[PATCH kvmtool v3 6/9] arm/arm64: Factor out ptrauth vcpu feature setup

Dave Martin
2019-05-30T15:14:22Z

In the interest of readability, factor out the vcpu feature setup
for ptrauth into a separate function.

Also, because aarch32 doesn't have this feature or the related
command line options anyway, move the actual code into aarch64/.

Since ARM_VCPU_PTRAUTH_FEATURE is only there to make the ptrauth
feature setup code compile on arm, it is no longer needed: inline
and remove it.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
---
arm/aarch32/include/kvm/kvm-cpu-arch.h | 3 ++-
arm/aarch64/include/kvm/kvm-cpu-arch.h | 3 +--
arm/aarch64/kvm-cpu.c | 22 ++++++++++++++++++++++
arm/kvm-cpu.c | 12 +-----------
4 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/arm/aarch32/include/kvm/kvm-cpu-arch.h b/arm/aarch32/include/kvm/kvm-cpu-arch.h
index 3ec6f03..01983f0 100644
--- a/arm/aarch32/include/kvm/kvm-cpu-arch.h
+++ b/arm/aarch32/include/kvm/kvm-cpu-arch.h
@@ -13,6 +13,7 @@
#define ARM_CPU_ID 0, 0, 0
#define ARM_CPU_ID_MPIDR 5

-#define ARM_VCPU_PTRAUTH_FEATURE 0
+static inline void kvm_cpu__select_features(struct kvm *kvm,
+ struct kvm_vcpu_init *init) { }

#endif /* KVM__KVM_CPU_ARCH_H */
diff --git a/arm/aarch64/include/kvm/kvm-cpu-arch.h b/arm/aarch64/include/kvm/kvm-cpu-arch.h
index 9fa99fb..e6875fc 100644
--- a/arm/aarch64/include/kvm/kvm-cpu-arch.h
+++ b/arm/aarch64/include/kvm/kvm-cpu-arch.h
@@ -17,7 +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))
+void kvm_cpu__select_features(struct kvm *kvm, struct kvm_vcpu_init *init);

#endif /* KVM__KVM_CPU_ARCH_H */
diff --git a/arm/aarch64/kvm-cpu.c b/arm/aarch64/kvm-cpu.c
index 0aaefaf..d3c32e0 100644
--- a/arm/aarch64/kvm-cpu.c
+++ b/arm/aarch64/kvm-cpu.c
@@ -128,6 +128,28 @@ static void reset_vcpu_aarch64(struct kvm_cpu *vcpu)
}
}

+static void select_ptrauth_feature(struct kvm *kvm, struct kvm_vcpu_init *init)
+{
+ /* 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) {
+ init->features[0] |= 1UL << KVM_ARM_VCPU_PTRAUTH_ADDRESS;
+ init->features[0] |= 1UL << KVM_ARM_VCPU_PTRAUTH_GENERIC;
+ }
+}
+
+void kvm_cpu__select_features(struct kvm *kvm, struct kvm_vcpu_init *init)
+{
+ select_ptrauth_feature(kvm, init);
+}
+
void kvm_cpu__reset_vcpu(struct kvm_cpu *vcpu)
{
if (vcpu->kvm->cfg.arch.aarch32_guest)
diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c
index acd1d5f..764fb05 100644
--- a/arm/kvm-cpu.c
+++ b/arm/kvm-cpu.c
@@ -68,17 +68,7 @@ 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;
+ kvm_cpu__select_features(kvm, &vcpu_init);

/*
* If the preferred target ioctl is successful then
--
2.1.4