[PATCH v10 00/21] TDX KVM selftests

[PATCH v10 00/21] TDX KVM selftests

[Sagi Shahar]

This is v10 of the TDX selftests.

This series is based on v6.17-rc4 and has a dependency on
"KVM: TDX: Force split irqchip for TDX at irqchip creation time" [1]

Changes from v9 [2]:
- Rebased on top of v6.17-rc4.
- Addressed the comments from v9.
- Removed special handling for split irqchip in the test code in favor
  for the kvm fix in [1].
- Removed outdated support for VM memory not backed by guest_memfd.
- Split "KVM: selftests: Hook TDX support to vm and vcpu creation" into
  4 separate patches.

[1] https://lore.kernel.org/lkml/20250904062007.622530-1-sagis@google.com/
[2] https://lore.kernel.org/lkml/20250821042915.3712925-1-sagis@google.com/

Ackerley Tng (2):
  KVM: selftests: Add helpers to init TDX memory and finalize VM
  KVM: selftests: Add ucall support for TDX

Erdem Aktas (2):
  KVM: selftests: Add TDX boot code
  KVM: selftests: Add support for TDX TDCALL from guest

Isaku Yamahata (2):
  KVM: selftests: Update kvm_init_vm_address_properties() for TDX
  KVM: selftests: TDX: Use KVM_TDX_CAPABILITIES to validate TDs'
    attribute configuration

Sagi Shahar (15):
  KVM: selftests: Allocate pgd in virt_map() as necessary
  KVM: selftests: Expose functions to get default sregs values
  KVM: selftests: Expose function to allocate guest vCPU stack
  KVM: selftests: Expose segment definitons to assembly files
  KVM: selftests: Add kbuild definitons
  KVM: selftests: Define structs to pass parameters to TDX boot code
  KVM: selftests: Set up TDX boot code region
  KVM: selftests: Set up TDX boot parameters region
  KVM: selftests: Add helper to initialize TDX VM
  KVM: selftests: Call TDX init when creating a new TDX vm
  KVM: selftests: Setup memory regions for TDX on vm creation
  KVM: selftests: Call KVM_TDX_INIT_VCPU when creating a new TDX vcpu
  KVM: selftests: Set entry point for TDX guest code
  KVM: selftests: Add wrapper for TDX MMIO from guest
  KVM: selftests: Add TDX lifecycle test

 tools/include/linux/kbuild.h                  |  18 +
 tools/testing/selftests/kvm/Makefile.kvm      |  32 ++
 .../selftests/kvm/include/x86/processor.h     |  35 ++
 .../selftests/kvm/include/x86/processor_asm.h |  12 +
 .../selftests/kvm/include/x86/tdx/td_boot.h   |  74 ++++
 .../kvm/include/x86/tdx/td_boot_asm.h         |  16 +
 .../selftests/kvm/include/x86/tdx/tdcall.h    |  34 ++
 .../selftests/kvm/include/x86/tdx/tdx.h       |  14 +
 .../selftests/kvm/include/x86/tdx/tdx_util.h  |  86 +++++
 .../testing/selftests/kvm/include/x86/ucall.h |   4 +-
 tools/testing/selftests/kvm/lib/kvm_util.c    |  10 +-
 .../testing/selftests/kvm/lib/x86/processor.c |  91 +++--
 .../selftests/kvm/lib/x86/tdx/td_boot.S       |  60 +++
 .../kvm/lib/x86/tdx/td_boot_offsets.c         |  21 ++
 .../selftests/kvm/lib/x86/tdx/tdcall.S        |  93 +++++
 .../kvm/lib/x86/tdx/tdcall_offsets.c          |  16 +
 tools/testing/selftests/kvm/lib/x86/tdx/tdx.c |  23 ++
 .../selftests/kvm/lib/x86/tdx/tdx_util.c      | 354 ++++++++++++++++++
 tools/testing/selftests/kvm/lib/x86/ucall.c   |  45 ++-
 tools/testing/selftests/kvm/x86/tdx_vm_test.c |  31 ++
 20 files changed, 1032 insertions(+), 37 deletions(-)
 create mode 100644 tools/include/linux/kbuild.h
 create mode 100644 tools/testing/selftests/kvm/include/x86/processor_asm.h
 create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/td_boot.h
 create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/td_boot_asm.h
 create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/tdcall.h
 create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/tdx.h
 create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
 create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/td_boot.S
 create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/td_boot_offsets.c
 create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/tdcall.S
 create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/tdcall_offsets.c
 create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/tdx.c
 create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
 create mode 100644 tools/testing/selftests/kvm/x86/tdx_vm_test.c

-- 
2.51.0.338.gd7d06c2dae-goog

[PATCH v10 01/21] KVM: selftests: Allocate pgd in virt_map() as necessary

[Sagi Shahar]

If virt_map() is called before any call to ____vm_vaddr_alloc() it
will create the mapping using an invalid pgd.

Add call to virt_pgd_alloc() as part of virt_map() before creating the
mapping, similarly to ____vm_vaddr_alloc()

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
---
 tools/testing/selftests/kvm/lib/kvm_util.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index c3f5142b0a54..b4c8702ba4bd 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -1609,6 +1609,7 @@ void virt_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
 	TEST_ASSERT(vaddr + size > vaddr, "Vaddr overflow");
 	TEST_ASSERT(paddr + size > paddr, "Paddr overflow");
 
+	virt_pgd_alloc(vm);
 	while (npages--) {
 		virt_pg_map(vm, vaddr, paddr);
 		sparsebit_set(vm->vpages_mapped, vaddr >> vm->page_shift);
-- 
2.51.0.338.gd7d06c2dae-goog

[PATCH v10 02/21] KVM: selftests: Expose functions to get default sregs values

[Sagi Shahar]

TDX can't set sregs values directly using KVM_SET_SREGS. Expose the
default values of certain sregs used by TDX VMs so they can be set
manually.

Signed-off-by: Sagi Shahar <sagis@google.com>
---
 .../selftests/kvm/include/x86/processor.h     | 33 +++++++++++++++++++
 .../testing/selftests/kvm/lib/x86/processor.c | 12 +++----
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86/processor.h b/tools/testing/selftests/kvm/include/x86/processor.h
index 2efb05c2f2fb..f610c09cadf4 100644
--- a/tools/testing/selftests/kvm/include/x86/processor.h
+++ b/tools/testing/selftests/kvm/include/x86/processor.h
@@ -27,6 +27,10 @@ extern uint64_t guest_tsc_khz;
 #define MAX_NR_CPUID_ENTRIES 100
 #endif
 
+#ifndef NUM_INTERRUPTS
+#define NUM_INTERRUPTS 256
+#endif
+
 #define NONCANONICAL 0xaaaaaaaaaaaaaaaaull
 
 /* Forced emulation prefix, used to invoke the emulator unconditionally. */
@@ -1456,4 +1460,33 @@ void virt_map_level(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
 
 bool sys_clocksource_is_based_on_tsc(void);
 
+static inline uint16_t kvm_get_default_idt_limit(void)
+{
+	return NUM_INTERRUPTS * sizeof(struct idt_entry) - 1;
+}
+
+static inline uint16_t kvm_get_default_gdt_limit(void)
+{
+	return getpagesize() - 1;
+}
+
+static inline uint64_t kvm_get_default_cr0(void)
+{
+	return X86_CR0_PE | X86_CR0_NE | X86_CR0_PG;
+}
+
+static inline uint64_t kvm_get_default_cr4(void)
+{
+	uint64_t cr4 = X86_CR4_PAE | X86_CR4_OSFXSR;
+
+	if (kvm_cpu_has(X86_FEATURE_XSAVE))
+		cr4 |= X86_CR4_OSXSAVE;
+	return cr4;
+}
+
+static inline uint64_t kvm_get_default_efer(void)
+{
+	return EFER_LME | EFER_LMA | EFER_NX;
+}
+
 #endif /* SELFTEST_KVM_PROCESSOR_H */
diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
index d4c19ac885a9..83efcf48faad 100644
--- a/tools/testing/selftests/kvm/lib/x86/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86/processor.c
@@ -498,15 +498,13 @@ static void vcpu_init_sregs(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
 	vcpu_sregs_get(vcpu, &sregs);
 
 	sregs.idt.base = vm->arch.idt;
-	sregs.idt.limit = NUM_INTERRUPTS * sizeof(struct idt_entry) - 1;
+	sregs.idt.limit = kvm_get_default_idt_limit();
 	sregs.gdt.base = vm->arch.gdt;
-	sregs.gdt.limit = getpagesize() - 1;
+	sregs.gdt.limit = kvm_get_default_gdt_limit();
 
-	sregs.cr0 = X86_CR0_PE | X86_CR0_NE | X86_CR0_PG;
-	sregs.cr4 |= X86_CR4_PAE | X86_CR4_OSFXSR;
-	if (kvm_cpu_has(X86_FEATURE_XSAVE))
-		sregs.cr4 |= X86_CR4_OSXSAVE;
-	sregs.efer |= (EFER_LME | EFER_LMA | EFER_NX);
+	sregs.cr0 = kvm_get_default_cr0();
+	sregs.cr4 |= kvm_get_default_cr4();
+	sregs.efer |= kvm_get_default_efer();
 
 	kvm_seg_set_unusable(&sregs.ldt);
 	kvm_seg_set_kernel_code_64bit(&sregs.cs);
-- 
2.51.0.338.gd7d06c2dae-goog

Re: [PATCH v10 02/21] KVM: selftests: Expose functions to get default sregs values

[Binbin Wu]

On 9/4/2025 2:54 PM, Sagi Shahar wrote:
> TDX can't set sregs values directly using KVM_SET_SREGS. Expose the
> default values of certain sregs used by TDX VMs so they can be set
> manually.
>
> Signed-off-by: Sagi Shahar <sagis@google.com>

Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>

One suggestion:
It's better to add change history so that reviewers can know the change quickly
without comparing b/t versions.

> ---
>   .../selftests/kvm/include/x86/processor.h     | 33 +++++++++++++++++++
>   .../testing/selftests/kvm/lib/x86/processor.c | 12 +++----
>   2 files changed, 38 insertions(+), 7 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/include/x86/processor.h b/tools/testing/selftests/kvm/include/x86/processor.h
> index 2efb05c2f2fb..f610c09cadf4 100644
> --- a/tools/testing/selftests/kvm/include/x86/processor.h
> +++ b/tools/testing/selftests/kvm/include/x86/processor.h
> @@ -27,6 +27,10 @@ extern uint64_t guest_tsc_khz;
>   #define MAX_NR_CPUID_ENTRIES 100
>   #endif
>   
> +#ifndef NUM_INTERRUPTS
> +#define NUM_INTERRUPTS 256
> +#endif
> +
>   #define NONCANONICAL 0xaaaaaaaaaaaaaaaaull
>   
>   /* Forced emulation prefix, used to invoke the emulator unconditionally. */
> @@ -1456,4 +1460,33 @@ void virt_map_level(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
>   
>   bool sys_clocksource_is_based_on_tsc(void);
>   
> +static inline uint16_t kvm_get_default_idt_limit(void)
> +{
> +	return NUM_INTERRUPTS * sizeof(struct idt_entry) - 1;
> +}
> +
> +static inline uint16_t kvm_get_default_gdt_limit(void)
> +{
> +	return getpagesize() - 1;
> +}
> +
> +static inline uint64_t kvm_get_default_cr0(void)
> +{
> +	return X86_CR0_PE | X86_CR0_NE | X86_CR0_PG;
> +}
> +
> +static inline uint64_t kvm_get_default_cr4(void)
> +{
> +	uint64_t cr4 = X86_CR4_PAE | X86_CR4_OSFXSR;
> +
> +	if (kvm_cpu_has(X86_FEATURE_XSAVE))
> +		cr4 |= X86_CR4_OSXSAVE;
> +	return cr4;
> +}
> +
> +static inline uint64_t kvm_get_default_efer(void)
> +{
> +	return EFER_LME | EFER_LMA | EFER_NX;
> +}
> +
>   #endif /* SELFTEST_KVM_PROCESSOR_H */
> diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
> index d4c19ac885a9..83efcf48faad 100644
> --- a/tools/testing/selftests/kvm/lib/x86/processor.c
> +++ b/tools/testing/selftests/kvm/lib/x86/processor.c
> @@ -498,15 +498,13 @@ static void vcpu_init_sregs(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
>   	vcpu_sregs_get(vcpu, &sregs);
>   
>   	sregs.idt.base = vm->arch.idt;
> -	sregs.idt.limit = NUM_INTERRUPTS * sizeof(struct idt_entry) - 1;
> +	sregs.idt.limit = kvm_get_default_idt_limit();
>   	sregs.gdt.base = vm->arch.gdt;
> -	sregs.gdt.limit = getpagesize() - 1;
> +	sregs.gdt.limit = kvm_get_default_gdt_limit();
>   
> -	sregs.cr0 = X86_CR0_PE | X86_CR0_NE | X86_CR0_PG;
> -	sregs.cr4 |= X86_CR4_PAE | X86_CR4_OSFXSR;
> -	if (kvm_cpu_has(X86_FEATURE_XSAVE))
> -		sregs.cr4 |= X86_CR4_OSXSAVE;
> -	sregs.efer |= (EFER_LME | EFER_LMA | EFER_NX);
> +	sregs.cr0 = kvm_get_default_cr0();
> +	sregs.cr4 |= kvm_get_default_cr4();
> +	sregs.efer |= kvm_get_default_efer();
>   
>   	kvm_seg_set_unusable(&sregs.ldt);
>   	kvm_seg_set_kernel_code_64bit(&sregs.cs);

[PATCH v10 03/21] KVM: selftests: Expose function to allocate guest vCPU stack

[Sagi Shahar]

TDX guests' registers cannot be initialized directly using
vcpu_regs_set(), hence the stack pointer needs to be initialized by
the guest itself, running boot code beginning at the reset vector.

Expose the function to allocate the guest stack so that TDX
initialization code can allocate it itself and skip the allocation in
vm_arch_vcpu_add() in that case.

Signed-off-by: Sagi Shahar <sagis@google.com>
---
 .../selftests/kvm/include/x86/processor.h        |  2 ++
 tools/testing/selftests/kvm/lib/x86/processor.c  | 16 +++++++++++-----
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86/processor.h b/tools/testing/selftests/kvm/include/x86/processor.h
index f610c09cadf4..8e75df5e6bc9 100644
--- a/tools/testing/selftests/kvm/include/x86/processor.h
+++ b/tools/testing/selftests/kvm/include/x86/processor.h
@@ -1109,6 +1109,8 @@ static inline void vcpu_clear_cpuid_feature(struct kvm_vcpu *vcpu,
 	vcpu_set_or_clear_cpuid_feature(vcpu, feature, false);
 }
 
+vm_vaddr_t kvm_allocate_vcpu_stack(struct kvm_vm *vm);
+
 uint64_t vcpu_get_msr(struct kvm_vcpu *vcpu, uint64_t msr_index);
 int _vcpu_set_msr(struct kvm_vcpu *vcpu, uint64_t msr_index, uint64_t msr_value);
 
diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
index 83efcf48faad..82369373e843 100644
--- a/tools/testing/selftests/kvm/lib/x86/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86/processor.c
@@ -658,12 +658,9 @@ void vcpu_arch_set_entry_point(struct kvm_vcpu *vcpu, void *guest_code)
 	vcpu_regs_set(vcpu, &regs);
 }
 
-struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
+vm_vaddr_t kvm_allocate_vcpu_stack(struct kvm_vm *vm)
 {
-	struct kvm_mp_state mp_state;
-	struct kvm_regs regs;
 	vm_vaddr_t stack_vaddr;
-	struct kvm_vcpu *vcpu;
 
 	stack_vaddr = __vm_vaddr_alloc(vm, DEFAULT_STACK_PGS * getpagesize(),
 				       DEFAULT_GUEST_STACK_VADDR_MIN,
@@ -684,6 +681,15 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
 		    "__vm_vaddr_alloc() did not provide a page-aligned address");
 	stack_vaddr -= 8;
 
+	return stack_vaddr;
+}
+
+struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
+{
+	struct kvm_mp_state mp_state;
+	struct kvm_regs regs;
+	struct kvm_vcpu *vcpu;
+
 	vcpu = __vm_vcpu_add(vm, vcpu_id);
 	vcpu_init_cpuid(vcpu, kvm_get_supported_cpuid());
 	vcpu_init_sregs(vm, vcpu);
@@ -692,7 +698,7 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
 	/* Setup guest general purpose registers */
 	vcpu_regs_get(vcpu, &regs);
 	regs.rflags = regs.rflags | 0x2;
-	regs.rsp = stack_vaddr;
+	regs.rsp = kvm_allocate_vcpu_stack(vm);
 	vcpu_regs_set(vcpu, &regs);
 
