arch/arm64/include/asm/kvm_mmu.h - linux - Git at Google

 /*
  * Copyright (C) 2012,2013 - ARM Ltd
  * Author: Marc Zyngier <marc.zyngier@arm.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */

 #ifndef __ARM64_KVM_MMU_H__
 #define __ARM64_KVM_MMU_H__

 #include <asm/page.h>
 #include <asm/memory.h>

 /*
  * As we only have the TTBR0_EL2 register, we cannot express
  * "negative" addresses. This makes it impossible to directly share
  * mappings with the kernel.
  *
  * Instead, give the HYP mode its own VA region at a fixed offset from
  * the kernel by just masking the top bits (which are all ones for a
  * kernel address).
  */
 #define HYP_PAGE_OFFSET_SHIFT	VA_BITS
 #define HYP_PAGE_OFFSET_MASK	((UL(1) << HYP_PAGE_OFFSET_SHIFT) - 1)
 #define HYP_PAGE_OFFSET		(PAGE_OFFSET & HYP_PAGE_OFFSET_MASK)

 /*
  * Our virtual mapping for the idmap-ed MMU-enable code. Must be
  * shared across all the page-tables. Conveniently, we use the last
  * possible page, where no kernel mapping will ever exist.
  */
 #define TRAMPOLINE_VA		(HYP_PAGE_OFFSET_MASK & PAGE_MASK)

 /*
  * KVM_MMU_CACHE_MIN_PAGES is the number of stage2 page table translation
  * levels in addition to the PGD and potentially the PUD which are
  * pre-allocated (we pre-allocate the fake PGD and the PUD when the Stage-2
  * tables use one level of tables less than the kernel.
  */
 #ifdef CONFIG_ARM64_64K_PAGES
 #define KVM_MMU_CACHE_MIN_PAGES	1
 #else
 #define KVM_MMU_CACHE_MIN_PAGES	2
 #endif

 #ifdef __ASSEMBLY__

 /*
  * Convert a kernel VA into a HYP VA.
  * reg: VA to be converted.
  */
 .macro kern_hyp_va	reg
 	and	\reg, \reg, #HYP_PAGE_OFFSET_MASK
 .endm

 #else

 #include <asm/pgalloc.h>
 #include <asm/cachetype.h>
 #include <asm/cacheflush.h>

 #define KERN_TO_HYP(kva)	((unsigned long)kva - PAGE_OFFSET + HYP_PAGE_OFFSET)

 /*
  * We currently only support a 40bit IPA.
  */
 #define KVM_PHYS_SHIFT	(40)
 #define KVM_PHYS_SIZE	(1UL << KVM_PHYS_SHIFT)
 #define KVM_PHYS_MASK	(KVM_PHYS_SIZE - 1UL)

 int create_hyp_mappings(void *from, void *to);
 int create_hyp_io_mappings(void *from, void *to, phys_addr_t);
 void free_boot_hyp_pgd(void);
 void free_hyp_pgds(void);

 void stage2_unmap_vm(struct kvm *kvm);
 int kvm_alloc_stage2_pgd(struct kvm *kvm);
 void kvm_free_stage2_pgd(struct kvm *kvm);
 int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
 			  phys_addr_t pa, unsigned long size, bool writable);

 int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run);

 void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu);

 phys_addr_t kvm_mmu_get_httbr(void);
 phys_addr_t kvm_mmu_get_boot_httbr(void);
 phys_addr_t kvm_get_idmap_vector(void);
 int kvm_mmu_init(void);
 void kvm_clear_hyp_idmap(void);

 #define	kvm_set_pte(ptep, pte)		set_pte(ptep, pte)
 #define	kvm_set_pmd(pmdp, pmd)		set_pmd(pmdp, pmd)

 static inline void kvm_clean_pgd(pgd_t *pgd) {}
 static inline void kvm_clean_pmd(pmd_t *pmd) {}
 static inline void kvm_clean_pmd_entry(pmd_t *pmd) {}
 static inline void kvm_clean_pte(pte_t *pte) {}
 static inline void kvm_clean_pte_entry(pte_t *pte) {}

 static inline void kvm_set_s2pte_writable(pte_t *pte)
 {
 	pte_val(*pte) |= PTE_S2_RDWR;
 }

 static inline void kvm_set_s2pmd_writable(pmd_t *pmd)
 {
 	pmd_val(*pmd) |= PMD_S2_RDWR;
 }

 #define kvm_pgd_addr_end(addr, end)	pgd_addr_end(addr, end)
 #define kvm_pud_addr_end(addr, end)	pud_addr_end(addr, end)
 #define kvm_pmd_addr_end(addr, end)	pmd_addr_end(addr, end)

