From: Eric Auger <eric.auger@linaro.org>
To: Pavel Fedin <p.fedin@samsung.com>,
'Andre Przywara' <andre.przywara@arm.com>,
'Marc Zyngier' <Marc.Zyngier@arm.com>,
christoffer.dall@linaro.org, kvmarm@lists.cs.columbia.edu
Cc: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org
Subject: Re: [PATCH v2 14/15] KVM: arm64: implement MSI injection in ITS emulation
Date: Mon, 03 Aug 2015 11:07:29 +0200 [thread overview]
Message-ID: <55BF2F51.6020701@linaro.org> (raw)
In-Reply-To: <00a201d0cdb7$70a623f0$51f26bd0$@samsung.com>
Hi Andre, Pavel,
On 08/03/2015 08:41 AM, Pavel Fedin wrote:
> Hi!
>
>> When I reworked our code to only use a flag and not a separate routing
>> type I ended up with the flag only guarding assignments, which wouldn't
>> hurt if done unconditionally (since they are all u32's). So the whole
>> usage of the flag is somewhat in jeopardy now.
>> Either the eventual MSI consumer requires a DevID (ITS emulation, which
>> will not work without it) or the consumer does not care at all and can
>> totally ignore it (GICv2m). So I think we can always pass on the DevID
>
> I have just checked my current code, and you know what... You are right. We already have a per-VM
> capability which actually tells us that MSIs for this VM require devID. Therefore, we really don't
> need this flag at all, neither for MSI doorbell, nor for GSI routing.
> All we need is 'devid' field, which indeed can be just ignored for GICv2(m), just for simplicity.
> Ignoring would happen automatically, because IIRC older kernels do not explicitly check 'pad' for
> being zero, do they? And indeed in this case the userland can supply devid unconditionally, making
> things even simpler.
Again the case that leaves me uncomfortable is the one where the
userspace does not provide the devid whereas it must (GICv3 ITS case).
We cannot be confident in userspace to behave correctly. In such a case
devid == 0 and we cannot discriminate this from a valid devid. Do I miss
something?
Best Regards
Eric
>
> Kind regards,
> Pavel Fedin
> Expert Engineer
> Samsung Electronics Research center Russia
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
WARNING: multiple messages have this Message-ID (diff)
From: eric.auger@linaro.org (Eric Auger)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 14/15] KVM: arm64: implement MSI injection in ITS emulation
Date: Mon, 03 Aug 2015 11:07:29 +0200 [thread overview]
Message-ID: <55BF2F51.6020701@linaro.org> (raw)
In-Reply-To: <00a201d0cdb7$70a623f0$51f26bd0$@samsung.com>
Hi Andre, Pavel,
On 08/03/2015 08:41 AM, Pavel Fedin wrote:
> Hi!
>
>> When I reworked our code to only use a flag and not a separate routing
>> type I ended up with the flag only guarding assignments, which wouldn't
>> hurt if done unconditionally (since they are all u32's). So the whole
>> usage of the flag is somewhat in jeopardy now.
>> Either the eventual MSI consumer requires a DevID (ITS emulation, which
>> will not work without it) or the consumer does not care at all and can
>> totally ignore it (GICv2m). So I think we can always pass on the DevID
>
> I have just checked my current code, and you know what... You are right. We already have a per-VM
> capability which actually tells us that MSIs for this VM require devID. Therefore, we really don't
> need this flag at all, neither for MSI doorbell, nor for GSI routing.
> All we need is 'devid' field, which indeed can be just ignored for GICv2(m), just for simplicity.
> Ignoring would happen automatically, because IIRC older kernels do not explicitly check 'pad' for
> being zero, do they? And indeed in this case the userland can supply devid unconditionally, making
> things even simpler.
Again the case that leaves me uncomfortable is the one where the
userspace does not provide the devid whereas it must (GICv3 ITS case).
We cannot be confident in userspace to behave correctly. In such a case
devid == 0 and we cannot discriminate this from a valid devid. Do I miss
something?
