* [PATCH v2 0/3] Drivers: hv: vmbus: Miscellaneous improvements
@ 2019-10-10 15:45 Andrea Parri
2019-10-10 15:45 ` [PATCH v2 1/3] Drivers: hv: vmbus: Introduce table of VMBus protocol versions Andrea Parri
` (2 more replies)
0 siblings, 3 replies; 8+ messages in thread
From: Andrea Parri @ 2019-10-10 15:45 UTC (permalink / raw)
To: linux-kernel, linux-hyperv, netdev
Cc: K . Y . Srinivasan, Haiyang Zhang, Stephen Hemminger,
Sasha Levin, David S . Miller, Michael Kelley, Vitaly Kuznetsov,
Dexuan Cui, Andrea Parri
Hi all,
The patchset:
- refactors the VMBus negotiation code by introducing the table of
VMBus protocol versions (patch 1/3),
- enables VMBus protocol version 4.1, 5.1 and 5.2 (patch 2/3),
- introduces a module parameter to cap the VMBus protocol versions
which a guest can negotiate with the hypervisor (patch 3/3).
Thanks,
Andrea
---
Changes since v1 ([1]):
- remove the VERSION_INVAL macro (Vitaly Kuznetsov and Dexuan Cui)
- make the table of VMBus protocol versions static (Dexuan Cui)
- enable VMBus protocol version 4.1 (Michael Kelley)
- introduce module parameter to cap the VMBus version (Dexuan Cui)
[1] https://lkml.kernel.org/r/20191007163115.26197-1-parri.andrea@gmail.com
Andrea Parri (3):
Drivers: hv: vmbus: Introduce table of VMBus protocol versions
Drivers: hv: vmbus: Enable VMBus protocol versions 4.1, 5.1 and 5.2
Drivers: hv: vmbus: Add module parameter to cap the VMBus version
drivers/hv/connection.c | 68 ++++++++++++++++----------------
drivers/hv/vmbus_drv.c | 3 +-
drivers/net/hyperv/netvsc.c | 6 +--
include/linux/hyperv.h | 12 +++---
net/vmw_vsock/hyperv_transport.c | 4 +-
5 files changed, 48 insertions(+), 45 deletions(-)
--
2.23.0
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v2 1/3] Drivers: hv: vmbus: Introduce table of VMBus protocol versions
2019-10-10 15:45 [PATCH v2 0/3] Drivers: hv: vmbus: Miscellaneous improvements Andrea Parri
@ 2019-10-10 15:45 ` Andrea Parri
2019-10-12 13:47 ` Michael Kelley
2019-10-10 15:45 ` [PATCH v2 2/3] Drivers: hv: vmbus: Enable VMBus protocol versions 4.1, 5.1 and 5.2 Andrea Parri
2019-10-10 15:46 ` [PATCH v2 3/3] Drivers: hv: vmbus: Add module parameter to cap the VMBus version Andrea Parri
2 siblings, 1 reply; 8+ messages in thread
From: Andrea Parri @ 2019-10-10 15:45 UTC (permalink / raw)
To: linux-kernel, linux-hyperv, netdev
Cc: K . Y . Srinivasan, Haiyang Zhang, Stephen Hemminger,
Sasha Levin, David S . Miller, Michael Kelley, Vitaly Kuznetsov,
Dexuan Cui, Andrea Parri
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 | 46 ++++++++++++++---------------------------
drivers/hv/vmbus_drv.c | 3 +--
include/linux/hyperv.h | 4 ----
3 files changed, 17 insertions(+), 36 deletions(-)
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 6e4c015783ffc..b1f805426e6b4 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 */
@@ -244,20 +232,18 @@ int vmbus_connect(void)
* version.
