Message-ID: <20250821042915.3712925-16-sagis@google.com>
Date: Wed, 20 Aug 2025 21:29:08 -0700
From: Sagi Shahar <sagis@...gle.com>
To: linux-kselftest@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>, 
	Shuah Khan <shuah@...nel.org>, Sean Christopherson <seanjc@...gle.com>, 
	Ackerley Tng <ackerleytng@...gle.com>, Ryan Afranji <afranji@...gle.com>, 
	Andrew Jones <ajones@...tanamicro.com>, Isaku Yamahata <isaku.yamahata@...el.com>, 
	Erdem Aktas <erdemaktas@...gle.com>, Rick Edgecombe <rick.p.edgecombe@...el.com>, 
	Sagi Shahar <sagis@...gle.com>, Roger Wang <runanwang@...gle.com>, 
	Binbin Wu <binbin.wu@...ux.intel.com>, Oliver Upton <oliver.upton@...ux.dev>, 
	"Pratik R. Sampat" <pratikrajesh.sampat@....com>, Reinette Chatre <reinette.chatre@...el.com>, 
	Ira Weiny <ira.weiny@...el.com>, Chao Gao <chao.gao@...el.com>, 
	Chenyi Qiang <chenyi.qiang@...el.com>
Cc: linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Subject: [PATCH v9 15/19] KVM: selftests: Hook TDX support to vm and vcpu creation

TDX require special handling for VM and VCPU initialization for various
reasons:
- Special ioctlss for creating VM and VCPU.
- TDX registers are inaccessible to KVM.
- TDX require special boot code trampoline for loading parameters.
- TDX only supports KVM_CAP_SPLIT_IRQCHIP.

Hook this special handling into __vm_create() and vm_arch_vcpu_add()
using the utility functions added in previous patches.

Signed-off-by: Sagi Shahar <sagis@...gle.com>
---
 tools/testing/selftests/kvm/lib/kvm_util.c    | 24 ++++++++-
 .../testing/selftests/kvm/lib/x86/processor.c | 49 ++++++++++++++-----
 2 files changed, 61 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index b4c8702ba4bd..d9f0ff97770d 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -4,6 +4,7 @@
  *
  * Copyright (C) 2018, Google LLC.
  */
+#include "tdx/tdx_util.h"
 #include "test_util.h"
 #include "kvm_util.h"
 #include "processor.h"
@@ -465,7 +466,7 @@ void kvm_set_files_rlimit(uint32_t nr_vcpus)
 static bool is_guest_memfd_required(struct vm_shape shape)
 {
 #ifdef __x86_64__
-	return shape.type == KVM_X86_SNP_VM;
+	return (shape.type == KVM_X86_SNP_VM || shape.type == KVM_X86_TDX_VM);
 #else
 	return false;
 #endif
@@ -499,6 +500,12 @@ struct kvm_vm *__vm_create(struct vm_shape shape, uint32_t nr_runnable_vcpus,
 	for (i = 0; i < NR_MEM_REGIONS; i++)
 		vm->memslots[i] = 0;
 
+	if (is_tdx_vm(vm)) {
+		/* Setup additional mem regions for TDX. */
+		vm_tdx_setup_boot_code_region(vm);
+		vm_tdx_setup_boot_parameters_region(vm, nr_runnable_vcpus);
+	}
+
 	kvm_vm_elf_load(vm, program_invocation_name);
 
 	/*
@@ -1728,11 +1735,26 @@ void *addr_gpa2alias(struct kvm_vm *vm, vm_paddr_t gpa)
 	return (void *) ((uintptr_t) region->host_alias + offset);
 }
 
+static bool is_split_irqchip_required(struct kvm_vm *vm)
+{
+#ifdef __x86_64__
+	return is_tdx_vm(vm);
+#else
+	return false;
+#endif
+}
+
 /* Create an interrupt controller chip for the specified VM. */
 void vm_create_irqchip(struct kvm_vm *vm)
 {
 	int r;
 