Best Regards
Eric
>
> Kind regards,
> Pavel Fedin
> Expert Engineer
> Samsung Electronics Research center Russia
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
next prev parent reply other threads:[~2015-08-03 9:08 UTC|newest]
Thread overview: 138+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-10 14:21 [PATCH v2 00/15] KVM: arm64: GICv3 ITS emulation Andre Przywara
2015-07-10 14:21 ` Andre Przywara
2015-07-10 14:21 ` [PATCH v2 01/15] KVM: arm/arm64: VGIC: don't track used LRs in the distributor Andre Przywara
2015-07-10 14:21 ` Andre Przywara
2015-08-12 9:01 ` Eric Auger
2015-08-12 9:01 ` Eric Auger
2015-08-24 16:33 ` Andre Przywara
2015-08-24 16:33 ` Andre Przywara
2015-08-31 8:42 ` Eric Auger
2015-08-31 8:42 ` Eric Auger
2015-09-02 9:00 ` Andre Przywara
2015-09-02 9:00 ` Andre Przywara
2015-10-02 9:55 ` Pavel Fedin
2015-10-02 9:55 ` Pavel Fedin
2015-10-02 10:32 ` Andre Przywara
2015-10-02 10:32 ` Andre Przywara
2015-10-02 10:39 ` Pavel Fedin
2015-10-02 10:39 ` Pavel Fedin
2015-10-02 12:39 ` Pavel Fedin
2015-10-02 12:39 ` Pavel Fedin
2015-10-02 12:49 ` Andre Przywara
2015-10-02 12:49 ` Andre Przywara
2015-07-10 14:21 ` [PATCH v2 02/15] KVM: extend struct kvm_msi to hold a 32-bit device ID Andre Przywara
2015-07-10 14:21 ` Andre Przywara
2015-07-10 14:21 ` [PATCH v2 03/15] KVM: arm/arm64: add emulation model specific destroy function Andre Przywara
2015-07-10 14:21 ` Andre Przywara
2015-07-10 14:21 ` [PATCH v2 04/15] KVM: arm/arm64: extend arch CAP checks to allow per-VM capabilities Andre Przywara
2015-07-10 14:21 ` Andre Przywara
2015-08-12 12:26 ` Eric Auger
2015-08-12 12:26 ` Eric Auger
2015-07-10 14:21 ` [PATCH v2 05/15] KVM: arm/arm64: make GIC frame address initialization model specific Andre Przywara
2015-07-10 14:21 ` Andre Przywara
2015-08-12 13:02 ` Eric Auger
2015-08-12 13:02 ` Eric Auger
2015-08-24 17:24 ` Andre Przywara
2015-08-24 17:24 ` Andre Przywara
2015-08-31 9:31 ` Eric Auger
2015-08-31 9:31 ` Eric Auger
2015-07-10 14:21 ` [PATCH v2 06/15] KVM: arm64: Introduce new MMIO region for the ITS base address Andre Przywara
2015-07-10 14:21 ` Andre Przywara
2015-08-13 12:17 ` Eric Auger
2015-08-13 12:17 ` Eric Auger
2015-07-10 14:21 ` [PATCH v2 07/15] KVM: arm64: handle ITS related GICv3 redistributor registers Andre Przywara
2015-07-10 14:21 ` Andre Przywara
2015-08-13 12:17 ` Eric Auger
2015-08-13 12:17 ` Eric Auger
2015-08-24 18:08 ` Andre Przywara
2015-08-24 18:08 ` Andre Przywara
2015-07-10 14:21 ` [PATCH v2 08/15] KVM: arm64: introduce ITS emulation file with stub functions Andre Przywara
2015-07-10 14:21 ` Andre Przywara
2015-08-13 12:48 ` Eric Auger
2015-08-13 12:48 ` Eric Auger
2015-08-25 9:39 ` Andre Przywara
2015-08-25 9:39 ` Andre Przywara
2015-07-10 14:21 ` [PATCH v2 09/15] KVM: arm64: implement basic ITS register handlers Andre Przywara
2015-07-10 14:21 ` Andre Przywara
2015-08-13 15:25 ` Eric Auger
2015-08-13 15:25 ` Eric Auger
2015-08-25 10:23 ` Andre Przywara
2015-08-25 10:23 ` Andre Przywara
2015-10-02 7:51 ` Pavel Fedin
