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authorMarc Zyngier <marc.zyngier@arm.com>2018-02-06 20:56:14 +0300
committerCatalin Marinas <catalin.marinas@arm.com>2018-02-07 01:54:05 +0300
commit6167ec5c9145cdf493722dfd80a5d48bafc4a18a (patch)
treecdabac4f0a97488800cf46264d53b3cbbefbd65c /virt
parenta4097b351118e821841941a79ec77d3ce3f1c5d9 (diff)
downloadlinux-6167ec5c9145cdf493722dfd80a5d48bafc4a18a.tar.xz
arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support
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>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/arm/psci.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c
index e105c1153794..6919352cbf15 100644
--- a/virt/kvm/arm/psci.c
+++ b/virt/kvm/arm/psci.c
@@ -405,13 +405,20 @@ 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);