 	/* Setup the MP state */
-- 
2.51.0.338.gd7d06c2dae-goog

Re: [PATCH v10 03/21] KVM: selftests: Expose function to allocate guest vCPU stack

[Binbin Wu]

On 9/4/2025 2:54 PM, Sagi Shahar wrote:
> TDX guests' registers cannot be initialized directly using
> vcpu_regs_set(), hence the stack pointer needs to be initialized by
> the guest itself, running boot code beginning at the reset vector.
>
> Expose the function to allocate the guest stack so that TDX
> initialization code can allocate it itself and skip the allocation in
> vm_arch_vcpu_add() in that case.
>
> Signed-off-by: Sagi Shahar <sagis@google.com>

Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>

> ---
>   .../selftests/kvm/include/x86/processor.h        |  2 ++
>   tools/testing/selftests/kvm/lib/x86/processor.c  | 16 +++++++++++-----
>   2 files changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/include/x86/processor.h b/tools/testing/selftests/kvm/include/x86/processor.h
> index f610c09cadf4..8e75df5e6bc9 100644
> --- a/tools/testing/selftests/kvm/include/x86/processor.h
> +++ b/tools/testing/selftests/kvm/include/x86/processor.h
> @@ -1109,6 +1109,8 @@ static inline void vcpu_clear_cpuid_feature(struct kvm_vcpu *vcpu,
>   	vcpu_set_or_clear_cpuid_feature(vcpu, feature, false);
>   }
>   
> +vm_vaddr_t kvm_allocate_vcpu_stack(struct kvm_vm *vm);
> +
>   uint64_t vcpu_get_msr(struct kvm_vcpu *vcpu, uint64_t msr_index);
>   int _vcpu_set_msr(struct kvm_vcpu *vcpu, uint64_t msr_index, uint64_t msr_value);
>   
> diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
> index 83efcf48faad..82369373e843 100644
> --- a/tools/testing/selftests/kvm/lib/x86/processor.c
> +++ b/tools/testing/selftests/kvm/lib/x86/processor.c
> @@ -658,12 +658,9 @@ void vcpu_arch_set_entry_point(struct kvm_vcpu *vcpu, void *guest_code)
>   	vcpu_regs_set(vcpu, &regs);
>   }
>   
> -struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
> +vm_vaddr_t kvm_allocate_vcpu_stack(struct kvm_vm *vm)
>   {
> -	struct kvm_mp_state mp_state;
> -	struct kvm_regs regs;
>   	vm_vaddr_t stack_vaddr;
> -	struct kvm_vcpu *vcpu;
>   
>   	stack_vaddr = __vm_vaddr_alloc(vm, DEFAULT_STACK_PGS * getpagesize(),
>   				       DEFAULT_GUEST_STACK_VADDR_MIN,
> @@ -684,6 +681,15 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
>   		    "__vm_vaddr_alloc() did not provide a page-aligned address");
>   	stack_vaddr -= 8;
>   
> +	return stack_vaddr;
> +}
> +
> +struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
> +{
> +	struct kvm_mp_state mp_state;
> +	struct kvm_regs regs;
> +	struct kvm_vcpu *vcpu;
> +
>   	vcpu = __vm_vcpu_add(vm, vcpu_id);
>   	vcpu_init_cpuid(vcpu, kvm_get_supported_cpuid());
>   	vcpu_init_sregs(vm, vcpu);
> @@ -692,7 +698,7 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id)
>   	/* Setup guest general purpose registers */
>   	vcpu_regs_get(vcpu, &regs);
>   	regs.rflags = regs.rflags | 0x2;
> -	regs.rsp = stack_vaddr;
> +	regs.rsp = kvm_allocate_vcpu_stack(vm);
>   	vcpu_regs_set(vcpu, &regs);
>   
>   	/* Setup the MP state */

[PATCH v10 04/21] KVM: selftests: Update kvm_init_vm_address_properties() for TDX

[Sagi Shahar]

From: Isaku Yamahata <isaku.yamahata@intel.com>

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

TDX sets the shared bit based on the guest physical address width and
currently supports 48 and 52 widths.

Co-developed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Sagi Shahar <sagis@google.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
---
 .../selftests/kvm/include/x86/tdx/tdx_util.h       | 14 ++++++++++++++
 tools/testing/selftests/kvm/lib/x86/processor.c    | 12 ++++++++++--
 2 files changed, 24 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h

diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
new file mode 100644
index 000000000000..286d5e3c24b1
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef SELFTESTS_TDX_TDX_UTIL_H
+#define SELFTESTS_TDX_TDX_UTIL_H
+
+#include <stdbool.h>
+
+#include "kvm_util.h"
+
+static inline bool is_tdx_vm(struct kvm_vm *vm)
+{
+	return vm->type == KVM_X86_TDX_VM;
+}
+
+#endif // SELFTESTS_TDX_TDX_UTIL_H
diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
index 82369373e843..2a44831e0cc9 100644
--- a/tools/testing/selftests/kvm/lib/x86/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86/processor.c
@@ -8,6 +8,7 @@
 #include "kvm_util.h"
 #include "processor.h"
 #include "sev.h"
+#include "tdx/tdx_util.h"
 
 #ifndef NUM_INTERRUPTS
 #define NUM_INTERRUPTS 256
@@ -1160,12 +1161,19 @@ void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits)
 
 void kvm_init_vm_address_properties(struct kvm_vm *vm)
 {
+	uint32_t gpa_bits = kvm_cpu_property(X86_PROPERTY_GUEST_MAX_PHY_ADDR);
+
+	vm->arch.sev_fd = -1;
+
 	if (is_sev_vm(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 {
-		vm->arch.sev_fd = -1;
+	} else if (is_tdx_vm(vm)) {
+		TEST_ASSERT(gpa_bits == 48 || gpa_bits == 52,
+			    "TDX: bad X86_PROPERTY_GUEST_MAX_PHY_ADDR value: %u", gpa_bits);
+		vm->arch.s_bit = BIT_ULL(gpa_bits - 1);
+		vm->gpa_tag_mask = vm->arch.s_bit;
 	}
 }
 
-- 
2.51.0.338.gd7d06c2dae-goog

Re: [PATCH v10 04/21] KVM: selftests: Update kvm_init_vm_address_properties() for TDX

[Binbin Wu]

On 9/4/2025 2:54 PM, Sagi Shahar wrote:
> From: Isaku Yamahata <isaku.yamahata@intel.com>
>
> Let kvm_init_vm_address_properties() initialize vm->arch.{s_bit, tag_mask}
> similar to SEV.
>
> TDX sets the shared bit based on the guest physical address width and
> currently supports 48 and 52 widths.
>
> Co-developed-by: Adrian Hunter <adrian.hunter@intel.com>
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> Co-developed-by: Sagi Shahar <sagis@google.com>
> Signed-off-by: Sagi Shahar <sagis@google.com>

Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>

> ---
>   .../selftests/kvm/include/x86/tdx/tdx_util.h       | 14 ++++++++++++++
>   tools/testing/selftests/kvm/lib/x86/processor.c    | 12 ++++++++++--
>   2 files changed, 24 insertions(+), 2 deletions(-)
>   create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
>
> diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
> new file mode 100644
> index 000000000000..286d5e3c24b1
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
> @@ -0,0 +1,14 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef SELFTESTS_TDX_TDX_UTIL_H
> +#define SELFTESTS_TDX_TDX_UTIL_H
> +
> +#include <stdbool.h>
> +
> +#include "kvm_util.h"
> +
> +static inline bool is_tdx_vm(struct kvm_vm *vm)
> +{
> +	return vm->type == KVM_X86_TDX_VM;
> +}
> +
> +#endif // SELFTESTS_TDX_TDX_UTIL_H
> diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
> index 82369373e843..2a44831e0cc9 100644
> --- a/tools/testing/selftests/kvm/lib/x86/processor.c
> +++ b/tools/testing/selftests/kvm/lib/x86/processor.c
> @@ -8,6 +8,7 @@
>   #include "kvm_util.h"
>   #include "processor.h"
>   #include "sev.h"
> +#include "tdx/tdx_util.h"
>   
>   #ifndef NUM_INTERRUPTS
>   #define NUM_INTERRUPTS 256
> @@ -1160,12 +1161,19 @@ void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits)
>   
>   void kvm_init_vm_address_properties(struct kvm_vm *vm)
>   {
> +	uint32_t gpa_bits = kvm_cpu_property(X86_PROPERTY_GUEST_MAX_PHY_ADDR);
> +
> +	vm->arch.sev_fd = -1;
> +
>   	if (is_sev_vm(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 {
> -		vm->arch.sev_fd = -1;
> +	} else if (is_tdx_vm(vm)) {
> +		TEST_ASSERT(gpa_bits == 48 || gpa_bits == 52,
> +			    "TDX: bad X86_PROPERTY_GUEST_MAX_PHY_ADDR value: %u", gpa_bits);
> +		vm->arch.s_bit = BIT_ULL(gpa_bits - 1);
> +		vm->gpa_tag_mask = vm->arch.s_bit;
>   	}
>   }
>   

[PATCH v10 05/21] KVM: selftests: Expose segment definitons to assembly files

[Sagi Shahar]

Move kernel segment definitions to a separate file which can be included
from assembly files.

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
---
 .../selftests/kvm/include/x86/processor_asm.h        | 12 ++++++++++++
 tools/testing/selftests/kvm/lib/x86/processor.c      |  5 +----
 2 files changed, 13 insertions(+), 4 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/include/x86/processor_asm.h

diff --git a/tools/testing/selftests/kvm/include/x86/processor_asm.h b/tools/testing/selftests/kvm/include/x86/processor_asm.h
new file mode 100644
index 000000000000..7e5386a85ca8
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/x86/processor_asm.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Used for storing defines used by both processor.c and assembly code.
+ */
+#ifndef SELFTEST_KVM_PROCESSOR_ASM_H
+#define SELFTEST_KVM_PROCESSOR_ASM_H
+
+#define KERNEL_CS	0x8
+#define KERNEL_DS	0x10
+#define KERNEL_TSS	0x18
+
+#endif  // SELFTEST_KVM_PROCESSOR_ASM_H
diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
index 2a44831e0cc9..623168ea9a44 100644
--- a/tools/testing/selftests/kvm/lib/x86/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86/processor.c
@@ -7,6 +7,7 @@
 #include "test_util.h"
 #include "kvm_util.h"
 #include "processor.h"
+#include "processor_asm.h"
 #include "sev.h"
 #include "tdx/tdx_util.h"
 
@@ -14,10 +15,6 @@
 #define NUM_INTERRUPTS 256
 #endif
 
-#define KERNEL_CS	0x8
-#define KERNEL_DS	0x10
-#define KERNEL_TSS	0x18
-
 vm_vaddr_t exception_handlers;
 bool host_cpu_is_amd;
 bool host_cpu_is_intel;
-- 
2.51.0.338.gd7d06c2dae-goog

Re: [PATCH v10 05/21] KVM: selftests: Expose segment definitons to assembly files

[Binbin Wu]

On 9/4/2025 2:54 PM, Sagi Shahar wrote:
> Move kernel segment definitions to a separate file which can be included
> from assembly files.
>
> Reviewed-by: Ira Weiny <ira.weiny@intel.com>
> Signed-off-by: Sagi Shahar <sagis@google.com>

Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>

> ---
>   .../selftests/kvm/include/x86/processor_asm.h        | 12 ++++++++++++
>   tools/testing/selftests/kvm/lib/x86/processor.c      |  5 +----
>   2 files changed, 13 insertions(+), 4 deletions(-)
>   create mode 100644 tools/testing/selftests/kvm/include/x86/processor_asm.h
>
> diff --git a/tools/testing/selftests/kvm/include/x86/processor_asm.h b/tools/testing/selftests/kvm/include/x86/processor_asm.h
> new file mode 100644
> index 000000000000..7e5386a85ca8
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/include/x86/processor_asm.h
> @@ -0,0 +1,12 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Used for storing defines used by both processor.c and assembly code.
> + */
> +#ifndef SELFTEST_KVM_PROCESSOR_ASM_H
> +#define SELFTEST_KVM_PROCESSOR_ASM_H
> +
> +#define KERNEL_CS	0x8
> +#define KERNEL_DS	0x10
> +#define KERNEL_TSS	0x18
> +
> +#endif  // SELFTEST_KVM_PROCESSOR_ASM_H
> diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
> index 2a44831e0cc9..623168ea9a44 100644
> --- a/tools/testing/selftests/kvm/lib/x86/processor.c
> +++ b/tools/testing/selftests/kvm/lib/x86/processor.c
> @@ -7,6 +7,7 @@
>   #include "test_util.h"
>   #include "kvm_util.h"
>   #include "processor.h"
> +#include "processor_asm.h"
>   #include "sev.h"
>   #include "tdx/tdx_util.h"
>   
> @@ -14,10 +15,6 @@
>   #define NUM_INTERRUPTS 256
>   #endif
>   
> -#define KERNEL_CS	0x8
> -#define KERNEL_DS	0x10
> -#define KERNEL_TSS	0x18
> -
>   vm_vaddr_t exception_handlers;
>   bool host_cpu_is_amd;
>   bool host_cpu_is_intel;

[PATCH v10 06/21] KVM: selftests: Add kbuild definitons

[Sagi Shahar]

Add kbuild.h that can be used by files under tools/

Definitions are taken from the original definitions at
include/linux/kbuild.h

This is needed to expose values from c code to assembly code.

Signed-off-by: Sagi Shahar <sagis@google.com>
---
 tools/include/linux/kbuild.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 tools/include/linux/kbuild.h

diff --git a/tools/include/linux/kbuild.h b/tools/include/linux/kbuild.h
new file mode 100644
index 000000000000..62e20ba9380e
--- /dev/null
+++ b/tools/include/linux/kbuild.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __TOOLS_LINUX_KBUILD_H
+#define __TOOLS_LINUX_KBUILD_H
+
+#include <stddef.h>
+
+#define DEFINE(sym, val) \
+	asm volatile("\n.ascii \"->" #sym " %0 " #val "\"" : : "i" (val))
+
+#define BLANK() asm volatile("\n.ascii \"->\"" : : )
+
+#define OFFSET(sym, str, mem) \
+	DEFINE(sym, offsetof(struct str, mem))
+
+#define COMMENT(x) \
+	asm volatile("\n.ascii \"->#" x "\"")
+
+#endif /* __TOOLS_LINUX_KBUILD_H */
-- 
2.51.0.338.gd7d06c2dae-goog

[PATCH v10 07/21] KVM: selftests: Define structs to pass parameters to TDX boot code

[Sagi Shahar]

TDX registers are inaccesible to KVM. Therefore we need a different
mechanism to load boot parameters for TDX code. TDX boot code will read
the registers values from memory and set the registers manually.

This patch defines the data structures used to communicate between c
code and the TDX assembly boot code which will be added in a later
patch.

Use kbuild.h to expose the offsets into the structs from c code to
assembly code.

