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Diffstat (limited to 'arch/arm64/kvm/nested.c')
-rw-r--r--arch/arm64/kvm/nested.c164
1 files changed, 83 insertions, 81 deletions
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index fb54f6dad995..dfb96edbdc43 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -24,6 +24,7 @@ struct vncr_tlb {
struct s1_walk_result wr;
u64 hpa;
+ bool hpa_writable;
/* -1 when not mapped on a CPU */
int cpu;
@@ -1401,15 +1402,19 @@ static int kvm_translate_vncr(struct kvm_vcpu *vcpu, bool *is_gmem)
gfn = vt->wr.pa >> PAGE_SHIFT;
memslot = gfn_to_memslot(vcpu->kvm, gfn);
- if (!memslot)
+ if (!memslot) {
+ fail_s1_walk(&vt->wr, ESR_ELx_FSC_EXTABT, false);
return -EFAULT;
+ }
*is_gmem = kvm_slot_has_gmem(memslot);
if (!*is_gmem) {
pfn = __kvm_faultin_pfn(memslot, gfn, write_fault ? FOLL_WRITE : 0,
&writable, &page);
- if (is_error_noslot_pfn(pfn) || (write_fault && !writable))
+ if (is_error_noslot_pfn(pfn)) {
+ fail_s1_walk(&vt->wr, ESR_ELx_FSC_EXTABT, false);
return -EFAULT;
+ }
} else {
ret = kvm_gmem_get_pfn(vcpu->kvm, memslot, gfn, &pfn, &page, NULL);
if (ret) {
@@ -1417,6 +1422,19 @@ static int kvm_translate_vncr(struct kvm_vcpu *vcpu, bool *is_gmem)
write_fault, false, false);
return ret;
}
+
+ writable = !(memslot->flags & KVM_MEM_READONLY);
+ }
+
+ /*
+ * FIXME: This check is too restrictive as KVM allows cacheable memory
+ * attributes for PFNMAP VMAs that have cacheable attributes in host
+ * stage-1.
+ */
+ if (!pfn_is_map_memory(pfn)) {
+ kvm_release_faultin_page(vcpu->kvm, page, true, false);
+ fail_s1_walk(&vt->wr, ESR_ELx_FSC_EXTABT, false);
+ return -EINVAL;
}
scoped_guard(write_lock, &vcpu->kvm->mmu_lock) {
@@ -1427,116 +1445,100 @@ static int kvm_translate_vncr(struct kvm_vcpu *vcpu, bool *is_gmem)
vt->gva = va;
vt->hpa = pfn << PAGE_SHIFT;
+ vt->hpa_writable = writable;
vt->valid = true;
vt->cpu = -1;
kvm_make_request(KVM_REQ_MAP_L1_VNCR_EL2, vcpu);
- kvm_release_faultin_page(vcpu->kvm, page, false, vt->wr.pw);
+ kvm_release_faultin_page(vcpu->kvm, page, false, vt->wr.pw && vt->hpa_writable);
}
- if (vt->wr.pw)
+ if (vt->wr.pw && vt->hpa_writable)
mark_page_dirty(vcpu->kvm, gfn);
return 0;
}
-static void inject_vncr_perm(struct kvm_vcpu *vcpu)
+static void handle_vncr_perm(struct kvm_vcpu *vcpu)
{
struct vncr_tlb *vt = vcpu->arch.vncr_tlb;
u64 esr = kvm_vcpu_get_esr(vcpu);
+ u64 fsc;
+
+ /*
+ * Promote to an external abort if the stage-1 permits writes but the
+ * HPA is read-only (e.g. RO memslot).
+ */
+ if (kvm_is_write_fault(vcpu) && vt->wr.pw && !vt->hpa_writable)
+ fsc = ESR_ELx_FSC_EXTABT;
+ /*
+ * Otherwise, inject a permission fault using the guest's translation
+ * level rather than the host's.
