[PATCH v6 05/30] KVM: selftests: Update kvm_init_vm_address_properties() for TDX

From: Sagi Shahar
Date: Mon Apr 14 2025 - 17:50:23 EST


From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

Let kvm_init_vm_address_properties() initialize vm->arch.{s_bit, tag_mask}
similar to SEV.

Set shared bit position based on guest maximum physical address width
instead of maximum physical address width, because that is what KVM
uses, refer to setup_tdparams_eptp_controls(), and because maximum physical
address width can be different.

In the case of SRF, guest maximum physical address width is 48 because SRF
does not support 5-level EPT, even though the maximum physical address
width is 52.

Co-developed-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Signed-off-by: Sagi Shahar <sagis@xxxxxxxxxx>
---
.../testing/selftests/kvm/lib/x86/processor.c | 20 ++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
index 80b7c4482485..1c42af328f19 100644
--- a/tools/testing/selftests/kvm/lib/x86/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86/processor.c
@@ -1167,13 +1167,27 @@ void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits)

void kvm_init_vm_address_properties(struct kvm_vm *vm)
{
- if (vm->type == KVM_X86_SEV_VM || vm->type == KVM_X86_SEV_ES_VM ||
- vm->type == KVM_X86_SNP_VM) {
+ uint32_t gpa_bits = kvm_cpu_property(X86_PROPERTY_GUEST_MAX_PHY_ADDR);
+
+ switch (vm->type) {
+ case KVM_X86_SEV_VM:
+ case KVM_X86_SEV_ES_VM:
+ case KVM_X86_SNP_VM:
vm->arch.sev_fd = open_sev_dev_path_or_exit();
vm->arch.c_bit = BIT_ULL(this_cpu_property(X86_PROPERTY_SEV_C_BIT));
vm->gpa_tag_mask = vm->arch.c_bit;
- } else {
+ break;
+ case KVM_X86_TDX_VM:
+ TEST_ASSERT(gpa_bits == 48 || gpa_bits == 52,
+ "TDX: bad X86_PROPERTY_GUEST_MAX_PHY_ADDR value: %u", gpa_bits);
+ vm->arch.sev_fd = -1;
+ vm->arch.s_bit = 1ULL << (gpa_bits - 1);
+ vm->arch.c_bit = 0;
+ vm->gpa_tag_mask = vm->arch.s_bit;
+ break;
+ default:
vm->arch.sev_fd = -1;
+ break;
}
}

--
2.49.0.504.g3bcea36a83-goog