diff options
| author | Shanker Donthineni <shankerd@codeaurora.org> | 2018-01-05 23:28:59 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-02-16 22:22:54 +0300 |
| commit | 9b26a45c34e40575e53287365be7571b9cda21ab (patch) | |
| tree | 63085b5843ca9881b6cb627498da706a7f72a2e2 /arch/arm64/kvm | |
| parent | 48993dfa1af8c719576a18c0e2ca1d611297e34e (diff) | |
| download | linux-9b26a45c34e40575e53287365be7571b9cda21ab.tar.xz | |
arm64: Implement branch predictor hardening for Falkor
Commit ec82b567a74f upstream.
Falkor is susceptible to branch predictor aliasing and can
theoretically be attacked by malicious code. This patch
implements a mitigation for these attacks, preventing any
malicious entries from affecting other victim contexts.
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
[will: fix label name when !CONFIG_KVM and remove references to MIDR_FALKOR]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64/kvm')
| -rw-r--r-- | arch/arm64/kvm/hyp/entry.S | 12 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/switch.c | 8 |
2 files changed, 20 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S index 12ee62d6d410..9c45c6af1f58 100644 --- a/arch/arm64/kvm/hyp/entry.S +++ b/arch/arm64/kvm/hyp/entry.S @@ -196,3 +196,15 @@ alternative_endif eret ENDPROC(__fpsimd_guest_restore) + +ENTRY(__qcom_hyp_sanitize_btac_predictors) + /** + * Call SMC64 with Silicon provider serviceID 23<<8 (0xc2001700) + * 0xC2000000-0xC200FFFF: assigned to SiP Service Calls + * b15-b0: contains SiP functionID + */ + movz x0, #0x1700 + movk x0, #0xc200, lsl #16 + smc #0 + ret +ENDPROC(__qcom_hyp_sanitize_btac_predictors) diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 9b2a76d783eb..0d3d3f1e348c 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -364,6 +364,14 @@ again: /* 0 falls through to be handled out of EL2 */ } + if (cpus_have_const_cap(ARM64_HARDEN_BP_POST_GUEST_EXIT)) { + u32 midr = read_cpuid_id(); + + /* Apply BTAC predictors mitigation to all Falkor chips */ + if ((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR_V1) + __qcom_hyp_sanitize_btac_predictors(); + } + fp_enabled = __fpsimd_enabled(); __sysreg_save_guest_state(guest_ctxt); |