KVM: arm64: Add support for creating kernel-agnostic stage-1 page tables
The generic page-table walker is pretty useless as it stands, because it doesn't understand enough to allocate anything. Teach it about stage-1 page-tables, and hook up an API for allocating these for the hypervisor at EL2. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Gavin Shan <gshan@redhat.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20200911132529.19844-4-will@kernel.org
This commit is contained in:
Will Deacon
Marc Zyngier
Родитель
b1e57de62c
Коммит
bb0e92cbbc
|
|
@ -77,6 +77,46 @@ struct kvm_pgtable_walker {
|
|||
const enum kvm_pgtable_walk_flags flags;
|
||||
};
|
||||
|
||||
/**
|
||||
* kvm_pgtable_hyp_init() - Initialise a hypervisor stage-1 page-table.
|
||||
* @pgt: Uninitialised page-table structure to initialise.
|
||||
* @va_bits: Maximum virtual address bits.
|
||||
*
|
||||
* Return: 0 on success, negative error code on failure.
|
||||
*/
|
||||
int kvm_pgtable_hyp_init(struct kvm_pgtable *pgt, u32 va_bits);
|
||||
|
||||
/**
|
||||
* kvm_pgtable_hyp_destroy() - Destroy an unused hypervisor stage-1 page-table.
|
||||
* @pgt: Page-table structure initialised by kvm_pgtable_hyp_init().
|
||||
*
|
||||
* The page-table is assumed to be unreachable by any hardware walkers prior
|
||||
* to freeing and therefore no TLB invalidation is performed.
|
||||
*/
|
||||
void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt);
|
||||
|
||||
/**
|
||||
* kvm_pgtable_hyp_map() - Install a mapping in a hypervisor stage-1 page-table.
|
||||
* @pgt: Page-table structure initialised by kvm_pgtable_hyp_init().
|
||||
* @addr: Virtual address at which to place the mapping.
|
||||
* @size: Size of the mapping.
|
||||
* @phys: Physical address of the memory to map.
|
||||
* @prot: Permissions and attributes for the mapping.
|
||||
*
|
||||
* The offset of @addr within a page is ignored, @size is rounded-up to
|
||||
* the next page boundary and @phys is rounded-down to the previous page
|
||||
* boundary.
|
||||
*
|
||||
* If device attributes are not explicitly requested in @prot, then the
|
||||
* mapping will be normal, cacheable. Attempts to install a new mapping
|
||||
* for a virtual address that is already mapped will be rejected with an
|
||||
* error and a WARN().
|
||||
*
|
||||
* Return: 0 on success, negative error code on failure.
|
||||
*/
|
||||
int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys,
|
||||
enum kvm_pgtable_prot prot);
|
||||
|
||||
/**
|
||||
* kvm_pgtable_walk() - Walk a page-table.
|
||||
* @pgt: Page-table structure initialised by kvm_pgtable_*_init().
|
||||
|
|
|
|||
|
|
@ -24,8 +24,18 @@
|
|||
|
||||
#define KVM_PTE_LEAF_ATTR_LO GENMASK(11, 2)
|
||||
|
||||
#define KVM_PTE_LEAF_ATTR_LO_S1_ATTRIDX GENMASK(4, 2)
|
||||
#define KVM_PTE_LEAF_ATTR_LO_S1_AP GENMASK(7, 6)
|
||||
#define KVM_PTE_LEAF_ATTR_LO_S1_AP_RO 3
|
||||
#define KVM_PTE_LEAF_ATTR_LO_S1_AP_RW 1
|
||||
#define KVM_PTE_LEAF_ATTR_LO_S1_SH GENMASK(9, 8)
|
||||
#define KVM_PTE_LEAF_ATTR_LO_S1_SH_IS 3
|
||||
#define KVM_PTE_LEAF_ATTR_LO_S1_AF BIT(10)
|
||||
|
||||
#define KVM_PTE_LEAF_ATTR_HI GENMASK(63, 51)
|
||||
|
||||
#define KVM_PTE_LEAF_ATTR_HI_S1_XN BIT(54)
|
||||
|
||||
struct kvm_pgtable_walk_data {
|
||||
struct kvm_pgtable *pgt;
|
||||
struct kvm_pgtable_walker *walker;
|
||||
|
|
@ -283,3 +293,126 @@ int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size,
|
|||
|
||||
return _kvm_pgtable_walk(&walk_data);
|
||||
}
|
||||
|
||||
struct hyp_map_data {
|
||||
u64 phys;
|
||||
kvm_pte_t attr;
|
||||
};
|
||||
|
||||
static int hyp_map_set_prot_attr(enum kvm_pgtable_prot prot,
