[PATCH v4 5/7] KVM: arm64: Support handling access faults for PUD hugepages
From: Punit Agrawal <hidden>
Date: 2018-07-05 14:09:53
Also in:
kvmarm, lkml
Subsystem:
arm port, arm64 port (aarch64 architecture), kernel virtual machine (kvm), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Russell King, Catalin Marinas, Will Deacon, Paolo Bonzini, Marc Zyngier, Oliver Upton, Linus Torvalds
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: Punit Agrawal <redacted> Cc: Christoffer Dall <redacted> Cc: Marc Zyngier <redacted> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <redacted> --- arch/arm/include/asm/kvm_mmu.h | 8 ++++++++ arch/arm64/include/asm/kvm_mmu.h | 7 +++++++ arch/arm64/include/asm/pgtable.h | 6 ++++++ virt/kvm/arm/mmu.c | 14 +++++++++++++- 4 files changed, 34 insertions(+), 1 deletion(-)
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index d05c8986e495..a4298d429efc 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h@@ -78,6 +78,8 @@ 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_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT) + #define kvm_pmd_mkhuge(pmd) pmd_mkhuge(pmd) /*
@@ -102,6 +104,12 @@ 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 void kvm_set_pmd(pmd_t *pmd, pmd_t new_pmd) { *pmd = new_pmd;
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 15bc1be8f82f..4d2780c588b0 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h@@ -175,6 +175,8 @@ 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)
@@ -254,6 +256,11 @@ 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); +} + static inline bool kvm_page_empty(void *ptr) { struct page *ptr_page = virt_to_page(ptr);
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 1bdeca8918a6..a64a5c35beb1 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h@@ -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));
@@ -380,6 +385,7 @@ 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))
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index ccdea0edabb3..94a91bcdd152 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c@@ -1609,6 +1609,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, */ 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;
@@ -1618,7 +1619,18 @@ 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); + pud = stage2_get_pud(vcpu->kvm, NULL, fault_ipa); + if (!pud || pud_none(*pud)) + goto out; /* Nothing there */ + + if (pud_huge(*pud)) { /* HugeTLB */ + *pud = kvm_s2pud_mkyoung(*pud); + pfn = kvm_pud_pfn(*pud); + pfn_valid = true; + goto out; + } + + pmd = stage2_pmd_offset(pud, fault_ipa); if (!pmd || pmd_none(*pmd)) /* Nothing there */ goto out;
--
2.17.1