Co-developed-by: Ackerley Tng <ackerleytng@google.com>
Signed-off-by: Ackerley Tng <ackerleytng@google.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
---
 tools/testing/selftests/kvm/Makefile.kvm      | 18 +++++
 .../selftests/kvm/include/x86/tdx/td_boot.h   | 69 +++++++++++++++++++
 .../kvm/lib/x86/tdx/td_boot_offsets.c         | 21 ++++++
 3 files changed, 108 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/td_boot.h
 create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/td_boot_offsets.c

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
index 41b40c676d7f..3f93c093b046 100644
--- a/tools/testing/selftests/kvm/Makefile.kvm
+++ b/tools/testing/selftests/kvm/Makefile.kvm
@@ -19,6 +19,8 @@ LIBKVM += lib/userfaultfd_util.c
 
 LIBKVM_STRING += lib/string_override.c
 
+LIBKVM_ASM_DEFS += lib/x86/tdx/td_boot_offsets.c
+
 LIBKVM_x86 += lib/x86/apic.c
 LIBKVM_x86 += lib/x86/handlers.S
 LIBKVM_x86 += lib/x86/hyperv.c
@@ -230,6 +232,10 @@ OVERRIDE_TARGETS = 1
 include ../lib.mk
 include ../cgroup/lib/libcgroup.mk
 
+# Enable Kbuild tools.
+include $(top_srcdir)/scripts/Kbuild.include
+include $(top_srcdir)/scripts/Makefile.lib
+
 INSTALL_HDR_PATH = $(top_srcdir)/usr
 LINUX_HDR_PATH = $(INSTALL_HDR_PATH)/include/
 LINUX_TOOL_INCLUDE = $(top_srcdir)/tools/include
@@ -282,6 +288,7 @@ LIBKVM_S := $(filter %.S,$(LIBKVM))
 LIBKVM_C_OBJ := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBKVM_C))
 LIBKVM_S_OBJ := $(patsubst %.S, $(OUTPUT)/%.o, $(LIBKVM_S))
 LIBKVM_STRING_OBJ := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBKVM_STRING))
+LIBKVM_ASM_DEFS_OBJ += $(patsubst %.c, $(OUTPUT)/%.s, $(LIBKVM_ASM_DEFS))
 LIBKVM_OBJS = $(LIBKVM_C_OBJ) $(LIBKVM_S_OBJ) $(LIBKVM_STRING_OBJ) $(LIBCGROUP_O)
 SPLIT_TEST_GEN_PROGS := $(patsubst %, $(OUTPUT)/%, $(SPLIT_TESTS))
 SPLIT_TEST_GEN_OBJ := $(patsubst %, $(OUTPUT)/$(ARCH)/%.o, $(SPLIT_TESTS))
@@ -308,6 +315,7 @@ $(SPLIT_TEST_GEN_OBJ): $(OUTPUT)/$(ARCH)/%.o: $(ARCH)/%.c
 
 EXTRA_CLEAN += $(GEN_HDRS) \
 	       $(LIBKVM_OBJS) \
+	       $(LIBKVM_ASM_DEFS_OBJ) \
 	       $(SPLIT_TEST_GEN_OBJ) \
 	       $(TEST_DEP_FILES) \
 	       $(TEST_GEN_OBJ) \
@@ -319,18 +327,28 @@ $(LIBKVM_C_OBJ): $(OUTPUT)/%.o: %.c $(GEN_HDRS)
 $(LIBKVM_S_OBJ): $(OUTPUT)/%.o: %.S $(GEN_HDRS)
 	$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c $< -o $@
 
+$(LIBKVM_ASM_DEFS_OBJ): $(OUTPUT)/%.s: %.c FORCE
+	$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -S $< -o $@
+
 # Compile the string overrides as freestanding to prevent the compiler from
 # generating self-referential code, e.g. without "freestanding" the compiler may
 # "optimize" memcmp() by invoking memcmp(), thus causing infinite recursion.
 $(LIBKVM_STRING_OBJ): $(OUTPUT)/%.o: %.c
 	$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c -ffreestanding $< -o $@
 
+$(OUTPUT)/include/x86/tdx/td_boot_offsets.h: $(OUTPUT)/lib/x86/tdx/td_boot_offsets.s FORCE
+	$(call filechk,offsets,__TDX_BOOT_OFFSETS_H__)
+
+EXTRA_CLEAN += $(OUTPUT)/include/x86/tdx/td_boot_offsets.h
+
 $(shell mkdir -p $(sort $(dir $(TEST_GEN_PROGS))))
 $(SPLIT_TEST_GEN_OBJ): $(GEN_HDRS)
 $(TEST_GEN_PROGS): $(LIBKVM_OBJS)
 $(TEST_GEN_PROGS_EXTENDED): $(LIBKVM_OBJS)
 $(TEST_GEN_OBJ): $(GEN_HDRS)
 
+FORCE:
+
 cscope: include_paths = $(LINUX_TOOL_INCLUDE) $(LINUX_HDR_PATH) include lib ..
 cscope:
 	$(RM) cscope.*
diff --git a/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h b/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h
new file mode 100644
index 000000000000..8eda3ce10220
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef SELFTEST_TDX_TD_BOOT_H
+#define SELFTEST_TDX_TD_BOOT_H
+
+#include <stdint.h>
+
+#include <linux/compiler.h>
+#include <linux/sizes.h>
+
+/*
+ * Layout for boot section (not to scale)
+ *
+ *                                   GPA
+ * _________________________________ 0x1_0000_0000 (4GB)
+ * |   Boot code trampoline    |
+ * |___________________________|____ 0x0_ffff_fff0: Reset vector (16B below 4GB)
+ * |   Boot code               |
+ * |___________________________|____ td_boot will be copied here, so that the
+ * |                           |     jmp to td_boot is exactly at the reset vector
+ * |   Empty space             |
+ * |                           |
+ * |───────────────────────────|
+ * |                           |
+ * |                           |
+ * |   Boot parameters         |
+ * |                           |
+ * |                           |
+ * |___________________________|____ 0x0_ffff_0000: TD_BOOT_PARAMETERS_GPA
+ */
+#define FOUR_GIGABYTES_GPA (SZ_4G)
+
+/*
+ * The exact memory layout for LGDT or LIDT instructions.
+ */
+struct __packed td_boot_parameters_dtr {
+	uint16_t limit;
+	uint32_t base;
+};
+
+/*
+ * Allows each vCPU to be initialized with different eip and esp.
+ */
+struct td_per_vcpu_parameters {
+	uint32_t esp_gva;
+	uint64_t guest_code;
+};
+
+/*
+ * Boot parameters for the TD.
+ *
+ * Unlike a regular VM, KVM cannot set registers such as esp, eip, etc
+ * before boot, so to run selftests, these registers' values have to be
+ * initialized by the TD.
+ *
+ * This struct is loaded in TD private memory at TD_BOOT_PARAMETERS_GPA.
+ *
+ * The TD boot code will read off parameters from this struct and set up the
+ * vCPU for executing selftests.
+ */
+struct td_boot_parameters {
+	uint32_t cr0;
+	uint32_t cr3;
+	uint32_t cr4;
+	struct td_boot_parameters_dtr gdtr;
+	struct td_boot_parameters_dtr idtr;
+	struct td_per_vcpu_parameters per_vcpu[];
+};
+
+#endif /* SELFTEST_TDX_TD_BOOT_H */
diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/td_boot_offsets.c b/tools/testing/selftests/kvm/lib/x86/tdx/td_boot_offsets.c
new file mode 100644
index 000000000000..7f76a3585b99
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/x86/tdx/td_boot_offsets.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+#define COMPILE_OFFSETS
+
+#include <linux/kbuild.h>
+
+#include "tdx/td_boot.h"
+
+static void __attribute__((used)) common(void)
+{
+	OFFSET(TD_BOOT_PARAMETERS_CR0, td_boot_parameters, cr0);
+	OFFSET(TD_BOOT_PARAMETERS_CR3, td_boot_parameters, cr3);
+	OFFSET(TD_BOOT_PARAMETERS_CR4, td_boot_parameters, cr4);
+	OFFSET(TD_BOOT_PARAMETERS_GDT, td_boot_parameters, gdtr);
+	OFFSET(TD_BOOT_PARAMETERS_IDT, td_boot_parameters, idtr);
+	OFFSET(TD_BOOT_PARAMETERS_PER_VCPU, td_boot_parameters, per_vcpu);
+	OFFSET(TD_PER_VCPU_PARAMETERS_ESP_GVA, td_per_vcpu_parameters, esp_gva);
+	OFFSET(TD_PER_VCPU_PARAMETERS_GUEST_CODE, td_per_vcpu_parameters,
+	       guest_code);
+	DEFINE(SIZEOF_TD_PER_VCPU_PARAMETERS,
+	       sizeof(struct td_per_vcpu_parameters));
+}
-- 
2.51.0.338.gd7d06c2dae-goog

Re: [PATCH v10 07/21] KVM: selftests: Define structs to pass parameters to TDX boot code

[Binbin Wu]

On 9/4/2025 2:54 PM, Sagi Shahar wrote:
> TDX registers are inaccesible to KVM. Therefore we need a different

inaccesible -> inaccessible


> mechanism to load boot parameters for TDX code. TDX boot code will read
> the registers values from memory and set the registers manually.
>
> This patch defines the data structures used to communicate between c
> code and the TDX assembly boot code which will be added in a later
> patch.
>
> Use kbuild.h to expose the offsets into the structs from c code to
> assembly code.
>
> Co-developed-by: Ackerley Tng<ackerleytng@google.com>
> Signed-off-by: Ackerley Tng<ackerleytng@google.com>
> Signed-off-by: Sagi Shahar<sagis@google.com>

One typo above and one nit comment below.

Otherwise,
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>

> ---
>   tools/testing/selftests/kvm/Makefile.kvm      | 18 +++++
>   .../selftests/kvm/include/x86/tdx/td_boot.h   | 69 +++++++++++++++++++
>   .../kvm/lib/x86/tdx/td_boot_offsets.c         | 21 ++++++
>   3 files changed, 108 insertions(+)
>   create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/td_boot.h
>   create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/td_boot_offsets.c
>
> diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
> index 41b40c676d7f..3f93c093b046 100644
> --- a/tools/testing/selftests/kvm/Makefile.kvm
> +++ b/tools/testing/selftests/kvm/Makefile.kvm
> @@ -19,6 +19,8 @@ LIBKVM += lib/userfaultfd_util.c
>   
>   LIBKVM_STRING += lib/string_override.c
>   
> +LIBKVM_ASM_DEFS += lib/x86/tdx/td_boot_offsets.c
> +
>   LIBKVM_x86 += lib/x86/apic.c
>   LIBKVM_x86 += lib/x86/handlers.S
>   LIBKVM_x86 += lib/x86/hyperv.c
> @@ -230,6 +232,10 @@ OVERRIDE_TARGETS = 1
>   include ../lib.mk
>   include ../cgroup/lib/libcgroup.mk
>   
> +# Enable Kbuild tools.
> +include $(top_srcdir)/scripts/Kbuild.include
> +include $(top_srcdir)/scripts/Makefile.lib
> +
>   INSTALL_HDR_PATH = $(top_srcdir)/usr
>   LINUX_HDR_PATH = $(INSTALL_HDR_PATH)/include/
>   LINUX_TOOL_INCLUDE = $(top_srcdir)/tools/include
> @@ -282,6 +288,7 @@ LIBKVM_S := $(filter %.S,$(LIBKVM))
>   LIBKVM_C_OBJ := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBKVM_C))
>   LIBKVM_S_OBJ := $(patsubst %.S, $(OUTPUT)/%.o, $(LIBKVM_S))
>   LIBKVM_STRING_OBJ := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBKVM_STRING))
> +LIBKVM_ASM_DEFS_OBJ += $(patsubst %.c, $(OUTPUT)/%.s, $(LIBKVM_ASM_DEFS))
>   LIBKVM_OBJS = $(LIBKVM_C_OBJ) $(LIBKVM_S_OBJ) $(LIBKVM_STRING_OBJ) $(LIBCGROUP_O)
>   SPLIT_TEST_GEN_PROGS := $(patsubst %, $(OUTPUT)/%, $(SPLIT_TESTS))
>   SPLIT_TEST_GEN_OBJ := $(patsubst %, $(OUTPUT)/$(ARCH)/%.o, $(SPLIT_TESTS))
> @@ -308,6 +315,7 @@ $(SPLIT_TEST_GEN_OBJ): $(OUTPUT)/$(ARCH)/%.o: $(ARCH)/%.c
>   
>   EXTRA_CLEAN += $(GEN_HDRS) \
>   	       $(LIBKVM_OBJS) \
> +	       $(LIBKVM_ASM_DEFS_OBJ) \
>   	       $(SPLIT_TEST_GEN_OBJ) \
>   	       $(TEST_DEP_FILES) \
>   	       $(TEST_GEN_OBJ) \
> @@ -319,18 +327,28 @@ $(LIBKVM_C_OBJ): $(OUTPUT)/%.o: %.c $(GEN_HDRS)
>   $(LIBKVM_S_OBJ): $(OUTPUT)/%.o: %.S $(GEN_HDRS)
>   	$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c $< -o $@
>   
> +$(LIBKVM_ASM_DEFS_OBJ): $(OUTPUT)/%.s: %.c FORCE
> +	$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -S $< -o $@
> +
>   # Compile the string overrides as freestanding to prevent the compiler from
>   # generating self-referential code, e.g. without "freestanding" the compiler may
>   # "optimize" memcmp() by invoking memcmp(), thus causing infinite recursion.
>   $(LIBKVM_STRING_OBJ): $(OUTPUT)/%.o: %.c
>   	$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c -ffreestanding $< -o $@
>   
> +$(OUTPUT)/include/x86/tdx/td_boot_offsets.h: $(OUTPUT)/lib/x86/tdx/td_boot_offsets.s FORCE
> +	$(call filechk,offsets,__TDX_BOOT_OFFSETS_H__)
> +
> +EXTRA_CLEAN += $(OUTPUT)/include/x86/tdx/td_boot_offsets.h
> +
>   $(shell mkdir -p $(sort $(dir $(TEST_GEN_PROGS))))
>   $(SPLIT_TEST_GEN_OBJ): $(GEN_HDRS)
>   $(TEST_GEN_PROGS): $(LIBKVM_OBJS)
>   $(TEST_GEN_PROGS_EXTENDED): $(LIBKVM_OBJS)
>   $(TEST_GEN_OBJ): $(GEN_HDRS)
>   
> +FORCE:
> +
>   cscope: include_paths = $(LINUX_TOOL_INCLUDE) $(LINUX_HDR_PATH) include lib ..
>   cscope:
>   	$(RM) cscope.*
> diff --git a/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h b/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h
> new file mode 100644
> index 000000000000..8eda3ce10220
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h
> @@ -0,0 +1,69 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef SELFTEST_TDX_TD_BOOT_H
> +#define SELFTEST_TDX_TD_BOOT_H
> +
> +#include <stdint.h>
> +
> +#include <linux/compiler.h>
> +#include <linux/sizes.h>
> +
> +/*
> + * Layout for boot section (not to scale)
> + *
> + *                                   GPA
> + * _________________________________ 0x1_0000_0000 (4GB)
> + * |   Boot code trampoline    |
> + * |___________________________|____ 0x0_ffff_fff0: Reset vector (16B below 4GB)
> + * |   Boot code               |
> + * |___________________________|____ td_boot will be copied here, so that the
> + * |                           |     jmp to td_boot is exactly at the reset vector
> + * |   Empty space             |
> + * |                           |
> + * |───────────────────────────|
> + * |                           |
> + * |                           |
> + * |   Boot parameters         |
> + * |                           |
> + * |                           |
> + * |___________________________|____ 0x0_ffff_0000: TD_BOOT_PARAMETERS_GPA
> + */
> +#define FOUR_GIGABYTES_GPA (SZ_4G)
> +
> +/*
> + * The exact memory layout for LGDT or LIDT instructions.
> + */
> +struct __packed td_boot_parameters_dtr {
> +	uint16_t limit;
> +	uint32_t base;
> +};
> +
> +/*
> + * Allows each vCPU to be initialized with different eip and esp.
Nit:
Since guest_code is 64bit and the value is used when the vCPU is in 64bit mode,
eip -> rip?

> + */
> +struct td_per_vcpu_parameters {
> +	uint32_t esp_gva;
> +	uint64_t guest_code;
> +};
> +
> +/*
> + * Boot parameters for the TD.
> + *
> + * Unlike a regular VM, KVM cannot set registers such as esp, eip, etc
> + * before boot, so to run selftests, these registers' values have to be
> + * initialized by the TD.
> + *
> + * This struct is loaded in TD private memory at TD_BOOT_PARAMETERS_GPA.
> + *
> + * The TD boot code will read off parameters from this struct and set up the
> + * vCPU for executing selftests.
> + */
> +struct td_boot_parameters {
> +	uint32_t cr0;
> +	uint32_t cr3;
> +	uint32_t cr4;
> +	struct td_boot_parameters_dtr gdtr;
> +	struct td_boot_parameters_dtr idtr;
> +	struct td_per_vcpu_parameters per_vcpu[];
> +};
> +
> +#endif /* SELFTEST_TDX_TD_BOOT_H */
> diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/td_boot_offsets.c b/tools/testing/selftests/kvm/lib/x86/tdx/td_boot_offsets.c
> new file mode 100644
> index 000000000000..7f76a3585b99
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/lib/x86/tdx/td_boot_offsets.c
> @@ -0,0 +1,21 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#define COMPILE_OFFSETS
> +
> +#include <linux/kbuild.h>
> +
> +#include "tdx/td_boot.h"
> +
> +static void __attribute__((used)) common(void)
> +{
> +	OFFSET(TD_BOOT_PARAMETERS_CR0, td_boot_parameters, cr0);
> +	OFFSET(TD_BOOT_PARAMETERS_CR3, td_boot_parameters, cr3);
> +	OFFSET(TD_BOOT_PARAMETERS_CR4, td_boot_parameters, cr4);
> +	OFFSET(TD_BOOT_PARAMETERS_GDT, td_boot_parameters, gdtr);
> +	OFFSET(TD_BOOT_PARAMETERS_IDT, td_boot_parameters, idtr);
> +	OFFSET(TD_BOOT_PARAMETERS_PER_VCPU, td_boot_parameters, per_vcpu);
> +	OFFSET(TD_PER_VCPU_PARAMETERS_ESP_GVA, td_per_vcpu_parameters, esp_gva);
> +	OFFSET(TD_PER_VCPU_PARAMETERS_GUEST_CODE, td_per_vcpu_parameters,
> +	       guest_code);
> +	DEFINE(SIZEOF_TD_PER_VCPU_PARAMETERS,
> +	       sizeof(struct td_per_vcpu_parameters));
> +}

[PATCH v10 08/21] KVM: selftests: Add TDX boot code

[Sagi Shahar]

From: Erdem Aktas <erdemaktas@google.com>

Add code to boot a TDX test VM. Since TDX registers are inaccesible to
KVM, the boot code loads the relevant values from memory into the
registers before jumping to the guest code.