+	if (is_split_irqchip_required(vm)) {
+		vm_enable_cap(vm, KVM_CAP_SPLIT_IRQCHIP, 24);
+		vm->has_irqchip = true;
+		return;
+	}
+
 	/*
 	 * Allocate a fully in-kernel IRQ chip by default, but fall back to a
 	 * split model (x86 only) if that fails (KVM x86 allows compiling out
diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
index 4802fc81bea7..5cf14f09c1b6 100644
--- a/tools/testing/selftests/kvm/lib/x86/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86/processor.c
@@ -670,6 +670,11 @@ void kvm_arch_vm_post_create(struct kvm_vm *vm)
 		vm_sev_ioctl(vm, KVM_SEV_INIT2, &init);
 	}
 
+	if (is_tdx_vm(vm)) {
+		vm_tdx_init_vm(vm, 0);
+		vm_tdx_load_common_boot_parameters(vm);
+	}
+
 	r = __vm_ioctl(vm, KVM_GET_TSC_KHZ, NULL);
 	TEST_ASSERT(r > 0, "KVM_GET_TSC_KHZ did not provide a valid TSC frequency.");
 	guest_tsc_khz = r;
@@ -680,9 +685,13 @@ void vcpu_arch_set_entry_point(struct kvm_vcpu *vcpu, void *guest_code)
 {
 	struct kvm_regs regs;
 
-	vcpu_regs_get(vcpu, &regs);
-	regs.rip = (unsigned long) guest_code;
-	vcpu_regs_set(vcpu, &regs);
+	if (is_tdx_vm(vcpu->vm))
+		vm_tdx_set_vcpu_entry_point(vcpu, guest_code);
+	else {
+		vcpu_regs_get(vcpu, &regs);
+		regs.rip = (unsigned long) guest_code;
+		vcpu_regs_set(vcpu, &regs);
+	}
 }
 
 vm_vaddr_t kvm_allocate_vcpu_stack(struct kvm_vm *vm)
@@ -711,6 +720,19 @@ vm_vaddr_t kvm_allocate_vcpu_stack(struct kvm_vm *vm)
 	return stack_vaddr;
 }
 
+static void vm_tdx_vcpu_add(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
+{
+	struct kvm_cpuid2 *cpuid;
+
+	cpuid = allocate_kvm_cpuid2(MAX_NR_CPUID_ENTRIES);
+	vm_tdx_vcpu_ioctl(vcpu, KVM_TDX_GET_CPUID, 0, cpuid);
+	vcpu_init_cpuid(vcpu, cpuid);
+	free(cpuid);
+	vm_tdx_vcpu_ioctl(vcpu, KVM_TDX_INIT_VCPU, 0, NULL);
+
+	vm_tdx_load_vcpu_boot_parameters(vm, vcpu);
+}
+
 struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
 {
 	struct kvm_mp_state mp_state;
@@ -718,16 +740,21 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
 	struct kvm_vcpu *vcpu;
 
 	vcpu = __vm_vcpu_add(vm, vcpu_id);
-	vcpu_init_cpuid(vcpu, kvm_get_supported_cpuid());
-	vcpu_init_sregs(vm, vcpu);
-	vcpu_init_xcrs(vm, vcpu);
 
-	/* Setup guest general purpose registers */
-	vcpu_regs_get(vcpu, &regs);
-	regs.rflags = regs.rflags | 0x2;
-	if (vm->type != KVM_X86_TDX_VM)
+	if (is_tdx_vm(vm)) {
+		vm_tdx_vcpu_add(vm, vcpu);
+	} else {
+		vcpu_init_cpuid(vcpu, kvm_get_supported_cpuid());
+
+		vcpu_init_sregs(vm, vcpu);
+		vcpu_init_xcrs(vm, vcpu);
+
+		/* Setup guest general purpose registers */
+		vcpu_regs_get(vcpu, &regs);
+		regs.rflags = regs.rflags | 0x2;
 		regs.rsp = kvm_allocate_vcpu_stack(vm);
-	vcpu_regs_set(vcpu, &regs);
+		vcpu_regs_set(vcpu, &regs);
+	}
 
 	/* Setup the MP state */
 	mp_state.mp_state = 0;
-- 
2.51.0.rc1.193.gad69d77794-goog

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