From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-1.mimecast.com (us-smtp-1.mimecast.com [207.211.31.120]) by mx.groups.io with SMTP id smtpd.web11.13809.1590157179291566993 for ; Fri, 22 May 2020 07:19:40 -0700 Authentication-Results: mx.groups.io; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=EjnfQeRN; spf=pass (domain: redhat.com, ip: 207.211.31.120, mailfrom: lersek@redhat.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590157178; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/y4xvsApOl0WOuRkADrjcLiY6r9mPElR8yq2xQbZJXQ=; b=EjnfQeRNmrUisODEIpzaL5Y4UZSuI95ZGtrdA2u3bGFK3d6sK77Uj7sAmO+6NBGWSko6uv Yw+MVnOs6BWBrXsIgzTItCIn8cXA2wBKy/tL19+13+yeV5qeUkSRzccnKrz20PngWfxpFh HTDCr2grWQlo1gEw6NrISSCPsQg74H4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-419-aGKUqLc9PkOAiRcBps7qAA-1; Fri, 22 May 2020 10:19:36 -0400 X-MC-Unique: aGKUqLc9PkOAiRcBps7qAA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CC2F3100CCC0; Fri, 22 May 2020 14:19:34 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com (ovpn-112-40.ams2.redhat.com [10.36.112.40]) by smtp.corp.redhat.com (Postfix) with ESMTP id 972145D9CD; Fri, 22 May 2020 14:19:32 +0000 (UTC) Subject: Re: [edk2-devel] [PATCH v8 18/46] OvmfPkg/VmgExitLib: Add support for WBINVD NAE events To: devel@edk2.groups.io, thomas.lendacky@amd.com Cc: Jordan Justen , Ard Biesheuvel , Michael D Kinney , Liming Gao , Eric Dong , Ray Ni , Brijesh Singh , Ard Biesheuvel References: From: "Laszlo Ersek" Message-ID: <67168bb4-9d20-0ca3-08c5-30bbd38d06d7@redhat.com> Date: Fri, 22 May 2020 16:19:31 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit On 05/19/20 23:50, Lendacky, Thomas wrote: > BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198 > > Under SEV-ES, a WBINVD intercept generates a #VC exception. VMGEXIT must be > used to allow the hypervisor to handle this intercept. > > Cc: Jordan Justen > Cc: Laszlo Ersek > Cc: Ard Biesheuvel > Signed-off-by: Tom Lendacky > --- > .../Library/VmgExitLib/X64/VmgExitVcHandler.c | 36 +++++++++++++++++++ > 1 file changed, 36 insertions(+) > > diff --git a/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c b/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c > index 50199845ceef..0cf26c052b32 100644 > --- a/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c > +++ b/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c > @@ -843,6 +843,38 @@ MmioExit ( > return Status; > } > > +/** > + Handle a WBINVD event. > + > + Use the VMGEXIT instruction to handle a WBINVD event. > + > + @param[in, out] Ghcb Pointer to the Guest-Hypervisor Communication > + Block > + @param[in, out] Regs x64 processor context > + @param[in] InstructionData Instruction parsing context > + > + @retval 0 Event handled successfully > + @retval Others New exception value to propagate > + > +**/ > +STATIC > +UINT64 > +WbinvdExit ( > + IN OUT GHCB *Ghcb, > + IN OUT EFI_SYSTEM_CONTEXT_X64 *Regs, > + IN SEV_ES_INSTRUCTION_DATA *InstructionData > + ) > +{ > + UINT64 Status; > + > + Status = VmgExit (Ghcb, SVM_EXIT_WBINVD, 0, 0); > + if (Status) { > + return Status; > + } > + > + return 0; (1) I'd simplify: return VmgExit (Ghcb, SVM_EXIT_WBINVD, 0, 0); unless you want to keep the Status variable (maybe for inserting DEBUG statements more easily, if needed). Even in that case: Status = VmgExit (Ghcb, SVM_EXIT_WBINVD, 0, 0); return Status; With either option adopted: Acked-by: Laszlo Ersek (The real wart I'm trying to address here is the evaluation of "Status" in a logical context, as usual.) Thanks, Laszlo > +} > + > /** > Handle an MSR event. > > @@ -1238,6 +1270,10 @@ VmgExitHandleVc ( > NaeExit = MsrExit; > break; > > + case SVM_EXIT_WBINVD: > + NaeExit = WbinvdExit; > + break; > + > case SVM_EXIT_NPF: > NaeExit = MmioExit; > break; >