Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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>
+13
-13
+13
-13
arch/arm64/kvm/sys_regs.c
+13
-13
arch/arm64/kvm/sys_regs.c
···
1594
1594
return true;
1595
1595
}
1596
1596
1597
-
static bool access_hv_timer(struct kvm_vcpu *vcpu,
1598
-
struct sys_reg_params *p,
1599
-
const struct sys_reg_desc *r)
1600
-
{
1601
-
if (!vcpu_el2_e2h_is_set(vcpu))
1602
-
return undef_access(vcpu, p, r);
1603
-
1604
-
return access_arch_timer(vcpu, p, r);
1605
-
}
1606
-
1607
1597
static s64 kvm_arm64_ftr_safe_value(u32 id, const struct arm64_ftr_bits *ftrp,
1608
1598
s64 new, s64 cur)
1609
1599
{
···
2821
2831
return __el2_visibility(vcpu, rd, s1pie_visibility);
2822
2832
}
2823
2833
2834
+
static unsigned int cnthv_visibility(const struct kvm_vcpu *vcpu,
2835
+
const struct sys_reg_desc *rd)
2836
+
{
2837
+
if (vcpu_has_nv(vcpu) &&
2838
+
!vcpu_has_feature(vcpu, KVM_ARM_VCPU_HAS_EL2_E2H0))
2839
+
return 0;
2840
+
2841
+
return REG_HIDDEN;
2842
+
}
2843
+
2824
2844
static bool access_mdcr(struct kvm_vcpu *vcpu,
2825
2845
struct sys_reg_params *p,
2826
2846
const struct sys_reg_desc *r)
···
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3691
EL2_REG(CNTHP_CTL_EL2, access_arch_timer, reset_val, 0),
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3692
EL2_REG(CNTHP_CVAL_EL2, access_arch_timer, reset_val, 0),
3693
3693
3694
-
{ SYS_DESC(SYS_CNTHV_TVAL_EL2), access_hv_timer },
3695
-
EL2_REG(CNTHV_CTL_EL2, access_hv_timer, reset_val, 0),
3696
-
EL2_REG(CNTHV_CVAL_EL2, access_hv_timer, reset_val, 0),
3694
+
{ SYS_DESC(SYS_CNTHV_TVAL_EL2), access_arch_timer, .visibility = cnthv_visibility },
3695
+
EL2_REG_FILTERED(CNTHV_CTL_EL2, access_arch_timer, reset_val, 0, cnthv_visibility),
3696
+
EL2_REG_FILTERED(CNTHV_CVAL_EL2, access_arch_timer, reset_val, 0, cnthv_visibility),
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3698
{ SYS_DESC(SYS_CNTKCTL_EL12), access_cntkctl_el12 },
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3699