KVM: arm64: Introduce __pkvm_host_mkyoung_guest()

Plumb the kvm_pgtable_stage2_mkyoung() callback into pKVM for
non-protected guests. It will be called later from the fault handling
path.

Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20241218194059.3670226-16-qperret@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 4f97155d6323b84f207d20a4d7a5024572a8d3ae..a3b07db2776c6271e8ea9ac674035e6670eea40e 100644 (file)
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -70,6 +70,7 @@ enum __kvm_host_smccc_func {
        __KVM_HOST_SMCCC_FUNC___pkvm_host_relax_perms_guest,
        __KVM_HOST_SMCCC_FUNC___pkvm_host_wrprotect_guest,
        __KVM_HOST_SMCCC_FUNC___pkvm_host_test_clear_young_guest,
+       __KVM_HOST_SMCCC_FUNC___pkvm_host_mkyoung_guest,
        __KVM_HOST_SMCCC_FUNC___kvm_adjust_pc,
        __KVM_HOST_SMCCC_FUNC___kvm_vcpu_run,
        __KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context,

diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
index 74bd6c72fff2ed1d28a5d4f435fd8cfb1a1248e3..978f38c386ee53cb813055d5409820f5a57b2dcc 100644 (file)
--- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
@@ -45,6 +45,7 @@ int __pkvm_host_unshare_guest(u64 gfn, 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_wrprotect_guest(u64 gfn, struct pkvm_hyp_vm *hyp_vm);
 int __pkvm_host_test_clear_young_guest(u64 gfn, 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);
 int host_stage2_idmap_locked(phys_addr_t addr, u64 size, enum kvm_pgtable_prot prot);

diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 616e172a9c489eca09c738846739ff1d64c6b2fd..32c4627b5b5b26dd3177b30bf3ba67105d26770f 100644 (file)
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -324,6 +324,24 @@ out:
        cpu_reg(host_ctxt, 1) = ret;
 }
 
+static void handle___pkvm_host_mkyoung_guest(struct kvm_cpu_context *host_ctxt)
+{
+       DECLARE_REG(u64, gfn, host_ctxt, 1);
+       struct pkvm_hyp_vcpu *hyp_vcpu;
+       int ret = -EINVAL;
+
+       if (!is_protected_kvm_enabled())
+               goto out;
+
+       hyp_vcpu = pkvm_get_loaded_hyp_vcpu();
+       if (!hyp_vcpu || pkvm_hyp_vcpu_is_protected(hyp_vcpu))
+               goto out;
+
+       ret = __pkvm_host_mkyoung_guest(gfn, hyp_vcpu);
+out:
+       cpu_reg(host_ctxt, 1) =  ret;
+}
+
 static void handle___kvm_adjust_pc(struct kvm_cpu_context *host_ctxt)
 {
        DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1);
@@ -538,6 +556,7 @@ static const hcall_t host_hcall[] = {
        HANDLE_FUNC(__pkvm_host_relax_perms_guest),
        HANDLE_FUNC(__pkvm_host_wrprotect_guest),
        HANDLE_FUNC(__pkvm_host_test_clear_young_guest),
+       HANDLE_FUNC(__pkvm_host_mkyoung_guest),
        HANDLE_FUNC(__kvm_adjust_pc),
        HANDLE_FUNC(__kvm_vcpu_run),
        HANDLE_FUNC(__kvm_flush_vm_context),

diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 0e42c3baaf4bd95a270b4231ca331362435fd85b..eae03509d371378c91e1576f14b527c505b78e63 100644 (file)
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -1549,3 +1549,23 @@ int __pkvm_host_test_clear_young_guest(u64 gfn, bool mkold, struct pkvm_hyp_vm *
 
        return ret;
 }
+
+int __pkvm_host_mkyoung_guest(u64 gfn, struct pkvm_hyp_vcpu *vcpu)
+{
+       struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu);
+       u64 ipa = hyp_pfn_to_phys(gfn);
+       u64 phys;
+       int ret;
+
+       host_lock_component();
+       guest_lock_component(vm);
+
+       ret = __check_host_shared_guest(vm, &phys, ipa);
+       if (!ret)
+               kvm_pgtable_stage2_mkyoung(&vm->pgt, ipa, 0);
+
+       guest_unlock_component(vm);
+       host_unlock_component();
+
+       return ret;
+}