mirror of https://gitee.com/openkylin/linux.git
KVM: PPC: Book3S HV: Refactor radix page fault handler
The radix page fault handler accounts for all cases, including just needing to insert a pte. This breaks it up into separate functions for the two main cases; setting rc and inserting a pte. This allows us to make the setting of rc and inserting of a pte generic for any pgtable, not specific to the one for this guest. [paulus@ozlabs.org - reduced diffs from previous code] Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Suraj Jitindar Singh
Michael Ellerman
parent
9811c78e96
commit
04bae9d5b4
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@ -400,8 +400,9 @@ static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud,
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*/
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#define PTE_BITS_MUST_MATCH (~(_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED))
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static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long gpa,
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unsigned int level, unsigned long mmu_seq)
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static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
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unsigned long gpa, unsigned int level,
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unsigned long mmu_seq)
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{
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pgd_t *pgd;
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pud_t *pud, *new_pud = NULL;
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@ -410,7 +411,7 @@ static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long gpa,
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int ret;
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/* Traverse the guest's 2nd-level tree, allocate new levels needed */
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pgd = kvm->arch.pgtable + pgd_index(gpa);
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pgd = pgtable + pgd_index(gpa);
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pud = NULL;
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if (pgd_present(*pgd))
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pud = pud_offset(pgd, gpa);
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@ -565,95 +566,49 @@ static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long gpa,
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return ret;
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}
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int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
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unsigned long ea, unsigned long dsisr)
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static bool kvmppc_hv_handle_set_rc(struct kvm *kvm, pgd_t *pgtable,
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bool writing, unsigned long gpa)
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{
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unsigned long pgflags;
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unsigned int shift;
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pte_t *ptep;
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/*
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* Need to set an R or C bit in the 2nd-level tables;
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* since we are just helping out the hardware here,
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* it is sufficient to do what the hardware does.
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*/
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pgflags = _PAGE_ACCESSED;
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if (writing)
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pgflags |= _PAGE_DIRTY;
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/*
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* We are walking the secondary (partition-scoped) page table here.
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* We can do this without disabling irq because the Linux MM
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* subsystem doesn't do THP splits and collapses on this tree.
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*/
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ptep = __find_linux_pte(pgtable, gpa, NULL, &shift);
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if (ptep && pte_present(*ptep) && (!writing || pte_write(*ptep))) {
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kvmppc_radix_update_pte(kvm, ptep, 0, pgflags, gpa, shift);
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return true;
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}
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return false;
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}
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static int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu,
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unsigned long gpa,
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struct kvm_memory_slot *memslot,
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bool writing, bool kvm_ro,
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pte_t *inserted_pte, unsigned int *levelp)
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{
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struct kvm *kvm = vcpu->kvm;
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unsigned long mmu_seq;
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unsigned long gpa, gfn, hva;
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struct kvm_memory_slot *memslot;
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struct page *page = NULL;
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long ret;
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bool writing;
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unsigned long mmu_seq;
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unsigned long hva, gfn = gpa >> PAGE_SHIFT;
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bool upgrade_write = false;
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bool *upgrade_p = &upgrade_write;
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pte_t pte, *ptep;
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unsigned long pgflags;
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unsigned int shift, level;
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/* Check for unusual errors */
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if (dsisr & DSISR_UNSUPP_MMU) {
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pr_err("KVM: Got unsupported MMU fault\n");
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return -EFAULT;
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}
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if (dsisr & DSISR_BADACCESS) {
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/* Reflect to the guest as DSI */
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pr_err("KVM: Got radix HV page fault with DSISR=%lx\n", dsisr);
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kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
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return RESUME_GUEST;
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}
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/* Translate the logical address and get the page */
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gpa = vcpu->arch.fault_gpa & ~0xfffUL;
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gpa &= ~0xF000000000000000ul;
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gfn = gpa >> PAGE_SHIFT;
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if (!(dsisr & DSISR_PRTABLE_FAULT))
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gpa |= ea & 0xfff;
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memslot = gfn_to_memslot(kvm, gfn);
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/* No memslot means it's an emulated MMIO region */
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if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
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if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS |
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DSISR_SET_RC)) {
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/*
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* Bad address in guest page table tree, or other
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* unusual error - reflect it to the guest as DSI.
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*/
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kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
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return RESUME_GUEST;
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}
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return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
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dsisr & DSISR_ISSTORE);
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}
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writing = (dsisr & DSISR_ISSTORE) != 0;
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if (memslot->flags & KVM_MEM_READONLY) {
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if (writing) {
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/* give the guest a DSI */
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dsisr = DSISR_ISSTORE | DSISR_PROTFAULT;
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kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
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return RESUME_GUEST;
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}
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upgrade_p = NULL;
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}
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if (dsisr & DSISR_SET_RC) {
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/*
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* Need to set an R or C bit in the 2nd-level tables;
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* since we are just helping out the hardware here,
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* it is sufficient to do what the hardware does.