Signed-off-by: Erdem Aktas <erdemaktas@google.com>
Co-developed-by: Ackerley Tng <ackerleytng@google.com>
Signed-off-by: Ackerley Tng <ackerleytng@google.com>
Co-developed-by: Sagi Shahar <sagis@google.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
---
 tools/testing/selftests/kvm/Makefile.kvm      |  3 +
 .../selftests/kvm/include/x86/tdx/td_boot.h   |  5 ++
 .../kvm/include/x86/tdx/td_boot_asm.h         | 16 +++++
 .../selftests/kvm/lib/x86/tdx/td_boot.S       | 60 +++++++++++++++++++
 4 files changed, 84 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/td_boot_asm.h
 create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/td_boot.S

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
index 3f93c093b046..d11d02e17cc5 100644
--- a/tools/testing/selftests/kvm/Makefile.kvm
+++ b/tools/testing/selftests/kvm/Makefile.kvm
@@ -31,6 +31,7 @@ LIBKVM_x86 += lib/x86/sev.c
 LIBKVM_x86 += lib/x86/svm.c
 LIBKVM_x86 += lib/x86/ucall.c
 LIBKVM_x86 += lib/x86/vmx.c
+LIBKVM_x86 += lib/x86/tdx/td_boot.S
 
 LIBKVM_arm64 += lib/arm64/gic.c
 LIBKVM_arm64 += lib/arm64/gic_v3.c
@@ -336,6 +337,8 @@ $(LIBKVM_ASM_DEFS_OBJ): $(OUTPUT)/%.s: %.c FORCE
 $(LIBKVM_STRING_OBJ): $(OUTPUT)/%.o: %.c
 	$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c -ffreestanding $< -o $@
 
+$(OUTPUT)/lib/x86/tdx/td_boot.o: $(OUTPUT)/include/x86/tdx/td_boot_offsets.h
+
 $(OUTPUT)/include/x86/tdx/td_boot_offsets.h: $(OUTPUT)/lib/x86/tdx/td_boot_offsets.s FORCE
 	$(call filechk,offsets,__TDX_BOOT_OFFSETS_H__)
 
diff --git a/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h b/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h
index 8eda3ce10220..17c3083da9ca 100644
--- a/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h
+++ b/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h
@@ -66,4 +66,9 @@ struct td_boot_parameters {
 	struct td_per_vcpu_parameters per_vcpu[];
 };
 
+void td_boot(void);
+void td_boot_code_end(void);
+
+#define TD_BOOT_CODE_SIZE (td_boot_code_end - td_boot)
+
 #endif /* SELFTEST_TDX_TD_BOOT_H */
diff --git a/tools/testing/selftests/kvm/include/x86/tdx/td_boot_asm.h b/tools/testing/selftests/kvm/include/x86/tdx/td_boot_asm.h
new file mode 100644
index 000000000000..10b4b527595c
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/x86/tdx/td_boot_asm.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef SELFTEST_TDX_TD_BOOT_ASM_H
+#define SELFTEST_TDX_TD_BOOT_ASM_H
+
+/*
+ * GPA where TD boot parameters will be loaded.
+ *
+ * TD_BOOT_PARAMETERS_GPA is arbitrarily chosen to
+ *
+ * + be within the 4GB address space
+ * + provide enough contiguous memory for the struct td_boot_parameters such
+ *   that there is one struct td_per_vcpu_parameters for KVM_MAX_VCPUS
+ */
+#define TD_BOOT_PARAMETERS_GPA 0xffff0000
+
+#endif  // SELFTEST_TDX_TD_BOOT_ASM_H
diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/td_boot.S b/tools/testing/selftests/kvm/lib/x86/tdx/td_boot.S
new file mode 100644
index 000000000000..7aa33caa9a78
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/x86/tdx/td_boot.S
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include "tdx/td_boot_asm.h"
+#include "tdx/td_boot_offsets.h"
+#include "processor_asm.h"
+
+.code32
+
+.globl td_boot
+td_boot:
+	/* In this procedure, edi is used as a temporary register. */
+	cli
+
+	/* Paging is off. */
+
+	movl $TD_BOOT_PARAMETERS_GPA, %ebx
+
+	/*
+	 * Find the address of struct td_per_vcpu_parameters for this
+	 * vCPU based on esi (TDX spec: initialized with vCPU id). Put
+	 * struct address into register for indirect addressing.
+	 */
+	movl $SIZEOF_TD_PER_VCPU_PARAMETERS, %eax
+	mul %esi
+	leal TD_BOOT_PARAMETERS_PER_VCPU(%ebx), %edi
+	addl %edi, %eax
+
+	/* Setup stack. */
+	movl TD_PER_VCPU_PARAMETERS_ESP_GVA(%eax), %esp
+
+	/* Setup GDT. */
+	leal TD_BOOT_PARAMETERS_GDT(%ebx), %edi
+	lgdt (%edi)
+
+	/* Setup IDT. */
+	leal TD_BOOT_PARAMETERS_IDT(%ebx), %edi
+	lidt (%edi)
+
+	/*
+	 * Set up control registers (There are no instructions to mov from
+	 * memory to control registers, hence use edi as a scratch register).
+	 */
+	movl TD_BOOT_PARAMETERS_CR4(%ebx), %edi
+	movl %edi, %cr4
+	movl TD_BOOT_PARAMETERS_CR3(%ebx), %edi
+	movl %edi, %cr3
+	movl TD_BOOT_PARAMETERS_CR0(%ebx), %edi
+	movl %edi, %cr0
+
+	/* Switching to 64bit mode after ljmp and then jump to guest code */
+	ljmp $(KERNEL_CS),$1f
+1:
+	jmp *TD_PER_VCPU_PARAMETERS_GUEST_CODE(%eax)
+
+/* Leave marker so size of td_boot code can be computed. */
+.globl td_boot_code_end
+td_boot_code_end:
+
+/* Disable executable stack. */
+.section .note.GNU-stack,"",%progbits
-- 
2.51.0.338.gd7d06c2dae-goog

Re: [PATCH v10 08/21] KVM: selftests: Add TDX boot code

[Binbin Wu]

On 9/4/2025 2:54 PM, Sagi Shahar wrote:
> From: Erdem Aktas <erdemaktas@google.com>
>
> Add code to boot a TDX test VM. Since TDX registers are inaccesible to

inaccesible -> inaccessible

> KVM, the boot code loads the relevant values from memory into the
> registers before jumping to the guest code.
>
> Signed-off-by: Erdem Aktas <erdemaktas@google.com>
> Co-developed-by: Ackerley Tng <ackerleytng@google.com>
> Signed-off-by: Ackerley Tng <ackerleytng@google.com>
> Co-developed-by: Sagi Shahar <sagis@google.com>
> Signed-off-by: Sagi Shahar <sagis@google.com>

Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>

> ---
>   tools/testing/selftests/kvm/Makefile.kvm      |  3 +
>   .../selftests/kvm/include/x86/tdx/td_boot.h   |  5 ++
>   .../kvm/include/x86/tdx/td_boot_asm.h         | 16 +++++
>   .../selftests/kvm/lib/x86/tdx/td_boot.S       | 60 +++++++++++++++++++
>   4 files changed, 84 insertions(+)
>   create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/td_boot_asm.h
>   create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/td_boot.S
>
> diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
> index 3f93c093b046..d11d02e17cc5 100644
> --- a/tools/testing/selftests/kvm/Makefile.kvm
> +++ b/tools/testing/selftests/kvm/Makefile.kvm
> @@ -31,6 +31,7 @@ LIBKVM_x86 += lib/x86/sev.c
>   LIBKVM_x86 += lib/x86/svm.c
>   LIBKVM_x86 += lib/x86/ucall.c
>   LIBKVM_x86 += lib/x86/vmx.c
> +LIBKVM_x86 += lib/x86/tdx/td_boot.S
>   
>   LIBKVM_arm64 += lib/arm64/gic.c
>   LIBKVM_arm64 += lib/arm64/gic_v3.c
> @@ -336,6 +337,8 @@ $(LIBKVM_ASM_DEFS_OBJ): $(OUTPUT)/%.s: %.c FORCE
>   $(LIBKVM_STRING_OBJ): $(OUTPUT)/%.o: %.c
>   	$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c -ffreestanding $< -o $@
>   
> +$(OUTPUT)/lib/x86/tdx/td_boot.o: $(OUTPUT)/include/x86/tdx/td_boot_offsets.h
> +
>   $(OUTPUT)/include/x86/tdx/td_boot_offsets.h: $(OUTPUT)/lib/x86/tdx/td_boot_offsets.s FORCE
>   	$(call filechk,offsets,__TDX_BOOT_OFFSETS_H__)
>   
> diff --git a/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h b/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h
> index 8eda3ce10220..17c3083da9ca 100644
> --- a/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h
> +++ b/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h
> @@ -66,4 +66,9 @@ struct td_boot_parameters {
>   	struct td_per_vcpu_parameters per_vcpu[];
>   };
>   
> +void td_boot(void);
> +void td_boot_code_end(void);
> +
> +#define TD_BOOT_CODE_SIZE (td_boot_code_end - td_boot)
> +
>   #endif /* SELFTEST_TDX_TD_BOOT_H */
> diff --git a/tools/testing/selftests/kvm/include/x86/tdx/td_boot_asm.h b/tools/testing/selftests/kvm/include/x86/tdx/td_boot_asm.h
> new file mode 100644
> index 000000000000..10b4b527595c
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/include/x86/tdx/td_boot_asm.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef SELFTEST_TDX_TD_BOOT_ASM_H
> +#define SELFTEST_TDX_TD_BOOT_ASM_H
> +
> +/*
> + * GPA where TD boot parameters will be loaded.
> + *
> + * TD_BOOT_PARAMETERS_GPA is arbitrarily chosen to
> + *
> + * + be within the 4GB address space
> + * + provide enough contiguous memory for the struct td_boot_parameters such
> + *   that there is one struct td_per_vcpu_parameters for KVM_MAX_VCPUS
> + */
> +#define TD_BOOT_PARAMETERS_GPA 0xffff0000
> +
> +#endif  // SELFTEST_TDX_TD_BOOT_ASM_H
> diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/td_boot.S b/tools/testing/selftests/kvm/lib/x86/tdx/td_boot.S
> new file mode 100644
> index 000000000000..7aa33caa9a78
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/lib/x86/tdx/td_boot.S
> @@ -0,0 +1,60 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +#include "tdx/td_boot_asm.h"
> +#include "tdx/td_boot_offsets.h"
> +#include "processor_asm.h"
> +
> +.code32
> +
> +.globl td_boot
> +td_boot:
> +	/* In this procedure, edi is used as a temporary register. */
> +	cli
> +
> +	/* Paging is off. */
> +
> +	movl $TD_BOOT_PARAMETERS_GPA, %ebx
> +
> +	/*
> +	 * Find the address of struct td_per_vcpu_parameters for this
> +	 * vCPU based on esi (TDX spec: initialized with vCPU id). Put
> +	 * struct address into register for indirect addressing.
> +	 */
> +	movl $SIZEOF_TD_PER_VCPU_PARAMETERS, %eax
> +	mul %esi
> +	leal TD_BOOT_PARAMETERS_PER_VCPU(%ebx), %edi
> +	addl %edi, %eax
> +
> +	/* Setup stack. */
> +	movl TD_PER_VCPU_PARAMETERS_ESP_GVA(%eax), %esp
> +
> +	/* Setup GDT. */
> +	leal TD_BOOT_PARAMETERS_GDT(%ebx), %edi
> +	lgdt (%edi)
> +
> +	/* Setup IDT. */
> +	leal TD_BOOT_PARAMETERS_IDT(%ebx), %edi
> +	lidt (%edi)
> +
> +	/*
> +	 * Set up control registers (There are no instructions to mov from
> +	 * memory to control registers, hence use edi as a scratch register).
> +	 */
> +	movl TD_BOOT_PARAMETERS_CR4(%ebx), %edi
> +	movl %edi, %cr4
> +	movl TD_BOOT_PARAMETERS_CR3(%ebx), %edi
> +	movl %edi, %cr3
> +	movl TD_BOOT_PARAMETERS_CR0(%ebx), %edi
> +	movl %edi, %cr0
> +
> +	/* Switching to 64bit mode after ljmp and then jump to guest code */
> +	ljmp $(KERNEL_CS),$1f
> +1:
> +	jmp *TD_PER_VCPU_PARAMETERS_GUEST_CODE(%eax)
> +
> +/* Leave marker so size of td_boot code can be computed. */
> +.globl td_boot_code_end
> +td_boot_code_end:
> +
> +/* Disable executable stack. */
> +.section .note.GNU-stack,"",%progbits

[PATCH v10 09/21] KVM: selftests: Set up TDX boot code region

[Sagi Shahar]

Add memory for TDX boot code in a separate memslot.

Use virt_map() to get identity map in this memory region to allow for
seamless transition from paging disabled to paging enabled code.

Copy the boot code into the memory region and set up the reset vectors
at this point. While it's possible to separate the memory allocation and
boot code initialization into separate functions, having all the
calculations for memory size and offsets in one place simplifies the
code and avoids duplications.

Handcode the reset vector as suggested by Sean Christopherson.

Suggested-by: Sean Christopherson <seanjc@google.com>
Co-developed-by: Erdem Aktas <erdemaktas@google.com>
Signed-off-by: Erdem Aktas <erdemaktas@google.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
---
 tools/testing/selftests/kvm/Makefile.kvm      |  1 +
 .../selftests/kvm/include/x86/tdx/tdx_util.h  |  2 +
 .../selftests/kvm/lib/x86/tdx/tdx_util.c      | 54 +++++++++++++++++++
 3 files changed, 57 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
index d11d02e17cc5..52c90f1c0484 100644
--- a/tools/testing/selftests/kvm/Makefile.kvm
+++ b/tools/testing/selftests/kvm/Makefile.kvm
@@ -31,6 +31,7 @@ LIBKVM_x86 += lib/x86/sev.c
 LIBKVM_x86 += lib/x86/svm.c
 LIBKVM_x86 += lib/x86/ucall.c
 LIBKVM_x86 += lib/x86/vmx.c
+LIBKVM_x86 += lib/x86/tdx/tdx_util.c
 LIBKVM_x86 += lib/x86/tdx/td_boot.S
 
 LIBKVM_arm64 += lib/arm64/gic.c
diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
index 286d5e3c24b1..ec05bcd59145 100644
--- a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
+++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
@@ -11,4 +11,6 @@ static inline bool is_tdx_vm(struct kvm_vm *vm)
 	return vm->type == KVM_X86_TDX_VM;
 }
 
+void vm_tdx_setup_boot_code_region(struct kvm_vm *vm);
+
 #endif // SELFTESTS_TDX_TDX_UTIL_H
diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
new file mode 100644
index 000000000000..a1cf12de9d56
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <stdint.h>
+
+#include "kvm_util.h"
+#include "processor.h"
+#include "tdx/td_boot.h"
+#include "tdx/tdx_util.h"
+
+/* Arbitrarily selected to avoid overlaps with anything else */
+#define TD_BOOT_CODE_SLOT	20
+
+#define X86_RESET_VECTOR	0xfffffff0ul
+#define X86_RESET_VECTOR_SIZE	16
+
+void vm_tdx_setup_boot_code_region(struct kvm_vm *vm)
+{
+	size_t total_code_size = TD_BOOT_CODE_SIZE + X86_RESET_VECTOR_SIZE;
+	vm_paddr_t boot_code_gpa = X86_RESET_VECTOR - TD_BOOT_CODE_SIZE;
+	vm_paddr_t alloc_gpa = round_down(boot_code_gpa, PAGE_SIZE);
+	size_t nr_pages = DIV_ROUND_UP(total_code_size, PAGE_SIZE);
+	vm_paddr_t gpa;
+	uint8_t *hva;
+
+	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
+				    alloc_gpa,
+				    TD_BOOT_CODE_SLOT, nr_pages,
+				    KVM_MEM_GUEST_MEMFD);
+
+	gpa = vm_phy_pages_alloc(vm, nr_pages, alloc_gpa, TD_BOOT_CODE_SLOT);
+	TEST_ASSERT(gpa == alloc_gpa, "Failed vm_phy_pages_alloc\n");
+
+	virt_map(vm, alloc_gpa, alloc_gpa, nr_pages);
+	hva = addr_gpa2hva(vm, boot_code_gpa);
+	memcpy(hva, td_boot, TD_BOOT_CODE_SIZE);
+
+	hva += TD_BOOT_CODE_SIZE;
+	TEST_ASSERT(hva == addr_gpa2hva(vm, X86_RESET_VECTOR),
+		    "Expected RESET vector at hva 0x%lx, got %lx",
+		    (unsigned long)addr_gpa2hva(vm, X86_RESET_VECTOR), (unsigned long)hva);
+
+	/*
+	 * Handcode "JMP rel8" at the RESET vector to jump back to the TD boot
+	 * code, as there are only 16 bytes at the RESET vector before RIP will
+	 * wrap back to zero.  Insert a trailing int3 so that the vCPU crashes
+	 * in case the JMP somehow falls through.  Note!  The target address is
+	 * relative to the end of the instruction!
+	 */
+	TEST_ASSERT(TD_BOOT_CODE_SIZE + 2 <= 128,
+		    "TD boot code not addressable by 'JMP rel8'");
+	hva[0] = 0xeb;
+	hva[1] = 256 - 2 - TD_BOOT_CODE_SIZE;
+	hva[2] = 0xcc;
+}
-- 
2.51.0.338.gd7d06c2dae-goog

Re: [PATCH v10 09/21] KVM: selftests: Set up TDX boot code region

[Binbin Wu]

On 9/4/2025 2:54 PM, Sagi Shahar wrote:
> Add memory for TDX boot code in a separate memslot.
>
> Use virt_map() to get identity map in this memory region to allow for
> seamless transition from paging disabled to paging enabled code.
>
> Copy the boot code into the memory region and set up the reset vectors

vectors -> vector?

