From: Jan Kiszka <jan.kiszka@web.de> To: Paolo Bonzini <pbonzini@redhat.com>, Rusty Russell <rusty@rustcorp.com.au>, Henning Schild <henning.schild@siemens.com>, qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org Cc: Jailhouse <jailhouse-dev@googlegroups.com> Subject: Re: Using virtio for inter-VM communication Date: Sun, 15 Jun 2014 08:20:37 +0200 [thread overview] Message-ID: <539D3B35.2010706@web.de> (raw) In-Reply-To: <539ABA41.3070701@redhat.com> [-- Attachment #1: Type: text/plain, Size: 1677 bytes --] On 2014-06-13 10:45, Paolo Bonzini wrote: > Il 13/06/2014 08:23, Jan Kiszka ha scritto: >>>> That would preserve zero-copy capabilities (as long as you can work >>>> against the shared mem directly, e.g. doing DMA from a physical NIC or >>>> storage device into it) and keep the hypervisor out of the loop. >> > >> > This seems ill thought out. How will you program a NIC via the virtio >> > protocol without a hypervisor? And how will you make it safe? You'll >> > need an IOMMU. But if you have an IOMMU you don't need shared memory. >> >> Scenarios behind this are things like driver VMs: You pass through the >> physical hardware to a driver guest that talks to the hardware and >> relays data via one or more virtual channels to other VMs. This confines >> a certain set of security and stability risks to the driver VM. > > I think implementing Xen hypercalls in jailhouse for grant table and > event channels would actually make a lot of sense. The Xen > implementation is 2.5kLOC and I think it should be possible to compact > it noticeably, especially if you limit yourself to 64-bit guests. At least the grant table model seems unsuited for Jailhouse. It allows a guest to influence the mapping of another guest during runtime. This we want (or even have) to avoid in Jailhouse. I'm therefore more in favor of a model where the shared memory region is defined on cell (guest) creation by adding a virtual device that comes with such a region. Jan > > It should also be almost enough to run Xen PVH guests as jailhouse > partitions. > > If later Xen starts to support virtio, you will get that for free. > > Paolo [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 263 bytes --]
WARNING: multiple messages have this Message-ID (diff)
From: Jan Kiszka <jan.kiszka@web.de> To: Paolo Bonzini <pbonzini@redhat.com>, Rusty Russell <rusty@rustcorp.com.au>, Henning Schild <henning.schild@siemens.com>, qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org Cc: Jailhouse <jailhouse-dev@googlegroups.com> Subject: Re: [Qemu-devel] Using virtio for inter-VM communication Date: Sun, 15 Jun 2014 08:20:37 +0200 [thread overview] Message-ID: <539D3B35.2010706@web.de> (raw) In-Reply-To: <539ABA41.3070701@redhat.com> [-- Attachment #1: Type: text/plain, Size: 1677 bytes --] On 2014-06-13 10:45, Paolo Bonzini wrote: > Il 13/06/2014 08:23, Jan Kiszka ha scritto: >>>> That would preserve zero-copy capabilities (as long as you can work >>>> against the shared mem directly, e.g. doing DMA from a physical NIC or >>>> storage device into it) and keep the hypervisor out of the loop. >> > >> > This seems ill thought out. How will you program a NIC via the virtio >> > protocol without a hypervisor? And how will you make it safe? You'll >> > need an IOMMU. But if you have an IOMMU you don't need shared memory. >> >> Scenarios behind this are things like driver VMs: You pass through the >> physical hardware to a driver guest that talks to the hardware and >> relays data via one or more virtual channels to other VMs. This confines >> a certain set of security and stability risks to the driver VM. > > I think implementing Xen hypercalls in jailhouse for grant table and > event channels would actually make a lot of sense. The Xen > implementation is 2.5kLOC and I think it should be possible to compact > it noticeably, especially if you limit yourself to 64-bit guests. At least the grant table model seems unsuited for Jailhouse. It allows a guest to influence the mapping of another guest during runtime. This we want (or even have) to avoid in Jailhouse. I'm therefore more in favor of a model where the shared memory region is defined on cell (guest) creation by adding a virtual device that comes with such a region. Jan > > It should also be almost enough to run Xen PVH guests as jailhouse > partitions. > > If later Xen starts to support virtio, you will get that for free. > > Paolo [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 263 bytes --]
next prev parent reply other threads:[~2014-06-15 6:21 UTC|newest] Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-06-10 16:48 Using virtio for inter-VM communication Henning Schild 2014-06-10 16:48 ` [Qemu-devel] " Henning Schild 2014-06-10 22:15 ` Vincent JARDIN 2014-06-10 22:15 ` Vincent JARDIN 2014-06-10 22:15 ` [Qemu-devel] " Vincent JARDIN 2014-06-12 6:48 ` Markus Armbruster 2014-06-12 6:48 ` Markus Armbruster 2014-06-12 6:48 ` [Qemu-devel] " Markus Armbruster 2014-06-12 7:44 ` Henning Schild 2014-06-12 7:44 ` [Qemu-devel] " Henning Schild 2014-06-12 9:31 ` Vincent JARDIN 2014-06-12 9:31 ` Vincent JARDIN 2014-06-12 9:31 ` [Qemu-devel] " Vincent JARDIN 2014-06-12 12:55 ` Markus Armbruster 2014-06-12 14:40 ` Why I advise against using ivshmem (was: [Qemu-devel] Using virtio for inter-VM communication) Markus Armbruster 2014-06-12 14:40 ` Markus Armbruster 2014-06-12 14:40 ` [Qemu-devel] Why I advise against using ivshmem (was: " Markus Armbruster 2014-06-12 16:02 ` Why I advise against using ivshmem Vincent JARDIN 2014-06-12 16:02 ` [Qemu-devel] " Vincent JARDIN 2014-06-12 16:54 ` Paolo Bonzini 2014-06-12 16:54 ` [Qemu-devel] " Paolo Bonzini 2014-06-13 8:46 ` Markus Armbruster 2014-06-13 9:26 ` Vincent JARDIN 2014-06-13 9:31 ` Jobin Raju George 2014-06-13 9:31 ` Jobin Raju George 2014-06-13 9:31 ` Jobin Raju George 2014-06-13 9:48 ` Olivier MATZ 2014-06-13 9:48 ` Olivier MATZ 2014-06-13 9:48 ` Olivier MATZ 2014-06-13 10:09 ` Paolo Bonzini 2014-06-13 13:41 ` Vincent JARDIN 2014-06-13 13:41 ` Vincent JARDIN 2014-06-13 13:41 ` Vincent JARDIN 2014-06-13 14:10 ` Paolo Bonzini 2014-06-13 14:10 ` Paolo Bonzini 2014-06-14 18:01 ` Vincent JARDIN 2014-06-14 18:01 ` Vincent JARDIN 2014-06-17 2:54 ` Stefan Hajnoczi 2014-06-17 9:03 ` David Marchand 2014-06-17 9:03 ` David Marchand 2014-06-17 9:44 ` Paolo Bonzini 2014-06-18 10:48 ` Stefan Hajnoczi 2014-06-18 10:48 ` Stefan Hajnoczi 2014-06-18 14:57 ` David Marchand 2014-06-18 14:57 ` David Marchand 2014-06-18 14:57 ` David Marchand 2014-06-18 15:10 ` Paolo Bonzini 2014-06-21 9:34 ` Stefan Hajnoczi 2014-06-26 20:02 ` Cam Macdonell 2014-06-26 20:02 ` Cam Macdonell 2014-06-18 15:01 ` Andreas Färber 2014-06-18 15:01 ` Andreas Färber 2014-06-19 8:25 ` David Marchand 2014-06-19 8:25 ` David Marchand 2014-06-19 8:25 ` David Marchand 2014-06-18 15:01 ` Andreas Färber 2014-06-30 11:10 ` Markus Armbruster 2014-06-30 11:10 ` Markus Armbruster 2014-06-30 11:10 ` Markus Armbruster 2014-06-18 10:51 ` Stefan Hajnoczi 2014-06-18 10:51 ` Stefan Hajnoczi 2014-06-18 14:58 ` David Marchand 2014-06-18 14:58 ` David Marchand 2014-06-18 14:58 ` David Marchand 2014-06-18 14:22 ` Claudio Fontana 2014-06-17 9:03 ` David Marchand 2014-06-13 9:29 ` Jobin Raju George 2014-06-13 9:29 ` [Qemu-devel] " Jobin Raju George 2014-06-13 9:29 ` Jobin Raju George 2014-06-12 16:02 ` Vincent JARDIN 2014-06-12 2:27 ` Using virtio for inter-VM communication Rusty Russell 2014-06-12 2:27 ` Rusty Russell 2014-06-12 2:27 ` [Qemu-devel] " Rusty Russell 2014-06-12 5:32 ` Jan Kiszka 2014-06-12 5:32 ` [Qemu-devel] " Jan Kiszka 2014-06-13 0:47 ` Rusty Russell 2014-06-13 0:47 ` [Qemu-devel] " Rusty Russell 2014-06-13 6:23 ` Jan Kiszka 2014-06-13 6:23 ` [Qemu-devel] " Jan Kiszka 2014-06-13 8:45 ` Paolo Bonzini 2014-06-13 8:45 ` [Qemu-devel] " Paolo Bonzini 2014-06-15 6:20 ` Jan Kiszka 2014-06-15 6:20 ` Jan Kiszka [this message] 2014-06-15 6:20 ` [Qemu-devel] " Jan Kiszka 2014-06-17 5:24 ` Paolo Bonzini 2014-06-17 5:24 ` [Qemu-devel] " Paolo Bonzini 2014-06-17 5:57 ` Jan Kiszka 2014-06-17 5:57 ` Jan Kiszka 2014-06-17 5:57 ` [Qemu-devel] " Jan Kiszka 2014-06-17 5:24 ` Paolo Bonzini 2014-06-12 5:32 ` Jan Kiszka 2014-06-10 16:48 Henning Schild
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