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: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Christoffer 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: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index a49655f..3a40720 100644 (file)
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -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;

diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index c755b37..612032b 100644 (file)
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -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

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 50b1ef8..f51e227 100644 (file)
--- 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));
@@ -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))

diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 8e44dcc..bd74960 100644 (file)
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -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;
+       } else {
+               *pte = pte_mkyoung(*pte);       /* Just a page... */
+               pfn = pte_pfn(*pte);
+               pfn_valid = true;
        }
 
-       pte = pte_offset_kernel(pmd, fault_ipa);
-       if (pte_none(*pte))             /* Nothing there either */
-               goto out;
-
-       *pte = pte_mkyoung(*pte);       /* Just a page... */
-       pfn = pte_pfn(*pte);
-       pfn_valid = true;
 out:
        spin_unlock(&vcpu->kvm->mmu_lock);
        if (pfn_valid)