From: p.fedin@samsung.com (Pavel Fedin)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 00/13] arm64: KVM: GICv3 ITS emulation
Date: Mon, 08 Jun 2015 09:53:30 +0300 [thread overview]
Message-ID: <01ad01d0a1b7$d4d4fe40$7e7efac0$@samsung.com> (raw)
In-Reply-To: <1432893209-27313-1-git-send-email-andre.przywara@arm.com>
Hello everybody!
> The GICv3 ITS (Interrupt Translation Service) is a part of the
> ARM GICv3 interrupt controller used for implementing MSIs.
> It specifies a new kind of interrupts (LPIs), which are mapped to
> establish a connection between a device, its MSI payload value and
> the target processor the IRQ is eventually delivered to.
> In order to allow using MSIs in an ARM64 KVM guest, we emulate this
> ITS widget in the kernel.
I have tested the patch and got some more ideas for future extension...
First of all, it would be nice to have a possibility to directly inject LPIs by number.
This will be useful for irqfd support in qemu.
Next, irqfd support currently poses a problem. We need to somehow know IRQ number from
MSI-X data (device ID plus event ID). ITS has all this information, so it would be nice to
be able to query for the translation from within userspace. The question is - how to do
it? Should we add some ioctl for this purpose? Currently i am experimenting with extra
KVM_TRANSLATE_MSI ioctl which, given MSI data, would return LPI number.
Actually before your patch came out i have almost done the same thing. But instead i
decided to implement ITS in qemu while leaving LPI handling to kernel. In this case my
qemu would have everything needed.
By the way, why did you decide to put everything into kernel? Yes, in-kernel emulation is
faster, but ITS is not accessed frequently.
Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia
WARNING: multiple messages have this Message-ID (diff)
From: Pavel Fedin <p.fedin@samsung.com>
To: 'Andre Przywara' <andre.przywara@arm.com>,
christoffer.dall@linaro.org, marc.zyngier@arm.com
Cc: kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org
Subject: RE: [PATCH 00/13] arm64: KVM: GICv3 ITS emulation
Date: Mon, 08 Jun 2015 09:53:30 +0300 [thread overview]
Message-ID: <01ad01d0a1b7$d4d4fe40$7e7efac0$@samsung.com> (raw)
In-Reply-To: <1432893209-27313-1-git-send-email-andre.przywara@arm.com>
Hello everybody!
> The GICv3 ITS (Interrupt Translation Service) is a part of the
> ARM GICv3 interrupt controller used for implementing MSIs.
> It specifies a new kind of interrupts (LPIs), which are mapped to
> establish a connection between a device, its MSI payload value and
> the target processor the IRQ is eventually delivered to.
> In order to allow using MSIs in an ARM64 KVM guest, we emulate this
> ITS widget in the kernel.
I have tested the patch and got some more ideas for future extension...
First of all, it would be nice to have a possibility to directly inject LPIs by number.
This will be useful for irqfd support in qemu.
Next, irqfd support currently poses a problem. We need to somehow know IRQ number from
MSI-X data (device ID plus event ID). ITS has all this information, so it would be nice to
be able to query for the translation from within userspace. The question is - how to do
it? Should we add some ioctl for this purpose? Currently i am experimenting with extra
KVM_TRANSLATE_MSI ioctl which, given MSI data, would return LPI number.
Actually before your patch came out i have almost done the same thing. But instead i
decided to implement ITS in qemu while leaving LPI handling to kernel. In this case my
qemu would have everything needed.
By the way, why did you decide to put everything into kernel? Yes, in-kernel emulation is
faster, but ITS is not accessed frequently.
Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia
next prev parent reply other threads:[~2015-06-08 6:53 UTC|newest]
Thread overview: 104+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-29 9:53 [PATCH 00/13] arm64: KVM: GICv3 ITS emulation Andre Przywara
2015-05-29 9:53 ` Andre Przywara
2015-05-29 9:53 ` [PATCH 01/13] KVM: arm/arm64: VGIC: don't track used LRs in the distributor Andre Przywara
2015-05-29 9:53 ` Andre Przywara
2015-06-12 17:23 ` Eric Auger
