the device? Thanks,
Alex
next prev parent reply other threads:[~2009-05-07 17:16 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-07 17:09 [PATCH] kvm: device-assignment: Catch GSI overflow Alex Williamson
2009-05-07 17:16 ` Alex Williamson [this message]
2009-05-08 9:28 ` Sheng Yang
2009-05-12 22:14 ` [PATCH] kvm: device-assignment: Fix kvm_get_irq_route_gsi() return check Alex Williamson
2009-05-13 3:36 ` Yang, Sheng
2009-05-13 3:55 ` Alex Williamson
2009-05-13 4:09 ` Yang, Sheng
2009-05-13 4:45 ` [PATCH v2] " Alex Williamson
2009-05-13 4:58 ` Yang, Sheng
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