diff options
| author | Saurabh Sengar <ssengar@linux.microsoft.com> | 2024-03-30 11:51:57 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-07-06 12:00:09 +0300 |
| commit | ebba6cc0781c00566ab7a11d9307cd093a787881 (patch) | |
| tree | 2e220df0050a1d5c2e6ff90c944ae11d332e5cfb | |
| parent | 3bc5abf8e75a3d2cce8e0a1bfe2e4cb38df1a93a (diff) | |
| download | linux-ebba6cc0781c00566ab7a11d9307cd093a787881.tar.xz | |
Drivers: hv: vmbus: Add utility function for querying ring size
[ Upstream commit e8c4bd6c6e6b7e7b416c42806981c2a81370001e ]
Add a function to query for the preferred ring buffer size of VMBus
device. This will allow the drivers (eg. UIO) to allocate the most
optimized ring buffer size for devices.
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Link: https://lore.kernel.org/r/1711788723-8593-2-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 0315fef2aff9 ("uio_hv_generic: Align ring size to system page")
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/hv/channel_mgmt.c | 15 | ||||
| -rw-r--r-- | drivers/hv/hyperv_vmbus.h | 5 | ||||
| -rw-r--r-- | include/linux/hyperv.h | 2 |
3 files changed, 19 insertions, 3 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index 2f4d09ce027a..3c6011a48dab 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -120,7 +120,9 @@ const struct vmbus_device vmbus_devs[] = { }, /* File copy */ - { .dev_type = HV_FCOPY, + /* fcopy always uses 16KB ring buffer size and is working well for last many years */ + { .pref_ring_size = 0x4000, + .dev_type = HV_FCOPY, HV_FCOPY_GUID, .perf_device = false, .allowed_in_isolated = false, @@ -140,12 +142,19 @@ const struct vmbus_device vmbus_devs[] = { .allowed_in_isolated = false, }, - /* Unknown GUID */ - { .dev_type = HV_UNKNOWN, + /* + * Unknown GUID + * 64 KB ring buffer + 4 KB header should be sufficient size for any Hyper-V device apart + * from HV_NIC and HV_SCSI. This case avoid the fallback for unknown devices to allocate + * much bigger (2 MB) of ring size. + */ + { .pref_ring_size = 0x11000, + .dev_type = HV_UNKNOWN, .perf_device = false, .allowed_in_isolated = false, }, }; +EXPORT_SYMBOL_GPL(vmbus_devs); static const struct { guid_t guid; diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 787b15068641..34b60009114a 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -419,6 +419,11 @@ static inline bool hv_is_perf_channel(struct vmbus_channel *channel) return vmbus_devs[channel->device_id].perf_device; } +static inline size_t hv_dev_ring_size(struct vmbus_channel *channel) +{ + return vmbus_devs[channel->device_id].pref_ring_size; +} + static inline bool hv_is_allocated_cpu(unsigned int cpu) { struct vmbus_channel *channel, *sc; diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index b5bf5315ca8c..e4ad9760774e 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -820,6 +820,8 @@ struct vmbus_requestor { #define VMBUS_RQST_RESET (U64_MAX - 3) struct vmbus_device { + /* preferred ring buffer size in KB, 0 means no preferred size for this device */ + size_t pref_ring_size; u16 dev_type; guid_t guid; bool perf_device; |