|
||||
struct hyp_map_data *data)
|
||||
{
|
||||
bool device = prot & KVM_PGTABLE_PROT_DEVICE;
|
||||
u32 mtype = device ? MT_DEVICE_nGnRE : MT_NORMAL;
|
||||
kvm_pte_t attr = FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S1_ATTRIDX, mtype);
|
||||
u32 sh = KVM_PTE_LEAF_ATTR_LO_S1_SH_IS;
|
||||
u32 ap = (prot & KVM_PGTABLE_PROT_W) ? KVM_PTE_LEAF_ATTR_LO_S1_AP_RW :
|
||||
KVM_PTE_LEAF_ATTR_LO_S1_AP_RO;
|
||||
|
||||
if (!(prot & KVM_PGTABLE_PROT_R))
|
||||
return -EINVAL;
|
||||
|
||||
if (prot & KVM_PGTABLE_PROT_X) {
|
||||
if (prot & KVM_PGTABLE_PROT_W)
|
||||
return -EINVAL;
|
||||
|
||||
if (device)
|
||||
return -EINVAL;
|
||||
} else {
|
||||
attr |= KVM_PTE_LEAF_ATTR_HI_S1_XN;
|
||||
}
|
||||
|
||||
attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S1_AP, ap);
|
||||
attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S1_SH, sh);
|
||||
attr |= KVM_PTE_LEAF_ATTR_LO_S1_AF;
|
||||
data->attr = attr;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static bool hyp_map_walker_try_leaf(u64 addr, u64 end, u32 level,
|
||||
kvm_pte_t *ptep, struct hyp_map_data *data)
|
||||
{
|
||||
u64 granule = kvm_granule_size(level), phys = data->phys;
|
||||
|
||||
if (!kvm_block_mapping_supported(addr, end, phys, level))
|
||||
return false;
|
||||
|
||||
WARN_ON(!kvm_set_valid_leaf_pte(ptep, phys, data->attr, level));
|
||||
data->phys += granule;
|
||||
return true;
|
||||
}
|
||||
|
||||
static int hyp_map_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
|
||||
enum kvm_pgtable_walk_flags flag, void * const arg)
|
||||
{
|
||||
kvm_pte_t *childp;
|
||||
|
||||
if (hyp_map_walker_try_leaf(addr, end, level, ptep, arg))
|
||||
return 0;
|
||||
|
||||
if (WARN_ON(level == KVM_PGTABLE_MAX_LEVELS - 1))
|
||||
return -EINVAL;
|
||||
|
||||
childp = (kvm_pte_t *)get_zeroed_page(GFP_KERNEL);
|
||||
if (!childp)
|
||||
return -ENOMEM;
|
||||
|
||||
kvm_set_table_pte(ptep, childp);
|
||||
return 0;
|
||||
}
|
||||
|
||||
int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys,
|
||||
enum kvm_pgtable_prot prot)
|
||||
{
|
||||
int ret;
|
||||
struct hyp_map_data map_data = {
|
||||
.phys = ALIGN_DOWN(phys, PAGE_SIZE),
|
||||
};
|
||||
struct kvm_pgtable_walker walker = {
|
||||
.cb = hyp_map_walker,
|
||||
.flags = KVM_PGTABLE_WALK_LEAF,
|
||||
.arg = &map_data,
|
||||
};
|
||||
|
||||
ret = hyp_map_set_prot_attr(prot, &map_data);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
ret = kvm_pgtable_walk(pgt, addr, size, &walker);
|
||||
dsb(ishst);
|
||||
isb();
|
||||
return ret;
|
||||
}
|
||||
|
||||
int kvm_pgtable_hyp_init(struct kvm_pgtable *pgt, u32 va_bits)
|
||||
{
|
||||
u64 levels = ARM64_HW_PGTABLE_LEVELS(va_bits);
|
||||
|
||||
pgt->pgd = (kvm_pte_t *)get_zeroed_page(GFP_KERNEL);
|
||||
if (!pgt->pgd)
|
||||
return -ENOMEM;
|
||||
|
||||
pgt->ia_bits = va_bits;
|
||||
pgt->start_level = KVM_PGTABLE_MAX_LEVELS - levels;
|
||||
pgt->mmu = NULL;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int hyp_free_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
|
||||
enum kvm_pgtable_walk_flags flag, void * const arg)
|
||||
{
|
||||
free_page((unsigned long)kvm_pte_follow(*ptep));
|
||||
return 0;
|
||||
}
|
||||
|
||||
void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt)
|
||||
{
|
||||
struct kvm_pgtable_walker walker = {
|
||||
.cb = hyp_free_walker,
|
||||
.flags = KVM_PGTABLE_WALK_TABLE_POST,
|
||||
};
|
||||
|
||||
WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker));
|
||||
free_page((unsigned long)pgt->pgd);
|
||||
pgt->pgd = NULL;
|
||||
}
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче