From: Avi Kivity <avi@redhat.com>
To: Amos Kong <akong@redhat.com>
Cc: aliguori@us.ibm.com, mtosatti@redhat.com,
stefanha@linux.vnet.ibm.com, kvm@vger.kernel.org,
qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 0/2] virtio-pci: fix abort when fail to allocate ioeventfd
Date: Wed, 14 Mar 2012 11:22:30 +0200 [thread overview]
Message-ID: <4F606356.9080003@redhat.com> (raw)
In-Reply-To: <20120313103602.8741.71939.stgit@dhcp-8-167.nay.redhat.com>
On 03/13/2012 12:42 PM, Amos Kong wrote:
> Boot up guest with 232 virtio-blk disk, qemu will abort for fail to
> allocate ioeventfd. This patchset changes kvm_has_many_ioeventfds(),
> and check if available ioeventfd exists. If not, virtio-pci will
> fallback to userspace, and don't use ioeventfd for io notification.
How about an alternative way of solving this, within the memory core:
trap those writes in qemu and write to the ioeventfd yourself. This way
ioeventfds work even without kvm:
core: create eventfd
core: install handler for memory address that writes to ioeventfd
kvm (optional): install kernel handler for ioeventfd
even if the third step fails, the ioeventfd still works, it's just slower.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2012-03-14 9:22 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-13 10:42 [Qemu-devel] [PATCH 0/2] virtio-pci: fix abort when fail to allocate ioeventfd Amos Kong
2012-03-13 10:42 ` [Qemu-devel] [PATCH 1/2] return available ioeventfds count in kvm_has_many_ioeventfds() Amos Kong
2012-03-13 11:50 ` Jan Kiszka
2012-03-13 12:00 ` Amos Kong
2012-03-13 12:24 ` Jan Kiszka
2012-03-13 13:05 ` Amos Kong
2012-03-13 10:42 ` [Qemu-devel] [PATCH 2/2] virtio-pci: fallback to userspace when there is no enough available ioeventfd Amos Kong
2012-03-13 11:23 ` [Qemu-devel] [PATCH 0/2] virtio-pci: fix abort when fail to allocate ioeventfd Stefan Hajnoczi
2012-03-13 11:51 ` Amos Kong
2012-03-13 14:30 ` Stefan Hajnoczi
2012-03-13 14:47 ` Amos Kong
2012-03-13 16:36 ` Stefan Hajnoczi
2012-03-14 0:30 ` Amos Kong
2012-03-14 8:57 ` Stefan Hajnoczi
2012-03-14 9:22 ` Avi Kivity [this message]
2012-03-14 9:59 ` Stefan Hajnoczi
2012-03-14 10:05 ` Avi Kivity
2012-03-14 10:39 ` Stefan Hajnoczi
2012-03-14 10:46 ` Avi Kivity
2012-03-14 11:46 ` Stefan Hajnoczi
2012-03-16 8:59 ` Amos Kong
2012-03-19 8:21 ` Stefan Hajnoczi
2012-03-19 10:11 ` Avi Kivity
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