* [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID
@ 2015-01-29 11:02 ` Dexuan Cui
0 siblings, 0 replies; 15+ messages in thread
From: Dexuan Cui @ 2015-01-29 11:02 UTC (permalink / raw)
To: gregkh, linux-kernel, driverdev-devel, olaf, apw, jasowang, kys; +Cc: haiyangz
I got the hypercall error code on Hyper-V 2008 R2 when keeping running
"rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils; modprobe hv_utils"
in a Linux guest.
Without the patch, the driver can occasionally fail to load.
CC: "K. Y. Srinivasan" <kys@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
---
arch/x86/include/uapi/asm/hyperv.h | 1 +
drivers/hv/connection.c | 9 +++++++++
2 files changed, 10 insertions(+)
diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
index 90c458e..b9daffb 100644
--- a/arch/x86/include/uapi/asm/hyperv.h
+++ b/arch/x86/include/uapi/asm/hyperv.h
@@ -225,6 +225,7 @@
#define HV_STATUS_INVALID_HYPERCALL_CODE 2
#define HV_STATUS_INVALID_HYPERCALL_INPUT 3
#define HV_STATUS_INVALID_ALIGNMENT 4
+#define HV_STATUS_INVALID_CONNECTION_ID 18
#define HV_STATUS_INSUFFICIENT_BUFFERS 19
typedef struct _HV_REFERENCE_TSC_PAGE {
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index c4acd1c..8bd05f3 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -440,6 +440,15 @@ int vmbus_post_msg(void *buffer, size_t buflen)
ret = hv_post_message(conn_id, 1, buffer, buflen);
switch (ret) {
+ case HV_STATUS_INVALID_CONNECTION_ID:
+ /*
+ * We could get this if we send messages too
+ * frequently or the host is under low resource
+ * conditions: let's wait 1 more second before
+ * retrying the hypercall.
+ */
+ msleep(1000);
+ break;
case HV_STATUS_INSUFFICIENT_BUFFERS:
ret = -ENOMEM;
case -ENOMEM:
--
1.9.1
^ permalink raw reply related [flat|nested] 15+ messages in thread
* [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID
@ 2015-01-29 11:02 ` Dexuan Cui
0 siblings, 0 replies; 15+ messages in thread
From: Dexuan Cui @ 2015-01-29 11:02 UTC (permalink / raw)
To: gregkh, linux-kernel, driverdev-devel, olaf, apw, jasowang, kys; +Cc: haiyangz
I got the hypercall error code on Hyper-V 2008 R2 when keeping running
"rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils; modprobe hv_utils"
in a Linux guest.
Without the patch, the driver can occasionally fail to load.
CC: "K. Y. Srinivasan" <kys@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
---
arch/x86/include/uapi/asm/hyperv.h | 1 +
drivers/hv/connection.c | 9 +++++++++
2 files changed, 10 insertions(+)
diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
index 90c458e..b9daffb 100644
--- a/arch/x86/include/uapi/asm/hyperv.h
+++ b/arch/x86/include/uapi/asm/hyperv.h
@@ -225,6 +225,7 @@
#define HV_STATUS_INVALID_HYPERCALL_CODE 2
#define HV_STATUS_INVALID_HYPERCALL_INPUT 3
#define HV_STATUS_INVALID_ALIGNMENT 4
+#define HV_STATUS_INVALID_CONNECTION_ID 18
#define HV_STATUS_INSUFFICIENT_BUFFERS 19
typedef struct _HV_REFERENCE_TSC_PAGE {
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index c4acd1c..8bd05f3 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -440,6 +440,15 @@ int vmbus_post_msg(void *buffer, size_t buflen)
ret = hv_post_message(conn_id, 1, buffer, buflen);
switch (ret) {
+ case HV_STATUS_INVALID_CONNECTION_ID:
+ /*
+ * We could get this if we send messages too
+ * frequently or the host is under low resource
+ * conditions: let's wait 1 more second before
+ * retrying the hypercall.
+ */
+ msleep(1000);
+ break;
case HV_STATUS_INSUFFICIENT_BUFFERS:
ret = -ENOMEM;
case -ENOMEM:
--
1.9.1
_______________________________________________
devel mailing list
devel@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
^ permalink raw reply related [flat|nested] 15+ messages in thread
* Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID
2015-01-29 11:02 ` Dexuan Cui
@ 2015-01-29 13:30 ` Vitaly Kuznetsov
-1 siblings, 0 replies; 15+ messages in thread
From: Vitaly Kuznetsov @ 2015-01-29 13:30 UTC (permalink / raw)
To: Dexuan Cui
Cc: gregkh, linux-kernel, driverdev-devel, olaf, apw, jasowang, kys,
haiyangz
Dexuan Cui <decui@microsoft.com> writes:
> I got the hypercall error code on Hyper-V 2008 R2 when keeping running
> "rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils; modprobe hv_utils"
> in a Linux guest.
