[PATCH 08/20] KVM: arm64: Add a range to __pkvm_host_reclaim_page_guest()
Vincent Donnefort
vdonnefort at google.com
Mon Aug 3 03:08:52 PDT 2026
In preparation for supporting stage-2 huge mappings for protected VMs, add a
nr_pages argument to the __pkvm_host_reclaim_page_guest() hypercall. This
range supports only two values: 1 or PMD_SIZE / PAGE_SIZE (that is 512
on a 4K-pages system).
Signed-off-by: Vincent Donnefort <vdonnefort at google.com>
diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
index c13f258fffb7..678bb55c694a 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
@@ -42,7 +42,7 @@ int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages);
int __pkvm_host_donate_guest(u64 pfn, u64 gfn, u64 nr_pages, struct pkvm_hyp_vcpu *vcpu);
int __pkvm_vcpu_in_poison_fault(struct pkvm_hyp_vcpu *hyp_vcpu);
int __pkvm_host_force_reclaim_page_guest(phys_addr_t phys);
-int __pkvm_host_reclaim_page_guest(u64 gfn, struct pkvm_hyp_vm *vm);
+int __pkvm_host_reclaim_page_guest(u64 gfn, u64 nr_pages, struct pkvm_hyp_vm *vm);
int __pkvm_host_share_guest(u64 pfn, u64 gfn, u64 nr_pages, struct pkvm_hyp_vcpu *vcpu,
enum kvm_pgtable_prot prot);
int __pkvm_host_unshare_guest(u64 gfn, u64 nr_pages, struct pkvm_hyp_vm *hyp_vm);
diff --git a/arch/arm64/kvm/hyp/include/nvhe/pkvm.h b/arch/arm64/kvm/hyp/include/nvhe/pkvm.h
index f04cea5ff389..0d17e59d5335 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/pkvm.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/pkvm.h
@@ -74,7 +74,7 @@ int __pkvm_init_vm(struct kvm *host_kvm, unsigned long vm_hva,
int __pkvm_init_vcpu(pkvm_handle_t handle, struct kvm_vcpu *host_vcpu,
unsigned long vcpu_hva);
-int __pkvm_reclaim_dying_guest_page(pkvm_handle_t handle, u64 gfn);
+int __pkvm_reclaim_dying_guest_page(pkvm_handle_t handle, u64 gfn, u64 nr_pages);
int __pkvm_start_teardown_vm(pkvm_handle_t handle);
int __pkvm_finalize_teardown_vm(pkvm_handle_t handle);
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index c7a8c2eea157..18d314ea034c 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -624,8 +624,9 @@ static void handle___pkvm_reclaim_dying_guest_page(struct kvm_cpu_context *host_
{
DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
DECLARE_REG(u64, gfn, host_ctxt, 2);
+ DECLARE_REG(u64, nr_pages, host_ctxt, 3);
- cpu_reg(host_ctxt, 1) = __pkvm_reclaim_dying_guest_page(handle, gfn);
+ cpu_reg(host_ctxt, 1) = __pkvm_reclaim_dying_guest_page(handle, gfn, nr_pages);
}
static void handle___pkvm_start_teardown_vm(struct kvm_cpu_context *host_ctxt)
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 9ea448895c15..ce637f1a55b3 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -891,7 +891,8 @@ static int __guest_check_page_state_range(struct pkvm_hyp_vm *vm, u64 addr,
return check_page_state_range(&vm->pgt, addr, size, &d);
}
-static int get_valid_guest_pte(struct pkvm_hyp_vm *vm, u64 ipa, kvm_pte_t *ptep, u64 *physp)
+static int __get_valid_guest_pte(struct pkvm_hyp_vm *vm, u64 ipa,
+ kvm_pte_t *ptep, u64 *physp, s8 *levelp)
{
kvm_pte_t pte;
