Commit eb3f0624 authored by Punit Agrawal's avatar Punit Agrawal Committed by Marc Zyngier
Browse files

KVM: arm64: Support handling access faults for PUD hugepages 



In preparation for creating larger hugepages at Stage 2, extend the
access fault handling at Stage 2 to support PUD hugepages when
encountered.

Provide trivial helpers for arm32 to allow sharing of code.

Signed-off-by: default avatarPunit Agrawal <punit.agrawal@arm.com>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[ Replaced BUG() => WARN_ON(1) in PUD helpers ]
Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 86d1c55e

arch/arm/include/asm/kvm_mmu.h

+9 −0
Original line number Diff line number Diff line
@@ -85,6 +85,9 @@ void kvm_clear_hyp_idmap(void); 
#define kvm_pfn_pte(pfn, prot)	pfn_pte(pfn, prot)

#define kvm_pfn_pmd(pfn, prot)	pfn_pmd(pfn, prot)



#define kvm_pud_pfn(pud)	({ WARN_ON(1); 0; })





#define kvm_pmd_mkhuge(pmd)	pmd_mkhuge(pmd)



/*
@@ -108,6 +111,12 @@ static inline bool kvm_s2pud_exec(pud_t *pud) 
	return false;

}



static inline pud_t kvm_s2pud_mkyoung(pud_t pud)

{

	BUG();

	return pud;

}



static inline pte_t kvm_s2pte_mkwrite(pte_t pte)

{

	pte_val(pte) |= L_PTE_S2_RDWR;

arch/arm64/include/asm/kvm_mmu.h

+7 −0
Original line number Diff line number Diff line
@@ -187,6 +187,8 @@ void kvm_clear_hyp_idmap(void); 
#define kvm_pfn_pte(pfn, prot)		pfn_pte(pfn, prot)

#define kvm_pfn_pmd(pfn, prot)		pfn_pmd(pfn, prot)



#define kvm_pud_pfn(pud)		pud_pfn(pud)



#define kvm_pmd_mkhuge(pmd)		pmd_mkhuge(pmd)



static inline pte_t kvm_s2pte_mkwrite(pte_t pte)
@@ -266,6 +268,11 @@ static inline bool kvm_s2pud_exec(pud_t *pudp) 
	return !(READ_ONCE(pud_val(*pudp)) & PUD_S2_XN);

}



static inline pud_t kvm_s2pud_mkyoung(pud_t pud)

{

	return pud_mkyoung(pud);

}



#define hyp_pte_table_empty(ptep) kvm_page_empty(ptep)



#ifdef __PAGETABLE_PMD_FOLDED

arch/arm64/include/asm/pgtable.h

+6 −0
Original line number Diff line number Diff line
@@ -314,6 +314,11 @@ static inline pte_t pud_pte(pud_t pud) 
	return __pte(pud_val(pud));

}



static inline pud_t pte_pud(pte_t pte)

{

	return __pud(pte_val(pte));

}



static inline pmd_t pud_pmd(pud_t pud)

{

	return __pmd(pud_val(pud));
@@ -381,6 +386,7 @@ static inline int pmd_protnone(pmd_t pmd) 
#define pfn_pmd(pfn,prot)	__pmd(__phys_to_pmd_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))

#define mk_pmd(page,prot)	pfn_pmd(page_to_pfn(page),prot)



#define pud_mkyoung(pud)	pte_pud(pte_mkyoung(pud_pte(pud)))

#define pud_write(pud)		pte_write(pud_pte(pud))



#define __pud_to_phys(pud)	__pte_to_phys(pud_pte(pud))

virt/kvm/arm/mmu.c

+11 −11
Original line number Diff line number Diff line
@@ -1698,6 +1698,7 @@ out_unlock: 
 */

static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)

{

	pud_t *pud;

	pmd_t *pmd;

	pte_t *pte;

	kvm_pfn_t pfn;
@@ -1707,24 +1708,23 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) 


	spin_lock(&vcpu->kvm->mmu_lock);



	pmd = stage2_get_pmd(vcpu->kvm, NULL, fault_ipa);

	if (!pmd || pmd_none(*pmd))	/* Nothing there */

	if (!stage2_get_leaf_entry(vcpu->kvm, fault_ipa, &pud, &pmd, &pte))

		goto out;



	if (pmd_thp_or_huge(*pmd)) {	/* THP, HugeTLB */

	if (pud) {		/* HugeTLB */

		*pud = kvm_s2pud_mkyoung(*pud);

		pfn = kvm_pud_pfn(*pud);

		pfn_valid = true;

	} else	if (pmd) {	/* THP, HugeTLB */

		*pmd = pmd_mkyoung(*pmd);

		pfn = pmd_pfn(*pmd);

		pfn_valid = true;

		goto out;

	}



	pte = pte_offset_kernel(pmd, fault_ipa);

	if (pte_none(*pte))		/* Nothing there either */

		goto out;



	} else {

		*pte = pte_mkyoung(*pte);	/* Just a page... */

		pfn = pte_pfn(*pte);

		pfn_valid = true;

	}



out:

	spin_unlock(&vcpu->kvm->mmu_lock);

	if (pfn_valid)

CRA Git | Maintained and supported by SUSTech CRA and CCSE