From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.81]) by mx.groups.io with SMTP id smtpd.web12.14341.1590158535597770262 for ; Fri, 22 May 2020 07:42:15 -0700 Authentication-Results: mx.groups.io; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=W2jRH66G; spf=pass (domain: redhat.com, ip: 207.211.31.81, mailfrom: lersek@redhat.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590158534; 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=7p6NzLhtPbaFHmnQ00GLiOai1pxNAGS0D37WG6miKzE=; b=W2jRH66GONQOnhGHNZFeH6xAwysWIZSWQJJbtWBYHQxI/d5GwrI0B5UjKuZnYUM4A0bb3u nqHfbz8khBDTp1QgPTllCEPrSQB3t+ZlPKtVSxxh80seZo4sjq4yxq088lsyoQ+Eu8XXpo iHJqzN6y+SuFlh78LAgs5m6oYC9JaN8= 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-237-f4UmgAN_P4S1oRjlBqn2UQ-1; Fri, 22 May 2020 10:42:11 -0400 X-MC-Unique: f4UmgAN_P4S1oRjlBqn2UQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 339DA8014D7; Fri, 22 May 2020 14:42:09 +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 EBD396247E; Fri, 22 May 2020 14:42:06 +0000 (UTC) Subject: Re: [edk2-devel] [PATCH v8 19/46] OvmfPkg/VmgExitLib: Add support for RDTSC 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: <675998211a44fb140d5847db486c8a644e0ec003.1589925074.git.thomas.lendacky@amd.com> From: "Laszlo Ersek" Message-ID: Date: Fri, 22 May 2020 16:42:05 +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: <675998211a44fb140d5847db486c8a644e0ec003.1589925074.git.thomas.lendacky@amd.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 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 RDTSC 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 | 43 +++++++++++++++++++ > 1 file changed, 43 insertions(+) > > diff --git a/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c b/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c > index 0cf26c052b32..3d2a9c6f9bc9 100644 > --- a/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c > +++ b/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c > @@ -1214,6 +1214,45 @@ CpuidExit ( > return 0; > } > > +/** > + Handle a RDTSC event. > + > + Use the VMGEXIT instruction to handle a RDTSC 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 > +RdtscExit ( > + IN OUT GHCB *Ghcb, > + IN OUT EFI_SYSTEM_CONTEXT_X64 *Regs, > + IN SEV_ES_INSTRUCTION_DATA *InstructionData > + ) > +{ > + UINT64 Status; > + > + Status = VmgExit (Ghcb, SVM_EXIT_RDTSC, 0, 0); > + if (Status) { (1) Please write (Status > 0) or (Status != 0) explicitly. With that: Acked-by: Laszlo Ersek Thanks, Laszlo > + return Status; > + } > + > + if (!GhcbIsRegValid (Ghcb, GhcbRax) || > + !GhcbIsRegValid (Ghcb, GhcbRdx)) { > + return UnsupportedExit (Ghcb, Regs, InstructionData); > + } > + Regs->Rax = Ghcb->SaveArea.Rax; > + Regs->Rdx = Ghcb->SaveArea.Rdx; > + > + return 0; > +} > + > /** > Handle a #VC exception. > > @@ -1258,6 +1297,10 @@ VmgExitHandleVc ( > > ExitCode = Regs->ExceptionData; > switch (ExitCode) { > + case SVM_EXIT_RDTSC: > + NaeExit = RdtscExit; > + break; > + > case SVM_EXIT_CPUID: > NaeExit = CpuidExit; > break; >