This is a runtime capabality for KVM tool to enable Arm64 8.3 Pointer
Authentication in guest kernel. Two vcpu features
KVM_ARM_VCPU_PTRAUTH_[ADDRESS/GENERIC] are supplied together to enable
Pointer Authentication in KVM guest after checking the capability.
A command line option --ptrauth is also required to select this feature.
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@xxxxxxx>
---
Changes since v7:
* Added check for capability KVM_CAP_ARM_PTRAUTH_GENERIC
arm/aarch32/include/kvm/kvm-cpu-arch.h | 1 +
arm/aarch64/include/asm/kvm.h | 2 ++
arm/aarch64/include/kvm/kvm-config-arch.h | 4 +++-
arm/aarch64/include/kvm/kvm-cpu-arch.h | 2 ++
arm/include/arm-common/kvm-config-arch.h | 1 +
arm/kvm-cpu.c | 7 +++++++
include/linux/kvm.h | 2 ++
7 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/arm/aarch32/include/kvm/kvm-cpu-arch.h b/arm/aarch32/include/kvm/kvm-cpu-arch.h
index d28ea67..520ea76 100644
--- a/arm/aarch32/include/kvm/kvm-cpu-arch.h
+++ b/arm/aarch32/include/kvm/kvm-cpu-arch.h
@@ -13,4 +13,5 @@
#define ARM_CPU_ID 0, 0, 0
#define ARM_CPU_ID_MPIDR 5
+#define ARM_VCPU_PTRAUTH_FEATURE 0
#endif /* KVM__KVM_CPU_ARCH_H */
diff --git a/arm/aarch64/include/asm/kvm.h b/arm/aarch64/include/asm/kvm.h
index 97c3478..d4d0d8c 100644
--- a/arm/aarch64/include/asm/kvm.h
+++ b/arm/aarch64/include/asm/kvm.h
@@ -102,6 +102,8 @@ struct kvm_regs {
#define KVM_ARM_VCPU_EL1_32BIT 1 /* CPU running a 32bit VM */
#define KVM_ARM_VCPU_PSCI_0_2 2 /* CPU uses PSCI v0.2 */
#define KVM_ARM_VCPU_PMU_V3 3 /* Support guest PMUv3 */
+#define KVM_ARM_VCPU_PTRAUTH_ADDRESS 4 /* CPU uses address pointer authentication */
+#define KVM_ARM_VCPU_PTRAUTH_GENERIC 5 /* CPU uses generic pointer authentication */
struct kvm_vcpu_init {
__u32 target;
diff --git a/arm/aarch64/include/kvm/kvm-config-arch.h b/arm/aarch64/include/kvm/kvm-config-arch.h
index 04be43d..2074684 100644
--- a/arm/aarch64/include/kvm/kvm-config-arch.h
+++ b/arm/aarch64/include/kvm/kvm-config-arch.h
@@ -8,7 +8,9 @@
"Create PMUv3 device"), \
OPT_U64('\0', "kaslr-seed", &(cfg)->kaslr_seed, \
"Specify random seed for Kernel Address Space " \
- "Layout Randomization (KASLR)"),
+ "Layout Randomization (KASLR)"), \
+ OPT_BOOLEAN('\0', "ptrauth", &(cfg)->has_ptrauth, \
+ "Enable address authentication"),
#include "arm-common/kvm-config-arch.h"
diff --git a/arm/aarch64/include/kvm/kvm-cpu-arch.h b/arm/aarch64/include/kvm/kvm-cpu-arch.h
index a9d8563..fcc2107 100644
--- a/arm/aarch64/include/kvm/kvm-cpu-arch.h
+++ b/arm/aarch64/include/kvm/kvm-cpu-arch.h
@@ -17,4 +17,6 @@
#define ARM_CPU_CTRL 3, 0, 1, 0
#define ARM_CPU_CTRL_SCTLR_EL1 0
+#define ARM_VCPU_PTRAUTH_FEATURE ((1UL << KVM_ARM_VCPU_PTRAUTH_ADDRESS) \
+ | (1UL << KVM_ARM_VCPU_PTRAUTH_GENERIC))
#endif /* KVM__KVM_CPU_ARCH_H */
diff --git a/arm/include/arm-common/kvm-config-arch.h b/arm/include/arm-common/kvm-config-arch.h
index 5734c46..5badcbd 100644
--- a/arm/include/arm-common/kvm-config-arch.h
+++ b/arm/include/arm-common/kvm-config-arch.h
@@ -10,6 +10,7 @@ struct kvm_config_arch {
bool aarch32_guest;
bool has_pmuv3;
u64 kaslr_seed;
+ bool has_ptrauth;
enum irqchip_type irqchip;
u64 fw_addr;
};
diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c
index 7780251..398c9d6 100644
--- a/arm/kvm-cpu.c
+++ b/arm/kvm-cpu.c
@@ -68,6 +68,13 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, unsigned long cpu_id)
vcpu_init.features[0] |= (1UL << KVM_ARM_VCPU_PSCI_0_2);
}
+ /* Set KVM_ARM_VCPU_PTRAUTH_[ADDRESS/GENERIC] if available */
+ if (kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_ADDRESS) &&
+ kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_GENERIC)) {
+ if (kvm->cfg.arch.has_ptrauth)
+ vcpu_init.features[0] |= ARM_VCPU_PTRAUTH_FEATURE;
+ }
+
/*
* If the preferred target ioctl is successful then
* use preferred target else try each and every target type
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 6d4ea4b..500ac2b 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -988,6 +988,8 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_ARM_VM_IPA_SIZE 165
#define KVM_CAP_MANUAL_DIRTY_LOG_PROTECT 166
#define KVM_CAP_HYPERV_CPUID 167
+#define KVM_CAP_ARM_PTRAUTH_ADDRESS 168
+#define KVM_CAP_ARM_PTRAUTH_GENERIC 169
#ifdef KVM_CAP_IRQ_ROUTING
--
2.7.4
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