2015-10-02 7:51 ` Pavel Fedin
2015-07-10 14:21 ` [PATCH v2 10/15] KVM: arm64: add data structures to model ITS interrupt translation Andre Przywara
2015-07-10 14:21 ` Andre Przywara
2015-08-13 15:46 ` Eric Auger
2015-08-13 15:46 ` Eric Auger
2015-08-25 11:15 ` Andre Przywara
2015-08-25 11:15 ` Andre Przywara
2015-08-27 14:16 ` Eric Auger
2015-08-27 14:16 ` Eric Auger
2015-07-10 14:21 ` [PATCH v2 11/15] KVM: arm64: handle pending bit for LPIs in ITS emulation Andre Przywara
2015-07-10 14:21 ` Andre Przywara
2015-08-14 11:58 ` Eric Auger
2015-08-14 11:58 ` Eric Auger
2015-08-25 14:34 ` Andre Przywara
2015-08-25 14:34 ` Andre Przywara
2015-08-31 9:45 ` Eric Auger
2015-08-31 9:45 ` Eric Auger
2015-10-07 8:39 ` Pavel Fedin
2015-10-07 8:39 ` Pavel Fedin
2015-10-07 19:53 ` Christoffer Dall
2015-10-07 19:53 ` Christoffer Dall
2015-07-10 14:21 ` [PATCH v2 12/15] KVM: arm64: sync LPI configuration and pending tables Andre Przywara
2015-07-10 14:21 ` Andre Przywara
2015-08-14 11:58 ` Eric Auger
2015-08-14 11:58 ` Eric Auger
2015-08-14 12:35 ` Eric Auger
2015-08-14 12:35 ` Eric Auger
2015-08-25 15:47 ` Andre Przywara
2015-08-25 15:47 ` Andre Przywara
2015-08-31 9:51 ` Eric Auger
2015-08-31 9:51 ` Eric Auger
2015-08-25 15:27 ` Andre Przywara
2015-08-25 15:27 ` Andre Przywara
2015-08-31 9:47 ` Eric Auger
2015-08-31 9:47 ` Eric Auger
2015-07-10 14:21 ` [PATCH v2 13/15] KVM: arm64: implement ITS command queue command handlers Andre Przywara
2015-07-10 14:21 ` Andre Przywara
2015-08-17 13:33 ` Eric Auger
2015-08-17 13:33 ` Eric Auger
2015-10-07 14:54 ` Andre Przywara
2015-10-07 14:54 ` Andre Przywara
2015-07-10 14:21 ` [PATCH v2 14/15] KVM: arm64: implement MSI injection in ITS emulation Andre Przywara
2015-07-10 14:21 ` Andre Przywara
2015-07-31 13:22 ` Eric Auger
2015-07-31 13:22 ` Eric Auger
2015-08-02 20:20 ` Andre Przywara
2015-08-02 20:20 ` Andre Przywara
2015-08-03 6:41 ` Pavel Fedin
2015-08-03 6:41 ` Pavel Fedin
2015-08-03 9:07 ` Eric Auger [this message]
2015-08-03 9:07 ` Eric Auger
2015-08-03 9:16 ` Pavel Fedin
2015-08-03 9:16 ` Pavel Fedin
2015-08-03 15:37 ` Eric Auger
2015-08-03 15:37 ` Eric Auger
2015-08-03 17:06 ` Marc Zyngier
2015-08-03 17:06 ` Marc Zyngier
2015-08-04 6:53 ` Pavel Fedin
2015-08-04 6:53 ` Pavel Fedin
2015-08-24 14:14 ` Andre Przywara
2015-08-24 14:14 ` Andre Przywara
2015-08-17 13:44 ` Eric Auger
2015-08-17 13:44 ` Eric Auger
2015-07-10 14:21 ` [PATCH v2 15/15] KVM: arm64: enable ITS emulation as a virtual MSI controller Andre Przywara
2015-07-10 14:21 ` Andre Przywara
2015-07-15 9:10 ` Pavel Fedin
2015-07-15 9:10 ` Pavel Fedin
2015-07-15 9:52 ` Andre Przywara
2015-07-15 9:52 ` Andre Przywara
2015-07-15 10:01 ` Pavel Fedin
2015-07-15 10:01 ` Pavel Fedin
2015-07-15 12:02 ` [PATCH v2 00/15] KVM: arm64: GICv3 ITS emulation Pavel Fedin
2015-07-15 12:02 ` Pavel Fedin
2015-09-24 11:18 ` Pavel Fedin
2015-09-24 11:18 ` Pavel Fedin
2015-09-24 11:35 ` Andre Przywara
2015-09-24 11:35 ` Andre Przywara
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