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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 C2B94C10F11 for ; Wed, 24 Apr 2019 17:52:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9497721902 for ; Wed, 24 Apr 2019 17:52:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390905AbfDXRw2 (ORCPT ); Wed, 24 Apr 2019 13:52:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58366 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390570AbfDXR17 (ORCPT ); Wed, 24 Apr 2019 13:27:59 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id F3102309D04C; Wed, 24 Apr 2019 17:27:58 +0000 (UTC) Received: from [10.36.116.17] (ovpn-116-17.ams2.redhat.com [10.36.116.17]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B4C9161B99; Wed, 24 Apr 2019 17:27:53 +0000 (UTC) Subject: Re: [PATCH v2 09/19] iommu/vt-d: Enlightened PASID allocation To: Jacob Pan , iommu@lists.linux-foundation.org, LKML , Joerg Roedel , David Woodhouse , Alex Williamson , Jean-Philippe Brucker Cc: Yi Liu , "Tian, Kevin" , Raj Ashok , Christoph Hellwig , Lu Baolu , Andriy Shevchenko References: <1556062279-64135-1-git-send-email-jacob.jun.pan@linux.intel.com> <1556062279-64135-10-git-send-email-jacob.jun.pan@linux.intel.com> From: Auger Eric Message-ID: <143adac1-d58b-dde6-593b-74ea71da73c8@redhat.com> Date: Wed, 24 Apr 2019 19:27:52 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <1556062279-64135-10-git-send-email-jacob.jun.pan@linux.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Wed, 24 Apr 2019 17:27:59 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jacob, On 4/24/19 1:31 AM, Jacob Pan wrote: > From: Lu Baolu > > If Intel IOMMU runs in caching mode, a.k.a. virtual IOMMU, the > IOMMU driver should rely on the emulation software to allocate > and free PASID IDs. Do we make the decision depending on the CM or depending on the VCCAP_REG? VCCAP_REG description says: If Set, software must use Virtual Command Register interface to allocate and free PASIDs. The Intel vt-d spec revision 3.0 defines a > register set to support this. This includes a capability register, > a virtual command register and a virtual response register. Refer > to section 10.4.42, 10.4.43, 10.4.44 for more information. > > This patch adds the enlightened PASID allocation/free interfaces For mu curiosity why is it called "enlightened"? > via the virtual command register. > > Cc: Ashok Raj > Cc: Jacob Pan > Cc: Kevin Tian > Signed-off-by: Liu Yi L > Signed-off-by: Lu Baolu > --- > drivers/iommu/intel-pasid.c | 70 +++++++++++++++++++++++++++++++++++++++++++++ > drivers/iommu/intel-pasid.h | 13 ++++++++- > include/linux/intel-iommu.h | 2 ++ > 3 files changed, 84 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/intel-pasid.c b/drivers/iommu/intel-pasid.c > index 03b12d2..5b1d3be 100644 > --- a/drivers/iommu/intel-pasid.c > +++ b/drivers/iommu/intel-pasid.c > @@ -63,6 +63,76 @@ void *intel_pasid_lookup_id(int pasid) > return p; > } > > +int vcmd_alloc_pasid(struct intel_iommu *iommu, unsigned int *pasid) > +{ > + u64 res; > + u64 cap; > + u8 err_code; > + unsigned long flags; > + int ret = 0; > + > + if (!ecap_vcs(iommu->ecap)) { > + pr_warn("IOMMU: %s: Hardware doesn't support virtual command\n", > + iommu->name); nit: other pr_* messages don't have the "IOMMU: %s:" prefix. > + return -ENODEV; > + } > + > + cap = dmar_readq(iommu->reg + DMAR_VCCAP_REG); > + if (!