From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BA0713C6A5F; Thu, 4 Jun 2026 20:36:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780605361; cv=none; b=PLvV6YTSFe2hr760EpT6/ExyLPatuYOYa+fOD/e328+08PD0eLHf1h74dnr8XVrx4PSGZGl40enOj5JlKZ/oLOGDEJME+h5u33Z5IJjJIN046lgmbdTdgmKaKMV/7RKzzSFYSKFnm4MJkhT7AsKCSjunJMKarMH3oCNqyyCfhmw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780605361; c=relaxed/simple; bh=o+gRf/jJkkQT7GrXgVPHQbiVu+EFRgY7NIiZfDaYg54=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OoMDRMlJFe1ZxHUo8BBXddnEY4xpJ0K1sGXGHQCCtflLraotLFG+SqXIO0Wm0xHBnPUvVT1M/OmiIsOtHqIImoFfh79mG7FAbN+qpHyBoQe/AB119KkBgYOpa3LzcGnqs3DaJ9/cAHzOqW391aYQRrPIu7pvMf8lloI2V9I2hiU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SRYqw7c5; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SRYqw7c5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 683FA1F0089A; Thu, 4 Jun 2026 20:36:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780605360; bh=iyNtZBVOFOFiHv/bxlZAV8NqRiBzVXC6M4IsHF/XRWw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=SRYqw7c57VATQRJQ8MPK9gQBEfEXhLqVO2uy2mfxkaGUxQRF+YJhvEMHbNsoBgUZH qKELDlXCpCacmMovDq615Kp/Y6ft6/jQetu24mA70MmOSLKqxt3p6vSE7UIKuDI6ZF ABliST0ic3QlmgwiGiZv6ljRgIG7uVhIuIvWdtw7FhtoUUM8bZhj9b90k02P2HRnIy /tgA09EYywF/c58h6furNNwlRLt/NLBt7Ky/pqgzA1qIIy+Y94fHgIZYgjWgZLsNz1 PZOZaqt6YoIwxDln3mI5AZHjSfqKV8WTIr2D4oy2JMZR/1hStWUkiSxVfH+riToxhR 4Z0hfNYg+v/Sw== From: Yosry Ahmed To: Sean Christopherson Cc: Paolo Bonzini , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Yosry Ahmed , Sashiko Subject: [PATCH v2 02/10] KVM: selftests: Fix RAX and RFLAGS VMCB offsets when running L2 Date: Thu, 4 Jun 2026 20:35:38 +0000 Message-ID: <20260604203546.365658-3-yosry@kernel.org> X-Mailer: git-send-email 2.54.0.1032.g2f8565e1d1-goog In-Reply-To: <20260604203546.365658-1-yosry@kernel.org> References: <20260604203546.365658-1-yosry@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The offsets used (0x170 and 0x1f8) are offsets within vmcb_save_area, not vmcb. The correct offsets should include the base of vmcb_save_area within vmcb (which is 0x400 -- so 0x570 and 0x5f8). Instead of just correcting the offsets, use vmcb->save.rax and vmcb->save.rflags as parameters to the asm block and avoid hardcoding offsets completely. While at it, also use guest_regs.rax directly instead of assuming it's at offset 0 of guest_regs. Note: "+m" must be used for vmcb_rax and vmcb_rflags, as caching those fields in registers would be wrong as the underlying KVM will update them in memory. The same problem was recently fixed (differently) for kvm-unit-tests [1]. [1]https://lore.kernel.org/all/20260521092311.86030-1-pbonzini@redhat.com/ Reported-by: Sashiko Closes: https://sashiko.dev/#/patchset/20260518202514.2037078-1-yosry%40kernel.org?part=1 Signed-off-by: Yosry Ahmed --- tools/testing/selftests/kvm/lib/x86/svm.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/tools/testing/selftests/kvm/lib/x86/svm.c b/tools/testing/selftests/kvm/lib/x86/svm.c index 3b01605ab016c..f9ea1a2aeb8bc 100644 --- a/tools/testing/selftests/kvm/lib/x86/svm.c +++ b/tools/testing/selftests/kvm/lib/x86/svm.c @@ -162,19 +162,22 @@ void run_guest(struct vmcb *vmcb, u64 vmcb_gpa) { asm volatile ( "vmload %[vmcb_gpa]\n\t" - "mov rflags, %%r15\n\t" // rflags - "mov %%r15, 0x170(%[vmcb])\n\t" - "mov guest_regs, %%r15\n\t" // rax - "mov %%r15, 0x1f8(%[vmcb])\n\t" + "mov rflags, %%r15\n\t" + "mov %%r15, %[vmcb_rflags]\n\t" + "mov %[guest_regs_rax], %%r15\n\t" + "mov %%r15, %[vmcb_rax]\n\t" LOAD_GPR_C "vmrun %[vmcb_gpa]\n\t" SAVE_GPR_C - "mov 0x170(%[vmcb]), %%r15\n\t" // rflags + "mov %[vmcb_rflags], %%r15\n\t" "mov %%r15, rflags\n\t" - "mov 0x1f8(%[vmcb]), %%r15\n\t" // rax - "mov %%r15, guest_regs\n\t" + "mov %[vmcb_rax], %%r15\n\t" // rax + "mov %%r15, %[guest_regs_rax]\n\t" "vmsave %[vmcb_gpa]\n\t" - : : [vmcb] "r" (vmcb), [vmcb_gpa] "a" (vmcb_gpa) + : [vmcb_rflags] "+m" (vmcb->save.rflags), + [vmcb_rax] "+m" (vmcb->save.rax), + [guest_regs_rax] "+rm" (guest_regs.rax) + : [vmcb_gpa] "a" (vmcb_gpa) : "r15", "memory"); } -- 2.54.0.1032.g2f8565e1d1-goog