[PATCH v18 13/23] KVM: arm64: Add a helper for VMs running on hyp that don't trust the host
From: Suzuki K Poulose <suzuki.poulose@arm.com>
Date: 2026-09-15 16:02:32
Also in:
kvm, kvmarm, linux-coco, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
PKVM and RMM, both do not trust the host. Add a helper to detect the VMs that have "distrusting" hyp. Use this for blocking ioremap of vgic-v2 into stage2. Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> --- arch/arm64/include/asm/kvm_host.h | 3 +++ arch/arm64/kvm/mmu.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 1bb43c57fb0f0..09910b2c61bfb 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h@@ -328,6 +328,8 @@ enum fgt_group_id { enum kvm_arm_vm_flavor { VM_NVHE, VM_VHE, + /* VMs running on a hyp that doesn't trust */ + MARKER(__VM_DISTRUSTING_HYP), VM_PKVM, /* Normal guests on pKVM */ MARKER(__VM_PROTECTED), VM_PROTECTED_PKVM, /* Protected VM */
@@ -1540,6 +1542,7 @@ struct kvm *kvm_arch_alloc_vm(void); #define kvm_vm_is_protected_pkvm(kvm) ((kvm)->arch.vm_flavor == VM_PROTECTED_PKVM) #define kvm_vm_is_unprotected_pkvm(kvm) ((kvm)->arch.vm_flavor == VM_PKVM) +#define kvm_vm_hyp_is_distrusting(kvm) ((kvm)->arch.vm_flavor > __VM_DISTRUSTING_HYP) #define kvm_vm_hyp_is_pkvm(kvm) (is_protected_kvm_enabled()) #define vcpu_is_protected(vcpu) kvm_vm_is_protected((vcpu)->kvm)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 38f3bf772278f..559a8286807cd 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c@@ -1251,7 +1251,7 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, KVM_PGTABLE_PROT_R | (writable ? KVM_PGTABLE_PROT_W : 0); - if (is_protected_kvm_enabled()) + if (kvm_vm_hyp_is_distrusting(kvm)) return -EPERM; size += offset_in_page(guest_ipa);
--
2.43.0