[PATCH v5 34/37] KVM: arm64: Disable hierarchical permissions when POE is enabled

Marc Zyngier
2024-10-23T14:53:58Z

The hierarchical permissions must be disabled when POE is enabled
in the translation regime used for a given table walk.

We store the two enable bits in the s1_walk_info structure so that
they can be retrieved down the line, as they will be useful.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/at.c | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)

diff --git a/arch/arm64/kvm/at.c b/arch/arm64/kvm/at.c
index ef1643faedeb4..8d1dc6327ec5b 100644
--- a/arch/arm64/kvm/at.c
+++ b/arch/arm64/kvm/at.c
@@ -24,6 +24,8 @@ struct s1_walk_info {
unsigned int txsz;
int sl;
bool hpd;
+ bool e0poe;
+ bool poe;
bool be;
bool s2;
};
@@ -110,6 +112,34 @@ static bool s1pie_enabled(struct kvm_vcpu *vcpu, enum trans_regime regime)
}
}

+static void compute_s1poe(struct kvm_vcpu *vcpu, struct s1_walk_info *wi)
+{
+ u64 val;
+
+ if (!kvm_has_s1poe(vcpu->kvm)) {
+ wi->poe = wi->e0poe = false;
+ return;
+ }
+
+ switch (wi->regime) {
+ case TR_EL2:
+ case TR_EL20:
+ val = vcpu_read_sys_reg(vcpu, TCR2_EL2);
+ wi->poe = val & TCR2_EL2_POE;
+ wi->e0poe = (wi->regime == TR_EL20) && (val & TCR2_EL2_E0POE);
+ break;
+ case TR_EL10:
+ if (__vcpu_sys_reg(vcpu, HCRX_EL2) & HCRX_EL2_TCR2En) {
+ wi->poe = wi->e0poe = false;
+ return;
+ }
+
+ val = __vcpu_sys_reg(vcpu, TCR2_EL1);
+ wi->poe = val & TCR2_EL1x_POE;
+ wi->e0poe = val & TCR2_EL1x_E0POE;
+ }
+}
+
static int setup_s1_walk(struct kvm_vcpu *vcpu, u32 op, struct s1_walk_info *wi,
struct s1_walk_result *wr, u64 va)
{
@@ -206,6 +236,12 @@ static int setup_s1_walk(struct kvm_vcpu *vcpu, u32 op, struct s1_walk_info *wi,
/* R_JHSVW */
wi->hpd |= s1pie_enabled(vcpu, wi->regime);

+ /* Do we have POE? */
+ compute_s1poe(vcpu, wi);
+
+ /* R_BVXDG */
+ wi->hpd |= (wi->poe || wi->e0poe);
+
/* Someone was silly enough to encode TG0/TG1 differently */
if (va55) {
wi->txsz = FIELD_GET(TCR_T1SZ_MASK, tcr);
--
2.39.2