[RFC PATCH v3 15/16] KVM: arm64: Enable SPE for guests
From: Alexandru Elisei <hidden>
Date: 2020-10-27 17:31:50
Also in:
kvmarm
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
We have all the bits in place to expose SPE to guests, allow userspace to set the feature and advertise the presence of SPE in the ID_AA64DFR0_EL1 register. Signed-off-by: Alexandru Elisei <redacted> --- arch/arm64/include/asm/kvm_host.h | 2 +- arch/arm64/kvm/sys_regs.c | 8 ++++++-- 2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index bcecc6224c59..e5504c9847fc 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h@@ -39,7 +39,7 @@ #define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS -#define KVM_VCPU_MAX_FEATURES 7 +#define KVM_VCPU_MAX_FEATURES 8 #define KVM_REQ_SLEEP \ KVM_ARCH_REQ_FLAGS(0, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 3a0687602839..076be04d2e28 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c@@ -1178,8 +1178,12 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu, val = cpuid_feature_cap_perfmon_field(val, ID_AA64DFR0_PMUVER_SHIFT, ID_AA64DFR0_PMUVER_8_1); - /* Don't advertise SPE to guests */ - val &= ~(0xfUL << ID_AA64DFR0_PMSVER_SHIFT); + /* + * Don't advertise SPE to guests without SPE. Otherwise, allow + * the guest to detect the hardware SPE version. + */ + if (!vcpu_has_spe(vcpu)) + val &= ~(0xfUL << ID_AA64DFR0_PMSVER_SHIFT); } else if (id == SYS_ID_DFR0_EL1) { /* Limit guests to PMUv3 for ARMv8.1 */ val = cpuid_feature_cap_perfmon_field(val,
--
2.29.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel