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,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 4747AC49EA3 for ; Mon, 28 Jun 2021 14:28:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 315EE61C9A for ; Mon, 28 Jun 2021 14:28:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234226AbhF1O3V (ORCPT ); Mon, 28 Jun 2021 10:29:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:55032 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233594AbhF1OXV (ORCPT ); Mon, 28 Jun 2021 10:23:21 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 876B061C93; Mon, 28 Jun 2021 14:20:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624890016; bh=GTUkTwvqEfSZdLkhjYwvkEu+T1WS+lZaUwzDLgB4YW4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=poH2/NbIrGRN1DNhl9ygqnCJ0yhOljfVRa2UNF/CTSRLB+SQJuxNcojsPG3tBuXjY WNDfOSkl41DMiqjSxXgiJTuBR0MGFdIGRK4yPd2XwKhegvh5J4SNaaf210bgsO8NN8 4XLG81AnMUOQOyVfFch80e47jZ36K0nDsr1NavIVWbp31nZt5ts+JtA/u5Iu95KzVc RLMnqqDV4a3WsmgdEyIVDzP28kQ/o+ef7e0STKojpf6B1P6vu9SxHWkAOVeWS1Xv4J zLocN1DVBLLBzi2Ayou4ajFFqQMv4n2IeoFr4T+2NI3+2Jf/1fez2fFyEKp477psuJ DeKe1Q3078sxw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Alper Gun , Peter Gonda , Marc Orr , Paolo Bonzini , Greg Kroah-Hartman Subject: [PATCH 5.12 101/110] KVM: SVM: Call SEV Guest Decommission if ASID binding fails Date: Mon, 28 Jun 2021 10:18:19 -0400 Message-Id: <20210628141828.31757-102-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210628141828.31757-1-sashal@kernel.org> References: <20210628141828.31757-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.12.14-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.12.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.12.14-rc1 X-KernelTest-Deadline: 2021-06-30T14:18+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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/sev.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index dbc6214d69de..8f3b438f6fd3 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -143,9 +143,25 @@ static void sev_asid_free(int asid) mutex_unlock(&sev_bitmap_lock); } -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) @@ -165,15 +181,7 @@ static void sev_unbind_asid(struct kvm *kvm, unsigned int handle) 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 int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp) @@ -303,8 +311,10 @@ static int sev_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp) /* 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; -- 2.30.2