From: Jan Kiszka <jan.kiszka@siemens.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: virtualization@lists.linux-foundation.org, kvm@vger.kernel.org,
Alex Williamson <alex.williamson@redhat.com>
Subject: Re: virtio PCI on KVM without IO BARs
Date: Thu, 28 Feb 2013 16:43:38 +0100 [thread overview]
Message-ID: <512F7B2A.5080108@siemens.com> (raw)
In-Reply-To: <20130228152433.GA13832@redhat.com>
On 2013-02-28 16:24, Michael S. Tsirkin wrote:
> Another problem with PIO is support for physical virtio devices,
> and nested virt: KVM currently programs all PIO accesses
> to cause vm exit, so using this device in a VM will be slow.
Not answering your question, but support for programming direct PIO
access into KVM's I/O bitmap would be feasible. Such feature may have
some value for assigned devices that use PIO more heavily. They cause
lengthy user-space exists so far.
Jan
--
Siemens AG, Corporate Technology, CT RTC ITP SDP-DE
Corporate Competence Center Embedded Linux
next prev parent reply other threads:[~2013-02-28 15:43 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-28 15:24 virtio PCI on KVM without IO BARs Michael S. Tsirkin
2013-02-28 15:43 ` Jan Kiszka [this message]
2013-03-04 22:01 ` Marcelo Tosatti
2013-03-06 0:05 ` H. Peter Anvin
2013-03-06 7:14 ` H. Peter Anvin
2013-03-06 9:21 ` Michael S. Tsirkin
2013-03-06 11:15 ` H. Peter Anvin
2013-03-06 12:02 ` Michael S. Tsirkin
2013-04-29 14:48 ` Don Dutile
2013-04-29 23:03 ` H. Peter Anvin
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