From: Alex Williamson <alex.williamson@redhat.com> To: qemu-devel@nongnu.org Cc: alex.williamson@redhat.com, kvm@vger.kernel.org Subject: [RFC PATCH 0/5] vfio: ioeventfd support Date: Tue, 06 Feb 2018 17:26:07 -0700 [thread overview] Message-ID: <20180207001615.1156.10547.stgit@gimli.home> (raw) For the matching kernel patch, see: https://lkml.org/lkml/2018/2/6/866 This series enables ioeventfd support and makes use of a proposed vfio kernel ioeventfd interface for accelerating high frequency writes through to the device. In the specific case addressed, the writes are to a range of MMIO space virtualized in QEMU for NVIDIA GeForce support, but which also hosts a register which is used to allow the MSI interrupt for the device to re-trigger. Applications which generate a very high interrupt rate on the GPU can see noticeable overhead as a result of this trap through QEMU. We added an option for users to disable these quirks entirely for non-Geforce cards[1] for optimal performance, but for GeForce users and users that can't tweak their VM config, this gets us to within 95% of that performance for an interrupt intensive micro-benchmark (from 83%). I'd be interested in more typical benchmark results to understand if there's an improvement there as well. Thanks, Alex [1] https://lists.gnu.org/archive/html/qemu-devel/2018-01/msg06878.html --- Alex Williamson (5): vfio/quirks: Add common quirk alloc helper vfio/quirks: Add generic support for ioveventfds vfio/quirks: Automatic ioeventfd enabling for NVIDIA BAR0 quirks vfio: Update linux header vfio/quirks: Enable ioeventfd quirks to be handled by vfio directly hw/vfio/pci-quirks.c | 184 +++++++++++++++++++++++++++++++++++++------- hw/vfio/pci.h | 13 +++ linux-headers/linux/vfio.h | 24 ++++++ 3 files changed, 192 insertions(+), 29 deletions(-)
WARNING: multiple messages have this Message-ID (diff)
From: Alex Williamson <alex.williamson@redhat.com> To: qemu-devel@nongnu.org Cc: alex.williamson@redhat.com, kvm@vger.kernel.org Subject: [Qemu-devel] [RFC PATCH 0/5] vfio: ioeventfd support Date: Tue, 06 Feb 2018 17:26:07 -0700 [thread overview] Message-ID: <20180207001615.1156.10547.stgit@gimli.home> (raw) For the matching kernel patch, see: https://lkml.org/lkml/2018/2/6/866 This series enables ioeventfd support and makes use of a proposed vfio kernel ioeventfd interface for accelerating high frequency writes through to the device. In the specific case addressed, the writes are to a range of MMIO space virtualized in QEMU for NVIDIA GeForce support, but which also hosts a register which is used to allow the MSI interrupt for the device to re-trigger. Applications which generate a very high interrupt rate on the GPU can see noticeable overhead as a result of this trap through QEMU. We added an option for users to disable these quirks entirely for non-Geforce cards[1] for optimal performance, but for GeForce users and users that can't tweak their VM config, this gets us to within 95% of that performance for an interrupt intensive micro-benchmark (from 83%). I'd be interested in more typical benchmark results to understand if there's an improvement there as well. Thanks, Alex [1] https://lists.gnu.org/archive/html/qemu-devel/2018-01/msg06878.html --- Alex Williamson (5): vfio/quirks: Add common quirk alloc helper vfio/quirks: Add generic support for ioveventfds vfio/quirks: Automatic ioeventfd enabling for NVIDIA BAR0 quirks vfio: Update linux header vfio/quirks: Enable ioeventfd quirks to be handled by vfio directly hw/vfio/pci-quirks.c | 184 +++++++++++++++++++++++++++++++++++++------- hw/vfio/pci.h | 13 +++ linux-headers/linux/vfio.h | 24 ++++++ 3 files changed, 192 insertions(+), 29 deletions(-)
next reply other threads:[~2018-02-07 0:26 UTC|newest] Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-02-07 0:26 Alex Williamson [this message] 2018-02-07 0:26 ` [Qemu-devel] [RFC PATCH 0/5] vfio: ioeventfd support Alex Williamson 2018-02-07 0:26 ` [RFC PATCH 1/5] vfio/quirks: Add common quirk alloc helper Alex Williamson 2018-02-07 0:26 ` [Qemu-devel] " Alex Williamson 2018-02-08 11:10 ` Auger Eric 2018-02-08 11:10 ` [Qemu-devel] " Auger Eric 2018-02-08 18:28 ` Alex Williamson 2018-02-08 18:28 ` [Qemu-devel] " Alex Williamson 2018-02-07 0:26 ` [RFC PATCH 2/5] vfio/quirks: Add generic support for ioveventfds Alex Williamson 2018-02-07 0:26 ` [Qemu-devel] " Alex Williamson 2018-02-08 11:11 ` Auger Eric 2018-02-08 11:11 ` [Qemu-devel] " Auger Eric 2018-02-08 18:33 ` Alex Williamson 2018-02-08 18:33 ` [Qemu-devel] " Alex Williamson 2018-02-08 20:37 ` Auger Eric 2018-02-07 0:26 ` [RFC PATCH 3/5] vfio/quirks: Automatic ioeventfd enabling for NVIDIA BAR0 quirks Alex Williamson 2018-02-07 0:26 ` [Qemu-devel] " Alex Williamson 2018-02-08 11:10 ` Auger Eric 2018-02-08 11:10 ` [Qemu-devel] " Auger Eric 2018-02-08 11:33 ` Auger Eric 2018-02-08 18:24 ` Alex Williamson 2018-02-08 18:24 ` [Qemu-devel] " Alex Williamson 2018-02-08 20:52 ` Auger Eric 2018-02-08 20:52 ` [Qemu-devel] " Auger Eric 2018-02-07 0:26 ` [RFC PATCH 4/5] vfio: Update linux header Alex Williamson 2018-02-07 0:26 ` [Qemu-devel] " Alex Williamson 2018-02-07 0:26 ` [RFC PATCH 5/5] vfio/quirks: Enable ioeventfd quirks to be handled by vfio directly Alex Williamson 2018-02-07 0:26 ` [Qemu-devel] " Alex Williamson 2018-02-08 11:42 ` Auger Eric 2018-02-08 11:42 ` [Qemu-devel] " Auger Eric 2018-02-08 18:41 ` Alex Williamson 2018-02-08 18:41 ` [Qemu-devel] " Alex Williamson 2018-02-09 7:11 ` Peter Xu 2018-02-09 22:09 ` Alex Williamson 2018-02-11 2:38 ` Peter Xu
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20180207001615.1156.10547.stgit@gimli.home \ --to=alex.williamson@redhat.com \ --cc=kvm@vger.kernel.org \ --cc=qemu-devel@nongnu.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.