[PATCH v18 12/23] KVM: arm64: Widen the scope of "protected" VMs

[Suzuki K Poulose <suzuki.poulose@arm.com>]

On arm64 we have "protected" VMs that run on PKVM as a confidential compute
guest. Given we already have the construct of "kvm_vm_is_protected" in the core
KVM code, use that for all confidential compute guests including Realms that
we are about to add.

Use the VM flavor to detect the "protected" VMs by introducing a marker.
Add explicit helper to detect if a given VM is a "protected" VM under PKVM.
Change the existing users that precisely want to check the VM type. These
include :
  - kvm_arch_prepare_memory_region - For preventing memslot changes after pVM
    creation.

All the others are retained as a wider check for confidential guest VMs.
These are:
 - kvm_vm_ioctl_set_counter_offset - For disallowing timer offset configuration
 - io_mem_abort for dabt handling without valid syndrome information

Both of which are true for Realms too.

Realms support is restricted to VHE host and thus "kvm_vm_is_protected()"
checks in the pkvm hyp specific code doesn't need to change, as the only
protected guests it deals with is "protected PKVM" guests.

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 arch/arm64/include/asm/kvm_host.h | 4 +++-
 arch/arm64/kvm/mmu.c              | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 7ce46d853c47e..1bb43c57fb0f0 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -329,6 +329,7 @@ enum kvm_arm_vm_flavor {
 	VM_NVHE,
 	VM_VHE,
 	VM_PKVM,		/* Normal guests on pKVM */
+	MARKER(__VM_PROTECTED),
 	VM_PROTECTED_PKVM,	/* Protected VM */
 	VM_FLAVOR_MAX,
 };
@@ -1535,7 +1536,8 @@ struct kvm *kvm_arch_alloc_vm(void);
 
 #define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLBS_RANGE
 
-#define kvm_vm_is_protected(kvm)	((kvm)->arch.vm_flavor == VM_PROTECTED_PKVM)
+#define kvm_vm_is_protected(kvm)	((kvm)->arch.vm_flavor >= __VM_PROTECTED)
+#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_pkvm(kvm)		(is_protected_kvm_enabled())
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 607c908c15c42..38f3bf772278f 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -2678,7 +2678,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
 	hva_t hva, reg_end;
 	int ret = 0;
 
-	if (kvm_vm_is_protected(kvm)) {
+	if (kvm_vm_is_protected_pkvm(kvm)) {
 		/* Cannot modify memslots once a pVM has run. */
 		if (pkvm_hyp_vm_is_created(kvm) &&
 		    (change == KVM_MR_DELETE || change == KVM_MR_MOVE)) {
-- 
2.43.0