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author | James Morse <james.morse@arm.com> | 2022-11-30 21:29:07 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-12-08 13:18:34 +0300 |
commit | 51febca41ae0333c29b4b12778f045a705d89370 (patch) | |
tree | a8d290589abdff7aca86bd2480c98d3c8d787081 /include | |
parent | 70133fb6e3cebb7c7b295d848f3ab76ee22ab4dd (diff) | |
download | linux-51febca41ae0333c29b4b12778f045a705d89370.tar.xz |
arm64: errata: Fix KVM Spectre-v2 mitigation selection for Cortex-A57/A72
Both the Spectre-v2 and Spectre-BHB mitigations involve running a sequence
immediately after exiting a guest, before any branches. In the stable
kernels these sequences are built by copying templates into an empty vector
slot.
For Spectre-BHB, Cortex-A57 and A72 require the branchy loop with k=8.
If Spectre-v2 needs mitigating at the same time, a firmware call to EL3 is
needed. The work EL3 does at this point is also enough to mitigate
Spectre-BHB.
When enabling the Spectre-BHB mitigation, spectre_bhb_enable_mitigation()
should check if a slot has already been allocated for Spectre-v2, meaning
no work is needed for Spectre-BHB.
This check was missed in the earlier backport, add it.
Fixes: c20d55174479 ("arm64: Mitigate spectre style branch history side channels")
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
0 files changed, 0 insertions, 0 deletions