Re: [PATCH 15/18] KVM: selftests: Allocate x86's TSS at VM creation

[Ackerley Tng]

Sean Christopherson <seanjc@xxxxxxxxxx> writes:

> Allocate x86's per-VM TSS at creation of a non-barebones VM.  Like the
> GDT, the TSS is needed to actually run vCPUs, i.e. every non-barebones VM
> is all but guaranteed to allocate the TSS sooner or later.
>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
>  tools/testing/selftests/kvm/lib/x86_64/processor.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
> index 5cf845975f66..03b9387a1d2e 100644
> --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
> +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
> @@ -519,9 +519,6 @@ vm_paddr_t addr_arch_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
>  static void kvm_setup_tss_64bit(struct kvm_vm *vm, struct kvm_segment *segp,
>  				int selector)
>  {
> -	if (!vm->arch.tss)
> -		vm->arch.tss = __vm_vaddr_alloc_page(vm, MEM_REGION_DATA);
> -
>  	memset(segp, 0, sizeof(*segp));
>  	segp->base = vm->arch.tss;
>  	segp->limit = 0x67;
> @@ -619,6 +616,8 @@ static void vm_init_descriptor_tables(struct kvm_vm *vm)
>  	vm->arch.gdt = __vm_vaddr_alloc_page(vm, MEM_REGION_DATA);
>  	vm->arch.idt = __vm_vaddr_alloc_page(vm, MEM_REGION_DATA);
>  	vm->handlers = __vm_vaddr_alloc_page(vm, MEM_REGION_DATA);
> +	vm->arch.tss = __vm_vaddr_alloc_page(vm, MEM_REGION_DATA);
> +
>  	/* Handlers have the same address in both address spaces.*/
>  	for (i = 0; i < NUM_INTERRUPTS; i++)
>  		set_idt_entry(vm, i, (unsigned long)(&idt_handlers)[i], 0,
> -- 
> 2.44.0.291.gc1ea87d7ee-goog

Reviewed-by: Ackerley Tng <ackerleytng@xxxxxxxxxx>