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[83.52.54.50]) by smtp.gmail.com with ESMTPSA id o6sm2966838wrm.76.2020.09.03.05.28.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Sep 2020 05:28:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599136127; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=aOcjV7su5QwStC1VAK815NSfg5qEBVvoHtC3IGwZAQM=; b=dRGrU0xSR+coUb3qpegtU2hYs7uOScU9mSxmlfuF+I48D7tVv0jApxHR/mcPiDz//0rtHM RqV1zynEXZ1i0Y2twxWpPpY9cikrEf9N6zybAsONgQ/Gv5wxeZSfPIcMGJfESAQLWjJQ6a WtZWdUWb1vklHRkXM718JQRt0iNTlMc= X-MC-Unique: Ro-ZUWYwOGKkb67WjuB38w-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=aOcjV7su5QwStC1VAK815NSfg5qEBVvoHtC3IGwZAQM=; b=CbqNaNVy9GbwBruoLw8qrGOG7Ig+vVaJn5f1AF2+WdpOofvZHQIq2gJkOmF9Cin0zz Pea9PVuNqZ0wQ1IrFebze9WNz+sQBQq3lVK42SHxeVp7dJajUJVZxDIetp7kL7UR03mX zn9VvCE3oAJeVoOEKBXcqzAkjTTgV/wJs6r4euat2aDD5huoNEigJKJFo9qhgU04JBND Swx+UAQvfXlteaAZgqwNwlIS6Y7B1Ly6BcLYOjjIVMEFdDZiz/pLzTyoAMYpsA0giXoO qxOJVuNVDTEG8CmPeCsVwlb9FtpMtW0p83C3Uo3fU4JC7LLU1/IilipIrIOA+ah7Uv6A wg9w== X-Gm-Message-State: AOAM531EtDFRqMKk4FpGjo+gCyPehwMKF4yfpV6Aa3Ytwf27DgzTiYOP XN08xrANvSv0xpItl98ZcFg5qkefoccrW+6ktj8PEjxVE3KhJswseE1lO9sPxDEjZz+MdBACpUk mTmrFrXaiXA0v/g== X-Received: by 2002:a5d:574c:: with SMTP id q12mr2194100wrw.253.1599136124630; Thu, 03 Sep 2020 05:28:44 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyEpS27EsHSq1Iv/j/QMP8BSqyIEFn+6TH/JW5kRISOmgmT/ihYefQc4XEonpVfSN2ctoQPPA== X-Received: by 2002:a5d:574c:: with SMTP id q12mr2194068wrw.253.1599136124366; Thu, 03 Sep 2020 05:28:44 -0700 (PDT) From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, Klaus Jensen , Fam Zheng , Max Reitz , Keith Busch , Kevin Wolf , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Stefan Hajnoczi , Stefano Garzarella Subject: [PATCH v7 08/15] block/nvme: Use union of NvmeIdCtrl / NvmeIdNs structures Date: Thu, 3 Sep 2020 14:27:56 +0200 Message-Id: <20200903122803.405265-9-philmd@redhat.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200903122803.405265-1-philmd@redhat.com> References: <20200903122803.405265-1-philmd@redhat.com> MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=philmd@redhat.com X-Mimecast-Spam-Score: 0.002 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="utf-8"; text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @redhat.com) We allocate an unique chunk of memory then use it for two different structures. By using an union, we make it clear the data is overlapping (and we can remove the casts). Suggested-by: Stefan Hajnoczi Reviewed-by: Stefan Hajnoczi Reviewed-by: Stefano Garzarella Signed-off-by: Philippe Mathieu-Daud=C3=A9 --- block/nvme.