*/
- version = VERSION_CURRENT;
+ for (i = 0; i < ARRAY_SIZE(vmbus_versions); i++) {
+ 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)
+ if (vmbus_connection.conn_state != CONNECTED)
goto cleanup;
vmbus_proto_version = version;
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 391f0b225c9ae..a0cd65ab9a950 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -2215,8 +2215,7 @@ 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
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v2 2/3] Drivers: hv: vmbus: Enable VMBus protocol versions 4.1, 5.1 and 5.2
2019-10-10 15:45 [PATCH v2 0/3] Drivers: hv: vmbus: Miscellaneous improvements Andrea Parri
2019-10-10 15:45 ` [PATCH v2 1/3] Drivers: hv: vmbus: Introduce table of VMBus protocol versions Andrea Parri
@ 2019-10-10 15:45 ` Andrea Parri
2019-10-12 13:34 ` Michael Kelley
2019-10-10 15:46 ` [PATCH v2 3/3] Drivers: hv: vmbus: Add module parameter to cap the VMBus version Andrea Parri
2 siblings, 1 reply; 8+ messages in thread
From: Andrea Parri @ 2019-10-10 15:45 UTC (permalink / raw)
To: linux-kernel, linux-hyperv, netdev
Cc: K . Y . Srinivasan, Haiyang Zhang, Stephen Hemminger,
Sasha Levin, David S . Miller, Michael Kelley, Vitaly Kuznetsov,
Dexuan Cui, Andrea Parri
Hyper-V has added VMBus protocol versions 5.1 and 5.2 in recent release
versions. Allow Linux guests to negotiate these new protocol versions
on versions of Hyper-V that support them. While on this, also allow
guests to negotiate the VMBus protocol version 4.1 (which was missing).
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
---
drivers/hv/connection.c | 15 +++++++++------
drivers/net/hyperv/netvsc.c | 6 +++---
include/linux/hyperv.h | 8 +++++++-
net/vmw_vsock/hyperv_transport.c | 4 ++--
4 files changed, 21 insertions(+), 12 deletions(-)
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index b1f805426e6b4..2f6961ac8c996 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -44,8 +44,11 @@ EXPORT_SYMBOL_GPL(vmbus_proto_version);
* Table of VMBus versions listed from newest to oldest.
*/
static __u32 vmbus_versions[] = {
+ VERSION_WIN10_V5_2,
+ VERSION_WIN10_V5_1,
VERSION_WIN10_V5,
- VERSION_WIN10,
+ VERSION_WIN10_V4_1,
+ VERSION_WIN10_V4,
VERSION_WIN8_1,
VERSION_WIN8,
VERSION_WIN7,
@@ -68,12 +71,12 @@ int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
msg->vmbus_version_requested = version;
/*
- * VMBus protocol 5.0 (VERSION_WIN10_V5) requires that we must use
- * VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate Contact Message,
+ * VMBus protocol 5.0 (VERSION_WIN10_V5) and higher require that we must
+ * use VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate Contact Message,
* and for subsequent messages, we must use the Message Connection ID
* field in the host-returned Version Response Message. And, with
- * VERSION_WIN10_V5, we don't use msg->interrupt_page, but we tell
- * the host explicitly that we still use VMBUS_MESSAGE_SINT(2) for
+ * VERSION_WIN10_V5 and higher, we don't use msg->interrupt_page, but we
+ * tell the host explicitly that we still use VMBUS_MESSAGE_SINT(2) for
* compatibility.
*
* On old hosts, we should always use VMBUS_MESSAGE_CONNECTION_ID (1).
@@ -399,7 +402,7 @@ int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep)
case HV_STATUS_INVALID_CONNECTION_ID:
/*
* See vmbus_negotiate_version(): VMBus protocol 5.0
- * requires that we must use
+ * and higher require that we must use
* VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate
* Contact message, but on old hosts that only
* support VMBus protocol 4.0 or lower, here we get
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index d22a36fc7a7c6..d4c1a776b314a 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -624,11 +624,11 @@ void netvsc_device_remove(struct hv_device *device)
* receive buffer GPADL. Do the same for send buffer.
