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authorSaurabh Sengar <ssengar@linux.microsoft.com>2024-03-30 11:51:57 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-04-11 15:55:53 +0300
commite8c4bd6c6e6b7e7b416c42806981c2a81370001e (patch)
tree3dd3fdd1ac0cab7040d84db5a1341bbe72d16fc6 /drivers/hv
parenta36b69775fcaab42262f6dbf288ccb6d470158ae (diff)
downloadlinux-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>
Diffstat (limited to 'drivers/hv')
-rw-r--r--drivers/hv/channel_mgmt.c15
-rw-r--r--drivers/hv/hyperv_vmbus.h5
2 files changed, 17 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;