From patchwork Mon Jan 23 16:51:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeremi Piotrowski X-Patchwork-Id: 645679 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 A85E5C38142 for ; Mon, 23 Jan 2023 16:52:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233478AbjAWQwU (ORCPT ); Mon, 23 Jan 2023 11:52:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58878 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233482AbjAWQwS (ORCPT ); Mon, 23 Jan 2023 11:52:18 -0500 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 011872DE4E; Mon, 23 Jan 2023 08:52:05 -0800 (PST) Received: from vm02.corp.microsoft.com (unknown [167.220.196.155]) by linux.microsoft.com (Postfix) with ESMTPSA id AF73C20E2C03; Mon, 23 Jan 2023 08:52:03 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com AF73C20E2C03 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1674492725; bh=pp03YGGSPJklBjx3IO05F7RCBMZonuTyZ6VVAlGDVMI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bf5Vv0NXstLz3CaB5zygZxlKKX1GLIaTAcak1iUhWQBViY71Nnd7FvGy44lWis+Cx yKUi4GMz12SiI7eGx9b84+aOmcOTJroBQii8CKRc/JHOin4MPgBIdgqaCxaMjE0Zxl Yk7wCM8XCpISMrsxdGxPtfce3yJuYvr5+Up4s2Ok= From: Jeremi Piotrowski To: linux-kernel@vger.kernel.org Cc: Jeremi Piotrowski , Wei Liu , Dexuan Cui , Tianyu Lan , Michael Kelley , linux-hyperv@vger.kernel.org, Brijesh Singh , Michael Roth , Ashish Kalra , Tom Lendacky , linux-crypto@vger.kernel.org Subject: [RFC PATCH v1 6/6] crypto: ccp - Introduce quirk to always reclaim pages after SEV-legacy commands Date: Mon, 23 Jan 2023 16:51:28 +0000 Message-Id: <20230123165128.28185-7-jpiotrowski@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230123165128.28185-1-jpiotrowski@linux.microsoft.com> References: <20230123165128.28185-1-jpiotrowski@linux.microsoft.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Hyper-V, the rmp_mark_pages_shared() call after a SEV_PLATFORM_STATUS fails with return code 2 (FAIL_PERMISSION) due to the page having the immutable bit set in the RMP (SNP has been initialized). The comment above this spot mentions that firmware automatically clears the immutable bit, but I can't find any mention of this behavior in the SNP Firmware ABI Spec. Introduce a quirk to always attempt the page reclaim and set it for the platform PSP. It would be possible to make this behavior unconditional as the firmware spec defines that page reclaim results in success if the page does not have the immutable bit set. Signed-off-by: Jeremi Piotrowski --- drivers/crypto/ccp/sev-dev.c | 6 +++++- drivers/crypto/ccp/sp-dev.h | 4 ++++ drivers/crypto/ccp/sp-platform.c | 1 + 3 files changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index 6c4fdcaed72b..4719c0cafa28 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -658,8 +658,12 @@ static int __snp_cmd_buf_copy(int cmd, void *cmd_buf, bool to_fw, int fw_err) * no not need to reclaim the page. */ if (from_fw && sev_legacy_cmd_buf_writable(cmd)) { - if (rmp_mark_pages_shared(__pa(cmd_buf), 1)) + if (psp_master->vdata->quirks & PSP_QUIRK_ALWAYS_RECLAIM) { + if (snp_reclaim_pages(__pa(cmd_buf), 1, true)) + return -EFAULT; + } else if (rmp_mark_pages_shared(__pa(cmd_buf), 1)) { return -EFAULT; + } /* No need to go further if firmware failed to execute command. */ if (fw_err) diff --git a/drivers/crypto/ccp/sp-dev.h b/drivers/crypto/ccp/sp-dev.h index 083e57652c7b..6fb065a7d1fd 100644 --- a/drivers/crypto/ccp/sp-dev.h +++ b/drivers/crypto/ccp/sp-dev.h @@ -28,6 +28,9 @@ #define CACHE_NONE 0x00 #define CACHE_WB_NO_ALLOC 0xb7 +/* PSP requires a reclaim after every firmware command */ +#define PSP_QUIRK_ALWAYS_RECLAIM BIT(0) + /* Structure to hold CCP device data */ struct ccp_device; struct ccp_vdata { @@ -59,6 +62,7 @@ struct psp_vdata { unsigned int feature_reg; unsigned int inten_reg; unsigned int intsts_reg; + unsigned int quirks; }; /* Structure to hold SP device data */ diff --git a/drivers/crypto/ccp/sp-platform.c b/drivers/crypto/ccp/sp-platform.c index d56b34255b97..cae3e7e8f289 100644 --- a/drivers/crypto/ccp/sp-platform.c +++ b/drivers/crypto/ccp/sp-platform.c @@ -43,6 +43,7 @@ static struct psp_vdata psp_platform = { .feature_reg = -1, .inten_reg = -1, .intsts_reg = -1, + .quirks = PSP_QUIRK_ALWAYS_RECLAIM, }; #endif