Populate bits [56:55] of the leaf entry with the level provided
by the guest's S2 translation.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_nested.h | 7 +++++++
arch/arm64/kvm/mmu.c | 11 +++++++++++
2 files changed, 18 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h
index 847b652bd376..3b5838a2f29e 100644
--- a/arch/arm64/include/asm/kvm_nested.h
+++ b/arch/arm64/include/asm/kvm_nested.h
@@ -5,6 +5,8 @@
#include <linux/bitfield.h>
#include <linux/kvm_host.h>
+#include <asm/kvm_pgtable.h>
+
static inline bool vcpu_has_nv(const struct kvm_vcpu *vcpu)
{
return (!__is_defined(__KVM_NVHE_HYPERVISOR__) &&
@@ -140,4 +142,9 @@ void access_nested_id_reg(struct kvm_vcpu *v, struct sys_reg_params *p,
#define KVM_NV_GUEST_MAP_SZ (KVM_PGTABLE_PROT_SW1 | KVM_PGTABLE_PROT_SW0)
+static inline u64 kvm_encode_nested_level(struct kvm_s2_trans *trans)
+{
+ return FIELD_PREP(KVM_NV_GUEST_MAP_SZ, trans->level);
+}
+
#endif /* __ARM64_KVM_NESTED_H */
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 4b38f2f3c997..6caa48da1b2e 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1281,11 +1281,17 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
* Potentially reduce shadow S2 permissions to match the guest's own
* S2. For exec faults, we'd only reach this point if the guest
* actually allowed it (see kvm_s2_handle_perm_fault).
+ *
+ * Also encode the level of the nested translation in the SW bits of
+ * the PTE/PMD/PUD. This will be retrived on TLB invalidation from
+ * the guest.
*/
if (kvm_is_shadow_s2_fault(vcpu)) {
writable &= kvm_s2_trans_writable(nested);
if (!kvm_s2_trans_readable(nested))
prot &= ~KVM_PGTABLE_PROT_R;
+
+ prot |= kvm_encode_nested_level(nested);
}
spin_lock(&kvm->mmu_lock);
@@ -1336,6 +1342,11 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
* kvm_pgtable_stage2_map() should be called to change block size.
*/
if (fault_status == FSC_PERM && vma_pagesize == fault_granule) {
+ /*
+ * Drop the SW bits in favour of those stored in the
+ * PTE, which will be preserved.
+ */
+ prot &= ~KVM_NV_GUEST_MAP_SZ;
ret = kvm_pgtable_stage2_relax_perms(pgt, fault_ipa, prot);
} else {
ret = kvm_pgtable_stage2_map(pgt, fault_ipa, vma_pagesize,
--
2.30.2
