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| author | Saurabh Sengar <ssengar@linux.microsoft.com> | 2024-03-30 11:51:57 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-11 15:55:53 +0300 |
| commit | e8c4bd6c6e6b7e7b416c42806981c2a81370001e (patch) | |
| tree | 3dd3fdd1ac0cab7040d84db5a1341bbe72d16fc6 | |
| parent | a36b69775fcaab42262f6dbf288ccb6d470158ae (diff) | |
| download | linux-e8c4bd6c6e6b7e7b416c42806981c2a81370001e.tar.xz | |
Drivers: hv: vmbus: Add utility function for querying ring size
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>
| -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 f6b1e710f805..76ac5185a01a 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -417,6 +417,11 @@ 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 6ef0557b4bff..7de9f90d3f95 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; |