From: 李菲 <lifei.shirley@bytedance.com> To: "Michael S. Tsirkin" <mst@redhat.com> Cc: virtio-dev@lists.oasis-open.org, linux-kernel@vger.kernel.org, Jason Wang <jasowang@redhat.com>, Pawel Moll <pawel.moll@arm.com>, Suzuki K Poulose <suzuki.poulose@arm.com>, Fam Zheng <zhengfeiran@bytedance.com> Subject: Re: [External Email] Re: [PATCH v1 0/2] virtio-mmio: support multiple interrupt vectors Date: Mon, 22 Jul 2019 21:43:18 +0800 [thread overview] Message-ID: <CA+=e4K7ViADDq84i6ve1+F1=CrgfQJrY-O8LeBVV7eP4gUg21Q@mail.gmail.com> (raw) In-Reply-To: <20190722043707-mutt-send-email-mst@kernel.org> On Mon, Jul 22, 2019 at 4:39 PM Michael S. Tsirkin <mst@redhat.com> wrote: > > On Mon, Jul 22, 2019 at 11:22:02AM +0800, 李菲 wrote: > > On Fri, Jul 19, 2019 at 11:14 PM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > > > On Fri, Jul 19, 2019 at 09:31:33PM +0800, Fei Li wrote: > > > > Hi, > > > > > > > > This patch series implements multiple interrupt vectors support for > > > > virtio-mmio device. This is especially useful for multiqueue vhost-net > > > > device when using firecracker micro-vms as the guest. > > > > > > > > Test result: > > > > With 8 vcpus & 8 net queues set, one vhost-net device with 8 irqs can > > > > receive 9 times more pps comparing with only one irq: > > > > - 564830.38 rxpck/s for 8 irqs on > > > > - 67665.06 rxpck/s for 1 irq on > > > > > > > > Please help to review, thanks! > > > > > > > > Have a nice day > > > > Fei > > > > > > > > > Interesting. The spec says though: > > > > > > 4.2.3.4 > > > Notifications From The Device > > > The memory mapped virtio device is using a single, dedicated interrupt signal, which is asserted when at > > > least one of the bits described in the description of InterruptStatus is set. This is how the device sends a > > > used buffer notification or a configuration change notification to the device. > > > > > Yes, the spec needs to be updated if we want to use mult-irqs. > > > > > > So I'm guessing we need to change the host/guest interface? > > Just to confirm, does the "the host/guest interface" you mentioned mean how to > > pass the irq information from the user space tool to guest kernel? > > In this patch, we do this by passing the [irq_start, irq_end] > > interface via setting guest > > kernel command line, that is done in vm_cmdline_set(). > > Also there is another way to do this: add two new registers describing irq info > > (irq_start & irq_end OR irq_start & irq_numbers) to the virtio config space. > > > > Which one do you prefer? > > I'm not sure - so far irq was passed on the command line, right? Yes. > > The first step in implementing any spec change would be to update qemu > code to virtio 1. Which is not a huge project but so far no one > bothered. Emm, actually I only did the test with using firecracker to start a micro-vm, but without qemu. To be honest, the reason why implementing multi-irq on virtio-mmio is mainly because the current firecracker using virtio-mmio device and it has no pci thing, thus no msi/msix to handle the interruptions. On the other hand, considering pci is well supported in qemu, I am wondering whether we still need this. If needed, we would like to do this. :) Have a nice day, thanks Fei > > > > > If true pls cc virtio-dev. > > Sure. > > > > > > Also, do we need to update dt bindings documentation? > > You mean the following doc? Sure. :) > > https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/virtio/mmio.txt > > > > Thanks for the review! > > > > Have a nice day > > Fei > > > > > > > > > > > > > > > Fam Zheng (1): > > > > virtio-mmio: Process vrings more proactively > > > > > > > > Fei Li (1): > > > > virtio-mmio: support multiple interrupt vectors > > > > > > > > drivers/virtio/virtio_mmio.c | 238 +++++++++++++++++++++++++++++++++++-------- > > > > 1 file changed, 196 insertions(+), 42 deletions(-) > > > > > > > > -- > > > > 2.11.0
WARNING: multiple messages have this Message-ID (diff)
From: 李菲 <lifei.shirley@bytedance.com> To: "Michael S. Tsirkin" <mst@redhat.com> Cc: virtio-dev@lists.oasis-open.org, linux-kernel@vger.kernel.org, Jason Wang <jasowang@redhat.com>, Pawel Moll <pawel.moll@arm.com>, Suzuki K Poulose <suzuki.poulose@arm.com>, Fam Zheng <zhengfeiran@bytedance.com> Subject: [virtio-dev] Re: [External Email] Re: [PATCH v1 0/2] virtio-mmio: support multiple interrupt vectors Date: Mon, 22 Jul 2019 21:43:18 +0800 [thread overview] Message-ID: <CA+=e4K7ViADDq84i6ve1+F1=CrgfQJrY-O8LeBVV7eP4gUg21Q@mail.gmail.com> (raw) In-Reply-To: <20190722043707-mutt-send-email-mst@kernel.org> On Mon, Jul 22, 2019 at 4:39 PM Michael S. Tsirkin <mst@redhat.com> wrote: > > On Mon, Jul 22, 2019 at 