 /*
  * In the case where PGDIR_SHIFT is larger than KVM_PHYS_SHIFT, we can address
  * the entire IPA input range with a single pgd entry, and we would only need
  * one pgd entry.  Note that in this case, the pgd is actually not used by
  * the MMU for Stage-2 translations, but is merely a fake pgd used as a data
  * structure for the kernel pgtable macros to work.
  */
 #if PGDIR_SHIFT > KVM_PHYS_SHIFT
 #define PTRS_PER_S2_PGD_SHIFT	0
 #else
 #define PTRS_PER_S2_PGD_SHIFT	(KVM_PHYS_SHIFT - PGDIR_SHIFT)
 #endif
 #define PTRS_PER_S2_PGD		(1 << PTRS_PER_S2_PGD_SHIFT)
 #define S2_PGD_ORDER		get_order(PTRS_PER_S2_PGD * sizeof(pgd_t))

 /*
  * If we are concatenating first level stage-2 page tables, we would have less
  * than or equal to 16 pointers in the fake PGD, because that's what the
  * architecture allows.  In this case, (4 - CONFIG_ARM64_PGTABLE_LEVELS)
  * represents the first level for the host, and we add 1 to go to the next
  * level (which uses contatenation) for the stage-2 tables.
  */
 #if PTRS_PER_S2_PGD <= 16
 #define KVM_PREALLOC_LEVEL	(4 - CONFIG_ARM64_PGTABLE_LEVELS + 1)
 #else
 #define KVM_PREALLOC_LEVEL	(0)
 #endif

 /**
  * kvm_prealloc_hwpgd - allocate inital table for VTTBR
  * @kvm:	The KVM struct pointer for the VM.
  * @pgd:	The kernel pseudo pgd
  *
  * When the kernel uses more levels of page tables than the guest, we allocate
  * a fake PGD and pre-populate it to point to the next-level page table, which
  * will be the real initial page table pointed to by the VTTBR.
  *
  * When KVM_PREALLOC_LEVEL==2, we allocate a single page for the PMD and
  * the kernel will use folded pud.  When KVM_PREALLOC_LEVEL==1, we
  * allocate 2 consecutive PUD pages.
  */
 static inline int kvm_prealloc_hwpgd(struct kvm *kvm, pgd_t *pgd)
 {
 	unsigned int i;
 	unsigned long hwpgd;

 	if (KVM_PREALLOC_LEVEL == 0)
 		return 0;

 	hwpgd = __get_free_pages(GFP_KERNEL | __GFP_ZERO, PTRS_PER_S2_PGD_SHIFT);
 	if (!hwpgd)
 		return -ENOMEM;

 	for (i = 0; i < PTRS_PER_S2_PGD; i++) {
 		if (KVM_PREALLOC_LEVEL == 1)
 			pgd_populate(NULL, pgd + i,
 				     (pud_t *)hwpgd + i * PTRS_PER_PUD);
 		else if (KVM_PREALLOC_LEVEL == 2)
 			pud_populate(NULL, pud_offset(pgd, 0) + i,
 				     (pmd_t *)hwpgd + i * PTRS_PER_PMD);
 	}

 	return 0;
 }

 static inline void *kvm_get_hwpgd(struct kvm *kvm)
 {
 	pgd_t *pgd = kvm->arch.pgd;
 	pud_t *pud;

 	if (KVM_PREALLOC_LEVEL == 0)
 		return pgd;

 	pud = pud_offset(pgd, 0);
 	if (KVM_PREALLOC_LEVEL == 1)
 		return pud;

 	BUG_ON(KVM_PREALLOC_LEVEL != 2);
 	return pmd_offset(pud, 0);
 }

 static inline void kvm_free_hwpgd(struct kvm *kvm)
 {
 	if (KVM_PREALLOC_LEVEL > 0) {
 		unsigned long hwpgd = (unsigned long)kvm_get_hwpgd(kvm);
 		free_pages(hwpgd, PTRS_PER_S2_PGD_SHIFT);
 	}
 }

 static inline bool kvm_page_empty(void *ptr)
 {
 	struct page *ptr_page = virt_to_page(ptr);
 	return page_count(ptr_page) == 1;
 }

 #define kvm_pte_table_empty(kvm, ptep) kvm_page_empty(ptep)

 #ifdef __PAGETABLE_PMD_FOLDED
 #define kvm_pmd_table_empty(kvm, pmdp) (0)
 #else
 #define kvm_pmd_table_empty(kvm, pmdp) \
 	(kvm_page_empty(pmdp) && (!(kvm) || KVM_PREALLOC_LEVEL < 2))
 #endif

