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.web10.14466.1590159410178735455 for ; Fri, 22 May 2020 07:56:50 -0700 Authentication-Results: mx.groups.io; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=c/R1rrjy; 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=1590159409; 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=7CCu17NBnhKYxxSBs2rNn/N2fTlHlahj9EarJ6MRP3A=; b=c/R1rrjyaBdqDdVzvxSMt9LaQ55oiIwfUkVQU3y4isojOGRYReMpMajpXay/Mlngp0sCyt XgnxSs6UA1FuJYETHZCXVVAoLmQPXNp2JqM4ZvQFc4PJTURha2cZOJh2mWSanVtsybWfuz 7WZMo4sI1Ri7Ax6XnezdpsP+nuaNxWk= 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-405-vel0QdmVM1qDXqTtJmfGqg-1; Fri, 22 May 2020 10:56:47 -0400 X-MC-Unique: vel0QdmVM1qDXqTtJmfGqg-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 300A51005510; Fri, 22 May 2020 14:56:45 +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 153E05D9CC; Fri, 22 May 2020 14:56:42 +0000 (UTC) Subject: Re: [edk2-devel] [PATCH v8 25/46] OvmfPkg/VmgExitLib: Add support for MWAIT/MWAITX 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: Date: Fri, 22 May 2020 16:56:42 +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 MWAIT/MWAITX 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 9b7639069276..b028b20f255a 100644 > --- a/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c > +++ b/OvmfPkg/Library/VmgExitLib/X64/VmgExitVcHandler.c > @@ -843,6 +843,45 @@ MmioExit ( > return Status; > } > > +/** > + Handle a MWAIT event. > + > + Use the VMGEXIT instruction to handle a MWAIT 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 > +MwaitExit ( > + IN OUT GHCB *Ghcb, > + IN OUT EFI_SYSTEM_CONTEXT_X64 *Regs, > + IN SEV_ES_INSTRUCTION_DATA *InstructionData > + ) > +{ > + UINT64 Status; > + > + DecodeModRm (Regs, InstructionData); > + > + Ghcb->SaveArea.Rax = Regs->Rax; > + GhcbSetRegValid (Ghcb, GhcbRax); > + Ghcb->SaveArea.Rcx = Regs->Rcx; > + GhcbSetRegValid (Ghcb, GhcbRcx); > + > + Status = VmgExit (Ghcb, SVM_EXIT_MWAIT, 0, 0); > + if (Status) { > + return Status; > + } > + > + return 0; > +} > + (1) Please see my feedback under: [PATCH v8 18/46] OvmfPkg/VmgExitLib: Add support for WBINVD NAE events and pick the same approach here that you prefer there. With that: Acked-by: Laszlo Ersek Thanks Laszlo > /** > Handle a MONITOR event. > > @@ -1539,6 +1578,10 @@ VmgExitHandleVc ( > NaeExit = MonitorExit; > break; > > + case SVM_EXIT_MWAIT: > + NaeExit = MwaitExit; > + break; > + > case SVM_EXIT_NPF: > NaeExit = MmioExit; > break; >