From 0d95817e075314706b3e4086080a9bbb1421634c Mon Sep 17 00:00:00 2001 From: Ackerley Tng Date: Thu, 14 Mar 2024 16:26:23 -0700 Subject: [PATCH] KVM: selftests: Fix off-by-one initialization of GDT limit Fix an off-by-one bug in the initialization of the GDT limit, which as defined in the SDM is inclusive, not exclusive. Note, vcpu_init_descriptor_tables() gets the limit correct, it's only vcpu_setup() that is broken, i.e. only tests that _don't_ invoke vcpu_init_descriptor_tables() can have problems. And the fact that KVM effectively initializes the GDT twice will be cleaned up in the near future. Signed-off-by: Ackerley Tng [sean: rewrite changelog] Link: https://lore.kernel.org/r/20240314232637.2538648-5-seanjc@google.com Signed-off-by: Sean Christopherson --- tools/testing/selftests/kvm/lib/x86_64/processor.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index f2506b9edb37d..a04c2e623d099 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -523,7 +523,7 @@ static void kvm_setup_gdt(struct kvm_vm *vm, struct kvm_dtable *dt) vm->arch.gdt = __vm_vaddr_alloc_page(vm, MEM_REGION_DATA); dt->base = vm->arch.gdt; - dt->limit = getpagesize(); + dt->limit = getpagesize() - 1; } static void kvm_setup_tss_64bit(struct kvm_vm *vm, struct kvm_segment *segp, -- 2.30.2