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Re: [Qemu-devel] [PATCH 4/5] target/arm: Fill in ARMISARegisters for kvm
From: |
Marc Zyngier |
Subject: |
Re: [Qemu-devel] [PATCH 4/5] target/arm: Fill in ARMISARegisters for kvm32 |
Date: |
Mon, 29 Oct 2018 15:56:58 +0000 |
User-agent: |
Mozilla/5.0 (X11; Linux aarch64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 |
On 29/10/18 15:48, Peter Maydell wrote:
> On 29 October 2018 at 15:40, Marc Zyngier <address@hidden> wrote:
>> My temptation would be not to expose it at all when running on a v7
>> core, and return an error rather than zero.
>>
>> The other issue is that we currently don't support running 32bit KVM on
>> any ARMv8 platform, as we strictly check the CPUs we want to run on (A7
>> and A15). I remember seeing patches that would allow any host core to be
>> used (similar to what we have on the 64bit side), but that never made it
>> in the tree.
>
> Ah, that's convenient in some ways. It means we can define the
> API to be "for v7, no register available via the ONE_REG API;
> for v8, always present", provided we add the constant and the
> support before we turn on any actual v8 CPUs for 32-bit KVM
> (avoiding the awkward case of "v8 but kernel doesn't expose
> MVFR2").
>
> I don't think we particularly care about the 32-bit-kvm-on-v8
> part, but it would be good to nail down this wrinkle so we don't
> forget about it, maybe ?
Absolutely. I'll write something up.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
[Qemu-devel] [PATCH 2/5] target/arm: Fill in ARMISARegisters for kvm64, Richard Henderson, 2018/10/24
[Qemu-devel] [PATCH 3/5] target/arm: Introduce read_sys_reg32 for kvm32, Richard Henderson, 2018/10/24
[Qemu-devel] [PATCH 5/5] target/arm: Convert t32ee from feature bit to isar3 test, Richard Henderson, 2018/10/24
[Qemu-devel] [PATCH 1/5] target/arm: Install ARMISARegisters from kvm host, Richard Henderson, 2018/10/24