 #ifdef __PAGETABLE_PUD_FOLDED
 #define kvm_pud_table_empty(kvm, pudp) (0)
 #else
 #define kvm_pud_table_empty(kvm, pudp) \
 	(kvm_page_empty(pudp) && (!(kvm) || KVM_PREALLOC_LEVEL < 1))
 #endif


 struct kvm;

 #define kvm_flush_dcache_to_poc(a,l)	__flush_dcache_area((a), (l))

 static inline bool vcpu_has_cache_enabled(struct kvm_vcpu *vcpu)
 {
 	return (vcpu_sys_reg(vcpu, SCTLR_EL1) & 0b101) == 0b101;
 }

 static inline void __coherent_cache_guest_page(struct kvm_vcpu *vcpu, pfn_t pfn,
 					       unsigned long size,
 					       bool ipa_uncached)
 {
 	void *va = page_address(pfn_to_page(pfn));

 	if (!vcpu_has_cache_enabled(vcpu) || ipa_uncached)
 		kvm_flush_dcache_to_poc(va, size);

 	if (!icache_is_aliasing()) {		/* PIPT */
 		flush_icache_range((unsigned long)va,
 				   (unsigned long)va + size);
 	} else if (!icache_is_aivivt()) {	/* non ASID-tagged VIVT */
 		/* any kind of VIPT cache */
 		__flush_icache_all();
 	}
 }

 static inline void __kvm_flush_dcache_pte(pte_t pte)
 {
 	struct page *page = pte_page(pte);
 	kvm_flush_dcache_to_poc(page_address(page), PAGE_SIZE);
 }

 static inline void __kvm_flush_dcache_pmd(pmd_t pmd)
 {
 	struct page *page = pmd_page(pmd);
 	kvm_flush_dcache_to_poc(page_address(page), PMD_SIZE);
 }

 static inline void __kvm_flush_dcache_pud(pud_t pud)
 {
 	struct page *page = pud_page(pud);
 	kvm_flush_dcache_to_poc(page_address(page), PUD_SIZE);
 }

 #define kvm_virt_to_phys(x)		__virt_to_phys((unsigned long)(x))

 void kvm_set_way_flush(struct kvm_vcpu *vcpu);
 void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled);

 #endif /* __ASSEMBLY__ */
 #endif /* __ARM64_KVM_MMU_H__ */
	/*
	* Copyright (C) 2012,2013 - ARM Ltd
	* Author: Marc Zyngier <marc.zyngier@arm.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	*/

	#ifndef __ARM64_KVM_MMU_H__
	#define __ARM64_KVM_MMU_H__

	#include <asm/page.h>
	#include <asm/memory.h>

	/*
	* As we only have the TTBR0_EL2 register, we cannot express
	* "negative" addresses. This makes it impossible to directly share
	* mappings with the kernel.
	*
	* Instead, give the HYP mode its own VA region at a fixed offset from
	* the kernel by just masking the top bits (which are all ones for a
	* kernel address).
	*/
	#define HYP_PAGE_OFFSET_SHIFT VA_BITS
	#define HYP_PAGE_OFFSET_MASK ((UL(1) << HYP_PAGE_OFFSET_SHIFT) - 1)
	#define HYP_PAGE_OFFSET (PAGE_OFFSET & HYP_PAGE_OFFSET_MASK)

	/*
	* Our virtual mapping for the idmap-ed MMU-enable code. Must be
	* shared across all the page-tables. Conveniently, we use the last
	* possible page, where no kernel mapping will ever exist.
	*/
	#define TRAMPOLINE_VA (HYP_PAGE_OFFSET_MASK & PAGE_MASK)

	/*
	* KVM_MMU_CACHE_MIN_PAGES is the number of stage2 page table translation
	* levels in addition to the PGD and potentially the PUD which are
	* pre-allocated (we pre-allocate the fake PGD and the PUD when the Stage-2
	* tables use one level of tables less than the kernel.
	*/
	#ifdef CONFIG_ARM64_64K_PAGES
	#define KVM_MMU_CACHE_MIN_PAGES 1
	#else
	#define KVM_MMU_CACHE_MIN_PAGES 2
	#endif

	#ifdef __ASSEMBLY__

	/*
	* Convert a kernel VA into a HYP VA.
	* reg: VA to be converted.
	*/
	.macro kern_hyp_va reg
	and \reg, \reg, #HYP_PAGE_OFFSET_MASK
	.endm

	#else

	#include <asm/pgalloc.h>
	#include <asm/cachetype.h>
	#include <asm/cacheflush.h>

