UPSTREAM: 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.
Bug: 215557547
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I9e0964b54727930bbda4f089c91075447b046c91
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index fa2b411..0c93ab4 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -281,6 +281,11 @@
#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED 3
#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED (1U << 4)
+#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3 KVM_REG_ARM_FW_REG(3)
+#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_AVAIL 0
+#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_AVAIL 1
+#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_REQUIRED 2
+
/* SVE registers */
#define KVM_REG_ARM64_SVE (0x15 << KVM_REG_ARM_COPROC_SHIFT)
diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c
index a8fd2b1..e7c7139 100644
--- a/arch/arm64/kvm/hypercalls.c
+++ b/arch/arm64/kvm/hypercalls.c
@@ -125,6 +125,18 @@
break;
}
break;
+ case ARM_SMCCC_ARCH_WORKAROUND_3:
+ switch (arm64_get_spectre_bhb_state()) {
+ case SPECTRE_VULNERABLE:
+ break;
+ case SPECTRE_MITIGATED:
+ val[0] = SMCCC_RET_SUCCESS;
+ break;
+ case SPECTRE_UNAFFECTED:
+ val[0] = SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED;
+ break;
+ }
+ break;
case ARM_SMCCC_HV_PV_TIME_FEATURES:
val[0] = SMCCC_RET_SUCCESS;
break;
diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
index 09c1385..371ebbc 100644
--- a/arch/arm64/kvm/psci.c
+++ b/arch/arm64/kvm/psci.c
@@ -415,7 +415,7 @@
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)
@@ -429,6 +429,9 @@
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;
}
@@ -468,6 +471,17 @@
case SPECTRE_VULNERABLE:
return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
}
+ break;
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:
+ switch (arm64_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;
@@ -484,6 +498,7 @@
break;
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:
val = get_kernel_wa_level(reg->id) & KVM_REG_FEATURE_LEVEL_MASK;
break;
default:
@@ -530,6 +545,7 @@
}
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;
