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Diffstat (limited to 'virt/kvm/arm/psci.c')
-rw-r--r--virt/kvm/arm/psci.c162
1 files changed, 134 insertions, 28 deletions
diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c
index 34d08ee63747..87927f7e1ee7 100644
--- a/virt/kvm/arm/psci.c
+++ b/virt/kvm/arm/psci.c
@@ -1,18 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/arm-smccc.h>
@@ -412,8 +401,16 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
feature = smccc_get_arg1(vcpu);
switch(feature) {
case ARM_SMCCC_ARCH_WORKAROUND_1:
- if (kvm_arm_harden_branch_predictor())
+ switch (kvm_arm_harden_branch_predictor()) {
+ case KVM_BP_HARDEN_UNKNOWN:
+ break;
+ case KVM_BP_HARDEN_WA_NEEDED:
val = SMCCC_RET_SUCCESS;
+ break;
+ case KVM_BP_HARDEN_NOT_REQUIRED:
+ val = SMCCC_RET_NOT_REQUIRED;
+ break;
+ }
break;
case ARM_SMCCC_ARCH_WORKAROUND_2:
switch (kvm_arm_have_ssbd()) {
@@ -441,42 +438,103 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu)
{
- return 1; /* PSCI version */
+ return 3; /* PSCI version and two workaround registers */
}
int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
{
- if (put_user(KVM_REG_ARM_PSCI_VERSION, uindices))
+ if (put_user(KVM_REG_ARM_PSCI_VERSION, uindices++))
+ return -EFAULT;
+
+ if (put_user(KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1, uindices++))
+ return -EFAULT;
+
+ if (put_user(KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2, uindices++))
return -EFAULT;
return 0;
}
+#define KVM_REG_FEATURE_LEVEL_WIDTH 4
+#define KVM_REG_FEATURE_LEVEL_MASK (BIT(KVM_REG_FEATURE_LEVEL_WIDTH) - 1)
+
+/*
+ * Convert the workaround level into an easy-to-compare number, where higher
+ * values mean better protection.
+ */
+static int get_kernel_wa_level(u64 regid)
+{
+ switch (regid) {
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
+ switch (kvm_arm_harden_branch_predictor()) {
+ case KVM_BP_HARDEN_UNKNOWN:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL;
+ case KVM_BP_HARDEN_WA_NEEDED:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_AVAIL;
+ case KVM_BP_HARDEN_NOT_REQUIRED:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_REQUIRED;
+ }
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL;
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
+ switch (kvm_arm_have_ssbd()) {
+ case KVM_SSBD_FORCE_DISABLE:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
+ case KVM_SSBD_KERNEL:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL;
+ case KVM_SSBD_FORCE_ENABLE:
+ case KVM_SSBD_MITIGATED:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED;
+ case KVM_SSBD_UNKNOWN:
+ default:
+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_UNKNOWN;
+ }
+ }
+
+ return -EINVAL;
+}
+
int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
- if (reg->id == KVM_REG_ARM_PSCI_VERSION) {
- void __user *uaddr = (void __user *)(long)reg->addr;
- u64 val;
+ void __user *uaddr = (void __user *)(long)reg->addr;
+ u64 val;
+ switch (reg->id) {
+ case KVM_REG_ARM_PSCI_VERSION:
val = kvm_psci_version(vcpu, vcpu->kvm);
- if (copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)))
- return -EFAULT;
+ break;
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
+ val = get_kernel_wa_level(reg->id) & KVM_REG_FEATURE_LEVEL_MASK;
+ break;
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
+ val = get_kernel_wa_level(reg->id) & KVM_REG_FEATURE_LEVEL_MASK;
- return 0;
+ if (val == KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL &&
+ kvm_arm_get_vcpu_workaround_2_flag(vcpu))
+ val |= KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED;
+ break;
+ default:
+ return -ENOENT;
}
- return -EINVAL;
+ if (copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)))
+ return -EFAULT;
+
+ return 0;
}
int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
- if (reg->id == KVM_REG_ARM_PSCI_VERSION) {
- void __user *uaddr = (void __user *)(long)reg->addr;
- bool wants_02;
- u64 val;
+ void __user *uaddr = (void __user *)(long)reg->addr;
+ u64 val;
+ int wa_level;
+
+ if (copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id)))
+ return -EFAULT;
- if (copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id)))
- return -EFAULT;
+ switch (reg->id) {
+ case KVM_REG_ARM_PSCI_VERSION:
+ {
+ bool wants_02;
wants_02 = test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features);
@@ -493,6 +551,54 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
vcpu->kvm->arch.psci_version = val;
return 0;
}
+ break;
+ }
+
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
+ if (val & ~KVM_REG_FEATURE_LEVEL_MASK)
+ return -EINVAL;
+
+ if (get_kernel_wa_level(reg->id) < val)
+ return -EINVAL;
+
+ return 0;
+
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
+ if (val & ~(KVM_REG_FEATURE_LEVEL_MASK |
+ KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED))
+ return -EINVAL;
+
+ wa_level = val & KVM_REG_FEATURE_LEVEL_MASK;
+
+ if (get_kernel_wa_level(reg->id) < wa_level)
+ return -EINVAL;
+
+ /* The enabled bit must not be set unless the level is AVAIL. */
+ if (wa_level != KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL &&
+ wa_level != val)
+ return -EINVAL;
+
+ /* Are we finished or do we need to check the enable bit ? */
+ if (kvm_arm_have_ssbd() != KVM_SSBD_KERNEL)
+ return 0;
+
+ /*
+ * If this kernel supports the workaround to be switched on
+ * or off, make sure it matches the requested setting.
+ */
+ switch (wa_level) {
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL:
+ kvm_arm_set_vcpu_workaround_2_flag(vcpu,
+ val & KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED);
+ break;
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED:
+ kvm_arm_set_vcpu_workaround_2_flag(vcpu, true);
+ break;
+ }
+
+ return 0;
+ default:
+ return -ENOENT;
}
return -EINVAL;
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-15 18:41:01 +0000