[RFC PATCH v4 17/39] KVM: arm64: Set the VCPU SPE feature bit when SPE is available
From: Alexandru Elisei <hidden>
Date: 2021-08-25 16:18:00
Also in:
kvmarm, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
Check that KVM SPE emulation is supported before allowing userspace to set the KVM_ARM_VCPU_SPE feature. According to ARM DDI 0487G.a, page D9-2946 the Profiling Buffer is disabled if the owning Exception level is 32 bit, reject the SPE feature if the VCPU's execution state at EL1 is aarch32. Signed-off-by: Alexandru Elisei <redacted> --- arch/arm64/include/asm/kvm_host.h | 3 +++ arch/arm64/kvm/reset.c | 23 +++++++++++++++++++++++ 2 files changed, 26 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 1f3b46a6df81..948adb152104 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h@@ -807,6 +807,9 @@ bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu); #define kvm_vcpu_has_pmu(vcpu) \ (test_bit(KVM_ARM_VCPU_PMU_V3, (vcpu)->arch.features)) +#define kvm_vcpu_has_spe(vcpu) \ + (test_bit(KVM_ARM_VCPU_SPE, (vcpu)->arch.features)) + int kvm_trng_call(struct kvm_vcpu *vcpu); #ifdef CONFIG_KVM extern phys_addr_t hyp_mem_base;
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index cba7872d69a8..17b9f1b29c24 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c@@ -27,6 +27,7 @@ #include <asm/kvm_asm.h> #include <asm/kvm_emulate.h> #include <asm/kvm_mmu.h> +#include <asm/kvm_spe.h> #include <asm/virt.h> /* Maximum phys_shift supported for any VM on this host */
@@ -189,6 +190,21 @@ static bool vcpu_allowed_register_width(struct kvm_vcpu *vcpu) return true; } +static int kvm_vcpu_enable_spe(struct kvm_vcpu *vcpu) +{ + if (!kvm_supports_spe()) + return -EINVAL; + + /* + * The Profiling Buffer is disabled if the owning Exception level is + * aarch32. + */ + if (vcpu_has_feature(vcpu, KVM_ARM_VCPU_EL1_32BIT)) + return -EINVAL; + + return 0; +} + /** * kvm_reset_vcpu - sets core registers and sys_regs to reset value * @vcpu: The VCPU pointer
@@ -245,6 +261,13 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) goto out; } + if (kvm_vcpu_has_spe(vcpu)) { + if (kvm_vcpu_enable_spe(vcpu)) { + ret = -EINVAL; + goto out; + } + } + switch (vcpu->arch.target) { default: if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
--
2.33.0
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