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SubjectRe: [PATCH 0/3] KVM: support the cpu feature FLUSH_L1D
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Am 20/03/2023 um 17:52 schrieb Jim Mattson:
> On Wed, Feb 1, 2023 at 5:29 AM Emanuele Giuseppe Esposito
> <eesposit@redhat.com> wrote:
>>
>> As the title suggest, if the host cpu supports flush_l1d flag and
>> QEMU/userspace wants to boot a VM with the same flag (or emulate same
>> host features), KVM should be able to do so.
>>
>> Patch 3 is the main fix, because if flush_l1d is not advertised by
>> KVM, a linux VM will erroneously mark
>> /sys/devices/system/cpu/vulnerabilities/mmio_stale_data
>> as vulnerable, even though it isn't since the host has the feature
>> and takes care of this. Not sure what would happen in the nested case though.
>>
>> Patch 1 and 2 are just taken and refactored from Jim Mattison's serie that it
>> seems was lost a while ago:
>> https://patchwork.kernel.org/project/kvm/patch/20180814173049.21756-1-jmattson@google.com/
>>
>> I thought it was worth re-posting them.
>
> What has changed since the patches were originally posted, and Konrad
> dissed them?
>

From the upstream conversation, I honestly didn't really catch that
Konrad dissed them. Or at least, I didn't read a valid reason for doing
so, contrary to what Sean instead provided. I thought it was just forgotten.

My bad, next time I will be more careful when trying to resume old
patches :)

Thank you,
Emanuele

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