diff options
| author | James Morse <james.morse@arm.com> | 2022-03-15 18:24:15 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-03-19 13:40:15 +0100 |
| commit | 970a21404ebc854271055548a949731e65f959b2 (patch) | |
| tree | 1e394d9e010b8385facc946dfa61d5742f8c9b73 /arch/arm64/kvm | |
| parent | fb65675f6620528b0b86f0355634c22aa49aa767 (diff) | |
arm64: Use the clearbhb instruction in mitigations
commit 228a26b912287934789023b4132ba76065d9491c upstream.
Future CPUs may implement a clearbhb instruction that is sufficient
to mitigate SpectreBHB. CPUs that implement this instruction, but
not CSV2.3 must be affected by Spectre-BHB.
Add support to use this instruction as the BHB mitigation on CPUs
that support it. The instruction is in the hint space, so it will
be treated by a NOP as older CPUs.
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
[ modified for stable: Use a KVM vector template instead of alternatives,
removed bitmap of mitigations ]
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/arm64/kvm')
| -rw-r--r-- | arch/arm64/kvm/hyp/hyp-entry.S | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S index b59b66f1f905..99b8ecaae810 100644 --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S @@ -405,4 +405,10 @@ ENTRY(__spectre_bhb_loop_k32_start) ldp x0, x1, [sp, #(8 * 0)] add sp, sp, #(8 * 2) ENTRY(__spectre_bhb_loop_k32_end) + +ENTRY(__spectre_bhb_clearbhb_start) + esb + clearbhb + isb +ENTRY(__spectre_bhb_clearbhb_end) #endif |