On 10/9/2026 3:56 PM, Xiaoyao Li wrote: > On 10/2/2026 3:37 AM, Lisa Wang wrote: >> From: Sagi Shahar <[email protected]> >> >> Introduce kvm_allocate_vcpu_stack() to allocate a vCPU's stack >> in preparation for TDX to allocate a vCPU's stack and initialize >> its stack pointer. >> >> TDX VMs' registers are protected state and cannot be initialized >> using the KVM_SET_REGS ioctl() that is used for normal VMs. A TDX >> vCPU's stack address will be a property of the TDX specific boot code >> that initializes the vCPUs' stack pointers at boot. >> >> Signed-off-by: Sagi Shahar <[email protected]> >> Signed-off-by: Lisa Wang <[email protected]> >> Reviewed-by: Binbin Wu <[email protected]> >> Reviewed-by: Ira Weiny <[email protected]> >> Reviewed-by: Xiaoyao Li <[email protected]> >> --- >> .../testing/selftests/kvm/include/x86/processor.h | 2 ++ >> tools/testing/selftests/kvm/lib/x86/processor.c | 25 >> +++++++++++++++++++--- >> 2 files changed, 24 insertions(+), 3 deletions(-) >> >> diff --git a/tools/testing/selftests/kvm/include/x86/processor.h >> b/tools/testing/selftests/kvm/include/x86/processor.h >> index 8854ee052d29..1eb380dd216c 100644 >> --- a/tools/testing/selftests/kvm/include/x86/processor.h >> +++ b/tools/testing/selftests/kvm/include/x86/processor.h >> @@ -1212,6 +1212,8 @@ static inline void vcpu_clear_cpuid_feature(struct >> kvm_vcpu *vcpu, >> vcpu_set_or_clear_cpuid_feature(vcpu, feature, false); >> } >> >> +gva_t kvm_allocate_vcpu_stack(struct kvm_vm *vm); >> + >> u64 vcpu_get_msr(struct kvm_vcpu *vcpu, u64 msr_index); >> int _vcpu_set_msr(struct kvm_vcpu *vcpu, u64 msr_index, u64 msr_value); >> >> diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c >> b/tools/testing/selftests/kvm/lib/x86/processor.c >> index da430d4e7765..4a753fb43007 100644 >> --- a/tools/testing/selftests/kvm/lib/x86/processor.c >> +++ b/tools/testing/selftests/kvm/lib/x86/processor.c >> @@ -851,12 +851,31 @@ void vcpu_arch_set_entry_point(struct kvm_vcpu *vcpu, >> void *guest_code) >> vcpu_regs_set(vcpu, ®s); >> } >> >> -struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, u32 vcpu_id) >> +gva_t kvm_allocate_vcpu_stack(struct kvm_vm *vm) > > Besides what Sashiko pointed out[1], this patch was just messed up during the > rebase and it even doesn't compile.
Yes. And since the upstream code already has vm_alloc_stack(), which basically does the same thing. I think this patch can be dropped. > > [1] https://lore.kernel.org/all/[email protected]/ > >> { >> struct kvm_mp_state mp_state; >> struct kvm_regs regs; >> + gva_t stack_gva; >> struct kvm_vcpu *vcpu; >> >> + stack_gva = __vm_alloc(vm, DEFAULT_STACK_PGS * getpagesize(), >> + DEFAULT_GUEST_STACK_VADDR_MIN, MEM_REGION_DATA); >> + >> + stack_gva += DEFAULT_STACK_PGS * getpagesize(); >> + >> + /* >> + * Align stack to match calling sequence requirements in section "The >> + * Stack Frame" of the System V ABI AMD64 Architecture Processor >> + * Supplement, which requires the value (%rsp + 8) to be a multiple of >> + * 16 when control is transferred to the function entry point. >> + * >> + * If this code is ever used to launch a vCPU with 32-bit entry point it >> + * may need to subtract 4 bytes instead of 8 bytes. >> + */ >> + TEST_ASSERT(IS_ALIGNED(stack_gva, PAGE_SIZE), >> + "__vm_alloc() did not provide a page-aligned address"); >> + stack_gva -= 8; >> + >> vcpu = __vm_vcpu_add(vm, vcpu_id); >> vcpu_init_cpuid(vcpu, kvm_get_supported_cpuid()); >> vcpu_init_sregs(vm, vcpu); >> @@ -864,8 +883,8 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, u32 >> vcpu_id) >> >> /* Setup guest general purpose registers */ >> vcpu_regs_get(vcpu, ®s); >> - regs.rflags = regs.rflags | X86_EFLAGS_FIXED; >> - regs.rsp = vm_alloc_stack(vm, DEFAULT_STACK_PGS); >> + regs.rflags = regs.rflags | 0x2; >> + regs.rsp = kvm_allocate_vcpu_stack(vm); >> vcpu_regs_set(vcpu, ®s); >> >> /* Setup the MP state */ >> >
