From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f197.google.com (mail-pl1-f197.google.com [209.85.214.197]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 442DE26296 for ; Tue, 18 Aug 2026 21:56:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787090180; cv=none; b=Gk8oeWLLBeZoDqIhpakYUCDUytCrh/NPWxQpWT9e4LAP6z2Hv/IF0shHkYVfO/sGlr9FpUwaUs/Q32rs9vapJbfB0YB77xI4zRQkZXWTqS/TaZX2xE8Ro1fLinhVU0+EpHECmDnjPIOdLU7Hi2LIDLz96/dmhEzvSN7FCX6HYCY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787090180; c=relaxed/simple; bh=JuQe4wvhoTYyUuwxNJ/Cz6UJ4qgLwxXvjqd0Wlznc8c=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=uKKu16Q1xich/FaP2ukIsAn8vuzG8M4AHnlDlKBUuhF7PiJf8k4MDW04liEzK8nvlp4PrnSBfNqIZp7DGoh2J3+EG+fxSZ9y3GkDjCNll2lLEw9qPFBiKK8A2YisiMpaNpFZw/O4ixCFNuhh3sQE7gvTWvWnZ5dWKhsJpGts2EA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=aC1n6xqf; arc=none smtp.client-ip=209.85.214.197 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="aC1n6xqf" Received: by mail-pl1-f197.google.com with SMTP id d9443c01a7336-2d54187d8b0so6986675ad.0 for ; Tue, 18 Aug 2026 14:56:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1787090178; x=1787694978; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=9gNRvVZWlKLU6Jjew/a+f7LZJn1aPJd/qJ+Prwj4wzc=; b=aC1n6xqf29lqkY94bDlwoonMkd35GGtQwyFojDW0QWYkfnwhd9Ahl6m17NJQwQABae 0BRb5D+dHu2/hIP5N5WtuWJMgEvT8XM1Pg7rNFSyYPh8lnXhAjl94txv3jssH7MClTiQ 9aSVOToccTRgVujsdJZXyFvT0tQdIQz/Xcm9OEV/68GpJvXBI7U87kaUD22ldwcA+8xv O64fpew4aIegrQPsZluugWbBr1p5ZEifCQ2V4BYZerhRY3tJa54cLYGM/W+XpE9Oe3Ls L6BWahnd14llBCK5lppBmqRJ41eoVInT3ViDNLGxCL8r3fzXZxNTkt7klvPuM09CC4wJ wW8w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787090178; x=1787694978; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=9gNRvVZWlKLU6Jjew/a+f7LZJn1aPJd/qJ+Prwj4wzc=; b=BjbfUcOEWo+HJvF4+8mTwbDe9GHWYQcHSNu9Z9bXN3cwMZEPX2pbHtO4JVL+cZu2XK F6qnHquZdw4mRwTXglTyeUQLHZu66h3cWsrdZ7ITmvxe3PzSaETtU9gm6veBh9IgJYFT sIIhkdzOyg2j8Z7Sg66JKFBHrXR5jVfrA1gXM1auhom6aHUwB1C5xC9PXI+lS5h+F2uh +ZUSD4S5pA1Zdu4k0DiljsSvGA4EpNmtw7/NS4vrO6ltuAHNzSF1kyTRsND760X/rzPb MObmjqXZLkYz7g1D3U0NKM6JVYjNMaEGYWsdbv15WkeA3Wy5P4f9VA8bizUQTfjdZujb ufPw== X-Forwarded-Encrypted: i=1; AHgh+Ro9PZqR4LA/eXCtzscmtLvW9wGMSyC23dbrcVqR7uDh7ZXDU46Z5vG1ekBbo5LTQshBaZ8=@vger.kernel.org X-Gm-Message-State: AOJu0Yw8dfgRrd094qTFQBcKJY24SwcYHINeglfqv0+dJg/GyRZtDDxr LeJozC2TEhVaCc6OP25Fe5th5Zeox5sLctdSaIB9YP1gX14a2wLwchkw6O6uFo7I/dkpav44Abg bmyb4xA== X-Received: from plkk3.prod.google.com ([2002:a17:902:c403:b0:2d3:2362:d799]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:944:b0:2ca:d91d:d3a7 with SMTP id d9443c01a7336-2d5f6b21181mr14818565ad.10.1787090178421; Tue, 18 Aug 2026 14:56:18 -0700 (PDT) Date: Tue, 18 Aug 2026 14:56:17 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260818165258.2613603-1-vkuznets@redhat.com> <20260818165258.2613603-5-vkuznets@redhat.com> <20260818170534.07B561F000E9@smtp.kernel.org> Message-ID: Subject: Re: [PATCH v2 4/4] KVM: selftests: Check VMPTRLD with active eVMCS From: Sean Christopherson To: sashiko-reviews@lists.linux.dev Cc: Vitaly Kuznetsov , kvm@vger.kernel.org Content-Type: text/plain; charset="us-ascii" On Tue, Aug 18, 2026, Sean Christopherson wrote: > On Tue, Aug 18, 2026, sashiko-bot@kernel.org wrote: > > > + asm volatile(KVM_ASM_SAFE("vmptrld %[pa]") > > > + "\n\tsetna %[failed]" > > > > [Severity: Medium] > > Will this setna instruction incorrectly evaluate CPU flags? > > > > The KVM_ASM_SAFE macro executes xor %%r9, %%r9 on its success path, which > > unconditionally clears the Carry Flag (CF=0) and sets the Zero Flag (ZF=1). > > Shame on me, I should know better after dealing with ba5ca5e5e6a1 ("x86/retpoline: > Don't clobber RFLAGS during srso_safe_ret()"). > > Untested, but I think the fix is simply: > > diff --git tools/testing/selftests/kvm/include/x86/processor.h tools/testing/selftests/kvm/include/x86/processor.h > index 6e6f70035508..119715ffe93f 100644 > --- tools/testing/selftests/kvm/include/x86/processor.h > +++ tools/testing/selftests/kvm/include/x86/processor.h > @@ -1318,7 +1318,7 @@ gva_t vm_alloc_stack(struct kvm_vm *vm, int nr_pages); > "lea 1f(%%rip), %%r10\n\t" \ > "lea 2f(%%rip), %%r11\n\t" \ > fep "1: " insn "\n\t" \ > - "xor %%r9, %%r9\n\t" \ > + "mov $0, %%r9\n\t" \ > "2:\n\t" \ > "mov %%r9b, %[vector]\n\t" \ > "mov %%r10, %[error_code]\n\t" Vitaly, I'll send a v3 of this series with a rather large pile of additional selftests changes. As often seems to be the case, my desire validate a simple fix has snowballed...