From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B7BE5EBE; Mon, 17 Mar 2025 13:36:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742218590; cv=none; b=PX7z7UIEEjquxfXm9J+RBJDJx58ron1eEWLeOgv2LPXTnvZJRmDUHt1ryhysCrN27qOy7+py48imsiXoYB9WGGhsA3Wj7LbiHbNFfr5pafzPd00ylMwu9sdFsOiATczEu2yzp2EkzydFJslSvtP+8DbCQw5ZManOkGkbYFkLo6I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742218590; c=relaxed/simple; bh=RseWPBUm8jLujRzewLcvZ2BXS/0vv+m6EhD8xlnMnmA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ITmnWR2y4+0Rsn3IGuwS/yxHS0hJzcDbpXLQ2Unq0Bn9nKAvyPtXIr3NNvVzQYc4w/QbiX+eKxjvuaXxnTuYHCJH3UsAINBQcYNPXduVLvbcki8ell0AnFdSvN7cbPwLTHWtyCtV1W+QVTxTshCakE1hOO93GmNgdmn859cS3HA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=E8U12ekB; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="E8U12ekB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A95E9C4CEF1; Mon, 17 Mar 2025 13:36:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742218590; bh=RseWPBUm8jLujRzewLcvZ2BXS/0vv+m6EhD8xlnMnmA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=E8U12ekBW2a7Bin/kQfOEIUbrByUMBYu+5OR0NzDEUTrA43lTA0rFWJKazYJ+Ex5M 3o+/YJzUibV3yfvbeKe2NMEcNCFUikI2RTYD5W9k1K8FBYGO6bQsEjw//qw4WfN1Gi a/QvOf+9Bt/GOxYsnTdWuYccqB1mNu1WgiSNnQAlLkteaLCDb0Je37u7Z7z6fffxz8 qYSFsSjzWr3IauwfmC7xfu1sJmOTrJKOwCD24AWzsDWP9F09Stdrcx6YyoN/9Mf0mu uSUn9LE5JwCCtOmpkAPFkhYiukkDncrdt9j2xhDepIXGFLxTh/g8kDu2X9x+Ii9YRl qYadrHPbPCt9A== Date: Mon, 17 Mar 2025 15:36:26 +0200 From: Jarkko Sakkinen To: Tom Lendacky Cc: Stefano Garzarella , Peter Huewe , Jason Gunthorpe , x86@kernel.org, linux-kernel@vger.kernel.org, Borislav Petkov , linux-integrity@vger.kernel.org, Dov Murik , Dionna Glaze , linux-coco@lists.linux.dev, James Bottomley , Claudio Carvalho , Ingo Molnar , "H. Peter Anvin" , Thomas Gleixner , Dave Hansen , Joerg Roedel Subject: Re: [PATCH v3 1/4] x86/sev: add SVSM vTPM probe/send_command functions Message-ID: References: <20250311094225.35129-1-sgarzare@redhat.com> <20250311094225.35129-2-sgarzare@redhat.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Fri, Mar 14, 2025 at 10:27:07AM -0500, Tom Lendacky wrote: > On 3/11/25 04:42, Stefano Garzarella wrote: > > Add two new functions to probe and send commands to the SVSM vTPM. > > They leverage the two calls defined by the AMD SVSM specification [1] > > for the vTPM protocol: SVSM_VTPM_QUERY and SVSM_VTPM_CMD. > > > > Expose these functions to be used by other modules such as a tpm > > driver. > > > > [1] "Secure VM Service Module for SEV-SNP Guests" > > Publication # 58019 Revision: 1.00 > > > > Co-developed-by: James Bottomley > > Signed-off-by: James Bottomley > > Co-developed-by: Claudio Carvalho > > Signed-off-by: Claudio Carvalho > > Signed-off-by: Stefano Garzarella > > One minor nit below, otherwise: > > Reviewed-by: Tom Lendacky > > > --- > > v3: > > - removed link to the spec because those URLs are unstable [Borislav] > > - squashed "x86/sev: add SVSM call macros for the vTPM protocol" patch > > in this one [Borislav] > > - slimmed down snp_svsm_vtpm_probe() [Borislav] > > - removed features check and any print related [Tom] > > --- > > arch/x86/include/asm/sev.h | 7 +++++++ > > arch/x86/coco/sev/core.c | 31 +++++++++++++++++++++++++++++++ > > 2 files changed, 38 insertions(+) > > > > diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h > > index ba7999f66abe..09471d058ce5 100644 > > --- a/arch/x86/include/asm/sev.h > > +++ b/arch/x86/include/asm/sev.h > > @@ -384,6 +384,10 @@ struct svsm_call { > > #define SVSM_ATTEST_SERVICES 0 > > #define SVSM_ATTEST_SINGLE_SERVICE 1 > > > > +#define SVSM_VTPM_CALL(x) ((2ULL << 32) | (x)) > > +#define SVSM_VTPM_QUERY 0 > > +#define SVSM_VTPM_CMD 1 > > + > > #ifdef CONFIG_AMD_MEM_ENCRYPT > > > > extern u8 snp_vmpl; > > @@ -481,6 +485,9 @@ void snp_msg_free(struct snp_msg_desc *mdesc); > > int snp_send_guest_request(struct snp_msg_desc *mdesc, struct snp_guest_req *req, > > struct snp_guest_request_ioctl *rio); > > > > +bool snp_svsm_vtpm_probe(void); > > +int snp_svsm_vtpm_send_command(u8 *buffer); > > + > > void __init snp_secure_tsc_prepare(void); > > void __init snp_secure_tsc_init(void); > > > > diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c > > index 96c7bc698e6b..2166bdff88b7 100644 > > --- a/arch/x86/coco/sev/core.c > > +++ b/arch/x86/coco/sev/core.c > > @@ -2628,6 +2628,37 @@ static int snp_issue_guest_request(struct snp_guest_req *req, struct snp_req_dat > > return ret; > > } > > > > +bool snp_svsm_vtpm_probe(void) > > +{ > > + struct svsm_call call = {}; > > + > > + /* The vTPM device is available only if a SVSM is present */ > > + if (!snp_vmpl) > > + return false; > > + > > + call.caa = svsm_get_caa(); > > + call.rax = SVSM_VTPM_CALL(SVSM_VTPM_QUERY); > > + > > + if (svsm_perform_call_protocol(&call)) > > + return false; > > + > > + /* Check platform commands contains TPM_SEND_COMMAND - platform command 8 */ > > + return (call.rcx_out & BIT_ULL(8)) == BIT_ULL(8); > > It's a bool function, so this could simplified to just: > > return call.rcx_out & BIT_ULL(8); Or perhaps even just "call.rcx_out & 0x100". I don't think BIT_ULL() here brings much additional clarity or anything useful... > > Thanks, > Tom BR, Jarkko