From: Andrea Parri <parri.andrea@gmail.com>
To: linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org
Cc: "K . Y . Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Sasha Levin <sashal@kernel.org>,
Michael Kelley <mikelley@microsoft.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Dexuan Cui <decui@microsoft.com>, Wei Liu <wei.liu@kernel.org>,
Andrea Parri <parri.andrea@gmail.com>
Subject: [PATCH v3 1/3] Drivers: hv: vmbus: Introduce table of VMBus protocol versions
Date: Tue, 15 Oct 2019 13:46:44 +0200 [thread overview]
Message-ID: <20191015114646.15354-2-parri.andrea@gmail.com> (raw)
In-Reply-To: <20191015114646.15354-1-parri.andrea@gmail.com>
The technique used to get the next VMBus version seems increasisly
clumsy as the number of VMBus versions increases. Performance is
not a concern since this is only done once during system boot; it's
just that we'll end up with more lines of code than is really needed.
As an alternative, introduce a table with the version numbers listed
in order (from the most recent to the oldest). vmbus_connect() loops
through the versions listed in the table until it gets an accepted
connection or gets to the end of the table (invalid version).
Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
---
drivers/hv/connection.c | 50 +++++++++++++++--------------------------
drivers/hv/vmbus_drv.c | 3 +--
include/linux/hyperv.h | 4 ----
3 files changed, 19 insertions(+), 38 deletions(-)
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 6e4c015783ffc..8dc48f53c1ac4 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -40,29 +40,17 @@ EXPORT_SYMBOL_GPL(vmbus_connection);
__u32 vmbus_proto_version;
EXPORT_SYMBOL_GPL(vmbus_proto_version);
-static __u32 vmbus_get_next_version(__u32 current_version)
-{
- switch (current_version) {
- case (VERSION_WIN7):
- return VERSION_WS2008;
-
- case (VERSION_WIN8):
- return VERSION_WIN7;
-
- case (VERSION_WIN8_1):
- return VERSION_WIN8;
-
- case (VERSION_WIN10):
- return VERSION_WIN8_1;
-
- case (VERSION_WIN10_V5):
- return VERSION_WIN10;
-
- case (VERSION_WS2008):
- default:
- return VERSION_INVAL;
- }
-}
+/*
+ * Table of VMBus versions listed from newest to oldest.
+ */
+static __u32 vmbus_versions[] = {
+ VERSION_WIN10_V5,
+ VERSION_WIN10,
+ VERSION_WIN8_1,
+ VERSION_WIN8,
+ VERSION_WIN7,
+ VERSION_WS2008
+};
int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
{
@@ -169,8 +157,8 @@ int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
*/
int vmbus_connect(void)
{
- int ret = 0;
struct vmbus_channel_msginfo *msginfo = NULL;
+ int i, ret = 0;
__u32 version;
/* Initialize the vmbus connection */
@@ -244,21 +232,19 @@ int vmbus_connect(void)
* version.
*/
- version = VERSION_CURRENT;
+ for (i = 0; ; i++) {
+ if (i == ARRAY_SIZE(vmbus_versions))
+ goto cleanup;
+
+ version = vmbus_versions[i];
- do {
ret = vmbus_negotiate_version(msginfo, version);
if (ret == -ETIMEDOUT)
goto cleanup;
if (vmbus_connection.conn_state == CONNECTED)
break;
-
- version = vmbus_get_next_version(version);
- } while (version != VERSION_INVAL);
-
- if (version == VERSION_INVAL)
- goto cleanup;
+ }
vmbus_proto_version = version;
pr_info("Vmbus version:%d.%d\n",
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 53a60c81e220d..0ac874faf7209 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -2220,8 +2220,7 @@ static int vmbus_bus_resume(struct device *dev)
* We only use the 'vmbus_proto_version', which was in use before
* hibernation, to re-negotiate with the host.
*/
- if (vmbus_proto_version == VERSION_INVAL ||
- vmbus_proto_version == 0) {
+ if (!vmbus_proto_version) {
pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version);
return -EINVAL;
}
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index b4a017093b697..c08b62dbd151f 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -192,10 +192,6 @@ static inline u32 hv_get_avail_to_write_percent(
#define VERSION_WIN10 ((4 << 16) | (0))
#define VERSION_WIN10_V5 ((5 << 16) | (0))
-#define VERSION_INVAL -1
-
-#define VERSION_CURRENT VERSION_WIN10_V5
-
/* Make maximum size of pipe payload of 16K */
#define MAX_PIPE_DATA_PAYLOAD (sizeof(u8) * 16384)
--
2.23.0
next prev parent reply other threads:[~2019-10-15 11:47 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-15 11:46 [PATCH v3 0/3] Drivers: hv: vmbus: Miscellaneous improvements Andrea Parri
2019-10-15 11:46 ` Andrea Parri [this message]
2019-10-15 13:08 ` [PATCH v3 1/3] Drivers: hv: vmbus: Introduce table of VMBus protocol versions Michael Kelley
2019-10-15 11:46 ` [PATCH v3 2/3] Drivers: hv: vmbus: Enable VMBus protocol versions 4.1, 5.1 and 5.2 Andrea Parri
2019-10-15 13:12 ` Michael Kelley
2019-10-15 11:46 ` [PATCH v3 3/3] Drivers: hv: vmbus: Add module parameter to cap the VMBus version Andrea Parri
2019-10-15 13:15 ` Michael Kelley
2019-10-15 14:26 ` [PATCH v3 0/3] Drivers: hv: vmbus: Miscellaneous improvements Wei Liu
2019-10-28 16:26 ` Sasha Levin
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