On 09/07/18 15:41, Punit Agrawal wrote:
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.agra...@arm.com>
Cc: Christoffer Dall <christoffer.d...@arm.com>
Cc: Marc Zyngier <marc.zyng...@arm.com>
Cc: Russell King <li...@armlinux.org.uk>
Cc: Catalin Marinas <catalin.mari...@arm.com>
Cc: Will Deacon <will.dea...@arm.com>
---
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 | 29 ++++++++++++++++-------------
4 files changed, 37 insertions(+), 13 deletions(-)
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)
Since we don't have PUD in arm32, it would be good to trigger a BUG()
instead of silently doing something wrong.
@@ -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;
+}
+
Like this. ^
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index e73909a31e02..d2c705e31584 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -1637,33 +1637,36 @@ 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)
{
- pmd_t *pmd;
- pte_t *pte;
+ pud_t *pud = NULL;
+ pmd_t *pmd = NULL;
+ pte_t *pte = NULL;
kvm_pfn_t pfn;
- bool pfn_valid = false;
+ bool found, pfn_valid = false;
nit: You could use pfn_valid instead of a new "found" variable.
trace_kvm_access_fault(fault_ipa);
spin_lock(&vcpu->kvm->mmu_lock);
- pmd = stage2_get_pmd(vcpu->kvm, NULL, fault_ipa);
- if (!pmd || pmd_none(*pmd)) /* Nothing there */
+ found = stage2_get_leaf_entry(vcpu->kvm, fault_ipa, &pud, &pmd, &pte);
+ if (!found)
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;
+ goto out;
You don't need these goto's and the out lable anymore.
+ } 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)
Otherwise look good to me.
Suzuki
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