From: Amit Daniel Kachhap <amit.kachhap@xxxxxxx>
This patch adds 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.
Command line options --enable-ptrauth and --disable-ptrauth are added
to use this feature. However, if those options are not provided then
also this feature is enabled if host supports this capability.
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@xxxxxxx>
Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx> [merge new kernel heaers]
---
arm/aarch32/include/kvm/kvm-cpu-arch.h | 2 ++
arm/aarch64/include/kvm/kvm-config-arch.h | 6 +++++-
arm/aarch64/include/kvm/kvm-cpu-arch.h | 3 +++
arm/include/arm-common/kvm-config-arch.h | 2 ++
arm/kvm-cpu.c | 20 ++++++++++++++++++--
5 files changed, 30 insertions(+), 3 deletions(-)
diff --git a/arm/aarch32/include/kvm/kvm-cpu-arch.h b/arm/aarch32/include/kvm/kvm-cpu-arch.h
index d28ea67..3ec6f03 100644
--- a/arm/aarch32/include/kvm/kvm-cpu-arch.h
+++ b/arm/aarch32/include/kvm/kvm-cpu-arch.h
@@ -13,4 +13,6 @@
#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/kvm/kvm-config-arch.h b/arm/aarch64/include/kvm/kvm-config-arch.h
index 04be43d..0279b13 100644
--- a/arm/aarch64/include/kvm/kvm-config-arch.h
+++ b/arm/aarch64/include/kvm/kvm-config-arch.h
@@ -8,7 +8,11 @@
"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', "enable-ptrauth", &(cfg)->enable_ptrauth, \
+ "Enables pointer authentication"), \
+ OPT_BOOLEAN('\0', "disable-ptrauth", &(cfg)->disable_ptrauth, \
+ "Disables pointer 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..9fa99fb 100644
--- a/arm/aarch64/include/kvm/kvm-cpu-arch.h
+++ b/arm/aarch64/include/kvm/kvm-cpu-arch.h
@@ -17,4 +17,7 @@
#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..1b4287d 100644
--- a/arm/include/arm-common/kvm-config-arch.h
+++ b/arm/include/arm-common/kvm-config-arch.h
@@ -10,6 +10,8 @@ struct kvm_config_arch {
bool aarch32_guest;
bool has_pmuv3;
u64 kaslr_seed;
+ bool enable_ptrauth;
+ bool disable_ptrauth;
enum irqchip_type irqchip;
u64 fw_addr;
};
diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c
index 7780251..acd1d5f 100644
--- a/arm/kvm-cpu.c
+++ b/arm/kvm-cpu.c
@@ -68,6 +68,18 @@ 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);
}
+ /* Check Pointer Authentication command line arguments. */
+ if (kvm->cfg.arch.enable_ptrauth && kvm->cfg.arch.disable_ptrauth)
+ die("Both enable-ptrauth and disable-ptrauth option cannot be present");
+ /*
+ * Always enable Pointer Authentication if system supports
+ * this extension unless disable-ptrauth option is present.
+ */
+ if (kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_ADDRESS) &&
+ kvm__supports_extension(kvm, KVM_CAP_ARM_PTRAUTH_GENERIC) &&
+ !kvm->cfg.arch.disable_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
@@ -106,8 +118,12 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, unsigned long cpu_id)
die("Unable to find matching target");
}
- if (err || target->init(vcpu))
- die("Unable to initialise vcpu");
+ if (err || target->init(vcpu)) {
+ if (kvm->cfg.arch.enable_ptrauth)
+ die("Unable to initialise vcpu with pointer authentication feature");
+ else
+ die("Unable to initialise vcpu");
+ }
coalesced_offset = ioctl(kvm->sys_fd, KVM_CHECK_EXTENSION,
KVM_CAP_COALESCED_MMIO);
--
2.1.4
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