Commit adcd4e23 authored by Will Deacon's avatar Will Deacon Committed by Marc Zyngier

KVM: arm64: Add support for relaxing stage-2 perms in generic page-table code

Add support for relaxing the permissions of a stage-2 mapping (i.e.
adding additional permissions) to the generic page-table code.
Signed-off-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Reviewed-by: default avatarGavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200911132529.19844-17-will@kernel.org
parent 8d5207be
...@@ -236,6 +236,25 @@ kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr); ...@@ -236,6 +236,25 @@ kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr);
*/ */
kvm_pte_t kvm_pgtable_stage2_mkold(struct kvm_pgtable *pgt, u64 addr); kvm_pte_t kvm_pgtable_stage2_mkold(struct kvm_pgtable *pgt, u64 addr);
/**
* kvm_pgtable_stage2_relax_perms() - Relax the permissions enforced by a
* page-table entry.
* @pgt: Page-table structure initialised by kvm_pgtable_stage2_init().
* @addr: Intermediate physical address to identify the page-table entry.
* @prot: Additional permissions to grant for the mapping.
*
* The offset of @addr within a page is ignored.
*
* If there is a valid, leaf page-table entry used to translate @addr, then
* relax the permissions in that entry according to the read, write and
* execute permissions specified by @prot. No permissions are removed, and
* TLB invalidation is performed after updating the entry.
*
* Return: 0 on success, negative error code on failure.
*/
int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr,
enum kvm_pgtable_prot prot);
/** /**
* kvm_pgtable_stage2_is_young() - Test whether a page-table entry has the * kvm_pgtable_stage2_is_young() - Test whether a page-table entry has the
* access flag set. * access flag set.
......
...@@ -782,6 +782,26 @@ bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr) ...@@ -782,6 +782,26 @@ bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr)
return pte & KVM_PTE_LEAF_ATTR_LO_S2_AF; return pte & KVM_PTE_LEAF_ATTR_LO_S2_AF;
} }
int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr,
enum kvm_pgtable_prot prot)
{
int ret;
kvm_pte_t set = 0, clr = 0;
if (prot & KVM_PGTABLE_PROT_R)
set |= KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R;
if (prot & KVM_PGTABLE_PROT_W)
set |= KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W;
if (prot & KVM_PGTABLE_PROT_X)
clr |= KVM_PTE_LEAF_ATTR_HI_S2_XN;
ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL);
kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, pgt->mmu, addr, 0);
return ret;
}
static int stage2_flush_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, static int stage2_flush_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
enum kvm_pgtable_walk_flags flag, enum kvm_pgtable_walk_flags flag,
void * const arg) void * const arg)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment