[PATCH v8 6/8] KVM: arm64: Migrate to __kvm_follow_pfn

From: David Stevens
Date: Thu Aug 24 2023 - 04:07:07 EST


From: David Stevens <stevensd@xxxxxxxxxxxx>

Migrate from __gfn_to_pfn_memslot to __kvm_follow_pfn.

Signed-off-by: David Stevens <stevensd@xxxxxxxxxxxx>
---
arch/arm64/kvm/mmu.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index d3b4feed460c..e4abc2a57d7d 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1334,7 +1334,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
unsigned long fault_status)
{
int ret = 0;
- bool write_fault, writable, force_pte = false;
+ bool write_fault = kvm_is_write_fault(vcpu);
+ bool force_pte = false;
bool exec_fault, mte_allowed;
bool device = false;
unsigned long mmu_seq;
@@ -1342,16 +1343,19 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
struct vm_area_struct *vma;
short vma_shift;
- gfn_t gfn;
kvm_pfn_t pfn;
bool logging_active = memslot_is_logging(memslot);
unsigned long fault_level = kvm_vcpu_trap_get_fault_level(vcpu);
long vma_pagesize, fault_granule;
enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R;
struct kvm_pgtable *pgt;
+ struct kvm_follow_pfn foll = {
+ .slot = memslot,
+ .flags = FOLL_GET | (write_fault ? FOLL_WRITE : 0),
+ .try_map_writable = true,
+ };

fault_granule = 1UL << ARM64_HW_PGTABLE_LEVEL_SHIFT(fault_level);
- write_fault = kvm_is_write_fault(vcpu);
exec_fault = kvm_vcpu_trap_is_exec_fault(vcpu);
VM_BUG_ON(write_fault && exec_fault);

@@ -1425,7 +1429,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
if (vma_pagesize == PMD_SIZE || vma_pagesize == PUD_SIZE)
fault_ipa &= ~(vma_pagesize - 1);

- gfn = fault_ipa >> PAGE_SHIFT;
+ foll.gfn = fault_ipa >> PAGE_SHIFT;
mte_allowed = kvm_vma_mte_allowed(vma);

/* Don't use the VMA after the unlock -- it may have vanished */
@@ -1433,7 +1437,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,

/*
* Read mmu_invalidate_seq so that KVM can detect if the results of
- * vma_lookup() or __gfn_to_pfn_memslot() become stale prior to
+ * vma_lookup() or __kvm_follow_pfn() become stale prior to
* acquiring kvm->mmu_lock.
*
* Rely on mmap_read_unlock() for an implicit smp_rmb(), which pairs
@@ -1442,8 +1446,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
mmu_seq = vcpu->kvm->mmu_invalidate_seq;
mmap_read_unlock(current->mm);

- pfn = __gfn_to_pfn_memslot(memslot, gfn, false, false, NULL,
- write_fault, &writable, NULL);
+ pfn = __kvm_follow_pfn(&foll);
if (pfn == KVM_PFN_ERR_HWPOISON) {
kvm_send_hwpoison_signal(hva, vma_shift);
return 0;
@@ -1468,7 +1471,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
* Only actually map the page as writable if this was a write
* fault.
*/
- writable = false;
+ foll.writable = false;
}

if (exec_fault && device)
@@ -1508,7 +1511,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
}
}

- if (writable)
+ if (foll.writable)
prot |= KVM_PGTABLE_PROT_W;

if (exec_fault)
@@ -1534,9 +1537,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
KVM_PGTABLE_WALK_SHARED);

/* Mark the page dirty only if the fault is handled successfully */
- if (writable && !ret) {
+ if (foll.writable && !ret) {
kvm_set_pfn_dirty(pfn);
- mark_page_dirty_in_slot(kvm, memslot, gfn);
+ mark_page_dirty_in_slot(kvm, memslot, foll.gfn);
}

out_unlock:
--
2.42.0.rc1.204.g551eb34607-goog