	#define KERN_TO_HYP(kva) ((unsigned long)kva - PAGE_OFFSET + HYP_PAGE_OFFSET)

	/*
	* We currently only support a 40bit IPA.
	*/
	#define KVM_PHYS_SHIFT (40)
	#define KVM_PHYS_SIZE (1UL << KVM_PHYS_SHIFT)
	#define KVM_PHYS_MASK (KVM_PHYS_SIZE - 1UL)

	int create_hyp_mappings(void from, void to);
	int create_hyp_io_mappings(void from, void to, phys_addr_t);
	void free_boot_hyp_pgd(void);
	void free_hyp_pgds(void);

	void stage2_unmap_vm(struct kvm *kvm);
	int kvm_alloc_stage2_pgd(struct kvm *kvm);
	void kvm_free_stage2_pgd(struct kvm *kvm);
	int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
	phys_addr_t pa, unsigned long size, bool writable);

	int kvm_handle_guest_abort(struct kvm_vcpu vcpu, struct kvm_run run);

	void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu);

	phys_addr_t kvm_mmu_get_httbr(void);
	phys_addr_t kvm_mmu_get_boot_httbr(void);
	phys_addr_t kvm_get_idmap_vector(void);
	int kvm_mmu_init(void);
	void kvm_clear_hyp_idmap(void);

	#define kvm_set_pte(ptep, pte) set_pte(ptep, pte)
	#define kvm_set_pmd(pmdp, pmd) set_pmd(pmdp, pmd)

	static inline void kvm_clean_pgd(pgd_t *pgd) {}
	static inline void kvm_clean_pmd(pmd_t *pmd) {}
	static inline void kvm_clean_pmd_entry(pmd_t *pmd) {}
	static inline void kvm_clean_pte(pte_t *pte) {}
	static inline void kvm_clean_pte_entry(pte_t *pte) {}

	static inline void kvm_set_s2pte_writable(pte_t *pte)
	{
	pte_val(*pte) \|= PTE_S2_RDWR;
	}

	static inline void kvm_set_s2pmd_writable(pmd_t *pmd)
	{
	pmd_val(*pmd) \|= PMD_S2_RDWR;
	}

	#define kvm_pgd_addr_end(addr, end) pgd_addr_end(addr, end)
	#define kvm_pud_addr_end(addr, end) pud_addr_end(addr, end)
	#define kvm_pmd_addr_end(addr, end) pmd_addr_end(addr, end)

	/*
	* In the case where PGDIR_SHIFT is larger than KVM_PHYS_SHIFT, we can address
	* the entire IPA input range with a single pgd entry, and we would only need
	* one pgd entry. Note that in this case, the pgd is actually not used by
	* the MMU for Stage-2 translations, but is merely a fake pgd used as a data
	* structure for the kernel pgtable macros to work.
	*/
	#if PGDIR_SHIFT > KVM_PHYS_SHIFT
	#define PTRS_PER_S2_PGD_SHIFT 0
	#else
	#define PTRS_PER_S2_PGD_SHIFT (KVM_PHYS_SHIFT - PGDIR_SHIFT)
	#endif
	#define PTRS_PER_S2_PGD (1 << PTRS_PER_S2_PGD_SHIFT)
	#define S2_PGD_ORDER get_order(PTRS_PER_S2_PGD * sizeof(pgd_t))

	/*
	* If we are concatenating first level stage-2 page tables, we would have less
	* than or equal to 16 pointers in the fake PGD, because that's what the
	* architecture allows. In this case, (4 - CONFIG_ARM64_PGTABLE_LEVELS)
	* represents the first level for the host, and we add 1 to go to the next
	* level (which uses contatenation) for the stage-2 tables.
	*/
	#if PTRS_PER_S2_PGD <= 16
	#define KVM_PREALLOC_LEVEL (4 - CONFIG_ARM64_PGTABLE_LEVELS + 1)
	#else
	#define KVM_PREALLOC_LEVEL (0)
	#endif

