Commit 419edf48 authored by Ryan Roberts's avatar Ryan Roberts Committed by Marc Zyngier
Browse files

KVM: arm64: Convert translation level parameter to s8 



With the introduction of FEAT_LPA2, the Arm ARM adds a new level of
translation, level -1, so levels can now be in the range [-1;3]. 3 is
always the last level and the first level is determined based on the
number of VA bits in use.

Convert level variables to use a signed type in preparation for
supporting this new level -1.

Since the last level is always anchored at 3, and the first level varies
to suit the number of VA/IPA bits, take the opportunity to replace
KVM_PGTABLE_MAX_LEVELS with the 2 macros KVM_PGTABLE_FIRST_LEVEL and
KVM_PGTABLE_LAST_LEVEL. This removes the assumption from the code that
levels run from 0 to KVM_PGTABLE_MAX_LEVELS - 1, which will soon no
longer be true.

Reviewed-by: default avatarOliver Upton <oliver.upton@linux.dev>
Signed-off-by: default avatarRyan Roberts <ryan.roberts@arm.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231127111737.1897081-9-ryan.roberts@arm.com
parent bd412e2a

arch/arm64/include/asm/kvm_emulate.h

+1 −1
Original line number Diff line number Diff line
@@ -409,7 +409,7 @@ static __always_inline u8 kvm_vcpu_trap_get_fault_type(const struct kvm_vcpu *vc 
	return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC_TYPE;

}



static __always_inline u8 kvm_vcpu_trap_get_fault_level(const struct kvm_vcpu *vcpu)

static __always_inline s8 kvm_vcpu_trap_get_fault_level(const struct kvm_vcpu *vcpu)

{

	return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC_LEVEL;

}

arch/arm64/include/asm/kvm_pgtable.h

+16 −15
Original line number Diff line number Diff line
@@ -11,7 +11,8 @@ 
#include <linux/kvm_host.h>

#include <linux/types.h>



#define KVM_PGTABLE_MAX_LEVELS		4U

#define KVM_PGTABLE_FIRST_LEVEL		0

#define KVM_PGTABLE_LAST_LEVEL		3



/*

 * The largest supported block sizes for KVM (no 52-bit PA support):
@@ -20,9 +21,9 @@ 
 *  - 64K (level 2):	512MB

 */

#ifdef CONFIG_ARM64_4K_PAGES

#define KVM_PGTABLE_MIN_BLOCK_LEVEL	1U

#define KVM_PGTABLE_MIN_BLOCK_LEVEL	1

#else

#define KVM_PGTABLE_MIN_BLOCK_LEVEL	2U

#define KVM_PGTABLE_MIN_BLOCK_LEVEL	2

#endif



#define kvm_lpa2_is_enabled()		system_supports_lpa2()
@@ -103,28 +104,28 @@ static inline kvm_pfn_t kvm_pte_to_pfn(kvm_pte_t pte) 
	return __phys_to_pfn(kvm_pte_to_phys(pte));

}



static inline u64 kvm_granule_shift(u32 level)

static inline u64 kvm_granule_shift(s8 level)

{

	/* Assumes KVM_PGTABLE_MAX_LEVELS is 4 */

	/* Assumes KVM_PGTABLE_LAST_LEVEL is 3 */

	return ARM64_HW_PGTABLE_LEVEL_SHIFT(level);

}



static inline u64 kvm_granule_size(u32 level)

static inline u64 kvm_granule_size(s8 level)

{

	return BIT(kvm_granule_shift(level));

}



static inline bool kvm_level_supports_block_mapping(u32 level)

static inline bool kvm_level_supports_block_mapping(s8 level)

{

	return level >= KVM_PGTABLE_MIN_BLOCK_LEVEL;

}



static inline u32 kvm_supported_block_sizes(void)

{

	u32 level = KVM_PGTABLE_MIN_BLOCK_LEVEL;

	s8 level = KVM_PGTABLE_MIN_BLOCK_LEVEL;

	u32 r = 0;



	for (; level < KVM_PGTABLE_MAX_LEVELS; level++)

	for (; level <= KVM_PGTABLE_LAST_LEVEL; level++)

		r |= BIT(kvm_granule_shift(level));



	return r;
@@ -169,7 +170,7 @@ struct kvm_pgtable_mm_ops { 
	void*		(*zalloc_page)(void *arg);

	void*		(*zalloc_pages_exact)(size_t size);

	void		(*free_pages_exact)(void *addr, size_t size);

	void		(*free_unlinked_table)(void *addr, u32 level);

	void		(*free_unlinked_table)(void *addr, s8 level);

	void		(*get_page)(void *addr);

	void		(*put_page)(void *addr);

	int		(*page_count)(void *addr);
@@ -265,7 +266,7 @@ struct kvm_pgtable_visit_ctx { 
	u64					start;

	u64					addr;

	u64					end;

	u32					level;

	s8					level;

	enum kvm_pgtable_walk_flags		flags;