2015-05-29 9:53 ` [PATCH 02/13] KVM: extend struct kvm_msi to hold a 32-bit device ID Andre Przywara
2015-05-29 9:53 ` Andre Przywara
2015-06-09 8:49 ` Eric Auger
2015-06-09 8:49 ` Eric Auger
2015-06-28 19:12 ` Christoffer Dall
2015-06-28 19:12 ` Christoffer Dall
2015-06-29 14:53 ` Andre Przywara
2015-06-29 14:53 ` Andre Przywara
2015-06-29 15:02 ` Christoffer Dall
2015-06-29 15:02 ` Christoffer Dall
2015-05-29 9:53 ` [PATCH 03/13] KVM: arm/arm64: add emulation model specific destroy function Andre Przywara
2015-05-29 9:53 ` Andre Przywara
2015-06-09 8:51 ` Eric Auger
2015-06-09 8:51 ` Eric Auger
2015-06-28 19:14 ` Christoffer Dall
2015-06-28 19:14 ` Christoffer Dall
2015-05-29 9:53 ` [PATCH 04/13] KVM: arm64: Introduce new MMIO region for the ITS base address Andre Przywara
2015-05-29 9:53 ` Andre Przywara
2015-06-09 8:52 ` Eric Auger
2015-06-09 8:52 ` Eric Auger
2015-06-11 15:12 ` Andre Przywara
2015-06-11 15:12 ` Andre Przywara
2015-05-29 9:53 ` [PATCH 05/13] KVM: arm64: handle ITS related GICv3 redistributor registers Andre Przywara
2015-05-29 9:53 ` Andre Przywara
2015-06-09 8:52 ` Eric Auger
2015-06-09 8:52 ` Eric Auger
2015-06-12 17:03 ` Andre Przywara
2015-06-12 17:03 ` Andre Przywara
2015-05-29 9:53 ` [PATCH 06/13] KVM: arm64: introduce ITS emulation file with stub functions Andre Przywara
2015-05-29 9:53 ` Andre Przywara
2015-06-09 9:23 ` Eric Auger
2015-06-09 9:23 ` Eric Auger
2015-05-29 9:53 ` [PATCH 07/13] KVM: arm64: implement basic ITS register handlers Andre Przywara
2015-05-29 9:53 ` Andre Przywara
2015-06-09 13:34 ` Eric Auger
2015-06-09 13:34 ` Eric Auger
2015-06-28 19:36 ` Christoffer Dall
2015-06-28 19:36 ` Christoffer Dall
2015-05-29 9:53 ` [PATCH 08/13] KVM: arm64: add data structures to model ITS interrupt translation Andre Przywara
2015-05-29 9:53 ` Andre Przywara
2015-06-09 15:59 ` Eric Auger
2015-06-09 15:59 ` Eric Auger
2015-05-29 9:53 ` [PATCH 09/13] KVM: arm64: handle pending bit for LPIs in ITS emulation Andre Przywara
2015-05-29 9:53 ` Andre Przywara
2015-06-09 15:59 ` Eric Auger
2015-06-09 15:59 ` Eric Auger
2015-06-11 15:46 ` Andre Przywara
2015-06-11 15:46 ` Andre Przywara
2015-06-11 16:01 ` Marc Zyngier
2015-06-11 16:01 ` Marc Zyngier
2015-06-11 18:24 ` Eric Auger
2015-06-11 18:24 ` Eric Auger
2015-05-29 9:53 ` [PATCH 10/13] KVM: arm64: sync LPI properties and status between guest and KVM Andre Przywara
2015-05-29 9:53 ` Andre Przywara
2015-06-11 17:44 ` Eric Auger
2015-06-11 17:44 ` Eric Auger
2015-06-28 19:33 ` Christoffer Dall
2015-06-28 19:33 ` Christoffer Dall
2015-05-29 9:53 ` [PATCH 11/13] KVM: arm64: implement ITS command queue command handlers Andre Przywara
2015-05-29 9:53 ` Andre Przywara
2015-06-12 15:28 ` Eric Auger
2015-06-12 15:28 ` Eric Auger
2015-06-28 19:41 ` Christoffer Dall
2015-06-28 19:41 ` Christoffer Dall
2015-07-03 15:57 ` Andre Przywara
2015-07-03 15:57 ` Andre Przywara
2015-07-03 21:01 ` Christoffer Dall
2015-07-03 21:01 ` Christoffer Dall
2015-05-29 9:53 ` [PATCH 12/13] KVM: arm64: implement MSI injection in ITS emulation Andre Przywara
2015-05-29 9:53 ` Andre Przywara
2015-06-11 17:43 ` Eric Auger
2015-06-11 17:43 ` Eric Auger
2015-07-06 16:46 ` Andre Przywara
2015-07-06 16:46 ` Andre Przywara
2015-07-07 8:13 ` Christoffer Dall
2015-07-07 8:13 ` Christoffer Dall
2015-05-29 9:53 ` [PATCH 13/13] KVM: arm64: enable ITS emulation as a virtual MSI controller Andre Przywara
2015-05-29 9:53 ` Andre Przywara
2015-06-12 16:05 ` Eric Auger
2015-06-12 16:05 ` Eric Auger
2015-06-18 8:43 ` Eric Auger
2015-06-18 8:43 ` Eric Auger
2015-06-18 14:22 ` Andre Przywara
2015-06-18 14:22 ` Andre Przywara
2015-06-18 15:03 ` Pavel Fedin
2015-06-18 15:03 ` Pavel Fedin
2015-06-18 19:20 ` Andre Przywara
2015-06-18 19:20 ` Andre Przywara
2015-06-08 6:53 ` Pavel Fedin [this message]
2015-06-08 6:53 ` [PATCH 00/13] arm64: KVM: GICv3 ITS emulation Pavel Fedin
2015-06-08 8:23 ` Marc Zyngier
2015-06-08 8:23 ` Marc Zyngier
2015-06-08 10:54 ` Pavel Fedin
2015-06-08 10:54 ` Pavel Fedin
2015-06-08 17:13 ` Marc Zyngier
2015-06-08 17:13 ` Marc Zyngier
2015-06-09 8:12 ` Eric Auger
2015-06-09 8:12 ` Eric Auger
2015-06-10 12:18 ` Pavel Fedin
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