*/
netvsc_revoke_recv_buf(device, net_device, ndev);
- if (vmbus_proto_version < VERSION_WIN10)
+ if (vmbus_proto_version < VERSION_WIN10_V4)
netvsc_teardown_recv_gpadl(device, net_device, ndev);
netvsc_revoke_send_buf(device, net_device, ndev);
- if (vmbus_proto_version < VERSION_WIN10)
+ if (vmbus_proto_version < VERSION_WIN10_V4)
netvsc_teardown_send_gpadl(device, net_device, ndev);
RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
@@ -650,7 +650,7 @@ void netvsc_device_remove(struct hv_device *device)
* If host is Win2016 or higher then we do the GPADL tear down
* here after VMBus is closed.
*/
- if (vmbus_proto_version >= VERSION_WIN10) {
+ if (vmbus_proto_version >= VERSION_WIN10_V4) {
netvsc_teardown_recv_gpadl(device, net_device, ndev);
netvsc_teardown_send_gpadl(device, net_device, ndev);
}
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index c08b62dbd151f..a4f80e30b0207 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -182,15 +182,21 @@ static inline u32 hv_get_avail_to_write_percent(
* 2 . 4 (Windows 8)
* 3 . 0 (Windows 8 R2)
* 4 . 0 (Windows 10)
+ * 4 . 1 (Windows 10 RS3)
* 5 . 0 (Newer Windows 10)
+ * 5 . 1 (Windows 10 RS4)
+ * 5 . 2 (Windows Server 2019, RS5)
*/
#define VERSION_WS2008 ((0 << 16) | (13))
#define VERSION_WIN7 ((1 << 16) | (1))
#define VERSION_WIN8 ((2 << 16) | (4))
#define VERSION_WIN8_1 ((3 << 16) | (0))
-#define VERSION_WIN10 ((4 << 16) | (0))
+#define VERSION_WIN10_V4 ((4 << 16) | (0))
+#define VERSION_WIN10_V4_1 ((4 << 16) | (1))
#define VERSION_WIN10_V5 ((5 << 16) | (0))
+#define VERSION_WIN10_V5_1 ((5 << 16) | (1))
+#define VERSION_WIN10_V5_2 ((5 << 16) | (2))
/* Make maximum size of pipe payload of 16K */
#define MAX_PIPE_DATA_PAYLOAD (sizeof(u8) * 16384)
diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index c443db7af8d4a..cb0dbae4de14a 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -14,7 +14,7 @@
#include <net/sock.h>
#include <net/af_vsock.h>
-/* Older (VMBUS version 'VERSION_WIN10' or before) Windows hosts have some
+/* Older (VMBUS version 'VERSION_WIN10_V4' or before) Windows hosts have some
* stricter requirements on the hv_sock ring buffer size of six 4K pages. Newer
* hosts don't have this limitation; but, keep the defaults the same for compat.
*/
@@ -955,7 +955,7 @@ static int __init hvs_init(void)
{
int ret;
- if (vmbus_proto_version < VERSION_WIN10)
+ if (vmbus_proto_version < VERSION_WIN10_V4)
return -ENODEV;
ret = vmbus_driver_register(&hvs_drv);
--
2.23.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH v2 3/3] Drivers: hv: vmbus: Add module parameter to cap the VMBus version
2019-10-10 15:45 [PATCH v2 0/3] Drivers: hv: vmbus: Miscellaneous improvements Andrea Parri
2019-10-10 15:45 ` [PATCH v2 1/3] Drivers: hv: vmbus: Introduce table of VMBus protocol versions Andrea Parri
2019-10-10 15:45 ` [PATCH v2 2/3] Drivers: hv: vmbus: Enable VMBus protocol versions 4.1, 5.1 and 5.2 Andrea Parri
@ 2019-10-10 15:46 ` Andrea Parri
2 siblings, 0 replies; 8+ messages in thread
From: Andrea Parri @ 2019-10-10 15:46 UTC (permalink / raw)
To: linux-kernel, linux-hyperv, netdev
Cc: K . Y . Srinivasan, Haiyang Zhang, Stephen Hemminger,
Sasha Levin, David S . Miller, Michael Kelley, Vitaly Kuznetsov,
Dexuan Cui, Andrea Parri
Currently, Linux guests negotiate the VMBus version with Hyper-V
and use the highest available VMBus version they can connect to.