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) diff --git a/block/nvme.c b/block/nvme.c index 0992f2fb579..b0d55ecfb25 100644 --- a/block/nvme.c +++ b/block/nvme.c @@ -508,9 +508,10 @@ static int nvme_cmd_sync(BlockDriverState *bs, NVMeQue= uePair *q, static void nvme_identify(BlockDriverState *bs, int namespace, Error **err= p) { BDRVNVMeState *s =3D bs->opaque; - NvmeIdCtrl *idctrl; - NvmeIdNs *idns; - uint8_t *id; + union { + NvmeIdCtrl ctrl; + NvmeIdNs ns; + } *id; NvmeLBAF *lbaf; uint16_t oncs; int r; @@ -520,14 +521,12 @@ static void nvme_identify(BlockDriverState *bs, int n= amespace, Error **errp) .cdw10 =3D cpu_to_le32(0x1), }; =20 - id =3D qemu_try_blockalign0(bs, sizeof(NvmeIdCtrl)); + id =3D qemu_try_blockalign0(bs, sizeof(*id)); if (!id) { error_setg(errp, "Cannot allocate buffer for identify response"); goto out; } - idctrl =3D (NvmeIdCtrl *)id; - idns =3D (NvmeIdNs *)id; - r =3D qemu_vfio_dma_map(s->vfio, id, sizeof(NvmeIdCtrl), true, &iova); + r =3D qemu_vfio_dma_map(s->vfio, id, sizeof(*id), true, &iova); if (r) { error_setg(errp, "Cannot map buffer for DMA"); goto out; @@ -539,22 +538,22 @@ static void nvme_identify(BlockDriverState *bs, int n= amespace, Error **errp) goto out; } =20 - if (le32_to_cpu(idctrl->nn) < namespace) { + if (le32_to_cpu(id->ctrl.nn) < namespace) { error_setg(errp, "Invalid namespace"); goto out; } - s->write_cache_supported =3D le32_to_cpu(idctrl->vwc) & 0x1; - s->max_transfer =3D (idctrl->mdts ? 1 << idctrl->mdts : 0) * s->page_s= ize; + s->write_cache_supported =3D le32_to_cpu(id->ctrl.vwc) & 0x1; + s->max_transfer =3D (id->ctrl.mdts ? 1 << id->ctrl.mdts : 0) * s->page= _size; /* For now the page list buffer per command is one page, to hold at mo= st * s->page_size / sizeof(uint64_t) entries. */ s->max_transfer =3D MIN_NON_ZERO(s->max_transfer, s->page_size / sizeof(uint64_t) * s->page_size); =20 - oncs =3D le16_to_cpu(idctrl->oncs); + oncs =3D le16_to_cpu(id->ctrl.oncs); s->supports_write_zeroes =3D !!(oncs & NVME_ONCS_WRITE_ZEROES); s->supports_discard =3D !!(oncs & NVME_ONCS_DSM); =20 - memset(id, 0, 4096); + memset(id, 0, sizeof(*id)); cmd.cdw10 =3D 0; cmd.nsid =3D cpu_to_le32(namespace); if (nvme_cmd_sync(bs, s->queues[INDEX_ADMIN], &cmd)) { @@ -562,11 +561,11 @@ static void nvme_identify(BlockDriverState *bs, int n= amespace, Error **errp) goto out; } =20 - s->nsze =3D le64_to_cpu(idns->nsze); - lbaf =3D &idns->lbaf[NVME_ID_NS_FLBAS_INDEX(idns->flbas)]; + s->nsze =3D le64_to_cpu(id->ns.nsze); + lbaf =3D &id->ns.lbaf[NVME_ID_NS_FLBAS_INDEX(id->ns.flbas)]; =20 - if (NVME_ID_NS_DLFEAT_WRITE_ZEROES(idns->dlfeat) && - NVME_ID_NS_DLFEAT_READ_BEHAVIOR(idns->dlfeat) =3D=3D + if (NVME_ID_NS_DLFEAT_WRITE_ZEROES(id->ns.dlfeat) && + NVME_ID_NS_DLFEAT_READ_BEHAVIOR(id->ns.dlfeat) =3D=3D NVME_ID_NS_DLFEAT_READ_BEHAVIOR_ZEROES) { bs->supported_write_flags |=3D BDRV_REQ_MAY_UNMAP; } --=20 2.26.2