	/**
	* kvm_prealloc_hwpgd - allocate inital table for VTTBR
	* @kvm: The KVM struct pointer for the VM.
	* @pgd: The kernel pseudo pgd
	*
	* When the kernel uses more levels of page tables than the guest, we allocate
	* a fake PGD and pre-populate it to point to the next-level page table, which
	* will be the real initial page table pointed to by the VTTBR.
	*
	* When KVM_PREALLOC_LEVEL==2, we allocate a single page for the PMD and
	* the kernel will use folded pud. When KVM_PREALLOC_LEVEL==1, we
	* allocate 2 consecutive PUD pages.
	*/
	static inline int kvm_prealloc_hwpgd(struct kvm kvm, pgd_t pgd)
	{
	unsigned int i;
	unsigned long hwpgd;

	if (KVM_PREALLOC_LEVEL == 0)
	return 0;

	hwpgd = __get_free_pages(GFP_KERNEL \| __GFP_ZERO, PTRS_PER_S2_PGD_SHIFT);
	if (!hwpgd)
	return -ENOMEM;

	for (i = 0; i < PTRS_PER_S2_PGD; i++) {
	if (KVM_PREALLOC_LEVEL == 1)
	pgd_populate(NULL, pgd + i,
	(pud_t )hwpgd + i PTRS_PER_PUD);
	else if (KVM_PREALLOC_LEVEL == 2)
	pud_populate(NULL, pud_offset(pgd, 0) + i,
	(pmd_t )hwpgd + i PTRS_PER_PMD);
	}

	return 0;
	}

	static inline void kvm_get_hwpgd(struct kvm kvm)
	{
	pgd_t *pgd = kvm->arch.pgd;
	pud_t *pud;

	if (KVM_PREALLOC_LEVEL == 0)
	return pgd;

	pud = pud_offset(pgd, 0);
	if (KVM_PREALLOC_LEVEL == 1)
	return pud;

	BUG_ON(KVM_PREALLOC_LEVEL != 2);
	return pmd_offset(pud, 0);
	}

	static inline void kvm_free_hwpgd(struct kvm *kvm)
	{
	if (KVM_PREALLOC_LEVEL > 0) {
	unsigned long hwpgd = (unsigned long)kvm_get_hwpgd(kvm);
	free_pages(hwpgd, PTRS_PER_S2_PGD_SHIFT);
	}
	}

	static inline bool kvm_page_empty(void *ptr)
	{
	struct page *ptr_page = virt_to_page(ptr);
	return page_count(ptr_page) == 1;
	}

	#define kvm_pte_table_empty(kvm, ptep) kvm_page_empty(ptep)

	#ifdef __PAGETABLE_PMD_FOLDED
	#define kvm_pmd_table_empty(kvm, pmdp) (0)
	#else
	#define kvm_pmd_table_empty(kvm, pmdp) \
	(kvm_page_empty(pmdp) && (!(kvm) \|\| KVM_PREALLOC_LEVEL < 2))
	#endif

	#ifdef __PAGETABLE_PUD_FOLDED
	#define kvm_pud_table_empty(kvm, pudp) (0)
	#else
	#define kvm_pud_table_empty(kvm, pudp) \
	(kvm_page_empty(pudp) && (!(kvm) \|\| KVM_PREALLOC_LEVEL < 1))
	#endif


	struct kvm;

	#define kvm_flush_dcache_to_poc(a,l) __flush_dcache_area((a), (l))

	static inline bool vcpu_has_cache_enabled(struct kvm_vcpu *vcpu)
	{
	return (vcpu_sys_reg(vcpu, SCTLR_EL1) & 0b101) == 0b101;
	}

	static inline void __coherent_cache_guest_page(struct kvm_vcpu *vcpu, pfn_t pfn,
	unsigned long size,
	bool ipa_uncached)
	{
	void *va = page_address(pfn_to_page(pfn));

	if (!vcpu_has_cache_enabled(vcpu) \|\| ipa_uncached)
	kvm_flush_dcache_to_poc(va, size);

	if (!icache_is_aliasing()) { /* PIPT */
	flush_icache_range((unsigned long)va,
	(unsigned long)va + size);
	} else if (!icache_is_aivivt()) { /* non ASID-tagged VIVT */
	/* any kind of VIPT cache */
	__flush_icache_all();
	}
	}

	static inline void __kvm_flush_dcache_pte(pte_t pte)
	{
	struct page *page = pte_page(pte);
	kvm_flush_dcache_to_poc(page_address(page), PAGE_SIZE);
	}

	static inline void __kvm_flush_dcache_pmd(pmd_t pmd)
	{
	struct page *page = pmd_page(pmd);
	kvm_flush_dcache_to_poc(page_address(page), PMD_SIZE);
	}

	static inline void __kvm_flush_dcache_pud(pud_t pud)
	{
	struct page *page = pud_page(pud);
	kvm_flush_dcache_to_poc(page_address(page), PUD_SIZE);
	}

	#define kvm_virt_to_phys(x) __virt_to_phys((unsigned long)(x))

	void kvm_set_way_flush(struct kvm_vcpu *vcpu);
	void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled);

	#endif /* __ASSEMBLY__ */
	#endif /* __ARM64_KVM_MMU_H__ */