This patch adds an --sve command line option to allow the Scalable
Vector Extension to be enabled when creating a guest.
This requires use of the new KVM_ARM_VCPU_FINALIZE ioctl before the
vcpu is runnable, so a new hook kvm_cpu__configure_features() is
added to provide an appropiate place to do this work.
The kernel does not enable SVE by default, and for now kvmtool
adopts the same policy: without --sve, SVE is not enabled for the
guest even if the host supports it.
Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx>
---
arm/aarch32/include/kvm/kvm-cpu-arch.h | 5 +++++
arm/aarch64/include/kvm/kvm-config-arch.h | 4 +++-
arm/aarch64/include/kvm/kvm-cpu-arch.h | 7 ++++++-
arm/aarch64/kvm-cpu.c | 19 +++++++++++++++++++
arm/include/arm-common/kvm-config-arch.h | 1 +
arm/kvm-cpu.c | 3 +++
6 files changed, 37 insertions(+), 2 deletions(-)
diff --git a/arm/aarch32/include/kvm/kvm-cpu-arch.h b/arm/aarch32/include/kvm/kvm-cpu-arch.h
index d28ea67..04740d4 100644
--- a/arm/aarch32/include/kvm/kvm-cpu-arch.h
+++ b/arm/aarch32/include/kvm/kvm-cpu-arch.h
@@ -13,4 +13,9 @@
#define ARM_CPU_ID 0, 0, 0
#define ARM_CPU_ID_MPIDR 5
+static inline int kvm_cpu__configure_features(struct kvm_cpu *vcpu)
+{
+ return 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..50b7aae 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', "sve", &(cfg)->has_sve, \
+ "Enable SVE for the guest"),
#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..7f2bfb9 100644
--- a/arm/aarch64/include/kvm/kvm-cpu-arch.h
+++ b/arm/aarch64/include/kvm/kvm-cpu-arch.h
@@ -8,13 +8,18 @@
#define ARM_VCPU_FEATURE_FLAGS(kvm, cpuid) { \
[0] = ((!!(cpuid) << KVM_ARM_VCPU_POWER_OFF) | \
(!!(kvm)->cfg.arch.aarch32_guest << KVM_ARM_VCPU_EL1_32BIT) | \
- (!!(kvm)->cfg.arch.has_pmuv3 << KVM_ARM_VCPU_PMU_V3)) \
+ (!!(kvm)->cfg.arch.has_pmuv3 << KVM_ARM_VCPU_PMU_V3) | \
+ (!!(kvm)->cfg.arch.has_sve << KVM_ARM_VCPU_SVE)) \
}
+
+
#define ARM_MPIDR_HWID_BITMASK 0xFF00FFFFFFUL
#define ARM_CPU_ID 3, 0, 0, 0
#define ARM_CPU_ID_MPIDR 5
#define ARM_CPU_CTRL 3, 0, 1, 0
#define ARM_CPU_CTRL_SCTLR_EL1 0
+int kvm_cpu__configure_features(struct kvm_cpu *vcpu);
+
#endif /* KVM__KVM_CPU_ARCH_H */
diff --git a/arm/aarch64/kvm-cpu.c b/arm/aarch64/kvm-cpu.c
index 0aaefaf..43eb69e 100644
--- a/arm/aarch64/kvm-cpu.c
+++ b/arm/aarch64/kvm-cpu.c
@@ -128,6 +128,25 @@ static void reset_vcpu_aarch64(struct kvm_cpu *vcpu)
}
}
+static int configure_sve(struct kvm_cpu *vcpu)
+{
+ int feature = KVM_ARM_VCPU_SVE;
+
+ if (ioctl(vcpu->vcpu_fd, KVM_ARM_VCPU_FINALIZE, &feature))
+ return -1;
+
+ return 0;
+}
+
+int kvm_cpu__configure_features(struct kvm_cpu *vcpu)
+{
+ if (vcpu->kvm->cfg.arch.has_sve)
+ if (configure_sve(vcpu))
+ return -1;
+
+ return 0;
+}
+
void kvm_cpu__reset_vcpu(struct kvm_cpu *vcpu)
{
if (vcpu->kvm->cfg.arch.aarch32_guest)
diff --git a/arm/include/arm-common/kvm-config-arch.h b/arm/include/arm-common/kvm-config-arch.h
index 5734c46..bdab680 100644
--- a/arm/include/arm-common/kvm-config-arch.h
+++ b/arm/include/arm-common/kvm-config-arch.h
@@ -12,6 +12,7 @@ struct kvm_config_arch {
u64 kaslr_seed;
enum irqchip_type irqchip;
u64 fw_addr;
+ bool has_sve;
};
int irqchip_parser(const struct option *opt, const char *arg, int unset);
diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c
index 7780251..91d5241 100644
--- a/arm/kvm-cpu.c
+++ b/arm/kvm-cpu.c
@@ -122,6 +122,9 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, unsigned long cpu_id)
vcpu->cpu_compatible = target->compatible;
vcpu->is_running = true;
+ if (kvm_cpu__configure_features(vcpu))
+ die("Unable to configure requested vcpu features");
+
return vcpu;
}
--
2.1.4
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