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Commit c62ee2b2 authored by Marc Zyngier's avatar Marc Zyngier Committed by Christoffer Dall
Browse files

ARM: KVM: abstract most MMU operations 



Move low level MMU-related operations to kvm_mmu.h. This makes
the MMU code reusable by the arm64 port.

Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent c088f8f0

arch/arm/include/asm/kvm_mmu.h

+58 −0
Original line number Diff line number Diff line
@@ -19,6 +19,9 @@ 
#ifndef __ARM_KVM_MMU_H__

#define __ARM_KVM_MMU_H__



#include <asm/cacheflush.h>

#include <asm/pgalloc.h>



int create_hyp_mappings(void *from, void *to);

int create_hyp_io_mappings(void *from, void *to, phys_addr_t);

void free_hyp_pmds(void);
@@ -36,6 +39,16 @@ phys_addr_t kvm_mmu_get_httbr(void); 
int kvm_mmu_init(void);

void kvm_clear_hyp_idmap(void);



static inline void kvm_set_pte(pte_t *pte, pte_t new_pte)

{

	pte_val(*pte) = new_pte;

	/*

	 * flush_pmd_entry just takes a void pointer and cleans the necessary

	 * cache entries, so we can reuse the function for ptes.

	 */

	flush_pmd_entry(pte);

}



static inline bool kvm_is_write_fault(unsigned long hsr)

{

	unsigned long hsr_ec = hsr >> HSR_EC_SHIFT;
@@ -47,4 +60,49 @@ static inline bool kvm_is_write_fault(unsigned long hsr) 
		return true;

}



static inline void kvm_clean_pgd(pgd_t *pgd)

{

	clean_dcache_area(pgd, PTRS_PER_S2_PGD * sizeof(pgd_t));

}



static inline void kvm_clean_pmd_entry(pmd_t *pmd)

{

	clean_pmd_entry(pmd);

}



static inline void kvm_clean_pte(pte_t *pte)

{

	clean_pte_table(pte);

}



static inline void kvm_set_s2pte_writable(pte_t *pte)

{

	pte_val(*pte) |= L_PTE_S2_RDWR;

}



struct kvm;



static inline void coherent_icache_guest_page(struct kvm *kvm, gfn_t gfn)

{

	/*

	 * If we are going to insert an instruction page and the icache is

	 * either VIPT or PIPT, there is a potential problem where the host

	 * (or another VM) may have used the same page as this guest, and we

	 * read incorrect data from the icache.  If we're using a PIPT cache,

	 * we can invalidate just that page, but if we are using a VIPT cache

	 * we need to invalidate the entire icache - damn shame - as written

	 * in the ARM ARM (DDI 0406C.b - Page B3-1393).

	 *

	 * VIVT caches are tagged using both the ASID and the VMID and doesn't

	 * need any kind of flushing (DDI 0406C.b - Page B3-1392).

	 */

	if (icache_is_pipt()) {

		unsigned long hva = gfn_to_hva(kvm, gfn);

		__cpuc_coherent_user_range(hva, hva + PAGE_SIZE);

	} else if (!icache_is_vivt_asid_tagged()) {

		/* any kind of VIPT cache */

		__flush_icache_all();

	}

}



#endif /* __ARM_KVM_MMU_H__ */

arch/arm/kvm/mmu.c

+12 −46
Original line number Diff line number Diff line
@@ -28,8 +28,6 @@ 
#include <asm/kvm_mmio.h>

#include <asm/kvm_asm.h>

#include <asm/kvm_emulate.h>

#include <asm/mach/map.h>

#include <trace/events/kvm.h>



#include "trace.h"
@@ -42,16 +40,6 @@ static void kvm_tlb_flush_vmid(struct kvm *kvm) 
	kvm_call_hyp(__kvm_tlb_flush_vmid, kvm);

}



static void kvm_set_pte(pte_t *pte, pte_t new_pte)

{

	pte_val(*pte) = new_pte;

	/*

	 * flush_pmd_entry just takes a void pointer and cleans the necessary

	 * cache entries, so we can reuse the function for ptes.

