On 08/06/2011 01:39 PM, Christoffer Dall wrote:
Handles the guest faults in KVM by mapping in corresponding user pages
in the 2nd stage page tables.
Introduces new ARM-specific kernel memory types, PAGE_KVM_GUEST and
pgprot_guest variables used to map 2nd stage memory for KVM guests.
+static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
+ gfn_t gfn, struct kvm_memory_slot *memslot)
+{
+ pfn_t pfn;
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte, new_pte;
+
+ pfn = gfn_to_pfn(vcpu->kvm, gfn);
+
+ if (is_error_pfn(pfn)) {
+ kvm_err(-EFAULT, "Guest gfn %u (0x%08lx) does not have "
+ "corresponding host mapping",
+ gfn, gfn<< PAGE_SHIFT);
+ return -EFAULT;
+ }
+
+ /* Create 2nd stage page table mapping - Level 1 */
+ pgd = vcpu->kvm->arch.pgd + pgd_index(fault_ipa);
+ pud = pud_offset(pgd, fault_ipa);
+ if (pud_none(*pud)) {
+ pmd = pmd_alloc_one(NULL, fault_ipa);
+ if (!pmd) {
+ kvm_err(-ENOMEM, "Cannot allocate 2nd stage pmd");
+ return -ENOMEM;
+ }
+ pud_populate(NULL, pud, pmd);
+ pmd += pmd_index(fault_ipa);
Don't we need locking here? Another vcpu may have executed pud_populate
concurrently.
+ } else
+ pmd = pmd_offset(pud, fault_ipa);
+
+ /* Create 2nd stage page table mapping - Level 2 */
+ if (pmd_none(*pmd)) {
+ pte = pte_alloc_one_kernel(NULL, fault_ipa);
+ if (!pte) {
+ kvm_err(-ENOMEM, "Cannot allocate 2nd stage pte");
+ return -ENOMEM;
+ }
+ pmd_populate_kernel(NULL, pmd, pte);
+ pte += pte_index(fault_ipa);
+ } else
+ pte = pte_offset_kernel(pmd, fault_ipa);
+
+ /* Create 2nd stage page table mapping - Level 3 */
+ new_pte = pfn_pte(pfn, PAGE_KVM_GUEST);
+ set_pte_ext(pte, new_pte, 0);
+
+ return 0;
+}
+
+#define HSR_ABT_FS (0x3f)
--
error compiling committee.c: too many arguments to function
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