+ */
+ else
+ fsc = ESR_ELx_FSC_PERM_L(vt->wr.level);
- /* Adjust the fault level to reflect that of the guest's */
esr &= ~ESR_ELx_FSC;
- esr |= FIELD_PREP(ESR_ELx_FSC,
- ESR_ELx_FSC_PERM_L(vt->wr.level));
+ esr |= FIELD_PREP(ESR_ELx_FSC, fsc);
kvm_inject_nested_sync(vcpu, esr);
}
-static bool kvm_vncr_tlb_lookup(struct kvm_vcpu *vcpu)
-{
- struct vncr_tlb *vt = vcpu->arch.vncr_tlb;
-
- lockdep_assert_held_read(&vcpu->kvm->mmu_lock);
-
- if (!vt->valid)
- return false;
-
- if (read_vncr_el2(vcpu) != vt->gva)
- return false;
-
- if (vt->wr.nG)
- return get_asid_by_regime(vcpu, TR_EL20) == vt->wr.asid;
-
- return true;
-}
-
int kvm_handle_vncr_abort(struct kvm_vcpu *vcpu)
{
struct vncr_tlb *vt = vcpu->arch.vncr_tlb;
u64 esr = kvm_vcpu_get_esr(vcpu);
+ bool is_gmem = false;
+ bool perm;
+ int ret;
WARN_ON_ONCE(!(esr & ESR_ELx_VNCR));
if (kvm_vcpu_abt_issea(vcpu))
return kvm_handle_guest_sea(vcpu);
- if (esr_fsc_is_permission_fault(esr)) {
- inject_vncr_perm(vcpu);
- } else if (esr_fsc_is_translation_fault(esr)) {
- bool valid, is_gmem = false;
- int ret;
-
- scoped_guard(read_lock, &vcpu->kvm->mmu_lock)
- valid = kvm_vncr_tlb_lookup(vcpu);
-
- if (!valid)
- ret = kvm_translate_vncr(vcpu, &is_gmem);
- else
- ret = -EPERM;
-
- switch (ret) {
- case -EAGAIN:
- /* Let's try again... */
- break;
- case -ENOMEM:
- /*
- * For guest_memfd, this indicates that it failed to
- * create a folio to back the memory. Inform userspace.
- */
- if (is_gmem)
- return 0;
- /* Otherwise, let's try again... */
- break;
- case -EFAULT:
- case -EIO:
- case -EHWPOISON:
- if (is_gmem)
- return 0;
- fallthrough;
- case -EINVAL:
- case -ENOENT:
- case -EACCES:
- /*
- * Translation failed, inject the corresponding
- * exception back to EL2.
- */
- BUG_ON(!vt->wr.failed);
+ if (!esr_fsc_is_translation_fault(esr) && !esr_fsc_is_permission_fault(esr)) {
+ KVM_BUG(1, vcpu->kvm, "Unhandled VNCR abort, ESR=%llx\n", esr);
+ return -EIO;
+ }
- esr &= ~ESR_ELx_FSC;
- esr |= FIELD_PREP(ESR_ELx_FSC, vt->wr.fst);
+ ret = kvm_translate_vncr(vcpu, &is_gmem);
+ switch (ret) {
+ case -EAGAIN:
+ /* Let's try again... */
+ return 1;
+ case -ENOMEM:
+ /*
+ * For guest_memfd, this indicates that it failed to
+ * create a folio to back the memory. Inform userspace.
+ */
+ if (is_gmem)
+ return 0;
+ /* Otherwise, let's try again... */
+ break;
+ case -EFAULT:
+ case -EIO:
+ case -EHWPOISON:
+ if (is_gmem)
+ return 0;
+ fallthrough;
+ case -EINVAL:
+ case -ENOENT:
+ case -EACCES:
+ /*
+ * Translation failed, inject the corresponding
+ * exception back to EL2.
+ */
+ esr &= ~ESR_ELx_FSC;
+ esr |= FIELD_PREP(ESR_ELx_FSC, vt->wr.fst);
- kvm_inject_nested_sync(vcpu, esr);
- break;
- case -EPERM:
- /* Hack to deal with POE until we get kernel support */
- inject_vncr_perm(vcpu);
- break;
- case 0:
- break;
- }
- } else {
- WARN_ONCE(1, "Unhandled VNCR abort, ESR=%llx\n", esr);
+ kvm_inject_nested_sync(vcpu, esr);
+ break;
+ case 0:
+ perm = kvm_is_write_fault(vcpu) ? vt->wr.pw && vt->hpa_writable : vt->wr.pr;
+ if (!perm)
+ handle_vncr_perm(vcpu);
+ break;
}
return 1;
@@ -1574,7 +1576,7 @@ static void kvm_map_l1_vncr(struct kvm_vcpu *vcpu)
vt->cpu = smp_processor_id();
- if (vt->wr.pw && vt->wr.pr)
+ if (vt->hpa_writable && vt->wr.pw && vt->wr.pr)
prot = PAGE_KERNEL;
else if (vt->wr.pr)
prot = PAGE_KERNEL_RO;
generated by cgit v1.3.1 (git 2.54.0) at 2026-07-26 00:41:17 +0000