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*/
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pgflags = _PAGE_ACCESSED;
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if (writing)
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pgflags |= _PAGE_DIRTY;
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/*
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* We are walking the secondary page table here. We can do this
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* without disabling irq.
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*/
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spin_lock(&kvm->mmu_lock);
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ptep = __find_linux_pte(kvm->arch.pgtable,
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gpa, NULL, &shift);
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if (ptep && pte_present(*ptep) &&
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(!writing || pte_write(*ptep))) {
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kvmppc_radix_update_pte(kvm, ptep, 0, pgflags,
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gpa, shift);
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dsisr &= ~DSISR_SET_RC;
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}
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spin_unlock(&kvm->mmu_lock);
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if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
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DSISR_PROTFAULT | DSISR_SET_RC)))
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return RESUME_GUEST;
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}
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int ret;
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/* used to check for invalidations in progress */
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mmu_seq = kvm->mmu_notifier_seq;
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@ -666,7 +621,7 @@ int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
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* is that the page is writable.
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*/
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hva = gfn_to_hva_memslot(memslot, gfn);
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if (upgrade_p && __get_user_pages_fast(hva, 1, 1, &page) == 1) {
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if (!kvm_ro && __get_user_pages_fast(hva, 1, 1, &page) == 1) {
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upgrade_write = true;
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} else {
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unsigned long pfn;
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@ -724,7 +679,12 @@ int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
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}
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/* Allocate space in the tree and write the PTE */
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ret = kvmppc_create_pte(kvm, pte, gpa, level, mmu_seq);
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ret = kvmppc_create_pte(kvm, kvm->arch.pgtable, pte, gpa, level,
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mmu_seq);
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if (inserted_pte)
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*inserted_pte = pte;
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if (levelp)
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*levelp = level;
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if (page) {
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if (!ret && (pte_val(pte) & _PAGE_WRITE))
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@ -732,6 +692,82 @@ int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
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put_page(page);
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}
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return ret;
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}
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int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
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unsigned long ea, unsigned long dsisr)
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{
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struct kvm *kvm = vcpu->kvm;
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unsigned long gpa, gfn;
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struct kvm_memory_slot *memslot;
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long ret;
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bool writing = !!(dsisr & DSISR_ISSTORE);
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bool kvm_ro = false;
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/* Check for unusual errors */
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if (dsisr & DSISR_UNSUPP_MMU) {
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pr_err("KVM: Got unsupported MMU fault\n");
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return -EFAULT;
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}
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if (dsisr & DSISR_BADACCESS) {
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/* Reflect to the guest as DSI */
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pr_err("KVM: Got radix HV page fault with DSISR=%lx\n", dsisr);
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kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
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return RESUME_GUEST;
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}
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/* Translate the logical address */
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gpa = vcpu->arch.fault_gpa & ~0xfffUL;
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gpa &= ~0xF000000000000000ul;
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gfn = gpa >> PAGE_SHIFT;
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if (!(dsisr & DSISR_PRTABLE_FAULT))
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gpa |= ea & 0xfff;
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/* Get the corresponding memslot */
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memslot = gfn_to_memslot(kvm, gfn);
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/* No memslot means it's an emulated MMIO region */
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if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
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if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS |
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DSISR_SET_RC)) {
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/*
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* Bad address in guest page table tree, or other
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* unusual error - reflect it to the guest as DSI.
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*/
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kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
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return RESUME_GUEST;
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}
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return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea, writing);
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}
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if (memslot->flags & KVM_MEM_READONLY) {
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if (writing) {
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/* give the guest a DSI */
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kvmppc_core_queue_data_storage(vcpu, ea, DSISR_ISSTORE |
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DSISR_PROTFAULT);
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return RESUME_GUEST;
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}
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kvm_ro = true;
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}
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/* Failed to set the reference/change bits */
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if (dsisr & DSISR_SET_RC) {
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spin_lock(&kvm->mmu_lock);
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if (kvmppc_hv_handle_set_rc(kvm, kvm->arch.pgtable,
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writing, gpa))
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dsisr &= ~DSISR_SET_RC;
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spin_unlock(&kvm->mmu_lock);
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if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
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DSISR_PROTFAULT | DSISR_SET_RC)))
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return RESUME_GUEST;
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}
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/* Try to insert a pte */
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ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot, writing,
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kvm_ro, NULL, NULL);
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if (ret == 0 || ret == -EAGAIN)
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ret = RESUME_GUEST;
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return ret;
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