(cap & DMA_VCS_PAS)) { > + pr_warn("IOMMU: %s: Emulation software doesn't support PASID allocation\n", > + iommu->name); > + return -ENODEV; > + } > + > + raw_spin_lock_irqsave(&iommu->register_lock, flags); > + dmar_writeq(iommu->reg + DMAR_VCMD_REG, VCMD_CMD_ALLOC); > + IOMMU_WAIT_OP(iommu, DMAR_VCRSP_REG, dmar_readq, > + !(res & VCMD_VRSP_IP), res); > + raw_spin_unlock_irqrestore(&iommu->register_lock, flags); > + > + err_code = VCMD_VRSP_EC(res); > + switch (err_code) { > + case VCMD_VRSP_EC_SUCCESS: > + *pasid = VCMD_VRSP_RESULE(res); > + break; > + case VCMD_VRSP_EC_UNAVAIL: > + pr_info("IOMMU: %s: No PASID available\n", iommu->name); > + ret = -ENOMEM; > + break; > + default: > + ret = -ENODEV; > + pr_warn("IOMMU: %s: Unkonwn error code %d\n", unknown > + iommu->name, err_code); > + } > + > + return ret; > +} > + > +void vcmd_free_pasid(struct intel_iommu *iommu, unsigned int pasid) > +{ > + u64 res; > + u8 err_code; > + unsigned long flags; Shall we check as well the cap is set? > + > + raw_spin_lock_irqsave(&iommu->register_lock, flags); > + dmar_writeq(iommu->reg + DMAR_VCMD_REG, (pasid << 8) | VCMD_CMD_FREE); > + IOMMU_WAIT_OP(iommu, DMAR_VCRSP_REG, dmar_readq, > + !(res & VCMD_VRSP_IP), res); > + raw_spin_unlock_irqrestore(&iommu->register_lock, flags); > + > + err_code = VCMD_VRSP_EC(res); > + switch (err_code) { > + case VCMD_VRSP_EC_SUCCESS: > + break; > + case VCMD_VRSP_EC_INVAL: > + pr_info("IOMMU: %s: Invalid PASID\n", iommu->name); > + break; > + default: > + pr_warn("IOMMU: %s: Unkonwn error code %d\n", unknown > + iommu->name, err_code); > + } > +} > + > /* > * Per device pasid table management: > */ > diff --git a/drivers/iommu/intel-pasid.h b/drivers/iommu/intel-pasid.h > index 23537b3..0999dfe 100644 > --- a/drivers/iommu/intel-pasid.h > +++ b/drivers/iommu/intel-pasid.h > @@ -19,6 +19,16 @@ > #define PASID_PDE_SHIFT 6 > #define MAX_NR_PASID_BITS 20 > > +/* Virtual command interface for enlightened pasid management. */ > +#define VCMD_CMD_ALLOC 0x1 > +#define VCMD_CMD_FREE 0x2 > +#define VCMD_VRSP_IP 0x1 > +#define VCMD_VRSP_EC(e) (((e) >> 1) & 0x3) s/EC/SC? for Status Code and below > +#define VCMD_VRSP_EC_SUCCESS 0 > +#define VCMD_VRSP_EC_UNAVAIL 1 nit: _NO_VALID_PASID > +#define VCMD_VRSP_EC_INVAL 1 nit: _INVALID_PASID > +#define VCMD_VRSP_RESULE(e) (((e) >> 8) & 0xfffff) nit: s/RESULE/RSLT? > + > /* > * Domain ID reserved for pasid entries programmed for first-level > * only and pass-through transfer modes. > @@ -69,5 +79,6 @@ int intel_pasid_setup_pass_through(struct intel_iommu *iommu, > struct device *dev, int pasid); > void intel_pasid_tear_down_entry(struct intel_iommu *iommu, > struct device *dev, int pasid); > - > +int vcmd_alloc_pasid(struct intel_iommu *iommu, unsigned int *pasid); > +void vcmd_free_pasid(struct intel_iommu *iommu, unsigned int pasid); > #endif /* __INTEL_PASID_H */ > diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h > index 6925a18..bff907b 100644 > --- a/include/linux/intel-iommu.h > +++ b/include/linux/intel-iommu.h > @@ -173,6 +173,7 @@ > #define ecap_smpwc(e) (((e) >> 48) & 0x1) > #define ecap_flts(e) (((e) >> 47) & 0x1) > #define ecap_slts(e) (((e) >> 46) & 0x1) > +#define ecap_vcs(e) (((e) >> 44) & 0x1) > #define ecap_smts(e) (((e) >> 43) & 0x1) > #define ecap_dit(e) ((e >> 41) & 0x1) > #define ecap_pasid(e) ((e >> 40) & 0x1) > @@ -289,6 +290,7 @@ > > /* PRS_REG */ > #define DMA_PRS_PPR ((u32)1) > +#define DMA_VCS_PAS ((u64)1) > > #define IOMMU_WAIT_OP(iommu, offset, op, cond, sts) \ > do { \ > Thanks Eric