From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.9]) (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 CB5D3433B1; Thu, 28 Nov 2024 03:23:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.9 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732764186; cv=none; b=ZntChIVAblpGb8avzqrYQvX0/0KzU9awHrEVwWHKjeOV6xWbARzOTc8CqewI2FojMy7tX2Bxx1au3YpM+ECRjrweSMKS8noANHB6OHQ4cdMJWDt1sjKO6B93o+N2n3jy9uQUPQKhYiCWB+cWyV6VLy4YOOICmAkZVa958LS64fY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732764186; c=relaxed/simple; bh=fSHT19oGrWGL3EJD3BfhBB9vjecsxVX7dC/h5Hx7i8A=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=iMbQO+0I9FSwqU2ZVLsMbu6TM/a9khqj3dZV7Xnplu+6gX6+e7EzJjVa7X2LM4mAywy0wj+jKRgqpG/sS0tsLqqhXZl3BU1c4csIzAtkSffoWitd/B56vqBNCmy4Cr2pmeMIC5UX1ZatzDpapAii8gJY4Mc+A8xcfWfOUeC91BU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Fb8bjrYw; arc=none smtp.client-ip=192.198.163.9 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Fb8bjrYw" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1732764184; x=1764300184; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=fSHT19oGrWGL3EJD3BfhBB9vjecsxVX7dC/h5Hx7i8A=; b=Fb8bjrYwIgUh605yrE8id1wDf3aLJy+wusbBKIDnP8dbwdhfQTdOhemS vIEQTinfno+UblBIQKpb/t03Bz//LyzTaMiLLVLWRfuQeiXKTV4rosAt4 2m3TLLy3OttBGYKArrvaNenMc4P/BrICbE0X98lNhPdJ0aw0dB1tMHvfG rfSkWCV1+snJ5/XScMcgTyigjcbZBay9mcWmjs2OvADa9wtC3kXpczVr7 Vj1K65kLl/kmkrkmWEHNDeCU4V4paepYV+MU3mtog7Rpjk9TFBuy3eK0q i2Azi4dw9NBuKkH89TjtHdiPZ95uqWcNfSbk/oPLUWMSgIqe3piP6lkn1 g==; X-CSE-ConnectionGUID: iEwZELPxQwqSv8NIXa4gXw== X-CSE-MsgGUID: VxfJiSATTQqEk+9XbxTJ3w== X-IronPort-AV: E=McAfee;i="6700,10204,11269"; a="43651723" X-IronPort-AV: E=Sophos;i="6.12,191,1728975600"; d="scan'208";a="43651723" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by fmvoesa103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Nov 2024 19:23:03 -0800 X-CSE-ConnectionGUID: eJ2JsRbwQx+H5Ke9VNTu5A== X-CSE-MsgGUID: CxGZbfTRRQ+NI/GLR60NCw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,191,1728975600"; d="scan'208";a="97069239" Received: from xiaoyaol-hp-g830.ccr.corp.intel.com (HELO [10.124.247.1]) ([10.124.247.1]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Nov 2024 19:23:01 -0800 Message-ID: <2eaca3cd-ab33-412e-9603-ce7a5b09f5f2@intel.com> Date: Thu, 28 Nov 2024 11:22:58 +0800 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 1/6] KVM: x86: Play nice with protected guests in complete_hypercall_exit() To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Tom Lendacky , Binbin Wu , Isaku Yamahata , Kai Huang References: <20241128004344.4072099-1-seanjc@google.com> <20241128004344.4072099-2-seanjc@google.com> Content-Language: en-US From: Xiaoyao Li In-Reply-To: <20241128004344.4072099-2-seanjc@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 11/28/2024 8:43 AM, Sean Christopherson wrote: > Use is_64_bit_hypercall() instead of is_64_bit_mode() to detect a 64-bit > hypercall when completing said hypercall. For guests with protected state, > e.g. SEV-ES and SEV-SNP, KVM must assume the hypercall was made in 64-bit > mode as the vCPU state needed to detect 64-bit mode is unavailable. > > Hacking the sev_smoke_test selftest to generate a KVM_HC_MAP_GPA_RANGE > hypercall via VMGEXIT trips the WARN: > > ------------[ cut here ]------------ > WARNING: CPU: 273 PID: 326626 at arch/x86/kvm/x86.h:180 complete_hypercall_exit+0x44/0xe0 [kvm] > Modules linked in: kvm_amd kvm ... [last unloaded: kvm] > CPU: 273 UID: 0 PID: 326626 Comm: sev_smoke_test Not tainted 6.12.0-smp--392e932fa0f3-feat #470 > Hardware name: Google Astoria/astoria, BIOS 0.20240617.0-0 06/17/2024 > RIP: 0010:complete_hypercall_exit+0x44/0xe0 [kvm] > Call Trace: > > kvm_arch_vcpu_ioctl_run+0x2400/0x2720 [kvm] > kvm_vcpu_ioctl+0x54f/0x630 [kvm] > __se_sys_ioctl+0x6b/0xc0 > do_syscall_64+0x83/0x160 > entry_SYSCALL_64_after_hwframe+0x76/0x7e > > ---[ end trace 0000000000000000 ]--- Reviewed-by: Xiaoyao Li > Fixes: b5aead0064f3 ("KVM: x86: Assume a 64-bit hypercall for guests with protected state") > Cc: stable@vger.kernel.org > Cc: Tom Lendacky > Signed-off-by: Sean Christopherson > --- > arch/x86/kvm/x86.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 2e713480933a..0b2fe4aa04a2 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -9976,7 +9976,7 @@ static int complete_hypercall_exit(struct kvm_vcpu *vcpu) > { > u64 ret = vcpu->run->hypercall.ret; > > - if (!is_64_bit_mode(vcpu)) > + if (!is_64_bit_hypercall(vcpu)) > ret = (u32)ret; > kvm_rax_write(vcpu, ret); > ++vcpu->stat.hypercalls;