From patchwork Mon Feb 13 10:34:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeremi Piotrowski X-Patchwork-Id: 653565 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 412ABC636D7 for ; Mon, 13 Feb 2023 10:34:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230480AbjBMKew (ORCPT ); Mon, 13 Feb 2023 05:34:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231168AbjBMKeq (ORCPT ); Mon, 13 Feb 2023 05:34:46 -0500 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 51A861259F; Mon, 13 Feb 2023 02:34:41 -0800 (PST) Received: from vm02.corp.microsoft.com (unknown [167.220.196.155]) by linux.microsoft.com (Postfix) with ESMTPSA id DECB920C8B77; Mon, 13 Feb 2023 02:34:38 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com DECB920C8B77 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1676284480; bh=xy4n0PsUoqcPr+Y27mq9kcRn+aDYjUAZLw0FdyzM2VM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CpP2X4BqcHytwtx7qnNrvxPPHrAXu2hHh1Wa7HYW5nAQo+xEO2DaM1YDITuJBBzSu 41WPUDBqw1nTbnH1BqA9pv3TQmFBaXE2svX+DNk9SdfBSvcXGo9cgdBgVR+0OI3fht 8ubwil6ix/Hz8s4QxF5VEtXGYsjG0Ccyq39FqXyA= 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 v2 6/7] crypto: ccp - Introduce quirk to always reclaim pages after SEV-legacy commands Date: Mon, 13 Feb 2023 10:34:01 +0000 Message-Id: <20230213103402.1189285-7-jpiotrowski@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230213103402.1189285-1-jpiotrowski@linux.microsoft.com> References: <20230213103402.1189285-1-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 c05f1fa82ff4..d50f274462d4 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 { const unsigned int feature_reg; const unsigned int inten_reg; const unsigned int intsts_reg; + const 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 1926efbc7b32..937448f6391a 100644 --- a/drivers/crypto/ccp/sp-platform.c +++ b/drivers/crypto/ccp/sp-platform.c @@ -103,6 +103,7 @@ static void sp_platform_fill_vdata(struct sp_dev_vdata *vdata, .feature_reg = pdata->feature_reg, .inten_reg = pdata->irq_en_reg, .intsts_reg = pdata->irq_st_reg, + .quirks = PSP_QUIRK_ALWAYS_RECLAIM, }; memcpy(sev, &sevtmp, sizeof(*sev));