From e1026237f90677fd5a454f63057a62f984c2188d Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 16 Sep 2020 00:07:05 +0100 Subject: [PATCH] KVM: arm64: Set CSV2 for guests on hardware unaffected by Spectre-v2 If the system is not affected by Spectre-v2, then advertise to the KVM guest that it is not affected, without the need for a safelist in the guest. Signed-off-by: Marc Zyngier Signed-off-by: Will Deacon --- arch/arm64/kvm/sys_regs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 077293b5115f..7b8a8f6169d0 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1131,6 +1131,9 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu, if (!vcpu_has_sve(vcpu)) val &= ~(0xfUL << ID_AA64PFR0_SVE_SHIFT); val &= ~(0xfUL << ID_AA64PFR0_AMU_SHIFT); + if (!(val & (0xfUL << ID_AA64PFR0_CSV2_SHIFT)) && + arm64_get_spectre_v2_state() == SPECTRE_UNAFFECTED) + val |= (1UL << ID_AA64PFR0_CSV2_SHIFT); } else if (id == SYS_ID_AA64ISAR1_EL1 && !vcpu_has_ptrauth(vcpu)) { val &= ~((0xfUL << ID_AA64ISAR1_APA_SHIFT) | (0xfUL << ID_AA64ISAR1_API_SHIFT) | -- 2.20.1