[PATCH 2/3] kvmtool: arm64: Use the maximum supported IPA size when creating the VM

[Marc Zyngier]

Instead of just asking the the default VM size, request the maximum
IPA size to the kernel, and use this at VM creation time.

The IPA space is parametrized accordingly.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arm/aarch64/include/kvm/kvm-arch.h | 19 ++++++++++++++++---
 arm/aarch64/kvm.c                  | 15 +++++++++++++++
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/arm/aarch64/include/kvm/kvm-arch.h b/arm/aarch64/include/kvm/kvm-arch.h
index 55ef8ed..159567b 100644
--- a/arm/aarch64/include/kvm/kvm-arch.h
+++ b/arm/aarch64/include/kvm/kvm-arch.h
@@ -3,10 +3,23 @@
 
 struct kvm;
 unsigned long long kvm__arch_get_kern_offset(struct kvm *kvm, int fd);
+int kvm__arch_get_ipa_limit(struct kvm *kvm);
 
-#define ARM_MAX_MEMORY(kvm)	((kvm)->cfg.arch.aarch32_guest	?	\
-				ARM_LOMAP_MAX_MEMORY		:	\
-				ARM_HIMAP_MAX_MEMORY)
+#define ARM_MAX_MEMORY(kvm)	({					\
+	u64 max_ram;							\
+									\
+	if ((kvm)->cfg.arch.aarch32_guest) {				\
+		max_ram = ARM_LOMAP_MAX_MEMORY;				\
+	} else {							\
+		int ipabits = kvm__arch_get_ipa_limit(kvm);		\
+		if (ipabits <= 0)					\
+			max_ram = ARM_HIMAP_MAX_MEMORY;			\
+		else							\
+			max_ram = (1ULL << ipabits) - ARM_MEMORY_AREA;	\
+	}								\
+									\
+	max_ram;							\
+})
 
 #include "arm-common/kvm-arch.h"
 
diff --git a/arm/aarch64/kvm.c b/arm/aarch64/kvm.c
index 49e1dd3..c4f81d0 100644
--- a/arm/aarch64/kvm.c
+++ b/arm/aarch64/kvm.c
@@ -46,3 +46,18 @@ fail:
 	return 0x80000;
 }
 
+int kvm__arch_get_ipa_limit(struct kvm *kvm)
+{
+	int ret;
+
+	ret = ioctl(kvm->sys_fd, KVM_CHECK_EXTENSION, KVM_CAP_ARM_VM_IPA_SIZE);
+	if (ret <= 0)
+		ret = 0;
+
+	return ret;
+}
+
+int kvm__get_vm_type(struct kvm *kvm)
+{
+	return kvm__arch_get_ipa_limit(kvm);
+}
-- 
2.30.0