u64 phys;
@@ -905,20 +906,32 @@ static int get_valid_guest_pte(struct pkvm_hyp_vm *vm, u64 ipa, kvm_pte_t *ptep,
return -EHWPOISON;
if (!kvm_pte_valid(pte))
return -ENOENT;
- if (level != KVM_PGTABLE_LAST_LEVEL)
- return -E2BIG;
phys = kvm_pte_to_phys(pte);
- ret = check_range_allowed_memory(phys, phys + PAGE_SIZE);
+ ret = check_range_allowed_memory(phys, phys + kvm_granule_size(level));
if (WARN_ON(ret))
return ret;
*ptep = pte;
*physp = phys;
+ *levelp = level;
return 0;
}
+static int get_valid_guest_pte(struct pkvm_hyp_vm *vm, u64 ipa, u64 size,
+ kvm_pte_t *ptep, u64 *physp)
+{
+ s8 level;
+ int ret;
+
+ ret = __get_valid_guest_pte(vm, ipa, ptep, physp, &level);
+ if (ret)
+ return ret;
+
+ return kvm_granule_size(level) == size ? 0 : -E2BIG;
+}
+
int __pkvm_vcpu_in_poison_fault(struct pkvm_hyp_vcpu *hyp_vcpu)
{
struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(hyp_vcpu);
@@ -1001,7 +1014,7 @@ int __pkvm_guest_share_host(struct pkvm_hyp_vcpu *vcpu, u64 gfn)
host_lock_component();
guest_lock_component(vm);
- ret = get_valid_guest_pte(vm, ipa, &pte, &phys);
+ ret = get_valid_guest_pte(vm, ipa, PAGE_SIZE, &pte, &phys);
if (ret)
goto unlock;
@@ -1033,7 +1046,7 @@ int __pkvm_guest_unshare_host(struct pkvm_hyp_vcpu *vcpu, u64 gfn)
host_lock_component();
guest_lock_component(vm);
- ret = get_valid_guest_pte(vm, ipa, &pte, &phys);
+ ret = get_valid_guest_pte(vm, ipa, PAGE_SIZE, &pte, &phys);
if (ret)
goto unlock;
@@ -1285,6 +1298,14 @@ static void hyp_poison_page(phys_addr_t phys)
hyp_fixmap_unmap();
}
+static void hyp_poison_range(phys_addr_t phys, u64 size)
+{
+ u64 offset;
+
+ for (offset = 0; offset < size; offset += PAGE_SIZE)
+ hyp_poison_page(phys + offset);
+}
+
static int host_stage2_get_guest_info(phys_addr_t phys, struct pkvm_hyp_vm **vm,
u64 *gfn)
{
@@ -1337,7 +1358,7 @@ int __pkvm_host_force_reclaim_page_guest(phys_addr_t phys)
ipa = hyp_pfn_to_phys(gfn);
guest_lock_component(vm);
- ret = get_valid_guest_pte(vm, ipa, &pte, &pa);
+ ret = get_valid_guest_pte(vm, ipa, PAGE_SIZE, &pte, &pa);
if (ret)
goto unlock_guest;
@@ -1365,35 +1386,40 @@ int __pkvm_host_force_reclaim_page_guest(phys_addr_t phys)
return ret;
}
-int __pkvm_host_reclaim_page_guest(u64 gfn, struct pkvm_hyp_vm *vm)
+int __pkvm_host_reclaim_page_guest(u64 gfn, u64 nr_pages, struct pkvm_hyp_vm *vm)
{
u64 ipa = hyp_pfn_to_phys(gfn);
kvm_pte_t pte;
u64 phys;
+ u64 size;
int ret;
+ ret = __guest_check_transition_size(0, ipa, nr_pages, &size);
+ if (ret)
+ return ret;
+
host_lock_component();
guest_lock_component(vm);
- ret = get_valid_guest_pte(vm, ipa, &pte, &phys);
+ ret = get_valid_guest_pte(vm, ipa, size, &pte, &phys);
if (ret)
goto unlock;
switch (guest_get_page_state(pte, ipa)) {
case PKVM_PAGE_OWNED:
- WARN_ON(__host_check_page_state_range(phys, PAGE_SIZE, PKVM_NOPAGE));
- hyp_poison_page(phys);
+ WARN_ON(__host_check_page_state_range(phys, size, PKVM_NOPAGE));
+ hyp_poison_range(phys, size);
break;
case PKVM_PAGE_SHARED_OWNED:
- WARN_ON(__host_check_page_state_range(phys, PAGE_SIZE, PKVM_PAGE_SHARED_BORROWED));
