Fall back to GICv2 if GICv3 is not supported #421
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In the past, we had support for both requesting KVM the instantiation of a GICv3 or a GICv2. We lost this ability with the interrupt controller refactoring, supporting only GICv2. Turns out the SoC on some aarch64 boards (namely, the Raspberry Pi family) doesn't implement an architected vGIC, which is required by the GICv3 implementation in the KVM. As RPi boards are very popular, and the maintenance cost for this device is very small, let's reimplement support for requesting KVM the instantiation of a GICv2. Signed-off-by: Sergio Lopez <[email protected]>
The SoC in some popular boards (namely, the RPi family) doesn't support an architected vGIC, which is required for requesting KVM the instantiation of a GICv3. To relieve the users from having to configure the gic version manually, try first to instantiate a GICv3, and fall back to a GICv2 if it fails. Signed-off-by: Sergio Lopez <[email protected]>
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MatiasVara,
jakecorrenti,
mtjhrc and
tylerfanelli
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mtjhrc
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Oct 1, 2025
mtjhrc
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I'm not able to test this, but code LGTM
jakecorrenti
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Code LGTM. None of my Pis are available either (running various servers), so I can't test it.
Food for thought: I wonder if down the line we should consider making some of this code more generic? It seems to be fairly similar to the GicV3 implementation; maybe we could abstract some of it away.
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The SoC in some popular boards (namely, the RPi family) doesn't support an architected vGIC, which is required for requesting KVM the instantiation of a GICv3. To relieve the users from having to configure the gic version manually, try first to instantiate a GICv3, and fall back to a GICv2 if it fails.
Fixes: #420