> at this point. While it's possible to separate the memory allocation and
> boot code initialization into separate functions, having all the
> calculations for memory size and offsets in one place simplifies the
> code and avoids duplications.
>
> Handcode the reset vector as suggested by Sean Christopherson.
>
> Suggested-by: Sean Christopherson <seanjc@google.com>
> Co-developed-by: Erdem Aktas <erdemaktas@google.com>
> Signed-off-by: Erdem Aktas <erdemaktas@google.com>
> Signed-off-by: Sagi Shahar <sagis@google.com>

Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>

> ---
>   tools/testing/selftests/kvm/Makefile.kvm      |  1 +
>   .../selftests/kvm/include/x86/tdx/tdx_util.h  |  2 +
>   .../selftests/kvm/lib/x86/tdx/tdx_util.c      | 54 +++++++++++++++++++
>   3 files changed, 57 insertions(+)
>   create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
>
> diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
> index d11d02e17cc5..52c90f1c0484 100644
> --- a/tools/testing/selftests/kvm/Makefile.kvm
> +++ b/tools/testing/selftests/kvm/Makefile.kvm
> @@ -31,6 +31,7 @@ LIBKVM_x86 += lib/x86/sev.c
>   LIBKVM_x86 += lib/x86/svm.c
>   LIBKVM_x86 += lib/x86/ucall.c
>   LIBKVM_x86 += lib/x86/vmx.c
> +LIBKVM_x86 += lib/x86/tdx/tdx_util.c
>   LIBKVM_x86 += lib/x86/tdx/td_boot.S
>   
>   LIBKVM_arm64 += lib/arm64/gic.c
> diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
> index 286d5e3c24b1..ec05bcd59145 100644
> --- a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
> +++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
> @@ -11,4 +11,6 @@ static inline bool is_tdx_vm(struct kvm_vm *vm)
>   	return vm->type == KVM_X86_TDX_VM;
>   }
>   
> +void vm_tdx_setup_boot_code_region(struct kvm_vm *vm);
> +
>   #endif // SELFTESTS_TDX_TDX_UTIL_H
> diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
> new file mode 100644
> index 000000000000..a1cf12de9d56
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
> @@ -0,0 +1,54 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +#include <stdint.h>
> +
> +#include "kvm_util.h"
> +#include "processor.h"
> +#include "tdx/td_boot.h"
> +#include "tdx/tdx_util.h"
> +
> +/* Arbitrarily selected to avoid overlaps with anything else */
> +#define TD_BOOT_CODE_SLOT	20
> +
> +#define X86_RESET_VECTOR	0xfffffff0ul
> +#define X86_RESET_VECTOR_SIZE	16
> +
> +void vm_tdx_setup_boot_code_region(struct kvm_vm *vm)
> +{
> +	size_t total_code_size = TD_BOOT_CODE_SIZE + X86_RESET_VECTOR_SIZE;
> +	vm_paddr_t boot_code_gpa = X86_RESET_VECTOR - TD_BOOT_CODE_SIZE;
> +	vm_paddr_t alloc_gpa = round_down(boot_code_gpa, PAGE_SIZE);
> +	size_t nr_pages = DIV_ROUND_UP(total_code_size, PAGE_SIZE);
> +	vm_paddr_t gpa;
> +	uint8_t *hva;
> +
> +	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
> +				    alloc_gpa,
> +				    TD_BOOT_CODE_SLOT, nr_pages,
> +				    KVM_MEM_GUEST_MEMFD);
> +
> +	gpa = vm_phy_pages_alloc(vm, nr_pages, alloc_gpa, TD_BOOT_CODE_SLOT);
> +	TEST_ASSERT(gpa == alloc_gpa, "Failed vm_phy_pages_alloc\n");
> +
> +	virt_map(vm, alloc_gpa, alloc_gpa, nr_pages);
> +	hva = addr_gpa2hva(vm, boot_code_gpa);
> +	memcpy(hva, td_boot, TD_BOOT_CODE_SIZE);
> +
> +	hva += TD_BOOT_CODE_SIZE;
> +	TEST_ASSERT(hva == addr_gpa2hva(vm, X86_RESET_VECTOR),
> +		    "Expected RESET vector at hva 0x%lx, got %lx",
> +		    (unsigned long)addr_gpa2hva(vm, X86_RESET_VECTOR), (unsigned long)hva);
> +
> +	/*
> +	 * Handcode "JMP rel8" at the RESET vector to jump back to the TD boot
> +	 * code, as there are only 16 bytes at the RESET vector before RIP will
> +	 * wrap back to zero.  Insert a trailing int3 so that the vCPU crashes
> +	 * in case the JMP somehow falls through.  Note!  The target address is
> +	 * relative to the end of the instruction!
> +	 */
> +	TEST_ASSERT(TD_BOOT_CODE_SIZE + 2 <= 128,
> +		    "TD boot code not addressable by 'JMP rel8'");
> +	hva[0] = 0xeb;
> +	hva[1] = 256 - 2 - TD_BOOT_CODE_SIZE;
> +	hva[2] = 0xcc;
> +}

[PATCH v10 10/21] KVM: selftests: Set up TDX boot parameters region

[Sagi Shahar]

Allocate memory for TDX boot parameters and define the utility functions
necessary to fill this memory with the boot parameters.

Co-developed-by: Ackerley Tng <ackerleytng@google.com>
Signed-off-by: Ackerley Tng <ackerleytng@google.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
---
 .../selftests/kvm/include/x86/tdx/tdx_util.h  |  4 +
 .../selftests/kvm/lib/x86/tdx/tdx_util.c      | 75 +++++++++++++++++++
 2 files changed, 79 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
index ec05bcd59145..dafdc7e46abe 100644
--- a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
+++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
@@ -12,5 +12,9 @@ static inline bool is_tdx_vm(struct kvm_vm *vm)
 }
 
 void vm_tdx_setup_boot_code_region(struct kvm_vm *vm);
+void vm_tdx_setup_boot_parameters_region(struct kvm_vm *vm, uint32_t nr_runnable_vcpus);
+void vm_tdx_load_common_boot_parameters(struct kvm_vm *vm);
+void vm_tdx_load_vcpu_boot_parameters(struct kvm_vm *vm, struct kvm_vcpu *vcpu);
+void vm_tdx_set_vcpu_entry_point(struct kvm_vcpu *vcpu, void *guest_code);
 
 #endif // SELFTESTS_TDX_TDX_UTIL_H
diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
index a1cf12de9d56..ff61333bc848 100644
--- a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
+++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
@@ -5,10 +5,12 @@
 #include "kvm_util.h"
 #include "processor.h"
 #include "tdx/td_boot.h"
+#include "tdx/td_boot_asm.h"
 #include "tdx/tdx_util.h"
 
 /* Arbitrarily selected to avoid overlaps with anything else */
 #define TD_BOOT_CODE_SLOT	20
+#define TD_BOOT_PARAMETERS_SLOT	21
 
 #define X86_RESET_VECTOR	0xfffffff0ul
 #define X86_RESET_VECTOR_SIZE	16
@@ -52,3 +54,76 @@ void vm_tdx_setup_boot_code_region(struct kvm_vm *vm)
 	hva[1] = 256 - 2 - TD_BOOT_CODE_SIZE;
 	hva[2] = 0xcc;
 }
+
+void vm_tdx_setup_boot_parameters_region(struct kvm_vm *vm, uint32_t nr_runnable_vcpus)
+{
+	size_t boot_params_size =
+		sizeof(struct td_boot_parameters) +
+		nr_runnable_vcpus * sizeof(struct td_per_vcpu_parameters);
+	int npages = DIV_ROUND_UP(boot_params_size, PAGE_SIZE);
+	vm_paddr_t gpa;
+
+	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
+				    TD_BOOT_PARAMETERS_GPA,
+				    TD_BOOT_PARAMETERS_SLOT, npages,
+				    KVM_MEM_GUEST_MEMFD);
+	gpa = vm_phy_pages_alloc(vm, npages, TD_BOOT_PARAMETERS_GPA, TD_BOOT_PARAMETERS_SLOT);
+	TEST_ASSERT(gpa == TD_BOOT_PARAMETERS_GPA, "Failed vm_phy_pages_alloc\n");
+
+	virt_map(vm, TD_BOOT_PARAMETERS_GPA, TD_BOOT_PARAMETERS_GPA, npages);
+}
+
+void vm_tdx_load_common_boot_parameters(struct kvm_vm *vm)
+{
+	struct td_boot_parameters *params =
+		addr_gpa2hva(vm, TD_BOOT_PARAMETERS_GPA);
+	uint32_t cr4;
+
+	TEST_ASSERT_EQ(vm->mode, VM_MODE_PXXV48_4K);
+
+	cr4 = kvm_get_default_cr4();
+
+	/* TDX spec 11.6.2: CR4 bit MCE is fixed to 1 */
+	cr4 |= X86_CR4_MCE;
+
+	/* Set this because UEFI also sets this up, to handle XMM exceptions */
+	cr4 |= X86_CR4_OSXMMEXCPT;
+
+	/* TDX spec 11.6.2: CR4 bit VMXE and SMXE are fixed to 0 */
+	cr4 &= ~(X86_CR4_VMXE | X86_CR4_SMXE);
+
+	/* Set parameters! */
+	params->cr0 = kvm_get_default_cr0();
+	params->cr3 = vm->pgd;
+	params->cr4 = cr4;
+	params->idtr.base = vm->arch.idt;
+	params->idtr.limit = kvm_get_default_idt_limit();
+	params->gdtr.base = vm->arch.gdt;
+	params->gdtr.limit = kvm_get_default_gdt_limit();
+
+	TEST_ASSERT(params->cr0 != 0, "cr0 should not be 0");
+	TEST_ASSERT(params->cr3 != 0, "cr3 should not be 0");
+	TEST_ASSERT(params->cr4 != 0, "cr4 should not be 0");
+	TEST_ASSERT(params->gdtr.base != 0, "gdt base address should not be 0");
+	TEST_ASSERT(params->idtr.base != 0, "idt base address should not be 0");
+}
+
+void vm_tdx_load_vcpu_boot_parameters(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
+{
+	struct td_boot_parameters *params =
+		addr_gpa2hva(vm, TD_BOOT_PARAMETERS_GPA);
+	struct td_per_vcpu_parameters *vcpu_params =
+		&params->per_vcpu[vcpu->id];
+
+	vcpu_params->esp_gva = kvm_allocate_vcpu_stack(vm);
+}
+
+void vm_tdx_set_vcpu_entry_point(struct kvm_vcpu *vcpu, void *guest_code)
+{
+	struct td_boot_parameters *params =
+		addr_gpa2hva(vcpu->vm, TD_BOOT_PARAMETERS_GPA);
+	struct td_per_vcpu_parameters *vcpu_params =
+		&params->per_vcpu[vcpu->id];
+
+	vcpu_params->guest_code = (uint64_t)guest_code;
+}
-- 
2.51.0.338.gd7d06c2dae-goog

Re: [PATCH v10 10/21] KVM: selftests: Set up TDX boot parameters region

[Binbin Wu]

On 9/4/2025 2:54 PM, Sagi Shahar wrote:
[...]
> +
> +void vm_tdx_load_common_boot_parameters(struct kvm_vm *vm)
> +{
> +	struct td_boot_parameters *params =
> +		addr_gpa2hva(vm, TD_BOOT_PARAMETERS_GPA);
> +	uint32_t cr4;
> +
> +	TEST_ASSERT_EQ(vm->mode, VM_MODE_PXXV48_4K);
> +
> +	cr4 = kvm_get_default_cr4();
> +
> +	/* TDX spec 11.6.2: CR4 bit MCE is fixed to 1 */
> +	cr4 |= X86_CR4_MCE;
> +
> +	/* Set this because UEFI also sets this up, to handle XMM exceptions */

I don't get it.
Could you elaborate it a bit?

> +	cr4 |= X86_CR4_OSXMMEXCPT;
> +
> +	/* TDX spec 11.6.2: CR4 bit VMXE and SMXE are fixed to 0 */
> +	cr4 &= ~(X86_CR4_VMXE | X86_CR4_SMXE);
> +
> +	/* Set parameters! */
> +	params->cr0 = kvm_get_default_cr0();
> +	params->cr3 = vm->pgd;
> +	params->cr4 = cr4;
> +	params->idtr.base = vm->arch.idt;
> +	params->idtr.limit = kvm_get_default_idt_limit();
> +	params->gdtr.base = vm->arch.gdt;
> +	params->gdtr.limit = kvm_get_default_gdt_limit();
> +
> +	TEST_ASSERT(params->cr0 != 0, "cr0 should not be 0");
> +	TEST_ASSERT(params->cr3 != 0, "cr3 should not be 0");
> +	TEST_ASSERT(params->cr4 != 0, "cr4 should not be 0");
> +	TEST_ASSERT(params->gdtr.base != 0, "gdt base address should not be 0");
> +	TEST_ASSERT(params->idtr.base != 0, "idt base address should not be 0");
> +}
> +
[...]

Re: [PATCH v10 10/21] KVM: selftests: Set up TDX boot parameters region

[Sagi Shahar]

On Mon, Sep 8, 2025 at 3:07 AM Binbin Wu <binbin.wu@linux.intel.com> wrote:
>
>
>
> On 9/4/2025 2:54 PM, Sagi Shahar wrote:
> [...]
> > +
> > +void vm_tdx_load_common_boot_parameters(struct kvm_vm *vm)
> > +{
> > +     struct td_boot_parameters *params =
> > +             addr_gpa2hva(vm, TD_BOOT_PARAMETERS_GPA);
> > +     uint32_t cr4;
> > +
> > +     TEST_ASSERT_EQ(vm->mode, VM_MODE_PXXV48_4K);
> > +
> > +     cr4 = kvm_get_default_cr4();
> > +
> > +     /* TDX spec 11.6.2: CR4 bit MCE is fixed to 1 */
> > +     cr4 |= X86_CR4_MCE;
> > +
> > +     /* Set this because UEFI also sets this up, to handle XMM exceptions */
>
> I don't get it.
> Could you elaborate it a bit?
>

I'm not entirely sure where this code came from but it looks like this
is unnecessary, at least for now. Dropping this in the next version.

> > +     cr4 |= X86_CR4_OSXMMEXCPT;
> > +
> > +     /* TDX spec 11.6.2: CR4 bit VMXE and SMXE are fixed to 0 */
> > +     cr4 &= ~(X86_CR4_VMXE | X86_CR4_SMXE);
> > +
> > +     /* Set parameters! */
> > +     params->cr0 = kvm_get_default_cr0();
> > +     params->cr3 = vm->pgd;
> > +     params->cr4 = cr4;
> > +     params->idtr.base = vm->arch.idt;
> > +     params->idtr.limit = kvm_get_default_idt_limit();
> > +     params->gdtr.base = vm->arch.gdt;
> > +     params->gdtr.limit = kvm_get_default_gdt_limit();
> > +
> > +     TEST_ASSERT(params->cr0 != 0, "cr0 should not be 0");
> > +     TEST_ASSERT(params->cr3 != 0, "cr3 should not be 0");
> > +     TEST_ASSERT(params->cr4 != 0, "cr4 should not be 0");
> > +     TEST_ASSERT(params->gdtr.base != 0, "gdt base address should not be 0");
> > +     TEST_ASSERT(params->idtr.base != 0, "idt base address should not be 0");
> > +}
> > +
> [...]