+ WARN_ON(__host_check_page_state_range(phys, size, PKVM_PAGE_SHARED_BORROWED));
break;
default:
ret = -EPERM;
goto unlock;
}
- WARN_ON(kvm_pgtable_stage2_unmap(&vm->pgt, ipa, PAGE_SIZE));
- WARN_ON(host_stage2_set_owner_locked(phys, PAGE_SIZE, PKVM_ID_HOST));
+ WARN_ON(kvm_pgtable_stage2_unmap(&vm->pgt, ipa, size));
+ WARN_ON(host_stage2_set_owner_locked(phys, size, PKVM_ID_HOST));
unlock:
guest_unlock_component(vm);
@@ -1546,11 +1572,10 @@ static int __check_host_shared_guest(struct pkvm_hyp_vm *vm, u64 *__phys, u64 ip
s8 level;
int ret;
- ret = kvm_pgtable_get_leaf(&vm->pgt, ipa, &pte, &level);
+ ret = __get_valid_guest_pte(vm, ipa, &pte, &phys, &level);
if (ret)
return ret;
- if (!kvm_pte_valid(pte))
- return -ENOENT;
+
if (size && kvm_granule_size(level) != size)
return -E2BIG;
@@ -1561,11 +1586,6 @@ static int __check_host_shared_guest(struct pkvm_hyp_vm *vm, u64 *__phys, u64 ip
if (state != PKVM_PAGE_SHARED_BORROWED)
return -EPERM;
- phys = kvm_pte_to_phys(pte);
- ret = check_range_allowed_memory(phys, phys + size);
- if (WARN_ON(ret))
- return ret;
-
for_each_hyp_page(page, phys, size) {
if (get_host_state(page) != PKVM_PAGE_SHARED_OWNED)
return -EPERM;
@@ -1937,7 +1957,7 @@ int __pkvm_ownership_selftest(u64 pfn, u64 pgtable_pfn, unsigned long pgtable_nr
selftest_state.host = PKVM_PAGE_OWNED;
selftest_state.guest[1] = PKVM_NOPAGE;
- assert_transition_res(0, __pkvm_host_reclaim_page_guest, gfn + 1, vm);
+ assert_transition_res(0, __pkvm_host_reclaim_page_guest, gfn + 1, 1, vm);
assert_transition_res(-EPERM, __pkvm_host_donate_guest, pfn, gfn, 1, vcpu);
assert_transition_res(-EPERM, __pkvm_host_share_guest, pfn, gfn, 1, vcpu, prot);
diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c
index b7ec535da86b..8f5d32cdb4eb 100644
--- a/arch/arm64/kvm/hyp/nvhe/pkvm.c
+++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c
@@ -952,7 +952,7 @@ teardown_donated_memory(struct kvm_hyp_memcache *mc, void *addr, size_t size)
unmap_donated_memory_noclear(addr, size);
}
-int __pkvm_reclaim_dying_guest_page(pkvm_handle_t handle, u64 gfn)
+int __pkvm_reclaim_dying_guest_page(pkvm_handle_t handle, u64 gfn, u64 nr_pages)
{
struct pkvm_hyp_vm *hyp_vm = get_pkvm_hyp_vm(handle);
int ret = -EINVAL;
@@ -961,7 +961,7 @@ int __pkvm_reclaim_dying_guest_page(pkvm_handle_t handle, u64 gfn)
return ret;
if (hyp_vm->kvm.arch.pkvm.is_dying)
- ret = __pkvm_host_reclaim_page_guest(gfn, hyp_vm);
+ ret = __pkvm_host_reclaim_page_guest(gfn, nr_pages, hyp_vm);
put_pkvm_hyp_vm(hyp_vm);
return ret;
diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c
index 58d8474b563e..a9645480d164 100644
--- a/arch/arm64/kvm/pkvm.c
+++ b/arch/arm64/kvm/pkvm.c
@@ -373,7 +373,8 @@ static int __pkvm_pgtable_stage2_reclaim(struct kvm_pgtable *pgt, u64 start, u64
struct page *page;
ret = kvm_call_hyp_nvhe(__pkvm_reclaim_dying_guest_page,
- handle, mapping->gfn);
+ handle, mapping->gfn,
+ mapping->nr_pages);
if (WARN_ON(ret))
continue;
--
2.55.0.508.g3f0d502094-goog
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