This has some drawbacks: by using the highest available version,
certain code paths are never executed and can not be tested when
the guest runs on the newest host.
Add the module parameter "max_version", to upper-bound the VMBus
versions guests can negotiate.
Suggested-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
---
drivers/hv/connection.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 2f6961ac8c996..f60d7330ff3fd 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -14,6 +14,7 @@
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/mm.h>
+#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/hyperv.h>
@@ -55,6 +56,16 @@ static __u32 vmbus_versions[] = {
VERSION_WS2008
};
+/*
+ * Maximal VMBus protocol version guests can negotiate. Useful to cap the
+ * VMBus version for testing and debugging purpose.
+ */
+static uint max_version = VERSION_WIN10_V5_2;
+
+module_param(max_version, uint, S_IRUGO);
+MODULE_PARM_DESC(max_version,
+ "Maximal VMBus protocol version which can be negotiated");
+
int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
{
int ret = 0;
@@ -237,6 +248,8 @@ int vmbus_connect(void)
for (i = 0; i < ARRAY_SIZE(vmbus_versions); i++) {
version = vmbus_versions[i];
+ if (version > max_version)
+ continue;
ret = vmbus_negotiate_version(msginfo, version);
if (ret == -ETIMEDOUT)
--
2.23.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
* RE: [PATCH v2 2/3] Drivers: hv: vmbus: Enable VMBus protocol versions 4.1, 5.1 and 5.2
2019-10-10 15:45 ` [PATCH v2 2/3] Drivers: hv: vmbus: Enable VMBus protocol versions 4.1, 5.1 and 5.2 Andrea Parri
@ 2019-10-12 13:34 ` Michael Kelley
2019-10-14 10:09 ` Andrea Parri
0 siblings, 1 reply; 8+ messages in thread
From: Michael Kelley @ 2019-10-12 13:34 UTC (permalink / raw)
To: Andrea Parri, linux-kernel, linux-hyperv, netdev
Cc: KY Srinivasan, Haiyang Zhang, Stephen Hemminger, Sasha Levin,
David S . Miller, vkuznets, Dexuan Cui
From: Andrea Parri <parri.andrea@gmail.com> Sent: Thursday, October 10, 2019 8:46 AM
>
> Hyper-V has added VMBus protocol versions 5.1 and 5.2 in recent release
> versions. Allow Linux guests to negotiate these new protocol versions
> on versions of Hyper-V that support them. While on this, also allow
> guests to negotiate the VMBus protocol version 4.1 (which was missing).
>
> Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
> ---
> drivers/hv/connection.c | 15 +++++++++------
> drivers/net/hyperv/netvsc.c | 6 +++---
> include/linux/hyperv.h | 8 +++++++-
> net/vmw_vsock/hyperv_transport.c | 4 ++--
> 4 files changed, 21 insertions(+), 12 deletions(-)
>
> diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
> index c08b62dbd151f..a4f80e30b0207 100644
> --- a/include/linux/hyperv.h
> +++ b/include/linux/hyperv.h
> @@ -182,15 +182,21 @@ static inline u32 hv_get_avail_to_write_percent(
> * 2 . 4 (Windows 8)
> * 3 . 0 (Windows 8 R2)
> * 4 . 0 (Windows 10)
> + * 4 . 1 (Windows 10 RS3)
> * 5 . 0 (Newer Windows 10)
> + * 5 . 1 (Windows 10 RS4)
> + * 5 . 2 (Windows Server 2019, RS5)
> */
>
> #define VERSION_WS2008 ((0 << 16) | (13))
> #define VERSION_WIN7 ((1 << 16) | (1))
> #define VERSION_WIN8 ((2 << 16) | (4))
> #define VERSION_WIN8_1 ((3 << 16) | (0))
> -#define VERSION_WIN10 ((4 << 16) | (0))
> +#define VERSION_WIN10_V4 ((4 << 16) | (0))
I would recommend not changing the symbol name for version 4.0.
