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| author | Marc Zyngier <maz@kernel.org> | 2025-09-29 17:04:45 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2025-10-13 14:42:40 +0100 |
| commit | 4cab5c857d1f92b4b322e30349fdc5e2e38e7a2f (patch) | |
| tree | 521621584c2316e8ed14244b074415c8c813fd3b | |
| parent | Documentation: KVM: Update GICv3 docs for GICv5 hosts (diff) | |
| download | linux-4cab5c857d1f92b4b322e30349fdc5e2e38e7a2f.tar.gz linux-4cab5c857d1f92b4b322e30349fdc5e2e38e7a2f.zip | |
KVM: arm64: Hide CNTHV_*_EL2 from userspace for nVHE guests
Although we correctly UNDEF any CNTHV_*_EL2 access from the guest
when E2H==0, we still expose these registers to userspace, which
is a bad idea.
Drop the ad-hoc UNDEF injection and switch to a .visibility()
callback which will also hide the register from userspace.
Fixes: 0e45981028550 ("KVM: arm64: timer: Don't adjust the EL2 virtual timer offset")
Signed-off-by: Marc Zyngier <maz@kernel.org>
| -rw-r--r-- | arch/arm64/kvm/sys_regs.c | 26 |
1 files changed, 13 insertions, 13 deletions
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index ee8a7033c85b..9f2f4e0b042e 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1594,16 +1594,6 @@ static bool access_arch_timer(struct kvm_vcpu *vcpu, return true; } -static bool access_hv_timer(struct kvm_vcpu *vcpu, - struct sys_reg_params *p, - const struct sys_reg_desc *r) -{ - if (!vcpu_el2_e2h_is_set(vcpu)) - return undef_access(vcpu, p, r); - - return access_arch_timer(vcpu, p, r); -} - static s64 kvm_arm64_ftr_safe_value(u32 id, const struct arm64_ftr_bits *ftrp, s64 new, s64 cur) { @@ -2831,6 +2821,16 @@ static unsigned int s1pie_el2_visibility(const struct kvm_vcpu *vcpu, return __el2_visibility(vcpu, rd, s1pie_visibility); } +static unsigned int cnthv_visibility(const struct kvm_vcpu *vcpu, + const struct sys_reg_desc *rd) +{ + if (vcpu_has_nv(vcpu) && + !vcpu_has_feature(vcpu, KVM_ARM_VCPU_HAS_EL2_E2H0)) + return 0; + + return REG_HIDDEN; +} + static bool access_mdcr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) @@ -3691,9 +3691,9 @@ static const struct sys_reg_desc sys_reg_descs[] = { EL2_REG(CNTHP_CTL_EL2, access_arch_timer, reset_val, 0), EL2_REG(CNTHP_CVAL_EL2, access_arch_timer, reset_val, 0), - { SYS_DESC(SYS_CNTHV_TVAL_EL2), access_hv_timer }, - EL2_REG(CNTHV_CTL_EL2, access_hv_timer, reset_val, 0), - EL2_REG(CNTHV_CVAL_EL2, access_hv_timer, reset_val, 0), + { SYS_DESC(SYS_CNTHV_TVAL_EL2), access_arch_timer, .visibility = cnthv_visibility }, + EL2_REG_FILTERED(CNTHV_CTL_EL2, access_arch_timer, reset_val, 0, cnthv_visibility), + EL2_REG_FILTERED(CNTHV_CVAL_EL2, access_arch_timer, reset_val, 0, cnthv_visibility), { SYS_DESC(SYS_CNTKCTL_EL12), access_cntkctl_el12 }, |