@@ -279,6 +279,7 @@ struct kvm_x86_cpu_property {
#define X86_PROPERTY_MAX_EXT_LEAF KVM_X86_CPU_PROPERTY(0x80000000, 0, EAX, 0, 31)
#define X86_PROPERTY_MAX_PHY_ADDR KVM_X86_CPU_PROPERTY(0x80000008, 0, EAX, 0, 7)
#define X86_PROPERTY_MAX_VIRT_ADDR KVM_X86_CPU_PROPERTY(0x80000008, 0, EAX, 8, 15)
+#define X86_PROPERTY_GUEST_MAX_PHY_ADDR KVM_X86_CPU_PROPERTY(0x80000008, 0, EAX, 16, 23)
#define X86_PROPERTY_SEV_C_BIT KVM_X86_CPU_PROPERTY(0x8000001F, 0, EBX, 0, 5)
#define X86_PROPERTY_PHYS_ADDR_REDUCTION KVM_X86_CPU_PROPERTY(0x8000001F, 0, EBX, 6, 11)
@@ -1278,9 +1278,20 @@ unsigned long vm_compute_max_gfn(struct kvm_vm *vm)
{
const unsigned long num_ht_pages = 12 << (30 - vm->page_shift); /* 12 GiB */
unsigned long ht_gfn, max_gfn, max_pfn;
- uint8_t maxphyaddr;
+ uint8_t maxphyaddr, guest_maxphyaddr;
- max_gfn = (1ULL << (vm->pa_bits - vm->page_shift)) - 1;
+ /*
+ * Use "guest MAXPHYADDR" from KVM if it's available. Guest MAXPHYADDR
+ * enumerates the max _mappable_ GPA, which can be less than the raw
+ * MAXPHYADDR, e.g. if MAXPHYADDR=52, KVM is using TDP, and the CPU
+ * doesn't support 5-level TDP.
+ */
+ guest_maxphyaddr = kvm_cpu_property(X86_PROPERTY_GUEST_MAX_PHY_ADDR);
+ guest_maxphyaddr = guest_maxphyaddr ?: vm->pa_bits;
+ TEST_ASSERT(guest_maxphyaddr <= vm->pa_bits,
+ "Guest MAXPHYADDR should never be greater than raw MAXPHYADDR");
+
+ max_gfn = (1ULL << (guest_maxphyaddr - vm->page_shift)) - 1;
/* Avoid reserved HyperTransport region on AMD processors. */
if (!host_cpu_is_amd)