[PATCH v10 11/21] KVM: selftests: Add helper to initialize TDX VM

[Sagi Shahar]

KVM_TDX_INIT_VM needs to be called after KVM_CREATE_VM and before
creating any VCPUs, thus before KVM_SET_CPUID2. KVM_TDX_INIT_VM accepts
the CPUID values directly.

Since KVM_GET_CPUID2 can't be used at this point, calculate the CPUID
values manually by using kvm_get_supported_cpuid() and filter the
returned CPUIDs against the supported CPUID values read from the TDX
module.

Co-developed-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
---
 .../selftests/kvm/include/x86/tdx/tdx_util.h  |  54 +++++++
 .../selftests/kvm/lib/x86/tdx/tdx_util.c      | 132 ++++++++++++++++++
 2 files changed, 186 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
index dafdc7e46abe..a2509959c7ce 100644
--- a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
+++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
@@ -11,6 +11,60 @@ static inline bool is_tdx_vm(struct kvm_vm *vm)
 	return vm->type == KVM_X86_TDX_VM;
 }
 
+/*
+ * TDX ioctls
+ */
+
+#define __vm_tdx_vm_ioctl(vm, cmd, metadata, arg)			\
+({									\
+	int r;								\
+									\
+	union {								\
+		struct kvm_tdx_cmd c;					\
+		unsigned long raw;					\
+	} tdx_cmd = { .c = {						\
+		.id = (cmd),						\
+		.flags = (uint32_t)(metadata),				\
+		.data = (uint64_t)(arg),				\
+	} };								\
+									\
+	r = __vm_ioctl(vm, KVM_MEMORY_ENCRYPT_OP, &tdx_cmd.raw);	\
+	r ?: tdx_cmd.c.hw_error;					\
+})
+
+#define vm_tdx_vm_ioctl(vm, cmd, flags, arg)				\
+({									\
+	int ret = __vm_tdx_vm_ioctl(vm, cmd, flags, arg);		\
+									\
+	__TEST_ASSERT_VM_VCPU_IOCTL(!ret, #cmd,	ret, vm);		\
+})
+
+#define __vm_tdx_vcpu_ioctl(vcpu, cmd, metadata, arg)			\
+({									\
+	int r;								\
+									\
+	union {								\
+		struct kvm_tdx_cmd c;					\
+		unsigned long raw;					\
+	} tdx_cmd = { .c = {						\
+		.id = (cmd),						\
+		.flags = (uint32_t)(metadata),				\
+		.data = (uint64_t)(arg),				\
+	} };								\
+									\
+	r = __vcpu_ioctl(vcpu, KVM_MEMORY_ENCRYPT_OP, &tdx_cmd.raw);	\
+	r ?: tdx_cmd.c.hw_error;					\
+})
+
+#define vm_tdx_vcpu_ioctl(vcpu, cmd, flags, arg)			\
+({									\
+	int ret = __vm_tdx_vcpu_ioctl(vcpu, cmd, flags, arg);		\
+									\
+	__TEST_ASSERT_VM_VCPU_IOCTL(!ret, #cmd, ret, (vcpu)->vm);	\
+})
+
+void vm_tdx_init_vm(struct kvm_vm *vm, uint64_t attributes);
+
 void vm_tdx_setup_boot_code_region(struct kvm_vm *vm);
 void vm_tdx_setup_boot_parameters_region(struct kvm_vm *vm, uint32_t nr_runnable_vcpus);
 void vm_tdx_load_common_boot_parameters(struct kvm_vm *vm);
diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
index ff61333bc848..aa0cb6c2205b 100644
--- a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
+++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
@@ -127,3 +127,135 @@ void vm_tdx_set_vcpu_entry_point(struct kvm_vcpu *vcpu, void *guest_code)
 
 	vcpu_params->guest_code = (uint64_t)guest_code;
 }
+
+static struct kvm_tdx_capabilities *tdx_read_capabilities(struct kvm_vm *vm)
+{
+	struct kvm_tdx_capabilities *tdx_cap = NULL;
+	int nr_cpuid_configs = 4;
+	int rc = -1;
+	int i;
+
+	do {
+		nr_cpuid_configs *= 2;
+
+		tdx_cap = realloc(tdx_cap, sizeof(*tdx_cap) +
+					   sizeof(tdx_cap->cpuid) +
+					   (sizeof(struct kvm_cpuid_entry2) * nr_cpuid_configs));
+		TEST_ASSERT(tdx_cap,
+			    "Could not allocate memory for tdx capability nr_cpuid_configs %d\n",
+			    nr_cpuid_configs);
+
+		tdx_cap->cpuid.nent = nr_cpuid_configs;
+		rc = __vm_tdx_vm_ioctl(vm, KVM_TDX_CAPABILITIES, 0, tdx_cap);
+	} while (rc < 0 && errno == E2BIG);
+
+	TEST_ASSERT(rc == 0, "KVM_TDX_CAPABILITIES failed: %d %d",
+		    rc, errno);
+
+	pr_debug("tdx_cap: supported_attrs: 0x%016llx\n"
+		 "tdx_cap: supported_xfam 0x%016llx\n",
+		 tdx_cap->supported_attrs, tdx_cap->supported_xfam);
+
+	for (i = 0; i < tdx_cap->cpuid.nent; i++) {
+		const struct kvm_cpuid_entry2 *config = &tdx_cap->cpuid.entries[i];
+
+		pr_debug("cpuid config[%d]: leaf 0x%x sub_leaf 0x%x eax 0x%08x ebx 0x%08x ecx 0x%08x edx 0x%08x\n",
+			 i, config->function, config->index,
+			 config->eax, config->ebx, config->ecx, config->edx);
+	}
+
+	return tdx_cap;
+}
+
+static struct kvm_cpuid_entry2 *tdx_find_cpuid_config(struct kvm_tdx_capabilities *cap,
+						      uint32_t leaf, uint32_t sub_leaf)
+{
+	struct kvm_cpuid_entry2 *config;
+	uint32_t i;
+
+	for (i = 0; i < cap->cpuid.nent; i++) {
+		config = &cap->cpuid.entries[i];
+
+		if (config->function == leaf && config->index == sub_leaf)
+			return config;
+	}
+
+	return NULL;
+}
+
+/*
+ * Filter CPUID based on TDX supported capabilities
+ *
+ * Input Args:
+ *   vm - Virtual Machine
+ *   cpuid_data - CPUID fileds to filter
+ *
+ * Output Args: None
+ *
+ * Return: None
+ *
+ * For each CPUID leaf, filter out non-supported bits based on the capabilities reported
+ * by the TDX module
+ */
+static void vm_tdx_filter_cpuid(struct kvm_vm *vm,
+				struct kvm_cpuid2 *cpuid_data)
+{
+	struct kvm_tdx_capabilities *tdx_cap;
+	struct kvm_cpuid_entry2 *config;
+	struct kvm_cpuid_entry2 *e;
+	int i;
+
+	tdx_cap = tdx_read_capabilities(vm);
+
+	i = 0;
+	while (i < cpuid_data->nent) {
+		e = cpuid_data->entries + i;
+		config = tdx_find_cpuid_config(tdx_cap, e->function, e->index);
+
+		if (!config) {
+			int left = cpuid_data->nent - i - 1;
+
+			if (left > 0)
+				memmove(cpuid_data->entries + i,
+					cpuid_data->entries + i + 1,
+					sizeof(*cpuid_data->entries) * left);
+			cpuid_data->nent--;
+			continue;
+		}
+
+		e->eax &= config->eax;
+		e->ebx &= config->ebx;
+		e->ecx &= config->ecx;
+		e->edx &= config->edx;
+
+		i++;
+	}
+
+	free(tdx_cap);
+}
+
+void vm_tdx_init_vm(struct kvm_vm *vm, uint64_t attributes)
+{
+	struct kvm_tdx_init_vm *init_vm;
+	const struct kvm_cpuid2 *tmp;
+	struct kvm_cpuid2 *cpuid;
+
+	tmp = kvm_get_supported_cpuid();
+
+	cpuid = allocate_kvm_cpuid2(MAX_NR_CPUID_ENTRIES);
+	memcpy(cpuid, tmp, kvm_cpuid2_size(tmp->nent));
+	vm_tdx_filter_cpuid(vm, cpuid);
+
+	init_vm = calloc(1, sizeof(*init_vm) +
+			 sizeof(init_vm->cpuid.entries[0]) * cpuid->nent);
+	TEST_ASSERT(init_vm, "init_vm allocation failed");
+
+	memcpy(&init_vm->cpuid, cpuid, kvm_cpuid2_size(cpuid->nent));
+	free(cpuid);
+
+	init_vm->attributes = attributes;
+
+	vm_tdx_vm_ioctl(vm, KVM_TDX_INIT_VM, 0, init_vm);
+
+	free(init_vm);
+}
-- 
2.51.0.338.gd7d06c2dae-goog

[PATCH v10 12/21] KVM: selftests: TDX: Use KVM_TDX_CAPABILITIES to validate TDs' attribute configuration

[Sagi Shahar]

From: Isaku Yamahata <isaku.yamahata@intel.com>

Make sure that all the attributes enabled by the test are reported as
supported by the TDX module.

This also exercises the KVM_TDX_CAPABILITIES ioctl.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Sagi Shahar <sagis@google.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
---
 tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
index aa0cb6c2205b..1b5c01faf1cd 100644
--- a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
+++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
@@ -234,6 +234,18 @@ static void vm_tdx_filter_cpuid(struct kvm_vm *vm,
 	free(tdx_cap);
 }
 
+static void tdx_check_attributes(struct kvm_vm *vm, uint64_t attributes)
+{
+	struct kvm_tdx_capabilities *tdx_cap;
+
+	tdx_cap = tdx_read_capabilities(vm);
+
+	/* Make sure all the attributes are reported as supported by the TDX module */
+	TEST_ASSERT_EQ(attributes & tdx_cap->supported_attrs, attributes);
+
+	free(tdx_cap);
+}
+
 void vm_tdx_init_vm(struct kvm_vm *vm, uint64_t attributes)
 {
 	struct kvm_tdx_init_vm *init_vm;
@@ -253,6 +265,8 @@ void vm_tdx_init_vm(struct kvm_vm *vm, uint64_t attributes)
 	memcpy(&init_vm->cpuid, cpuid, kvm_cpuid2_size(cpuid->nent));
 	free(cpuid);
 
+	tdx_check_attributes(vm, attributes);
+
 	init_vm->attributes = attributes;
 
 	vm_tdx_vm_ioctl(vm, KVM_TDX_INIT_VM, 0, init_vm);
-- 
2.51.0.338.gd7d06c2dae-goog

Re: [PATCH v10 12/21] KVM: selftests: TDX: Use KVM_TDX_CAPABILITIES to validate TDs' attribute configuration

[Binbin Wu]

On 9/4/2025 2:54 PM, Sagi Shahar wrote:
> From: Isaku Yamahata <isaku.yamahata@intel.com>
>
> Make sure that all the attributes enabled by the test are reported as
> supported by the TDX module.
>
> This also exercises the KVM_TDX_CAPABILITIES ioctl.
>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> Co-developed-by: Sagi Shahar <sagis@google.com>
> Signed-off-by: Sagi Shahar <sagis@google.com>
> ---
>   tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c | 14 ++++++++++++++
>   1 file changed, 14 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
> index aa0cb6c2205b..1b5c01faf1cd 100644
> --- a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
> +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
> @@ -234,6 +234,18 @@ static void vm_tdx_filter_cpuid(struct kvm_vm *vm,
>   	free(tdx_cap);
>   }
>   
> +static void tdx_check_attributes(struct kvm_vm *vm, uint64_t attributes)
> +{
> +	struct kvm_tdx_capabilities *tdx_cap;
> +
> +	tdx_cap = tdx_read_capabilities(vm);
> +
> +	/* Make sure all the attributes are reported as supported by the TDX module */

I think "by the TDX module" can be dropped, since KVM only reports the
attributes it supports.

> +	TEST_ASSERT_EQ(attributes & tdx_cap->supported_attrs, attributes);
> +
> +	free(tdx_cap);
> +}
> +
>   void vm_tdx_init_vm(struct kvm_vm *vm, uint64_t attributes)
>   {
>   	struct kvm_tdx_init_vm *init_vm;
> @@ -253,6 +265,8 @@ void vm_tdx_init_vm(struct kvm_vm *vm, uint64_t attributes)
>   	memcpy(&init_vm->cpuid, cpuid, kvm_cpuid2_size(cpuid->nent));
>   	free(cpuid);
>   
> +	tdx_check_attributes(vm, attributes);
> +
>   	init_vm->attributes = attributes;
>   
>   	vm_tdx_vm_ioctl(vm, KVM_TDX_INIT_VM, 0, init_vm);

[PATCH v10 13/21] KVM: selftests: Add helpers to init TDX memory and finalize VM

[Sagi Shahar]

From: Ackerley Tng <ackerleytng@google.com>

TDX protected memory needs to be measured and encrypted before it can be
used by the guest. Traverse the VM's memory regions and initialize all
the protected ranges by calling KVM_TDX_INIT_MEM_REGION.

Once all the memory is initialized, the VM can be finalized by calling
KVM_TDX_FINALIZE_VM.

Signed-off-by: Ackerley Tng <ackerleytng@google.com>
Co-developed-by: Erdem Aktas <erdemaktas@google.com>
Signed-off-by: Erdem Aktas <erdemaktas@google.com>
Co-developed-by: Sagi Shahar <sagis@google.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
---
 .../selftests/kvm/include/x86/tdx/tdx_util.h  |  2 +
 .../selftests/kvm/lib/x86/tdx/tdx_util.c      | 61 +++++++++++++++++++
 2 files changed, 63 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
index a2509959c7ce..2467b6c35557 100644
--- a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
+++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
@@ -71,4 +71,6 @@ void vm_tdx_load_common_boot_parameters(struct kvm_vm *vm);
 void vm_tdx_load_vcpu_boot_parameters(struct kvm_vm *vm, struct kvm_vcpu *vcpu);
 void vm_tdx_set_vcpu_entry_point(struct kvm_vcpu *vcpu, void *guest_code);
 
+void vm_tdx_finalize(struct kvm_vm *vm);
+
 #endif // SELFTESTS_TDX_TDX_UTIL_H
diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
index 1b5c01faf1cd..d5df2de81a75 100644
--- a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
+++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
@@ -273,3 +273,64 @@ void vm_tdx_init_vm(struct kvm_vm *vm, uint64_t attributes)
 
 	free(init_vm);
 }
+
+static void tdx_init_mem_region(struct kvm_vm *vm, void *source_pages,
+				uint64_t gpa, uint64_t size)
+{
+	uint32_t metadata = KVM_TDX_MEASURE_MEMORY_REGION;
+	struct kvm_tdx_init_mem_region mem_region = {
+		.source_addr = (uint64_t)source_pages,
+		.gpa = gpa,
+		.nr_pages = size / PAGE_SIZE,
+	};
+	struct kvm_vcpu *vcpu;
+
+	vcpu = list_first_entry_or_null(&vm->vcpus, struct kvm_vcpu, list);
+
+	TEST_ASSERT((mem_region.nr_pages > 0) &&
+		    ((mem_region.nr_pages * PAGE_SIZE) == size),
+		    "Cannot add partial pages to the guest memory.\n");
+	TEST_ASSERT(((uint64_t)source_pages & (PAGE_SIZE - 1)) == 0,
+		    "Source memory buffer is not page aligned\n");
+	vm_tdx_vcpu_ioctl(vcpu, KVM_TDX_INIT_MEM_REGION, metadata, &mem_region);
+}
+
+static void load_td_private_memory(struct kvm_vm *vm)
+{
+	struct userspace_mem_region *region;
+	int ctr;
+
+	hash_for_each(vm->regions.slot_hash, ctr, region, slot_node) {
+		const struct sparsebit *protected_pages = region->protected_phy_pages;
+		const vm_paddr_t gpa_base = region->region.guest_phys_addr;
+		const uint64_t hva_base = region->region.userspace_addr;
+		const sparsebit_idx_t lowest_page_in_region = gpa_base >> vm->page_shift;
+
+		sparsebit_idx_t i;
+		sparsebit_idx_t j;
+
+		if (!sparsebit_any_set(protected_pages))
+			continue;
+
+		TEST_ASSERT(region->region.guest_memfd != -1,
+			    "TD private memory must be backed by guest_memfd");
+
+		sparsebit_for_each_set_range(protected_pages, i, j) {
+			const uint64_t size_to_load = (j - i + 1) * vm->page_size;
+			const uint64_t offset =
+				(i - lowest_page_in_region) * vm->page_size;
+			const uint64_t hva = hva_base + offset;
+			const uint64_t gpa = gpa_base + offset;
+
+			vm_set_memory_attributes(vm, gpa, size_to_load,
+						 KVM_MEMORY_ATTRIBUTE_PRIVATE);
+			tdx_init_mem_region(vm, (void *)hva, gpa, size_to_load);
+		}
+	}
+}
+
+void vm_tdx_finalize(struct kvm_vm *vm)
+{
+	load_td_private_memory(vm);
+	vm_tdx_vm_ioctl(vm, KVM_TDX_FINALIZE_VM, 0, NULL);
+}
-- 
2.51.0.338.gd7d06c2dae-goog

