From: Lisa Wang <wyihan@google.com>
To: sashiko-reviews@lists.linux.dev
Cc: kvm@vger.kernel.org
Subject: Re: [PATCH v15 10/23] KVM: selftests: Set up TDX boot parameters region
Date: Mon, 5 Oct 2026 22:33:56 +0000 [thread overview]
Message-ID: <asQl1OrH2vtnhHS4@google.com> (raw)
In-Reply-To: <20261002091329.9ACBE1F00893@smtp.kernel.org>
On Fri, Oct 02, 2026 at 09:13:29AM +0000, sashiko-bot@kernel.org wrote:
> [ ... ]
> > + /* Set parameters! */
> > + params->cr0 = kvm_get_default_cr0();
> > + TEST_ASSERT(vm->mmu.pgd < (1ULL << 32),
> > + "PGD must be within 32-bit address space for 32-bit boot code");
> > + params->cr3 = vm->mmu.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->idtr.base < (1ULL << 32),
> > + "idt must be within 32-bit address space for 32-bit boot code");
> > + TEST_ASSERT(params->gdtr.base < (1ULL << 32),
> > + "gdt must be within 32-bit address space for 32-bit boot code");
>
> [Severity: Low]
> Does this assignment silently truncate the 64-bit vm->arch.idt and
> vm->arch.gdt addresses?
>
> Since params->idtr.base and params->gdtr.base are 32-bit fields, the
> subsequent TEST_ASSERT checks evaluate the already-truncated values. If a
> test allocates an IDT or GDT address beyond 4GB, the assertions will
> always be trivially true because the upper 32 bits are lost before the
> check.
>
> This could lead to confusing test failures during guest execution instead
> of properly failing the assertion here.
>
> Should these assertions check vm->arch.idt and vm->arch.gdt directly
> before assigning them to the base fields?
Will update the assertions to check vm->arch.idt and vm->arch.gdt directly.
next prev parent reply other threads:[~2026-10-05 22:34 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-01 19:37 [PATCH v15 00/23] TDX KVM selftests Lisa Wang
2026-10-01 19:37 ` [PATCH v15 01/23] KVM: selftests: Add macros to simplify creating VM shapes for non-default types Lisa Wang
2026-10-01 19:37 ` [PATCH v15 02/23] KVM: selftests: Update kvm_init_vm_address_properties() for TDX Lisa Wang
2026-10-01 19:37 ` [PATCH v15 03/23] KVM: selftests: Initialize the TDX VM Lisa Wang
2026-10-02 9:13 ` sashiko-bot
2026-10-05 21:26 ` Lisa Wang
2026-10-01 19:37 ` [PATCH v15 04/23] KVM: selftests: Expose segment definitions to assembly files Lisa Wang
2026-10-01 19:37 ` [PATCH v15 05/23] tools: include: Add kbuild.h for assembly structure offsets Lisa Wang
2026-10-01 19:37 ` [PATCH v15 06/23] KVM: selftests: Introduce structures for TDX guest boot parameters Lisa Wang
2026-10-01 19:37 ` [PATCH v15 07/23] KVM: selftests: Add TDX boot code Lisa Wang
2026-10-02 9:13 ` sashiko-bot
2026-10-05 22:31 ` Lisa Wang
2026-10-01 19:37 ` [PATCH v15 08/23] KVM: selftests: Expose functions to get default sregs values Lisa Wang
2026-10-01 19:37 ` [PATCH v15 09/23] KVM: selftests: Set up TDX boot code region Lisa Wang
2026-10-01 19:37 ` [PATCH v15 10/23] KVM: selftests: Set up TDX boot parameters region Lisa Wang
2026-10-02 9:13 ` sashiko-bot
2026-10-05 22:33 ` Lisa Wang [this message]
2026-10-01 19:37 ` [PATCH v15 11/23] KVM: selftests: Set shared attributes for ucall guest_memfd pages Lisa Wang
2026-10-01 19:37 ` [PATCH v15 12/23] KVM: selftests: Require guest_memfd for TDX VMs Lisa Wang
2026-10-01 19:37 ` [PATCH v15 13/23] KVM: selftests: Support guest_memfd in-place conversion Lisa Wang
2026-10-01 19:37 ` [PATCH v15 14/23] KVM: selftests: Expose function to allocate vCPU stack Lisa Wang
2026-10-02 9:13 ` sashiko-bot
2026-10-01 19:37 ` [PATCH v15 15/23] KVM: selftests: Call KVM_TDX_INIT_VCPU when creating a new TDX vcpu Lisa Wang
2026-10-01 19:37 ` [PATCH v15 16/23] KVM: selftests: Load per-vCPU guest stack in TDX boot parameters Lisa Wang
2026-10-02 9:13 ` sashiko-bot
2026-10-07 19:07 ` Lisa Wang
2026-10-01 19:37 ` [PATCH v15 17/23] KVM: selftests: Set entry point for TDX guest code Lisa Wang
2026-10-02 9:13 ` sashiko-bot
2026-10-01 19:37 ` [PATCH v15 18/23] KVM: selftests: Add helpers to init TDX memory and finalize VM Lisa Wang
2026-10-01 19:37 ` [PATCH v15 19/23] KVM: selftests: Finalize TDX VM in kvm_arch_vm_finalize_vcpus() Lisa Wang
2026-10-01 19:37 ` [PATCH v15 20/23] KVM: selftests: Add a helper to issue TDVMCALLs from the TDX vm Lisa Wang
2026-10-02 9:13 ` sashiko-bot
2026-10-01 19:37 ` [PATCH v15 21/23] KVM: selftests: Add support for per-VM ucall ops on x86 Lisa Wang
2026-10-02 9:13 ` sashiko-bot
2026-10-01 19:37 ` [PATCH v15 22/23] KVM: selftests: Add support for TDX ucalls, via TDVMCALL_REPORT_FATAL_ERROR Lisa Wang
2026-10-02 9:13 ` sashiko-bot
2026-10-01 19:37 ` [PATCH v15 23/23] KVM: selftests: Add TDX lifecycle test Lisa Wang
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