11:22:02AM +0800, 李菲 wrote: > > On Fri, Jul 19, 2019 at 11:14 PM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > > > On Fri, Jul 19, 2019 at 09:31:33PM +0800, Fei Li wrote: > > > > Hi, > > > > > > > > This patch series implements multiple interrupt vectors support for > > > > virtio-mmio device. This is especially useful for multiqueue vhost-net > > > > device when using firecracker micro-vms as the guest. > > > > > > > > Test result: > > > > With 8 vcpus & 8 net queues set, one vhost-net device with 8 irqs can > > > > receive 9 times more pps comparing with only one irq: > > > > - 564830.38 rxpck/s for 8 irqs on > > > > - 67665.06 rxpck/s for 1 irq on > > > > > > > > Please help to review, thanks! > > > > > > > > Have a nice day > > > > Fei > > > > > > > > > Interesting. The spec says though: > > > > > > 4.2.3.4 > > > Notifications From The Device > > > The memory mapped virtio device is using a single, dedicated interrupt signal, which is asserted when at > > > least one of the bits described in the description of InterruptStatus is set. This is how the device sends a > > > used buffer notification or a configuration change notification to the device. > > > > > Yes, the spec needs to be updated if we want to use mult-irqs. > > > > > > So I'm guessing we need to change the host/guest interface? > > Just to confirm, does the "the host/guest interface" you mentioned mean how to > > pass the irq information from the user space tool to guest kernel? > > In this patch, we do this by passing the [irq_start, irq_end] > > interface via setting guest > > kernel command line, that is done in vm_cmdline_set(). > > Also there is another way to do this: add two new registers describing irq info > > (irq_start & irq_end OR irq_start & irq_numbers) to the virtio config space. > > > > Which one do you prefer? > > I'm not sure - so far irq was passed on the command line, right? Yes. > > The first step in implementing any spec change would be to update qemu > code to virtio 1. Which is not a huge project but so far no one > bothered. Emm, actually I only did the test with using firecracker to start a micro-vm, but without qemu. To be honest, the reason why implementing multi-irq on virtio-mmio is mainly because the current firecracker using virtio-mmio device and it has no pci thing, thus no msi/msix to handle the interruptions. On the other hand, considering pci is well supported in qemu, I am wondering whether we still need this. If needed, we would like to do this. :) Have a nice day, thanks Fei > > > > > If true pls cc virtio-dev. > > Sure. > > > > > > Also, do we need to update dt bindings documentation? > > You mean the following doc? Sure. :) > > https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/virtio/mmio.txt > > > > Thanks for the review! > > > > Have a nice day > > Fei > > > > > > > > > > > > > > > Fam Zheng (1): > > > > virtio-mmio: Process vrings more proactively > > > > > > > > Fei Li (1): > > > > virtio-mmio: support multiple interrupt vectors > > > > > > > > drivers/virtio/virtio_mmio.c | 238 +++++++++++++++++++++++++++++++++++-------- > > > > 1 file changed, 196 insertions(+), 42 deletions(-) > > > > > > > > -- > > > > 2.11.0 --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org
next prev parent reply other threads:[~2019-07-22 13:43 UTC|newest] Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-07-19 13:31 [PATCH v1 0/2] virtio-mmio: support multiple interrupt vectors Fei Li 2019-07-19 13:31 ` [PATCH 1/2] virtio-mmio: Process vrings more proactively Fei Li 2019-07-19 15:17 ` Michael S. Tsirkin 2019-07-22 2:28 ` [External Email] " Fam Zheng 2019-07-25 14:33 ` Michael S. Tsirkin 2019-07-19 13:31 ` [PATCH 2/2] virtio-mmio: support multiple interrupt vectors Fei Li 2019-07-19 15:14 ` [PATCH v1 0/2] " Michael S. Tsirkin 2019-07-22 3:22 ` [External Email] " 李菲 2019-07-22 5:10 ` [virtio-dev] Fwd: " 李菲 2019-07-22 8:39 ` Michael S. Tsirkin 2019-07-22 8:39 ` [virtio-dev] " Michael S. Tsirkin 2019-07-22 13:43 ` 李菲 [this message] 2019-07-22 13:43 ` 李菲 2019-07-30 20:26 ` Michael S. Tsirkin 2019-07-30 20:26 ` [virtio-dev] " Michael S. Tsirkin 2019-07-31 4:04 ` 李菲 2019-07-31 4:04 ` [virtio-dev] " 李菲 2019-08-02 11:01 ` Sergio Lopez 2019-07-31 4:10 ` 李菲
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='CA+=e4K7ViADDq84i6ve1+F1=CrgfQJrY-O8LeBVV7eP4gUg21Q@mail.gmail.com' \ --to=lifei.shirley@bytedance.com \ --cc=jasowang@redhat.com \ --cc=linux-kernel@vger.kernel.org \ --cc=mst@redhat.com \ --cc=pawel.moll@arm.com \ --cc=suzuki.poulose@arm.com \ --cc=virtio-dev@lists.oasis-open.org \ --cc=zhengfeiran@bytedance.com \ /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.