[PATCH v3 16/18] KVM: arm64: nv: Make AT+PAN instructions aware of FEAT_PAN3

Marc Zyngier
2024-08-13T10:06:27Z

FEAT_PAN3 added a check for executable permissions to FEAT_PAN2.
Add the required SCTLR_ELx.EPAN and descriptor checks to handle
this correctly.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/at.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/at.c b/arch/arm64/kvm/at.c
index 6d5555e98557..c134bcd0338d 100644
--- a/arch/arm64/kvm/at.c
+++ b/arch/arm64/kvm/at.c
@@ -728,6 +728,21 @@ static u64 compute_par_s1(struct kvm_vcpu *vcpu, struct s1_walk_result *wr,
return par;
}

+static bool pan3_enabled(struct kvm_vcpu *vcpu, enum trans_regime regime)
+{
+ u64 sctlr;
+
+ if (!kvm_has_feat(vcpu->kvm, ID_AA64MMFR1_EL1, PAN, PAN3))
+ return false;
+
+ if (regime == TR_EL10)
+ sctlr = vcpu_read_sys_reg(vcpu, SCTLR_EL1);
+ else
+ sctlr = vcpu_read_sys_reg(vcpu, SCTLR_EL2);
+
+ return sctlr & SCTLR_EL1_EPAN;
+}
+
static u64 handle_at_slow(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
{
bool perm_fail, ur, uw, ux, pr, pw, px;
@@ -794,7 +809,7 @@ static u64 handle_at_slow(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
bool pan;

pan = *vcpu_cpsr(vcpu) & PSR_PAN_BIT;
- pan &= ur || uw;
+ pan &= ur || uw || (pan3_enabled(vcpu, wi.regime) && ux);
pw &= !pan;
pr &= !pan;
}
--
2.39.2