From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C86FEC07E9E for ; Fri, 9 Jul 2021 13:22:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B3998613C3 for ; Fri, 9 Jul 2021 13:22:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232739AbhGINYu (ORCPT ); Fri, 9 Jul 2021 09:24:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:56494 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232588AbhGINYn (ORCPT ); Fri, 9 Jul 2021 09:24:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 52D5E611B0; Fri, 9 Jul 2021 13:21:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1625836919; bh=oHQ1gm4eQNg1mKCYKYKsR+xSheM7O4CGggSF8u4Jz4c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jsLIAn2tiRyh/ASITMjhCy+QgrcaU9USDN1Ox0A/hDJfH6tythiHVzxzq2q78bTx8 cxv79hojGPHYWh192+EGMsfHUPn8X7hmxTA/RSS21jhK1u3GnlnB4ReBrvNHH0ar8R tlRnqhYRC2rFx2ea40l2JZM9AZibTSndwdZRPB/M= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Gonda , Alper Gun , Marc Orr , Paolo Bonzini Subject: [PATCH 4.19 30/34] KVM: SVM: Call SEV Guest Decommission if ASID binding fails Date: Fri, 9 Jul 2021 15:20:46 +0200 Message-Id: <20210709131701.044926822@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210709131644.969303901@linuxfoundation.org> References: <20210709131644.969303901@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alper Gun commit 934002cd660b035b926438244b4294e647507e13 upstream. Send SEV_CMD_DECOMMISSION command to PSP firmware if ASID binding fails. If a failure happens after a successful LAUNCH_START command, a decommission command should be executed. Otherwise, guest context will be unfreed inside the AMD SP. After the firmware will not have memory to allocate more SEV guest context, LAUNCH_START command will begin to fail with SEV_RET_RESOURCE_LIMIT error. The existing code calls decommission inside sev_unbind_asid, but it is not called if a failure happens before guest activation succeeds. If sev_bind_asid fails, decommission is never called. PSP firmware has a limit for the number of guests. If sev_asid_binding fails many times, PSP firmware will not have resources to create another guest context. Cc: stable@vger.kernel.org Fixes: 59414c989220 ("KVM: SVM: Add support for KVM_SEV_LAUNCH_START command") Reported-by: Peter Gonda Signed-off-by: Alper Gun Reviewed-by: Marc Orr Signed-off-by: Paolo Bonzini Message-Id: <20210610174604.2554090-1-alpergun@google.com> Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/svm.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1791,9 +1791,25 @@ static void sev_asid_free(struct kvm *kv __sev_asid_free(sev->asid); } -static void sev_unbind_asid(struct kvm *kvm, unsigned int handle) +static void sev_decommission(unsigned int handle) { struct sev_data_decommission *decommission; + + if (!handle) + return; + + decommission = kzalloc(sizeof(*decommission), GFP_KERNEL); + if (!decommission) + return; + + decommission->handle = handle; + sev_guest_decommission(decommission, NULL); + + kfree(decommission); +} + +static void sev_unbind_asid(struct kvm *kvm, unsigned int handle) +{ struct sev_data_deactivate *data; if (!handle) @@ -1811,15 +1827,7 @@ static void sev_unbind_asid(struct kvm * sev_guest_df_flush(NULL); kfree(data); - decommission = kzalloc(sizeof(*decommission), GFP_KERNEL); - if (!decommission) - return; - - /* decommission handle */ - decommission->handle = handle; - sev_guest_decommission(decommission, NULL); - - kfree(decommission); + sev_decommission(handle); } static struct page **sev_pin_memory(struct kvm *kvm, unsigned long uaddr, @@ -6469,8 +6477,10 @@ static int sev_launch_start(struct kvm * /* Bind ASID to this guest */ ret = sev_bind_asid(kvm, start->handle, error); - if (ret) + if (ret) { + sev_decommission(start->handle); goto e_free_session; + } /* return handle to userspace */ params.handle = start->handle;