The change makes it more consistent with the later VERSION_WIN10_*
symbols, but it doesn't fundamentally add any clarity and I'm not sure
it's worth the churn in the other files that have to be touched. It's a
judgment call, and that's just my input.
> +#define VERSION_WIN10_V4_1 ((4 << 16) | (1))
> #define VERSION_WIN10_V5 ((5 << 16) | (0))
> +#define VERSION_WIN10_V5_1 ((5 << 16) | (1))
> +#define VERSION_WIN10_V5_2 ((5 << 16) | (2))
>
Michael
^ permalink raw reply [flat|nested] 8+ messages in thread
* RE: [PATCH v2 1/3] Drivers: hv: vmbus: Introduce table of VMBus protocol versions
2019-10-10 15:45 ` [PATCH v2 1/3] Drivers: hv: vmbus: Introduce table of VMBus protocol versions Andrea Parri
@ 2019-10-12 13:47 ` Michael Kelley
2019-10-14 9:52 ` Andrea Parri
0 siblings, 1 reply; 8+ messages in thread
From: Michael Kelley @ 2019-10-12 13:47 UTC (permalink / raw)
To: Andrea Parri, linux-kernel, linux-hyperv, netdev
Cc: KY Srinivasan, Haiyang Zhang, Stephen Hemminger, Sasha Levin,
David S . Miller, vkuznets, Dexuan Cui
From: Andrea Parri <parri.andrea@gmail.com> Sent: Thursday, October 10, 2019 8:46 AM
>
> 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 | 46 ++++++++++++++---------------------------
> drivers/hv/vmbus_drv.c | 3 +--
> include/linux/hyperv.h | 4 ----
> 3 files changed, 17 insertions(+), 36 deletions(-)
>
> @@ -244,20 +232,18 @@ int vmbus_connect(void)
> * version.
> */
>
> - version = VERSION_CURRENT;
> + for (i = 0; i < ARRAY_SIZE(vmbus_versions); i++) {
> + 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)
> + if (vmbus_connection.conn_state != CONNECTED)
> goto cleanup;
>
This is a nit, but the loop exit path bugs me. When a connection
is established, the loop is exited by the "break", and then
conn_state has to be tested again to decide whether the loop
exited due to getting a connection vs. hitting the end of the list.
Slightly cleaner in my mind would be:
for (i=0; ; i++) {
if (i == ARRAY_SIZE(vmbus_versions))
goto cleanup;
version = vmbus_versions[i];
ret = vmbus_negotiate_version(msginfo, version);
if (ret == -ETIMEDOUT)
goto cleanup;
if (vmbus_connection.conn_state == CONNECTED)
break;
}
Michael
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2 1/3] Drivers: hv: vmbus: Introduce table of VMBus protocol versions
2019-10-12 13:47 ` Michael Kelley
@ 2019-10-14 9:52 ` Andrea Parri
0 siblings, 0 replies; 8+ messages in thread
From: Andrea Parri @ 2019-10-14 9:52 UTC (permalink / raw)
To: Michael Kelley
Cc: linux-kernel, linux-hyperv, netdev, KY Srinivasan, Haiyang Zhang,
Stephen Hemminger, Sasha Levin, David S . Miller, vkuznets,
Dexuan Cui
> > @@ -244,20 +232,18 @@ int vmbus_connect(void)
> > * version.
