From: Henry Wang <Henry.Wang@arm.com>
To: Vikram Garhwal <vikram.garhwal@amd.com>,
"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
Cc: "sstabellini@kernel.org" <sstabellini@kernel.org>,
"michal.orzel@amd.com" <michal.orzel@amd.com>,
Julien Grall <julien@xen.org>
Subject: RE: [XEN][PATCH v6 14/19] common/device_tree: Add rwlock for dt_host
Date: Thu, 4 May 2023 04:38:26 +0000 [thread overview]
Message-ID: <AS8PR08MB799196697F990D65F00163C2926D9@AS8PR08MB7991.eurprd08.prod.outlook.com> (raw)
In-Reply-To: <20230502233650.20121-15-vikram.garhwal@amd.com>
Hi Vikram,
> -----Original Message-----
> Subject: [XEN][PATCH v6 14/19] common/device_tree: Add rwlock for dt_host
>
> Dynamic programming ops will modify the dt_host and there might be other
> function which are browsing the dt_host at the same time. To avoid the race
> conditions, adding rwlock for browsing the dt_host during runtime.
While now I understand why you use rwlock instead of spinlock in this patch
since you explained it in replying my comment in v5 (Thanks!). I would still
suggest that you can add that kind of explanation in the commit message to
make the commit message clear to everyone that reading this patch.
>
> Signed-off-by: Vikram Garhwal <vikram.garhwal@amd.com>
> ---
> xen/common/device_tree.c | 4 ++++
> xen/drivers/passthrough/device_tree.c | 18 ++++++++++++++++++
> xen/include/xen/device_tree.h | 6 ++++++
> 3 files changed, 28 insertions(+)
>
[...]
> ret = iommu_add_dt_device(dev);
> if ( ret < 0 )
> @@ -310,6 +321,8 @@ int iommu_do_dt_domctl(struct xen_domctl *domctl,
> struct domain *d,
> printk(XENLOG_G_ERR "XEN_DOMCTL_assign_dt_device: assign
> \"%s\""
> " to dom%u failed (%d)\n",
> dt_node_full_name(dev), d->domain_id, ret);
> +
> + read_unlock(&dt_host->lock);
Since you added "read_unlock(&dt_host->lock);" before the final return,
i.e. "return ret", I don't think you need to add "read_unlock(&dt_host->lock);"
here before the break. Or am I missing something?
> break;
>
> case XEN_DOMCTL_deassign_device:
> @@ -328,11 +341,15 @@ int iommu_do_dt_domctl(struct xen_domctl
> *domctl, struct domain *d,
> break;
>
> ret = xsm_deassign_dtdevice(XSM_HOOK, d, dt_node_full_name(dev));
> +
Nit: Unnecessary blank line addition here.
Kind regards,
Henry
next prev parent reply other threads:[~2023-05-04 4:39 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-02 23:36 [XEN][PATCH v6 00/19] dynamic node programming using overlay dtbo Vikram Garhwal
2023-05-02 23:36 ` [XEN][PATCH v6 01/19] xen/arm/device: Remove __init from function type Vikram Garhwal
2023-05-02 23:36 ` [XEN][PATCH v6 02/19] common/device_tree: handle memory allocation failure in __unflatten_device_tree() Vikram Garhwal
2023-05-04 3:54 ` Henry Wang
2023-05-05 9:38 ` Michal Orzel
[not found] ` <f854bfc4-1f3c-19df-ba22-89c8859cfe6d@amd.com>
2023-06-01 6:58 ` Michal Orzel
2023-05-02 23:36 ` [XEN][PATCH v6 03/19] common/device_tree: change __unflatten_device_tree() type Vikram Garhwal
2023-05-04 4:02 ` Henry Wang
2023-05-02 23:36 ` [XEN][PATCH v6 04/19] common/device_tree.c: unflatten_device_tree() propagate errors Vikram Garhwal
2023-05-04 4:08 ` Henry Wang
2023-05-02 23:36 ` [XEN][PATCH v6 05/19] xen/arm: Add CONFIG_OVERLAY_DTB Vikram Garhwal
2023-05-04 4:11 ` Henry Wang
2023-05-09 10:54 ` Michal Orzel
2023-05-02 23:36 ` [XEN][PATCH v6 06/19] libfdt: Keep fdt functions after init for CONFIG_OVERLAY_DTB Vikram Garhwal
2023-05-02 23:36 ` [XEN][PATCH v6 07/19] libfdt: overlay: change overlay_get_target() Vikram Garhwal
2023-05-04 4:13 ` Henry Wang
2023-05-02 23:36 ` [XEN][PATCH v6 08/19] xen/device-tree: Add device_tree_find_node_by_path() to find nodes in device tree Vikram Garhwal
2023-05-04 4:23 ` Henry Wang
2023-05-04 5:56 ` unsubscribe Terry Yang
2023-05-09 11:29 ` [XEN][PATCH v6 08/19] xen/device-tree: Add device_tree_find_node_by_path() to find nodes in device tree Michal Orzel
2023-05-31 21:31 ` Vikram Garhwal
2023-06-01 2:02 ` Henry Wang
2023-05-02 23:36 ` [XEN][PATCH v6 09/19] xen/iommu: Move spin_lock from iommu_dt_device_is_assigned to caller Vikram Garhwal
2023-05-03 7:53 ` Jan Beulich
2023-05-02 23:36 ` [XEN][PATCH v6 10/19] xen/iommu: protect iommu_add_dt_device() with dtdevs_lock Vikram Garhwal
2023-05-02 23:36 ` [XEN][PATCH v6 11/19] xen/iommu: Introduce iommu_remove_dt_device() Vikram Garhwal
2023-05-03 7:56 ` Jan Beulich
2023-05-02 23:36 ` [XEN][PATCH v6 12/19] xen/smmu: Add remove_device callback for smmu_iommu ops Vikram Garhwal
2023-05-02 23:36 ` [XEN][PATCH v6 13/19] asm/smp.h: Fix circular dependency for device_tree.h and rwlock.h Vikram Garhwal
2023-05-02 23:36 ` [XEN][PATCH v6 14/19] common/device_tree: Add rwlock for dt_host Vikram Garhwal
2023-05-04 4:38 ` Henry Wang [this message]
2023-05-02 23:36 ` [XEN][PATCH v6 15/19] xen/arm: Implement device tree node removal functionalities Vikram Garhwal
2023-05-03 7:59 ` Jan Beulich
2023-05-03 8:02 ` Jan Beulich
2023-05-09 14:30 ` Michal Orzel
2023-05-09 14:52 ` Andrew Cooper
2023-05-02 23:36 ` [XEN][PATCH v6 16/19] xen/arm: Implement device tree node addition functionalities Vikram Garhwal
2023-05-10 10:18 ` Michal Orzel
2023-06-02 0:49 ` Vikram Garhwal
2023-05-02 23:36 ` [XEN][PATCH v6 17/19] tools/libs/ctrl: Implement new xc interfaces for dt overlay Vikram Garhwal
2023-05-18 16:01 ` Anthony PERARD
2023-06-02 0:49 ` Vikram Garhwal
2023-05-02 23:36 ` [XEN][PATCH v6 18/19] tools/libs/light: Implement new libxl functions for device tree overlay ops Vikram Garhwal
2023-05-18 16:01 ` Anthony PERARD
2023-05-02 23:36 ` [XEN][PATCH v6 19/19] tools/xl: Add new xl command overlay for device tree overlay support Vikram Garhwal
2023-05-18 16:01 ` Anthony PERARD
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