};
@@ -368,7 +369,7 @@ static inline bool kvm_pgtable_walk_lock_held(void) 
 */

struct kvm_pgtable {

	u32					ia_bits;

	u32					start_level;

	s8					start_level;

	kvm_pteref_t				pgd;

	struct kvm_pgtable_mm_ops		*mm_ops;
@@ -502,7 +503,7 @@ void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt); 
 * 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_stage2_free_unlinked(struct kvm_pgtable_mm_ops *mm_ops, void *pgtable, u32 level);

void kvm_pgtable_stage2_free_unlinked(struct kvm_pgtable_mm_ops *mm_ops, void *pgtable, s8 level);



/**

 * kvm_pgtable_stage2_create_unlinked() - Create an unlinked stage-2 paging structure.
@@ -526,7 +527,7 @@ void kvm_pgtable_stage2_free_unlinked(struct kvm_pgtable_mm_ops *mm_ops, void *p 
 * an ERR_PTR(error) on failure.

 */

kvm_pte_t *kvm_pgtable_stage2_create_unlinked(struct kvm_pgtable *pgt,

					      u64 phys, u32 level,

					      u64 phys, s8 level,

					      enum kvm_pgtable_prot prot,

					      void *mc, bool force_pte);
@@ -752,7 +753,7 @@ int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size, 
 * Return: 0 on success, negative error code on failure.

 */

int kvm_pgtable_get_leaf(struct kvm_pgtable *pgt, u64 addr,

			 kvm_pte_t *ptep, u32 *level);

			 kvm_pte_t *ptep, s8 *level);



/**

 * kvm_pgtable_stage2_pte_prot() - Retrieve the protection attributes of a

arch/arm64/include/asm/kvm_pkvm.h

+3 −2
Original line number Diff line number Diff line
@@ -56,10 +56,11 @@ static inline unsigned long hyp_vm_table_pages(void) 


static inline unsigned long __hyp_pgtable_max_pages(unsigned long nr_pages)

{

	unsigned long total = 0, i;

	unsigned long total = 0;

	int i;



	/* Provision the worst case scenario */

	for (i = 0; i < KVM_PGTABLE_MAX_LEVELS; i++) {

	for (i = KVM_PGTABLE_FIRST_LEVEL; i <= KVM_PGTABLE_LAST_LEVEL; i++) {

		nr_pages = DIV_ROUND_UP(nr_pages, PTRS_PER_PTE);

		total += nr_pages;

	}

arch/arm64/kvm/hyp/nvhe/mem_protect.c

+3 −3
Original line number Diff line number Diff line
@@ -91,7 +91,7 @@ static void host_s2_put_page(void *addr) 
	hyp_put_page(&host_s2_pool, addr);

}



static void host_s2_free_unlinked_table(void *addr, u32 level)

static void host_s2_free_unlinked_table(void *addr, s8 level)

{

	kvm_pgtable_stage2_free_unlinked(&host_mmu.mm_ops, addr, level);

}
@@ -443,7 +443,7 @@ static int host_stage2_adjust_range(u64 addr, struct kvm_mem_range *range) 
{

	struct kvm_mem_range cur;

	kvm_pte_t pte;

	u32 level;

	s8 level;

	int ret;



	hyp_assert_lock_held(&host_mmu.lock);
@@ -462,7 +462,7 @@ static int host_stage2_adjust_range(u64 addr, struct kvm_mem_range *range) 
		cur.start = ALIGN_DOWN(addr, granule);

		cur.end = cur.start + granule;

		level++;

	} while ((level < KVM_PGTABLE_MAX_LEVELS) &&

	} while ((level <= KVM_PGTABLE_LAST_LEVEL) &&

			!(kvm_level_supports_block_mapping(level) &&

			  range_included(&cur, range)));

arch/arm64/kvm/hyp/nvhe/mm.c

+2 −2
Original line number Diff line number Diff line
@@ -260,7 +260,7 @@ static void fixmap_clear_slot(struct hyp_fixmap_slot *slot) 
	 * https://lore.kernel.org/kvm/20221017115209.2099-1-will@kernel.org/T/#mf10dfbaf1eaef9274c581b81c53758918c1d0f03

	 */

	dsb(ishst);

	__tlbi_level(vale2is, __TLBI_VADDR(addr, 0), (KVM_PGTABLE_MAX_LEVELS - 1));

	__tlbi_level(vale2is, __TLBI_VADDR(addr, 0), KVM_PGTABLE_LAST_LEVEL);

	dsb(ish);

	isb();

}
@@ -275,7 +275,7 @@ static int __create_fixmap_slot_cb(const struct kvm_pgtable_visit_ctx *ctx, 
{

	struct hyp_fixmap_slot *slot = per_cpu_ptr(&fixmap_slots, (u64)ctx->arg);



	if (!kvm_pte_valid(ctx->old) || ctx->level != KVM_PGTABLE_MAX_LEVELS - 1)

	if (!kvm_pte_valid(ctx->old) || ctx->level != KVM_PGTABLE_LAST_LEVEL)

		return -EINVAL;



	slot->addr = ctx->addr;