[PATCH v5 05/69] KVM: arm64: Allow preservation of the S2 SW bits
From: Marc Zyngier <maz@kernel.org>
Date: 2021-11-29 20:04:57
Also in:
kvm, kvmarm
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
The S2 page table code has a limited use the SW bits, but we are about to need them to encode some guest Stage-2 information (its mapping size in the form of the TTL encoding). Propagate the SW bits specified by the caller, and store them into the corresponding entry. Signed-off-by: Marc Zyngier <maz@kernel.org> --- arch/arm64/kvm/hyp/pgtable.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 8cdbc43fa651..d69e400b2de6 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c@@ -1064,9 +1064,6 @@ int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr, u32 level; kvm_pte_t set = 0, clr = 0; - if (prot & KVM_PTE_LEAF_ATTR_HI_SW) - return -EINVAL; - if (prot & KVM_PGTABLE_PROT_R) set |= KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R;
@@ -1076,6 +1073,10 @@ int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr, if (prot & KVM_PGTABLE_PROT_X) clr |= KVM_PTE_LEAF_ATTR_HI_S2_XN; + /* Always propagate the SW bits */ + clr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_HI_SW, 0xf); + set |= prot & KVM_PTE_LEAF_ATTR_HI_SW; + ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL, &level); if (!ret) kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, pgt->mmu, addr, level);
--
2.30.2
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