KVM: arm64: Add a range to __pkvm_host_test_clear_young_guest()

In preparation for supporting stage-2 huge mappings for np-guest. Add a
nr_pages argument to the __pkvm_host_test_clear_young_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@google.com>
Link: https://lore.kernel.org/r/20250521124834.1070650-7-vdonnefort@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>

diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
index 64d4f3bf6269454759de7f6060de0cee785c0688..5f9d56754e39f5ce9378dfe76a53c84ab5583e08 100644 (file)
--- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
@@ -43,8 +43,8 @@ int __pkvm_host_share_guest(u64 pfn, u64 gfn, u64 nr_pages, struct pkvm_hyp_vcpu
                            enum kvm_pgtable_prot prot);
 int __pkvm_host_unshare_guest(u64 gfn, u64 nr_pages, struct pkvm_hyp_vm *hyp_vm);
 int __pkvm_host_relax_perms_guest(u64 gfn, struct pkvm_hyp_vcpu *vcpu, enum kvm_pgtable_prot prot);
-int __pkvm_host_test_clear_young_guest(u64 gfn, bool mkold, struct pkvm_hyp_vm *vm);
 int __pkvm_host_wrprotect_guest(u64 gfn, u64 nr_pages, struct pkvm_hyp_vm *hyp_vm);
+int __pkvm_host_test_clear_young_guest(u64 gfn, u64 nr_pages, bool mkold, struct pkvm_hyp_vm *vm);
 int __pkvm_host_mkyoung_guest(u64 gfn, struct pkvm_hyp_vcpu *vcpu);
 
 bool addr_is_memory(phys_addr_t phys);

diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index fa7e2421d3594dc08cdc90a1b041c0f7d9b9698c..8e8848de4d4707cfb3260d7f013fdd2ef57db327 100644 (file)
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -331,7 +331,8 @@ static void handle___pkvm_host_test_clear_young_guest(struct kvm_cpu_context *ho
 {
        DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
        DECLARE_REG(u64, gfn, host_ctxt, 2);
-       DECLARE_REG(bool, mkold, host_ctxt, 3);
+       DECLARE_REG(u64, nr_pages, host_ctxt, 3);
+       DECLARE_REG(bool, mkold, host_ctxt, 4);
        struct pkvm_hyp_vm *hyp_vm;
        int ret = -EINVAL;
 
@@ -342,7 +343,7 @@ static void handle___pkvm_host_test_clear_young_guest(struct kvm_cpu_context *ho
        if (!hyp_vm)
                goto out;
 
-       ret = __pkvm_host_test_clear_young_guest(gfn, mkold, hyp_vm);
+       ret = __pkvm_host_test_clear_young_guest(gfn, nr_pages, mkold, hyp_vm);
        put_pkvm_hyp_vm(hyp_vm);
 out:
        cpu_reg(host_ctxt, 1) = ret;

diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index a6c45202aa856d1843f0c793c569930e3fde97bc..5a7a38c5d67c77c8462901e55d1bdf99838a2146 100644 (file)
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -1111,17 +1111,21 @@ int __pkvm_host_wrprotect_guest(u64 gfn, u64 nr_pages, struct pkvm_hyp_vm *vm)
        return ret;
 }
 
-int __pkvm_host_test_clear_young_guest(u64 gfn, bool mkold, struct pkvm_hyp_vm *vm)
+int __pkvm_host_test_clear_young_guest(u64 gfn, u64 nr_pages, bool mkold, struct pkvm_hyp_vm *vm)
 {
-       u64 ipa = hyp_pfn_to_phys(gfn);
+       u64 size, ipa = hyp_pfn_to_phys(gfn);
        int ret;
 
        if (pkvm_hyp_vm_is_protected(vm))
                return -EPERM;
 
-       assert_host_shared_guest(vm, ipa, PAGE_SIZE);
+       ret = __guest_check_transition_size(0, ipa, nr_pages, &size);
+       if (ret)
+               return ret;
+
+       assert_host_shared_guest(vm, ipa, size);
        guest_lock_component(vm);
-       ret = kvm_pgtable_stage2_test_clear_young(&vm->pgt, ipa, PAGE_SIZE, mkold);
+       ret = kvm_pgtable_stage2_test_clear_young(&vm->pgt, ipa, size, mkold);
        guest_unlock_component(vm);
 
        return ret;

diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c
index 02bebf0a17557a8ad0f32daa407e82f9abc789a2..f2c1d4c4e27ed19d83ab14bfa73fc612dea775af 100644 (file)
--- a/arch/arm64/kvm/pkvm.c
+++ b/arch/arm64/kvm/pkvm.c
@@ -439,7 +439,7 @@ bool pkvm_pgtable_stage2_test_clear_young(struct kvm_pgtable *pgt, u64 addr, u64
        lockdep_assert_held(&kvm->mmu_lock);
        for_each_mapping_in_range_safe(pgt, addr, addr + size, mapping)
                young |= kvm_call_hyp_nvhe(__pkvm_host_test_clear_young_guest, handle, mapping->gfn,
-                                          mkold);
+                                          1, mkold);
 
        return young;
 }