diff options
| author | Mark Rutland <mark.rutland@arm.com> | 2018-04-12 12:11:31 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-04-20 08:21:05 +0200 |
| commit | c9ae3d5717bf14c05299f184c4bfee79e9a22efe (patch) | |
| tree | 56e038254767f70d46c1bed63961d0c41aaf3519 /arch/arm/kvm | |
| parent | 142cfd60faba9cfa34adc1a3cf7e184a8066c12f (diff) | |
arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support
From: Marc Zyngier <marc.zyngier@arm.com>
commit 6167ec5c9145cdf493722dfd80a5d48bafc4a18a upstream.
A new feature of SMCCC 1.1 is that it offers firmware-based CPU
workarounds. In particular, SMCCC_ARCH_WORKAROUND_1 provides
BP hardening for CVE-2017-5715.
If the host has some mitigation for this issue, report that
we deal with it using SMCCC_ARCH_WORKAROUND_1, as we apply the
host workaround on every guest exit.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[v4.9: account for files moved to virt/ upstream]
Signed-off-by: Mark Rutland <mark.rutland@arm.com> [v4.9 backport]
Tested-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm/kvm')
| -rw-r--r-- | arch/arm/kvm/psci.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 1120ad0bd3d2..3d962257c166 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -403,13 +403,20 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) { u32 func_id = smccc_get_function(vcpu); u32 val = PSCI_RET_NOT_SUPPORTED; + u32 feature; switch (func_id) { case ARM_SMCCC_VERSION_FUNC_ID: val = ARM_SMCCC_VERSION_1_1; break; case ARM_SMCCC_ARCH_FEATURES_FUNC_ID: - /* Nothing supported yet */ + feature = smccc_get_arg1(vcpu); + switch(feature) { + case ARM_SMCCC_ARCH_WORKAROUND_1: + if (kvm_arm_harden_branch_predictor()) + val = 0; + break; + } break; default: return kvm_psci_call(vcpu); |