Re: [PATCH v10 13/21] KVM: selftests: Add helpers to init TDX memory and finalize VM

[Binbin Wu]

On 9/4/2025 2:54 PM, Sagi Shahar wrote:
> From: Ackerley Tng <ackerleytng@google.com>
>
> TDX protected memory needs to be measured and encrypted before it can be
> used by the guest. Traverse the VM's memory regions and initialize all
> the protected ranges by calling KVM_TDX_INIT_MEM_REGION.
>
> Once all the memory is initialized, the VM can be finalized by calling
> KVM_TDX_FINALIZE_VM.
>
> Signed-off-by: Ackerley Tng <ackerleytng@google.com>
> Co-developed-by: Erdem Aktas <erdemaktas@google.com>
> Signed-off-by: Erdem Aktas <erdemaktas@google.com>
> Co-developed-by: Sagi Shahar <sagis@google.com>
> Signed-off-by: Sagi Shahar <sagis@google.com>
> ---
>   .../selftests/kvm/include/x86/tdx/tdx_util.h  |  2 +
>   .../selftests/kvm/lib/x86/tdx/tdx_util.c      | 61 +++++++++++++++++++
>   2 files changed, 63 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
> index a2509959c7ce..2467b6c35557 100644
> --- a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
> +++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
> @@ -71,4 +71,6 @@ void vm_tdx_load_common_boot_parameters(struct kvm_vm *vm);
>   void vm_tdx_load_vcpu_boot_parameters(struct kvm_vm *vm, struct kvm_vcpu *vcpu);
>   void vm_tdx_set_vcpu_entry_point(struct kvm_vcpu *vcpu, void *guest_code);
>   
> +void vm_tdx_finalize(struct kvm_vm *vm);
> +
>   #endif // SELFTESTS_TDX_TDX_UTIL_H
> diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
> index 1b5c01faf1cd..d5df2de81a75 100644
> --- a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
> +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
> @@ -273,3 +273,64 @@ void vm_tdx_init_vm(struct kvm_vm *vm, uint64_t attributes)
>   
>   	free(init_vm);
>   }
> +
> +static void tdx_init_mem_region(struct kvm_vm *vm, void *source_pages,
> +				uint64_t gpa, uint64_t size)
> +{
> +	uint32_t metadata = KVM_TDX_MEASURE_MEMORY_REGION;
> +	struct kvm_tdx_init_mem_region mem_region = {
> +		.source_addr = (uint64_t)source_pages,
> +		.gpa = gpa,
> +		.nr_pages = size / PAGE_SIZE,
> +	};
> +	struct kvm_vcpu *vcpu;
> +
> +	vcpu = list_first_entry_or_null(&vm->vcpus, struct kvm_vcpu, list);
> +
> +	TEST_ASSERT((mem_region.nr_pages > 0) &&
> +		    ((mem_region.nr_pages * PAGE_SIZE) == size),
> +		    "Cannot add partial pages to the guest memory.\n");
> +	TEST_ASSERT(((uint64_t)source_pages & (PAGE_SIZE - 1)) == 0,
> +		    "Source memory buffer is not page aligned\n");
> +	vm_tdx_vcpu_ioctl(vcpu, KVM_TDX_INIT_MEM_REGION, metadata, &mem_region);
> +}
> +
> +static void load_td_private_memory(struct kvm_vm *vm)
> +{
> +	struct userspace_mem_region *region;
> +	int ctr;
> +
> +	hash_for_each(vm->regions.slot_hash, ctr, region, slot_node) {
> +		const struct sparsebit *protected_pages = region->protected_phy_pages;
> +		const vm_paddr_t gpa_base = region->region.guest_phys_addr;
> +		const uint64_t hva_base = region->region.userspace_addr;
> +		const sparsebit_idx_t lowest_page_in_region = gpa_base >> vm->page_shift;
> +

A spare white line?

> +		sparsebit_idx_t i;
> +		sparsebit_idx_t j;

i and j could be defined in one line.

> +
> +		if (!sparsebit_any_set(protected_pages))
> +			continue;
> +
> +		TEST_ASSERT(region->region.guest_memfd != -1,
> +			    "TD private memory must be backed by guest_memfd");
> +
> +		sparsebit_for_each_set_range(protected_pages, i, j) {
> +			const uint64_t size_to_load = (j - i + 1) * vm->page_size;
> +			const uint64_t offset =
> +				(i - lowest_page_in_region) * vm->page_size;
> +			const uint64_t hva = hva_base + offset;
> +			const uint64_t gpa = gpa_base + offset;
> +
> +			vm_set_memory_attributes(vm, gpa, size_to_load,
> +						 KVM_MEMORY_ATTRIBUTE_PRIVATE);
Nit:
There is a helper vm_mem_set_private() for it.

> +			tdx_init_mem_region(vm, (void *)hva, gpa, size_to_load);
> +		}
> +	}
> +}
> +
> +void vm_tdx_finalize(struct kvm_vm *vm)
> +{
> +	load_td_private_memory(vm);
> +	vm_tdx_vm_ioctl(vm, KVM_TDX_FINALIZE_VM, 0, NULL);
> +}

[PATCH v10 14/21] KVM: selftests: Call TDX init when creating a new TDX vm

[Sagi Shahar]

TDX VMs need to issue the KVM_TDX_INIT_VM ioctl after VM creation to
initialize the TD. This ioctl also sets the cpuids and attributes for
the VM.

Signed-off-by: Sagi Shahar <sagis@google.com>
---
 tools/testing/selftests/kvm/lib/x86/processor.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
index 623168ea9a44..c255fe1951be 100644
--- a/tools/testing/selftests/kvm/lib/x86/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86/processor.c
@@ -641,6 +641,9 @@ 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);
+
 	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;
-- 
2.51.0.338.gd7d06c2dae-goog

[PATCH v10 15/21] KVM: selftests: Setup memory regions for TDX on vm creation

[Sagi Shahar]

Guest registers are inaccessible to kvm for TDX VMs. In order to set
register values for TDX we use a special boot code which loads the
register values from memory and write them into the appropriate
registers.

This patch sets up the memory regions used for the boot code and the
boot parameters for TDX.

Signed-off-by: Sagi Shahar <sagis@google.com>
---
 tools/testing/selftests/kvm/lib/kvm_util.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index b4c8702ba4bd..d8a944b5ada3 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);
 
 	/*
-- 
2.51.0.338.gd7d06c2dae-goog

[PATCH v10 16/21] KVM: selftests: Call KVM_TDX_INIT_VCPU when creating a new TDX vcpu

[Sagi Shahar]

TDX VMs need to issue the KVM_TDX_INIT_VCPU ioctl for each vcpu after
vcpu creation.

Since the cpuids for TD are managed by the TDX module, read the values
virtualized for the TD using KVM_TDX_GET_CPUID and set them in kvm using
KVM_SET_CPUID2 so that kvm has an accurate view of the VM cpuid values.

Signed-off-by: Sagi Shahar <sagis@google.com>
---
 .../testing/selftests/kvm/lib/x86/processor.c | 35 ++++++++++++++-----
 1 file changed, 27 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
index c255fe1951be..b1e5f4137629 100644
--- a/tools/testing/selftests/kvm/lib/x86/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86/processor.c
@@ -685,6 +685,19 @@ 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;
@@ -692,15 +705,21 @@ 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;
-	regs.rsp = kvm_allocate_vcpu_stack(vm);
-	vcpu_regs_set(vcpu, &regs);
+	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);
+	}
 
 	/* Setup the MP state */
 	mp_state.mp_state = 0;
-- 
2.51.0.338.gd7d06c2dae-goog

[PATCH v10 17/21] KVM: selftests: Set entry point for TDX guest code

[Sagi Shahar]

Since the rip register is inaccessible for TDX VMs, we need a different
way to set the guest entry point for TDX VMs. This is done by writing
the guest code address to a predefined location in the guest memory and
loading it into rip as part of the TDX boot code.

Signed-off-by: Sagi Shahar <sagis@google.com>
---
 tools/testing/selftests/kvm/lib/x86/processor.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c
index b1e5f4137629..4a831b0f206e 100644
--- a/tools/testing/selftests/kvm/lib/x86/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86/processor.c
@@ -654,9 +654,13 @@ 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)
-- 
2.51.0.338.gd7d06c2dae-goog

[PATCH v10 18/21] KVM: selftests: Add support for TDX TDCALL from guest

[Sagi Shahar]

From: Erdem Aktas <erdemaktas@google.com>

Add support for TDX guests to issue TDCALLs to the TDX module.

Signed-off-by: Erdem Aktas <erdemaktas@google.com>
Co-developed-by: Sagi Shahar <sagis@google.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
---
 tools/testing/selftests/kvm/Makefile.kvm      |  8 ++
 .../selftests/kvm/include/x86/tdx/tdcall.h    | 34 +++++++
 .../selftests/kvm/lib/x86/tdx/tdcall.S        | 93 +++++++++++++++++++
 .../kvm/lib/x86/tdx/tdcall_offsets.c          | 16 ++++
 4 files changed, 151 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/tdcall.h
 create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/tdcall.S
 create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/tdcall_offsets.c

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
index 52c90f1c0484..2d4fd68984a0 100644
--- a/tools/testing/selftests/kvm/Makefile.kvm
+++ b/tools/testing/selftests/kvm/Makefile.kvm
@@ -20,6 +20,7 @@ LIBKVM += lib/userfaultfd_util.c
 LIBKVM_STRING += lib/string_override.c
 
 LIBKVM_ASM_DEFS += lib/x86/tdx/td_boot_offsets.c
+LIBKVM_ASM_DEFS += lib/x86/tdx/tdcall_offsets.c
 
 LIBKVM_x86 += lib/x86/apic.c
 LIBKVM_x86 += lib/x86/handlers.S
@@ -33,6 +34,7 @@ LIBKVM_x86 += lib/x86/ucall.c
 LIBKVM_x86 += lib/x86/vmx.c
 LIBKVM_x86 += lib/x86/tdx/tdx_util.c
 LIBKVM_x86 += lib/x86/tdx/td_boot.S
+LIBKVM_x86 += lib/x86/tdx/tdcall.S
 
 LIBKVM_arm64 += lib/arm64/gic.c
 LIBKVM_arm64 += lib/arm64/gic_v3.c
@@ -343,7 +345,13 @@ $(OUTPUT)/lib/x86/tdx/td_boot.o: $(OUTPUT)/include/x86/tdx/td_boot_offsets.h
 $(OUTPUT)/include/x86/tdx/td_boot_offsets.h: $(OUTPUT)/lib/x86/tdx/td_boot_offsets.s FORCE
 	$(call filechk,offsets,__TDX_BOOT_OFFSETS_H__)
 
+$(OUTPUT)/lib/x86/tdx/tdcall.o: $(OUTPUT)/include/x86/tdx/tdcall_offsets.h
+
+$(OUTPUT)/include/x86/tdx/tdcall_offsets.h: $(OUTPUT)/lib/x86/tdx/tdcall_offsets.s FORCE
+	$(call filechk,offsets,__TDCALL__OFFSETS_H__)
+
 EXTRA_CLEAN += $(OUTPUT)/include/x86/tdx/td_boot_offsets.h
+EXTRA_CLEAN += $(OUTPUT)/include/x86/tdx/tdcall_offsets.h
 
 $(shell mkdir -p $(sort $(dir $(TEST_GEN_PROGS))))
 $(SPLIT_TEST_GEN_OBJ): $(GEN_HDRS)
diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdcall.h b/tools/testing/selftests/kvm/include/x86/tdx/tdcall.h
new file mode 100644
index 000000000000..60c70646f876
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/x86/tdx/tdcall.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Adapted from arch/x86/include/asm/shared/tdx.h */
+
+#ifndef SELFTESTS_TDX_TDCALL_H
+#define SELFTESTS_TDX_TDCALL_H
+
+#include <linux/bits.h>
+
+#define TDX_TDCALL_HAS_OUTPUT BIT(0)
+
+#ifndef __ASSEMBLY__
+
+#include <linux/types.h>
+
+/*
+ * Used in __tdx_tdcall() to pass down and get back registers' values of
+ * the TDCALL instruction when requesting services from the VMM.
+ *
+ * This is a software only structure and not part of the TDX module/VMM ABI.
+ */
+struct tdx_tdcall_args {
+	u64 r10;
+	u64 r11;
+	u64 r12;
+	u64 r13;
+	u64 r14;
+	u64 r15;
+};
+
+/* Used to request services from the VMM */
+u64 __tdx_tdcall(struct tdx_tdcall_args *args, unsigned long flags);
+
+#endif // __ASSEMBLY__
+#endif // SELFTESTS_TDX_TDCALL_H
diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdcall.S b/tools/testing/selftests/kvm/lib/x86/tdx/tdcall.S
new file mode 100644
index 000000000000..05869e86b9d8
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdcall.S
@@ -0,0 +1,93 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Adapted from arch/x86/virt/vmx/tdx/tdxcall.S */
+
+#ifndef __ASSEMBLY__
+#define __ASSEMBLY__
+#endif
+
+#include <linux/bits.h>
+#include "tdx/tdcall.h"
+#include "tdx/tdcall_offsets.h"
+
+/*
+ * TDCALL is supported in Binutils >= 2.36, add it for older version.
+ */
+#define tdcall		.byte 0x66,0x0f,0x01,0xcc
+
+/*
+ * Bitmasks of exposed registers (with VMM).
+ */
+#define TDX_R10		BIT(10)
+#define TDX_R11		BIT(11)
+#define TDX_R12		BIT(12)
+#define TDX_R13		BIT(13)
+#define TDX_R14		BIT(14)
+#define TDX_R15		BIT(15)
+
+/*
+ * These registers are clobbered to hold arguments for each
+ * TDVMCALL. They are safe to expose to the VMM.
+ * Each bit in this mask represents a register ID. Bit field
+ * details can be found in TDX GHCI specification, section
+ * titled "TDCALL [TDG.VP.VMCALL] leaf".
+ */
+#define TDVMCALL_EXPOSE_REGS_MASK    \
+         (TDX_R10 | TDX_R11 | TDX_R12 | TDX_R13 | TDX_R14 | TDX_R15)
+
+.code64
+.section .text
+
+.globl __tdx_tdcall
+.type __tdx_tdcall, @function
+__tdx_tdcall:
+	/* Set up stack frame */
+	push %rbp
+	movq %rsp, %rbp
+
+	/* Save callee-saved GPRs as mandated by the x86_64 ABI */
+	push %r15
+	push %r14
+	push %r13
+	push %r12
+
+	/* Mangle function call ABI into TDCALL ABI: */
+	/* Set TDCALL leaf ID (TDVMCALL (0)) in RAX */
+	xor %eax, %eax
+
+	/* Copy tdcall registers from arg struct: */
+	movq TDX_TDCALL_R10(%rdi), %r10
+	movq TDX_TDCALL_R11(%rdi), %r11
+	movq TDX_TDCALL_R12(%rdi), %r12
+	movq TDX_TDCALL_R13(%rdi), %r13
+	movq TDX_TDCALL_R14(%rdi), %r14
+	movq TDX_TDCALL_R15(%rdi), %r15
+
+	movl $TDVMCALL_EXPOSE_REGS_MASK, %ecx
+
+	tdcall
+
+	/* TDVMCALL leaf return code is in R10 */
+	movq %r10, %rax
+
+	/* Copy tdcall result registers to arg struct if needed */
+	testq $TDX_TDCALL_HAS_OUTPUT, %rsi
+	jz .Lout
+
+	movq %r10, TDX_TDCALL_R10(%rdi)
+	movq %r11, TDX_TDCALL_R11(%rdi)
+	movq %r12, TDX_TDCALL_R12(%rdi)
+	movq %r13, TDX_TDCALL_R13(%rdi)
+	movq %r14, TDX_TDCALL_R14(%rdi)
+	movq %r15, TDX_TDCALL_R15(%rdi)
+.Lout:
+	/* Restore callee-saved GPRs as mandated by the x86_64 ABI */
+	pop %r12
+	pop %r13
+	pop %r14
+	pop %r15
+
+	pop %rbp
+	ret
+
+/* Disable executable stack */
+.section .note.GNU-stack,"",%progbits
diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdcall_offsets.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdcall_offsets.c
new file mode 100644
index 000000000000..dcd4457be6e5
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdcall_offsets.c
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0
+#define COMPILE_OFFSETS
+
+#include <linux/kbuild.h>
+
+#include "tdx/tdcall.h"
+
+static void __attribute__((used)) common(void)
+{
+	OFFSET(TDX_TDCALL_R10, tdx_tdcall_args, r10);
+	OFFSET(TDX_TDCALL_R11, tdx_tdcall_args, r11);
+	OFFSET(TDX_TDCALL_R12, tdx_tdcall_args, r12);
+	OFFSET(TDX_TDCALL_R13, tdx_tdcall_args, r13);
+	OFFSET(TDX_TDCALL_R14, tdx_tdcall_args, r14);
+	OFFSET(TDX_TDCALL_R15, tdx_tdcall_args, r15);
+}
-- 
2.51.0.338.gd7d06c2dae-goog

[PATCH v10 19/21] KVM: selftests: Add wrapper for TDX MMIO from guest

[Sagi Shahar]

Add utility function to issue MMIO TDCALL from TDX guests.

