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authorJames Morse <james.morse@arm.com>2022-03-15 18:24:14 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-03-19 13:40:15 +0100
commitfb65675f6620528b0b86f0355634c22aa49aa767 (patch)
tree45b42ba50cf95a63d132ef081a8385e9a0556abb /virt
parent9013fd4bc958b33c3b4d5a2eaf4ded9857600395 (diff)
KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated
commit a5905d6af492ee6a4a2205f0d550b3f931b03d03 upstream. KVM allows the guest to discover whether the ARCH_WORKAROUND SMCCC are implemented, and to preserve that state during migration through its firmware register interface. Add the necessary boiler plate for SMCCC_ARCH_WORKAROUND_3. Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> [ kvm code moved to virt/kvm/arm. ] Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/arm/psci.c34
1 files changed, 31 insertions, 3 deletions
diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c
index 48fde38d64c3..2f5dc7fb437b 100644
--- a/virt/kvm/arm/psci.c
+++ b/virt/kvm/arm/psci.c
@@ -426,6 +426,18 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
break;
}
break;
+ case ARM_SMCCC_ARCH_WORKAROUND_3:
+ switch (kvm_arm_get_spectre_bhb_state()) {
+ case SPECTRE_VULNERABLE:
+ break;
+ case SPECTRE_MITIGATED:
+ val = SMCCC_RET_SUCCESS;
+ break;
+ case SPECTRE_UNAFFECTED:
+ val = SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED;
+ break;
+ }
+ break;
}
break;
default:
@@ -438,7 +450,7 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu)
{
- return 3; /* PSCI version and two workaround registers */
+ return 4; /* PSCI version and three workaround registers */
}
int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
@@ -452,6 +464,9 @@ int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
if (put_user(KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2, uindices++))
return -EFAULT;
+ if (put_user(KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3, uindices++))
+ return -EFAULT;
+
return 0;
}
@@ -486,9 +501,20 @@ static int get_kernel_wa_level(u64 regid)
return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED;
case KVM_SSBD_UNKNOWN:
default:
- return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_UNKNOWN;
+ break;
}
- }
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_UNKNOWN;
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:
+ switch (kvm_arm_get_spectre_bhb_state()) {
+ case SPECTRE_VULNERABLE:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_AVAIL;
+ case SPECTRE_MITIGATED:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_AVAIL;
+ case SPECTRE_UNAFFECTED:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_REQUIRED;
+ }
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_AVAIL;
+ }
return -EINVAL;
}
@@ -503,6 +529,7 @@ int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
val = kvm_psci_version(vcpu, vcpu->kvm);
break;
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:
val = get_kernel_wa_level(reg->id) & KVM_REG_FEATURE_LEVEL_MASK;
break;
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
@@ -555,6 +582,7 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
}
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:
if (val & ~KVM_REG_FEATURE_LEVEL_MASK)
return -EINVAL;