	 */

	flush_pmd_entry(pte);

}



static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,

				  int min, int max)

{
@@ -290,7 +278,7 @@ int kvm_alloc_stage2_pgd(struct kvm *kvm) 
	VM_BUG_ON((unsigned long)pgd & (S2_PGD_SIZE - 1));



	memset(pgd, 0, PTRS_PER_S2_PGD * sizeof(pgd_t));

	clean_dcache_area(pgd, PTRS_PER_S2_PGD * sizeof(pgd_t));

	kvm_clean_pgd(pgd);

	kvm->arch.pgd = pgd;



	return 0;
@@ -422,9 +410,9 @@ static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, 
			return 0; /* ignore calls from kvm_set_spte_hva */

		pmd = mmu_memory_cache_alloc(cache);

		pud_populate(NULL, pud, pmd);

		pmd += pmd_index(addr);

		get_page(virt_to_page(pud));

	} else

	}



	pmd = pmd_offset(pud, addr);



	/* Create 2nd stage page table mapping - Level 2 */
@@ -432,11 +420,11 @@ static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, 
		if (!cache)

			return 0; /* ignore calls from kvm_set_spte_hva */

		pte = mmu_memory_cache_alloc(cache);

		clean_pte_table(pte);

		kvm_clean_pte(pte);

		pmd_populate_kernel(NULL, pmd, pte);

		pte += pte_index(addr);

		get_page(virt_to_page(pmd));

	} else

	}



	pte = pte_offset_kernel(pmd, addr);



	if (iomap && pte_present(*pte))
@@ -473,7 +461,8 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, 
	pfn = __phys_to_pfn(pa);



	for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {

		pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE | L_PTE_S2_RDWR);

		pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE);

		kvm_set_s2pte_writable(&pte);



		ret = mmu_topup_memory_cache(&cache, 2, 2);

		if (ret)
@@ -492,29 +481,6 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, 
	return ret;

}



static void coherent_icache_guest_page(struct kvm *kvm, gfn_t gfn)

{

	/*

	 * If we are going to insert an instruction page and the icache is

	 * either VIPT or PIPT, there is a potential problem where the host

	 * (or another VM) may have used the same page as this guest, and we

	 * read incorrect data from the icache.  If we're using a PIPT cache,

	 * we can invalidate just that page, but if we are using a VIPT cache

	 * we need to invalidate the entire icache - damn shame - as written

	 * in the ARM ARM (DDI 0406C.b - Page B3-1393).

	 *

	 * VIVT caches are tagged using both the ASID and the VMID and doesn't

	 * need any kind of flushing (DDI 0406C.b - Page B3-1392).

	 */

	if (icache_is_pipt()) {

		unsigned long hva = gfn_to_hva(kvm, gfn);

		__cpuc_coherent_user_range(hva, hva + PAGE_SIZE);

	} else if (!icache_is_vivt_asid_tagged()) {

		/* any kind of VIPT cache */

		__flush_icache_all();

	}

}



static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,

			  gfn_t gfn, struct kvm_memory_slot *memslot,

			  unsigned long fault_status)
@@ -560,7 +526,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, 
	if (mmu_notifier_retry(vcpu->kvm, mmu_seq))

		goto out_unlock;

	if (writable) {

		pte_val(new_pte) |= L_PTE_S2_RDWR;

		kvm_set_s2pte_writable(&new_pte);

		kvm_set_pfn_dirty(pfn);

	}

	stage2_set_pte(vcpu->kvm, memcache, fault_ipa, &new_pte, false);
@@ -774,7 +740,7 @@ void kvm_clear_hyp_idmap(void) 
		pmd = pmd_offset(pud, addr);



		pud_clear(pud);

		clean_pmd_entry(pmd);

		kvm_clean_pmd_entry(pmd);

		pmd_free(NULL, (pmd_t *)((unsigned long)pmd & PAGE_MASK));

	} while (pgd++, addr = next, addr < end);

}