Signed-off-by: Sagi Shahar <sagis@google.com>
---
 tools/testing/selftests/kvm/Makefile.kvm      |  1 +
 .../selftests/kvm/include/x86/tdx/tdx.h       | 14 +++++++++++
 tools/testing/selftests/kvm/lib/x86/tdx/tdx.c | 23 +++++++++++++++++++
 3 files changed, 38 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/tdx.h
 create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/tdx.c

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
index 2d4fd68984a0..1a73e08c8437 100644
--- a/tools/testing/selftests/kvm/Makefile.kvm
+++ b/tools/testing/selftests/kvm/Makefile.kvm
@@ -35,6 +35,7 @@ LIBKVM_x86 += lib/x86/vmx.c
 LIBKVM_x86 += lib/x86/tdx/tdx_util.c
 LIBKVM_x86 += lib/x86/tdx/td_boot.S
 LIBKVM_x86 += lib/x86/tdx/tdcall.S
+LIBKVM_x86 += lib/x86/tdx/tdx.c
 
 LIBKVM_arm64 += lib/arm64/gic.c
 LIBKVM_arm64 += lib/arm64/gic_v3.c
diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx.h
new file mode 100644
index 000000000000..22b096402998
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef SELFTESTS_TDX_TDX_H
+#define SELFTESTS_TDX_TDX_H
+
+#include <stdint.h>
+
+/* MMIO direction */
+#define MMIO_READ	0
+#define MMIO_WRITE	1
+
+uint64_t tdg_vp_vmcall_ve_request_mmio_write(uint64_t address, uint64_t size,
+					     uint64_t data_in);
+
+#endif // SELFTESTS_TDX_TDX_H
diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx.c
new file mode 100644
index 000000000000..f9c1acd5b30c
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "tdx/tdcall.h"
+#include "tdx/tdx.h"
+
+#define TDG_VP_VMCALL 0
+
+#define TDG_VP_VMCALL_VE_REQUEST_MMIO	48
+
+uint64_t tdg_vp_vmcall_ve_request_mmio_write(uint64_t address, uint64_t size,
+					     uint64_t data_in)
+{
+	struct tdx_tdcall_args args = {
+		.r10 = TDG_VP_VMCALL,
+		.r11 = TDG_VP_VMCALL_VE_REQUEST_MMIO,
+		.r12 = size,
+		.r13 = MMIO_WRITE,
+		.r14 = address,
+		.r15 = data_in,
+	};
+
+	return __tdx_tdcall(&args, 0);
+}
-- 
2.51.0.338.gd7d06c2dae-goog

[PATCH v10 20/21] KVM: selftests: Add ucall support for TDX

[Sagi Shahar]

From: Ackerley Tng <ackerleytng@google.com>

ucalls for non-Coco VMs work by having the guest write to the rdi
register, then perform an io instruction to exit to the host. The host
then reads rdi using kvm_get_regs().

CPU registers can't be read using kvm_get_regs() for TDX, so TDX
guests use MMIO to pass the struct ucall's hva to the host. MMIO was
chosen because it is one of the simplest (hence unlikely to fail)
mechanisms that support passing 8 bytes from guest to host.

Signed-off-by: Ackerley Tng <ackerleytng@google.com>
Co-developed-by: Sagi Shahar <sagis@google.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
---
 .../testing/selftests/kvm/include/x86/ucall.h |  4 +-
 tools/testing/selftests/kvm/lib/x86/ucall.c   | 45 ++++++++++++++++---
 2 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86/ucall.h b/tools/testing/selftests/kvm/include/x86/ucall.h
index d3825dcc3cd9..0494a4a21557 100644
--- a/tools/testing/selftests/kvm/include/x86/ucall.h
+++ b/tools/testing/selftests/kvm/include/x86/ucall.h
@@ -6,8 +6,6 @@
 
 #define UCALL_EXIT_REASON       KVM_EXIT_IO
 
-static inline void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
-{
-}
+void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa);
 
 #endif
diff --git a/tools/testing/selftests/kvm/lib/x86/ucall.c b/tools/testing/selftests/kvm/lib/x86/ucall.c
index 1265cecc7dd1..0ad24baaa3c4 100644
--- a/tools/testing/selftests/kvm/lib/x86/ucall.c
+++ b/tools/testing/selftests/kvm/lib/x86/ucall.c
@@ -5,11 +5,34 @@
  * Copyright (C) 2018, Red Hat, Inc.
  */
 #include "kvm_util.h"
+#include "tdx/tdx.h"
 
 #define UCALL_PIO_PORT ((uint16_t)0x1000)
 
+static uint8_t vm_type;
+static vm_paddr_t host_ucall_mmio_gpa;
+static vm_paddr_t ucall_mmio_gpa;
+
+void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
+{
+	vm_type = vm->type;
+	sync_global_to_guest(vm, vm_type);
+
+	host_ucall_mmio_gpa = ucall_mmio_gpa = mmio_gpa;
+
+	if (vm_type == KVM_X86_TDX_VM)
+		ucall_mmio_gpa |= vm->arch.s_bit;
+
+	sync_global_to_guest(vm, ucall_mmio_gpa);
+}
+
 void ucall_arch_do_ucall(vm_vaddr_t uc)
 {
+	if (vm_type == KVM_X86_TDX_VM) {
+		tdg_vp_vmcall_ve_request_mmio_write(ucall_mmio_gpa, 8, uc);
+		return;
+	}
+
 	/*
 	 * FIXME: Revert this hack (the entire commit that added it) once nVMX
 	 * preserves L2 GPRs across a nested VM-Exit.  If a ucall from L2, e.g.
@@ -46,11 +69,23 @@ void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu)
 {
 	struct kvm_run *run = vcpu->run;
 
-	if (run->exit_reason == KVM_EXIT_IO && run->io.port == UCALL_PIO_PORT) {
-		struct kvm_regs regs;
+	switch (vm_type) {
+	case KVM_X86_TDX_VM:
+		if (vcpu->run->exit_reason == KVM_EXIT_MMIO &&
+		    vcpu->run->mmio.phys_addr == host_ucall_mmio_gpa &&
+		    vcpu->run->mmio.len == 8 && vcpu->run->mmio.is_write) {
+			uint64_t data = *(uint64_t *)vcpu->run->mmio.data;
+
+			return (void *)data;
+		}
+		return NULL;
+	default:
+		if (run->exit_reason == KVM_EXIT_IO && run->io.port == UCALL_PIO_PORT) {
+			struct kvm_regs regs;
 
-		vcpu_regs_get(vcpu, &regs);
-		return (void *)regs.rdi;
+			vcpu_regs_get(vcpu, &regs);
+			return (void *)regs.rdi;
+		}
+		return NULL;
 	}
-	return NULL;
 }
-- 
2.51.0.338.gd7d06c2dae-goog

Re: [PATCH v10 20/21] KVM: selftests: Add ucall support for TDX

[Binbin Wu]

On 9/4/2025 2:54 PM, Sagi Shahar wrote:
> From: Ackerley Tng <ackerleytng@google.com>
>
> ucalls for non-Coco VMs work by having the guest write to the rdi
> register, then perform an io instruction to exit to the host. The host
> then reads rdi using kvm_get_regs().
>
> CPU registers can't be read using kvm_get_regs() for TDX, so TDX
> guests use MMIO to pass the struct ucall's hva to the host. MMIO was
> chosen because it is one of the simplest (hence unlikely to fail)
> mechanisms that support passing 8 bytes from guest to host.
>
> Signed-off-by: Ackerley Tng <ackerleytng@google.com>
> Co-developed-by: Sagi Shahar <sagis@google.com>
> Signed-off-by: Sagi Shahar <sagis@google.com>
> ---
>   .../testing/selftests/kvm/include/x86/ucall.h |  4 +-
>   tools/testing/selftests/kvm/lib/x86/ucall.c   | 45 ++++++++++++++++---
>   2 files changed, 41 insertions(+), 8 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/include/x86/ucall.h b/tools/testing/selftests/kvm/include/x86/ucall.h
> index d3825dcc3cd9..0494a4a21557 100644
> --- a/tools/testing/selftests/kvm/include/x86/ucall.h
> +++ b/tools/testing/selftests/kvm/include/x86/ucall.h
> @@ -6,8 +6,6 @@
>   
>   #define UCALL_EXIT_REASON       KVM_EXIT_IO
>   
> -static inline void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
> -{
> -}
> +void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa);

It has been declared in ucall_common.h,  this should be removed here?

>   
>   #endif
> diff --git a/tools/testing/selftests/kvm/lib/x86/ucall.c b/tools/testing/selftests/kvm/lib/x86/ucall.c
> index 1265cecc7dd1..0ad24baaa3c4 100644
> --- a/tools/testing/selftests/kvm/lib/x86/ucall.c
> +++ b/tools/testing/selftests/kvm/lib/x86/ucall.c
> @@ -5,11 +5,34 @@
>    * Copyright (C) 2018, Red Hat, Inc.
>    */
>   #include "kvm_util.h"
> +#include "tdx/tdx.h"
>   
>   #define UCALL_PIO_PORT ((uint16_t)0x1000)
>   
> +static uint8_t vm_type;
> +static vm_paddr_t host_ucall_mmio_gpa;
> +static vm_paddr_t ucall_mmio_gpa;
> +
> +void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
> +{
> +	vm_type = vm->type;
> +	sync_global_to_guest(vm, vm_type);
> +
> +	host_ucall_mmio_gpa = ucall_mmio_gpa = mmio_gpa;
> +
> +	if (vm_type == KVM_X86_TDX_VM)
Nit: is_tdx_vm(vm)

Also, maybe it can skip the initialization of mmio info for non TDX case to tell
that the info is only used by TDX?

> +		ucall_mmio_gpa |= vm->arch.s_bit;
> +
> +	sync_global_to_guest(vm, ucall_mmio_gpa);
> +}
> +
>   void ucall_arch_do_ucall(vm_vaddr_t uc)
>   {
> +	if (vm_type == KVM_X86_TDX_VM) {
> +		tdg_vp_vmcall_ve_request_mmio_write(ucall_mmio_gpa, 8, uc);
> +		return;
> +	}
> +
>   	/*
>   	 * FIXME: Revert this hack (the entire commit that added it) once nVMX
>   	 * preserves L2 GPRs across a nested VM-Exit.  If a ucall from L2, e.g.
> @@ -46,11 +69,23 @@ void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu)
>   {
>   	struct kvm_run *run = vcpu->run;
>   
> -	if (run->exit_reason == KVM_EXIT_IO && run->io.port == UCALL_PIO_PORT) {
> -		struct kvm_regs regs;
> +	switch (vm_type) {
> +	case KVM_X86_TDX_VM:
> +		if (vcpu->run->exit_reason == KVM_EXIT_MMIO &&
> +		    vcpu->run->mmio.phys_addr == host_ucall_mmio_gpa &&
> +		    vcpu->run->mmio.len == 8 && vcpu->run->mmio.is_write) {
> +			uint64_t data = *(uint64_t *)vcpu->run->mmio.data;
> +
> +			return (void *)data;
> +		}
> +		return NULL;
> +	default:
> +		if (run->exit_reason == KVM_EXIT_IO && run->io.port == UCALL_PIO_PORT) {
> +			struct kvm_regs regs;
>   
> -		vcpu_regs_get(vcpu, &regs);
> -		return (void *)regs.rdi;
> +			vcpu_regs_get(vcpu, &regs);
> +			return (void *)regs.rdi;
> +		}
> +		return NULL;
>   	}
> -	return NULL;
>   }

[PATCH v10 21/21] KVM: selftests: Add TDX lifecycle test

[Sagi Shahar]

Adding a test to verify TDX lifecycle by creating a simple TD.

Signed-off-by: Sagi Shahar <sagis@google.com>
---
 tools/testing/selftests/kvm/Makefile.kvm      |  1 +
 .../selftests/kvm/include/x86/tdx/tdx_util.h  | 10 ++++++
 .../selftests/kvm/lib/x86/tdx/tdx_util.c      | 18 +++++++++++
 tools/testing/selftests/kvm/x86/tdx_vm_test.c | 31 +++++++++++++++++++
 4 files changed, 60 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/x86/tdx_vm_test.c

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
index 1a73e08c8437..1a76e9fa45d6 100644
--- a/tools/testing/selftests/kvm/Makefile.kvm
+++ b/tools/testing/selftests/kvm/Makefile.kvm
@@ -155,6 +155,7 @@ TEST_GEN_PROGS_x86 += rseq_test
 TEST_GEN_PROGS_x86 += steal_time
 TEST_GEN_PROGS_x86 += system_counter_offset_test
 TEST_GEN_PROGS_x86 += pre_fault_memory_test
+TEST_GEN_PROGS_x86 += x86/tdx_vm_test
 
 # Compiled outputs used by test targets
 TEST_GEN_PROGS_EXTENDED_x86 += x86/nx_huge_pages_test
diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
index 2467b6c35557..775ca249f74d 100644
--- a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
+++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h
@@ -11,6 +11,14 @@ static inline bool is_tdx_vm(struct kvm_vm *vm)
 	return vm->type == KVM_X86_TDX_VM;
 }
 
+/*
+ * Verify that TDX is supported by KVM.
+ */
+static inline bool is_tdx_enabled(void)
+{
+	return !!(kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(KVM_X86_TDX_VM));
+}
+
 /*
  * TDX ioctls
  */
@@ -72,5 +80,7 @@ void vm_tdx_load_vcpu_boot_parameters(struct kvm_vm *vm, struct kvm_vcpu *vcpu);
 void vm_tdx_set_vcpu_entry_point(struct kvm_vcpu *vcpu, void *guest_code);
 
 void vm_tdx_finalize(struct kvm_vm *vm);
+struct kvm_vm *vm_tdx_create_with_one_vcpu(void *guest_code,
+					   struct kvm_vcpu **vcpu);
 
 #endif // SELFTESTS_TDX_TDX_UTIL_H
diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
index d5df2de81a75..a2764f5d687c 100644
--- a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
+++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c
@@ -334,3 +334,21 @@ void vm_tdx_finalize(struct kvm_vm *vm)
 	load_td_private_memory(vm);
 	vm_tdx_vm_ioctl(vm, KVM_TDX_FINALIZE_VM, 0, NULL);
 }
+
+struct kvm_vm *vm_tdx_create_with_one_vcpu(void *guest_code,
+					   struct kvm_vcpu **vcpu)
+{
+	struct vm_shape shape = {
+		.mode = VM_MODE_DEFAULT,
+		.type = KVM_X86_TDX_VM,
+	};
+	struct kvm_vm *vm;
+	struct kvm_vcpu *vcpus[1];
+
+	vm = __vm_create_with_vcpus(shape, 1, 0, guest_code, vcpus);
+	*vcpu = vcpus[0];
+
+	vm_tdx_finalize(vm);
+
+	return vm;
+}
diff --git a/tools/testing/selftests/kvm/x86/tdx_vm_test.c b/tools/testing/selftests/kvm/x86/tdx_vm_test.c
new file mode 100644
index 000000000000..a9ee489eea1a
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86/tdx_vm_test.c
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "kvm_util.h"
+#include "tdx/tdx_util.h"
+#include "ucall_common.h"
+#include "kselftest_harness.h"
+
+static void guest_code_lifecycle(void)
+{
+	GUEST_DONE();
+}
+
+TEST(verify_td_lifecycle)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	struct ucall uc;
+
+	vm = vm_tdx_create_with_one_vcpu(guest_code_lifecycle, &vcpu);
+
+	vcpu_run(vcpu);
+	TEST_ASSERT_EQ(get_ucall(vcpu, &uc), UCALL_DONE);
+
+	kvm_vm_free(vm);
+}
+
+int main(int argc, char **argv)
+{
+	TEST_REQUIRE(is_tdx_enabled());
+	return test_harness_run(argc, argv);
+}
-- 
2.51.0.338.gd7d06c2dae-goog