From patchwork Wed Feb 9 16:44:15 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Varad Gautam X-Patchwork-Id: 12740478 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA232C433F5 for ; Wed, 9 Feb 2022 16:44:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237353AbiBIQob (ORCPT ); Wed, 9 Feb 2022 11:44:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237019AbiBIQo1 (ORCPT ); Wed, 9 Feb 2022 11:44:27 -0500 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A014C0612BE for ; Wed, 9 Feb 2022 08:44:30 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 18400210F1; Wed, 9 Feb 2022 16:44:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1644425069; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qBTlha0CjsrMHt1g/w4Ous7VYPcZPCWrBblEAg0loqM=; b=Cd1dLj9HUJGJAcFYer7Adm69rbAWXIuxc5aFQGLRk2+/a96YFcKI5qL7ZBygKTML8nIOaR CuhAhrsI5SRNHdDTytmA7mgsVtiq8L454sTvj+XJUnrZye7CTzM46Dlt3RzMSQF4nupGTI AqQUKMN6zZ9dI6FRDap48fLrHDN7lr4= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 57AB313D4F; Wed, 9 Feb 2022 16:44:28 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id UBYTE2zvA2LfNgAAMHmgww (envelope-from ); Wed, 09 Feb 2022 16:44:28 +0000 From: Varad Gautam To: kvm@vger.kernel.org, pbonzini@redhat.com, drjones@redhat.com Cc: marcorr@google.com, zxwang42@gmail.com, erdemaktas@google.com, rientjes@google.com, seanjc@google.com, brijesh.singh@amd.com, Thomas.Lendacky@amd.com, jroedel@suse.de, bp@suse.de, varad.gautam@suse.com Subject: [kvm-unit-tests PATCH v2 05/10] x86: AMD SEV-ES: Prepare for #VC processing Date: Wed, 9 Feb 2022 17:44:15 +0100 Message-Id: <20220209164420.8894-6-varad.gautam@suse.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220209164420.8894-1-varad.gautam@suse.com> References: <20220209164420.8894-1-varad.gautam@suse.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Lay the groundwork for processing #VC exceptions in the handler. This includes clearing the GHCB, decoding the insn that triggered this #VC, and continuing execution after the exception has been processed. Signed-off-by: Varad Gautam --- lib/x86/amd_sev_vc.c | 78 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) diff --git a/lib/x86/amd_sev_vc.c b/lib/x86/amd_sev_vc.c index 8226121..142f2cd 100644 --- a/lib/x86/amd_sev_vc.c +++ b/lib/x86/amd_sev_vc.c @@ -1,14 +1,92 @@ /* SPDX-License-Identifier: GPL-2.0 */ #include "amd_sev.h" +#include "svm.h" extern phys_addr_t ghcb_addr; +static void vc_ghcb_invalidate(struct ghcb *ghcb) +{ + ghcb->save.sw_exit_code = 0; + memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap)); +} + +static bool vc_decoding_needed(unsigned long exit_code) +{ + /* Exceptions don't require to decode the instruction */ + return !(exit_code >= SVM_EXIT_EXCP_BASE && + exit_code <= SVM_EXIT_LAST_EXCP); +} + +static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt) +{ + unsigned char buffer[MAX_INSN_SIZE]; + int ret; + + memcpy(buffer, (unsigned char *)ctxt->regs->rip, MAX_INSN_SIZE); + + ret = insn_decode(&ctxt->insn, buffer, MAX_INSN_SIZE, INSN_MODE_64); + if (ret < 0) + return ES_DECODE_FAILED; + else + return ES_OK; +} + +static enum es_result vc_init_em_ctxt(struct es_em_ctxt *ctxt, + struct ex_regs *regs, + unsigned long exit_code) +{ + enum es_result ret = ES_OK; + + memset(ctxt, 0, sizeof(*ctxt)); + ctxt->regs = regs; + + if (vc_decoding_needed(exit_code)) + ret = vc_decode_insn(ctxt); + + return ret; +} + +static void vc_finish_insn(struct es_em_ctxt *ctxt) +{ + ctxt->regs->rip += ctxt->insn.length; +} + +static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt, + struct ghcb *ghcb, + unsigned long exit_code) +{ + enum es_result result; + + switch (exit_code) { + default: + /* + * Unexpected #VC exception + */ + result = ES_UNSUPPORTED; + } + + return result; +} + void handle_sev_es_vc(struct ex_regs *regs) { struct ghcb *ghcb = (struct ghcb *) ghcb_addr; + unsigned long exit_code = regs->error_code; + struct es_em_ctxt ctxt; + enum es_result result; + if (!ghcb) { /* TODO: kill guest */ return; } + + vc_ghcb_invalidate(ghcb); + result = vc_init_em_ctxt(&ctxt, regs, exit_code); + if (result == ES_OK) + result = vc_handle_exitcode(&ctxt, ghcb, exit_code); + if (result == ES_OK) + vc_finish_insn(&ctxt); + + return; }