> > */
> >
> > - version = VERSION_CURRENT;
> > + for (i = 0; i < ARRAY_SIZE(vmbus_versions); i++) {
> > + 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)
> > + if (vmbus_connection.conn_state != CONNECTED)
> > goto cleanup;
> >
>
> This is a nit, but the loop exit path bugs me. When a connection
> is established, the loop is exited by the "break", and then
> conn_state has to be tested again to decide whether the loop
> exited due to getting a connection vs. hitting the end of the list.
> Slightly cleaner in my mind would be:
>
> for (i=0; ; i++) {
> if (i == ARRAY_SIZE(vmbus_versions))
> goto cleanup;
>
> version = vmbus_versions[i];
> ret = vmbus_negotiate_version(msginfo, version);
> if (ret == -ETIMEDOUT)
> goto cleanup;
>
> if (vmbus_connection.conn_state == CONNECTED)
> break;
> }
Indeed. I applied this locally, for the next iteration. Thank you for
the review, Michael.
Andrea
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2 2/3] Drivers: hv: vmbus: Enable VMBus protocol versions 4.1, 5.1 and 5.2
2019-10-12 13:34 ` Michael Kelley
@ 2019-10-14 10:09 ` Andrea Parri
0 siblings, 0 replies; 8+ messages in thread
From: Andrea Parri @ 2019-10-14 10:09 UTC (permalink / raw)
To: Michael Kelley
Cc: linux-kernel, linux-hyperv, netdev, KY Srinivasan, Haiyang Zhang,
Stephen Hemminger, Sasha Levin, David S . Miller, vkuznets,
Dexuan Cui
> > @@ -182,15 +182,21 @@ static inline u32 hv_get_avail_to_write_percent(
> > * 2 . 4 (Windows 8)
> > * 3 . 0 (Windows 8 R2)
> > * 4 . 0 (Windows 10)
> > + * 4 . 1 (Windows 10 RS3)
> > * 5 . 0 (Newer Windows 10)
> > + * 5 . 1 (Windows 10 RS4)
> > + * 5 . 2 (Windows Server 2019, RS5)
> > */
> >
> > #define VERSION_WS2008 ((0 << 16) | (13))
> > #define VERSION_WIN7 ((1 << 16) | (1))
> > #define VERSION_WIN8 ((2 << 16) | (4))
> > #define VERSION_WIN8_1 ((3 << 16) | (0))
> > -#define VERSION_WIN10 ((4 << 16) | (0))
> > +#define VERSION_WIN10_V4 ((4 << 16) | (0))
>
> I would recommend not changing the symbol name for version 4.0.
> The change makes it more consistent with the later VERSION_WIN10_*
> symbols, but it doesn't fundamentally add any clarity and I'm not sure
> it's worth the churn in the other files that have to be touched. It's a
> judgment call, and that's just my input.
My fingers were itching: ;-) I've reverted this change, following
your recommendation.
Thanks,
Andrea
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2019-10-14 10:09 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-10-10 15:45 [PATCH v2 0/3] Drivers: hv: vmbus: Miscellaneous improvements Andrea Parri
2019-10-10 15:45 ` [PATCH v2 1/3] Drivers: hv: vmbus: Introduce table of VMBus protocol versions Andrea Parri
2019-10-12 13:47 ` Michael Kelley
2019-10-14 9:52 ` Andrea Parri
2019-10-10 15:45 ` [PATCH v2 2/3] Drivers: hv: vmbus: Enable VMBus protocol versions 4.1, 5.1 and 5.2 Andrea Parri
2019-10-12 13:34 ` Michael Kelley
2019-10-14 10:09 ` Andrea Parri
2019-10-10 15:46 ` [PATCH v2 3/3] Drivers: hv: vmbus: Add module parameter to cap the VMBus version Andrea Parri
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