| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <6711909cd5d83_3f14294e@dwillia2-xfh.jf.intel.com.notmuch>
Date: Thu, 17 Oct 2024 15:33:00 -0700
From: Dan Williams <dan.j.williams@...el.com>
To: Huang Ying <ying.huang@...el.com>, Dan Williams
<dan.j.williams@...el.com>, Dave Jiang <dave.jiang@...el.com>
CC: <linux-cxl@...r.kernel.org>, <linux-kernel@...r.kernel.org>, Huang Ying
<ying.huang@...el.com>, Gregory Price <gourry@...rry.net>, Davidlohr Bueso
<dave@...olabs.net>, Jonathan Cameron <jonathan.cameron@...wei.com>, "Alison
Schofield" <alison.schofield@...el.com>, Vishal Verma
<vishal.l.verma@...el.com>, Ira Weiny <ira.weiny@...el.com>, Alejandro Lucero
<alucerop@....com>, Ben Cheatham <benjamin.cheatham@....com>
Subject: Re: [PATCH 4/5] cxl: Set type of region to that of the first endpoint
Huang Ying wrote:
> Current kernel hard-codes the type of region to type 3 expander now,
> because this is the only supported device type. As a preparation to
> support type 2 accelerators, the patch sets the type of region to that
> of the first endpoint. Then, the patch checks whether the type of
> region is same as the type of other endpoints of the region. Because
> what we really need is to make sure the type of all endpoints of a
> region is same. And, the patch lets expander/accelerator device
> drivers specify the target type of endpoint devices via struct
> cxl_dev_state.
>
> Signed-off-by: "Huang, Ying" <ying.huang@...el.com>
> Reviewed-by: Gregory Price <gourry@...rry.net>
> Cc: Dan Williams <dan.j.williams@...el.com>
> Cc: Davidlohr Bueso <dave@...olabs.net>
> Cc: Jonathan Cameron <jonathan.cameron@...wei.com>
> Cc: Dave Jiang <dave.jiang@...el.com>
> Cc: Alison Schofield <alison.schofield@...el.com>
> Cc: Vishal Verma <vishal.l.verma@...el.com>
> Cc: Ira Weiny <ira.weiny@...el.com>
> Cc: Alejandro Lucero <alucerop@....com>
> Cc: Ben Cheatham <benjamin.cheatham@....com>
> ---
> drivers/cxl/acpi.c | 1 -
> drivers/cxl/core/hdm.c | 28 +++++++++++++---------------
> drivers/cxl/core/port.c | 2 ++
> drivers/cxl/core/region.c | 13 +++++++------
> drivers/cxl/cxl.h | 1 +
> 5 files changed, 23 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
> index 21486e471305..29c2a44b122c 100644
> --- a/drivers/cxl/acpi.c
> +++ b/drivers/cxl/acpi.c
> @@ -382,7 +382,6 @@ static int __cxl_parse_cfmws(struct acpi_cedt_cfmws *cfmws,
>
> cxld = &cxlrd->cxlsd.cxld;
> cxld->flags = cfmws_to_decoder_flags(cfmws->restrictions);
> - cxld->target_type = CXL_DECODER_EXPANDER;
> cxld->hpa_range = (struct range) {
> .start = cfmws->base_hpa,
> .end = cfmws->base_hpa + cfmws->window_size - 1,
> diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
> index 478fb6691759..c9accf8be71f 100644
> --- a/drivers/cxl/core/hdm.c
> +++ b/drivers/cxl/core/hdm.c
> @@ -841,18 +841,25 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
> .end = base + size - 1,
> };
>
> + if (cxled) {
> + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
> + struct cxl_dev_state *cxlds = cxlmd->cxlds;
> +
> + if (cxlds->type == CXL_DEVTYPE_CLASSMEM)
> + cxld->target_type = CXL_DECODER_EXPANDER;
> + else
> + cxld->target_type = CXL_DECODER_ACCEL;
This looks broken there is no way to know the target type of the decoder
from the cxl_dev_state. An "accelerator" can have HDM and an "expander"
can have HDM-DB.
> + }
> +
> /* decoders are enabled if committed */
> if (committed) {
> cxld->flags |= CXL_DECODER_F_ENABLE;
> if (ctrl & CXL_HDM_DECODER0_CTRL_LOCK)
> cxld->flags |= CXL_DECODER_F_LOCK;
> - if (FIELD_GET(CXL_HDM_DECODER0_CTRL_HOSTONLY, ctrl)) {
> - cxld->target_type = CXL_DECODER_EXPANDER;
> + if (FIELD_GET(CXL_HDM_DECODER0_CTRL_HOSTONLY, ctrl))
> cxld->coherence = CXL_DECODER_HOSTONLYCOH;
> - } else {
> - cxld->target_type = CXL_DECODER_ACCEL;
> + else
> cxld->coherence = CXL_DECODER_DEVCOH;
> - }
>
> guard(rwsem_write)(&cxl_region_rwsem);
> if (cxld->id != cxl_num_decoders_committed(port)) {
> @@ -874,21 +881,12 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
> struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
> struct cxl_dev_state *cxlds = cxlmd->cxlds;
>
> - /*
> - * Default by devtype until a device arrives that needs
> - * more precision.
> - */
> - if (cxlds->type == CXL_DEVTYPE_CLASSMEM)
> - cxld->target_type = CXL_DECODER_EXPANDER;
> - else
> - cxld->target_type = CXL_DECODER_ACCEL;
> if (cxlds->coherence == CXL_DEVCOH_HOSTONLY)
> cxld->coherence = CXL_DECODER_HOSTONLYCOH;
> else
> cxld->coherence = CXL_DECODER_DEVCOH;
> } else {
> - /* To be overridden by region type/coherence at commit time */
> - cxld->target_type = CXL_DECODER_EXPANDER;
> + /* To be overridden by region coherence at commit time */
> cxld->coherence = CXL_DECODER_HOSTONLYCOH;
> }
>
> diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
> index 9ebbffcea26a..d1bc6aed6509 100644
> --- a/drivers/cxl/core/port.c
> +++ b/drivers/cxl/core/port.c
> @@ -139,6 +139,8 @@ static ssize_t target_type_show(struct device *dev,
> return sysfs_emit(buf, "accelerator\n");
> case CXL_DECODER_EXPANDER:
> return sysfs_emit(buf, "expander\n");
> + default:
> + break;
> }
> return -ENXIO;
> }
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index 21b877d8582f..d709738ada61 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -1926,7 +1926,10 @@ static int cxl_region_attach(struct cxl_region *cxlr,
> return -ENXIO;
> }
>
> - if (cxled->cxld.target_type != cxlr->type) {
> + /* Set the type of region to that of the first endpoint */
> + if (cxlr->type == CXL_DECODER_INVALID) {
> + cxlr->type = cxled->cxld.target_type;
> + } else if (cxled->cxld.target_type != cxlr->type) {
No, the type of the region is determined by the caller and should be
gated by the region capability. For type-2 region creation I doubt
userspace is going to be creating those vs the accelerator so this all
seems backwards to me.
Powered by blists - more mailing lists