public-mirrors/linux
1
0
Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-09-18 22:14:16 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

KVM: arm64: Enable retrieving protections attributes of PTEs

Browse source 
Introduce helper functions in the KVM stage-2 and stage-1 page-table
manipulation library allowing to retrieve the enum kvm_pgtable_prot of a
PTE. This will be useful to implement custom walkers outside of
pgtable.c.

Signed-off-by: Quentin Perret <qperret@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210809152448.1810400-17-qperret@google.com
This commit is contained in:
Quentin Perret 2021-08-09 16:24:43 +01:00 • committed by Marc Zyngier
parent e009dce129
commit 9024b3d006
2 changed files with 57 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

20
arch/arm64/include/asm/kvm_pgtable.h
View file

@ -507,4 +507,24 @@ int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size,
*/
int kvm_pgtable_get_leaf(struct kvm_pgtable *pgt, u64 addr,
kvm_pte_t *ptep, u32 *level);
/**
* kvm_pgtable_stage2_pte_prot() - Retrieve the protection attributes of a
* stage-2 Page-Table Entry.
* @pte: Page-table entry
*
* Return: protection attributes of the page-table entry in the enum
* kvm_pgtable_prot format.
*/
enum kvm_pgtable_prot kvm_pgtable_stage2_pte_prot(kvm_pte_t pte);
/**
* kvm_pgtable_hyp_pte_prot() - Retrieve the protection attributes of a stage-1
* Page-Table Entry.
* @pte: Page-table entry
*
* Return: protection attributes of the page-table entry in the enum
* kvm_pgtable_prot format.
*/
enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte);
#endif /* __ARM64_KVM_PGTABLE_H__ */

37
arch/arm64/kvm/hyp/pgtable.c
View file

@ -363,6 +363,26 @@ static int hyp_set_prot_attr(enum kvm_pgtable_prot prot, kvm_pte_t *ptep)
return 0;
}
enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte)
{
enum kvm_pgtable_prot prot = pte & KVM_PTE_LEAF_ATTR_HI_SW;
u32 ap;
if (!kvm_pte_valid(pte))
return prot;
if (!(pte & KVM_PTE_LEAF_ATTR_HI_S1_XN))
prot |= KVM_PGTABLE_PROT_X;
ap = FIELD_GET(KVM_PTE_LEAF_ATTR_LO_S1_AP, pte);
if (ap == KVM_PTE_LEAF_ATTR_LO_S1_AP_RO)
prot |= KVM_PGTABLE_PROT_R;
else if (ap == KVM_PTE_LEAF_ATTR_LO_S1_AP_RW)
prot |= KVM_PGTABLE_PROT_RW;
return prot;
}
static bool hyp_pte_needs_update(kvm_pte_t old, kvm_pte_t new)
{
/*
@ -565,6 +585,23 @@ static int stage2_set_prot_attr(struct kvm_pgtable *pgt, enum kvm_pgtable_prot p
return 0;
}
enum kvm_pgtable_prot kvm_pgtable_stage2_pte_prot(kvm_pte_t pte)
{
enum kvm_pgtable_prot prot = pte & KVM_PTE_LEAF_ATTR_HI_SW;
if (!kvm_pte_valid(pte))
return prot;
if (pte & KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R)
prot |= KVM_PGTABLE_PROT_R;
if (pte & KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W)
prot |= KVM_PGTABLE_PROT_W;
if (!(pte & KVM_PTE_LEAF_ATTR_HI_S2_XN))
prot |= KVM_PGTABLE_PROT_X;
return prot;
}
static bool stage2_pte_needs_update(kvm_pte_t old, kvm_pte_t new)
{
if (!kvm_pte_valid(old) || !kvm_pte_valid(new))