>
> Without the patch, the driver can occasionally fail to load.
>
> CC: "K. Y. Srinivasan" <kys@microsoft.com>
> Signed-off-by: Dexuan Cui <decui@microsoft.com>
> ---
> arch/x86/include/uapi/asm/hyperv.h | 1 +
> drivers/hv/connection.c | 9 +++++++++
> 2 files changed, 10 insertions(+)
>
> diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
> index 90c458e..b9daffb 100644
> --- a/arch/x86/include/uapi/asm/hyperv.h
> +++ b/arch/x86/include/uapi/asm/hyperv.h
> @@ -225,6 +225,7 @@
> #define HV_STATUS_INVALID_HYPERCALL_CODE 2
> #define HV_STATUS_INVALID_HYPERCALL_INPUT 3
> #define HV_STATUS_INVALID_ALIGNMENT 4
> +#define HV_STATUS_INVALID_CONNECTION_ID 18
> #define HV_STATUS_INSUFFICIENT_BUFFERS 19
The gap beween 4 and 18 tells me there are other codes here ;-) Are they
all 'permanent failures'?
>
> typedef struct _HV_REFERENCE_TSC_PAGE {
> diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
> index c4acd1c..8bd05f3 100644
> --- a/drivers/hv/connection.c
> +++ b/drivers/hv/connection.c
> @@ -440,6 +440,15 @@ int vmbus_post_msg(void *buffer, size_t buflen)
> ret = hv_post_message(conn_id, 1, buffer, buflen);
>
> switch (ret) {
> + case HV_STATUS_INVALID_CONNECTION_ID:
> + /*
> + * We could get this if we send messages too
> + * frequently or the host is under low resource
> + * conditions: let's wait 1 more second before
> + * retrying the hypercall.
> + */
> + msleep(1000);
> + break;
In case it is our last try (No. 10) we will return '18' from the
function. I suggest we set ret = -ENOMEM here as well.
> case HV_STATUS_INSUFFICIENT_BUFFERS:
> ret = -ENOMEM;
Or should we treat these two equally? There is a smaller (100ms) sleep
between tries already, we can consider changing it instead.
> case -ENOMEM:
--
Vitaly
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID
@ 2015-01-29 13:30 ` Vitaly Kuznetsov
0 siblings, 0 replies; 15+ messages in thread
From: Vitaly Kuznetsov @ 2015-01-29 13:30 UTC (permalink / raw)
To: Dexuan Cui
Cc: olaf, gregkh, jasowang, driverdev-devel, linux-kernel, apw, haiyangz
Dexuan Cui <decui@microsoft.com> writes:
> I got the hypercall error code on Hyper-V 2008 R2 when keeping running
> "rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils; modprobe hv_utils"
> in a Linux guest.
>
> Without the patch, the driver can occasionally fail to load.
>
> CC: "K. Y. Srinivasan" <kys@microsoft.com>
> Signed-off-by: Dexuan Cui <decui@microsoft.com>
> ---
> arch/x86/include/uapi/asm/hyperv.h | 1 +
> drivers/hv/connection.c | 9 +++++++++
> 2 files changed, 10 insertions(+)
>
> diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
> index 90c458e..b9daffb 100644
> --- a/arch/x86/include/uapi/asm/hyperv.h
> +++ b/arch/x86/include/uapi/asm/hyperv.h
> @@ -225,6 +225,7 @@
> #define HV_STATUS_INVALID_HYPERCALL_CODE 2
> #define HV_STATUS_INVALID_HYPERCALL_INPUT 3
> #define HV_STATUS_INVALID_ALIGNMENT 4
> +#define HV_STATUS_INVALID_CONNECTION_ID 18
> #define HV_STATUS_INSUFFICIENT_BUFFERS 19
The gap beween 4 and 18 tells me there are other codes here ;-) Are they
all 'permanent failures'?
>
> typedef struct _HV_REFERENCE_TSC_PAGE {
> diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
> index c4acd1c..8bd05f3 100644
> --- a/drivers/hv/connection.c
> +++ b/drivers/hv/connection.c
> @@ -440,6 +440,15 @@ int vmbus_post_msg(void *buffer, size_t buflen)
> ret = hv_post_message(conn_id, 1, buffer, buflen);
>
> switch (ret) {
> + case HV_STATUS_INVALID_CONNECTION_ID:
> + /*
> + * We could get this if we send messages too
> + * frequently or the host is under low resource
> + * conditions: let's wait 1 more second before
> + * retrying the hypercall.
> + */
> + msleep(1000);
> + break;
In case it is our last try (No. 10) we will return '18' from the
function. I suggest we set ret = -ENOMEM here as well.
> case HV_STATUS_INSUFFICIENT_BUFFERS:
> ret = -ENOMEM;
Or should we treat these two equally? There is a smaller (100ms) sleep
between tries already, we can consider changing it instead.
> case -ENOMEM:
--
Vitaly
_______________________________________________
devel mailing list
devel@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID
2015-01-29 11:02 ` Dexuan Cui
(?)
(?)
@ 2015-01-30 2:47 ` Jason Wang
2015-01-30 5:34 ` Dexuan Cui
-1 siblings, 1 reply; 15+ messages in thread
From: Jason Wang @ 2015-01-30 2:47 UTC (permalink / raw)
To: Dexuan Cui
Cc: gregkh, linux-kernel, driverdev-devel, olaf, apw, kys, haiyangz
On Thu, Jan 29, 2015 at 7:02 PM, Dexuan Cui <decui@microsoft.com> wrote:
> I got the hypercall error code on Hyper-V 2008 R2 when keeping running
> "rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils; modprobe
> hv_utils"
> in a Linux guest.
>
> Without the patch, the driver can occasionally fail to load.
>
> CC: "K. Y. Srinivasan" <kys@microsoft.com>
> Signed-off-by: Dexuan Cui <decui@microsoft.com>
> ---
> arch/x86/include/uapi/asm/hyperv.h | 1 +
> drivers/hv/connection.c | 9 +++++++++
> 2 files changed, 10 insertions(+)
>
> diff --git a/arch/x86/include/uapi/asm/hyperv.h
> b/arch/x86/include/uapi/asm/hyperv.h
> index 90c458e..b9daffb 100644
> --- a/arch/x86/include/uapi/asm/hyperv.h
> +++ b/arch/x86/include/uapi/asm/hyperv.h
> @@ -225,6 +225,7 @@
> #define HV_STATUS_INVALID_HYPERCALL_CODE 2
> #define HV_STATUS_INVALID_HYPERCALL_INPUT 3
> #define HV_STATUS_INVALID_ALIGNMENT 4
> +#define HV_STATUS_INVALID_CONNECTION_ID 18
> #define HV_STATUS_INSUFFICIENT_BUFFERS 19
>
> typedef struct _HV_REFERENCE_TSC_PAGE {
> diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
> index c4acd1c..8bd05f3 100644
> --- a/drivers/hv/connection.c
> +++ b/drivers/hv/connection.c
> @@ -440,6 +440,15 @@ int vmbus_post_msg(void *buffer, size_t buflen)
> ret = hv_post_message(conn_id, 1, buffer, buflen);
>
> switch (ret) {
> + case HV_STATUS_INVALID_CONNECTION_ID:
> + /*
> + * We could get this if we send messages too
> + * frequently or the host is under low resource
> + * conditions: let's wait 1 more second before
> + * retrying the hypercall.
> + */
The name HV_STATUS_INVALID_CONNECTION_ID is really confusing in this
case. Since it does not show any meaning of lacking resources.
> + msleep(1000);
> + break;
> case HV_STATUS_INSUFFICIENT_BUFFERS:
> ret = -ENOMEM;
I thought host should return this error value when lacking resources?
>
> case -ENOMEM:
> --
> 1.9.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe
> linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
^ permalink raw reply [flat|nested] 15+ messages in thread
* RE: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID
2015-01-29 13:30 ` Vitaly Kuznetsov
@ 2015-01-30 5:30 ` Dexuan Cui
-1 siblings, 0 replies; 15+ messages in thread
From: Dexuan Cui @ 2015-01-30 5:30 UTC (permalink / raw)
To: Vitaly Kuznetsov
Cc: gregkh, linux-kernel, driverdev-devel, olaf, apw, jasowang,
KY Srinivasan, Haiyang Zhang
> -----Original Message-----
> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
> Sent: Thursday, January 29, 2015 21:31 PM
> To: Dexuan Cui
> Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; driverdev-
> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com;
> jasowang@redhat.com; KY Srinivasan; Haiyang Zhang
> Subject: Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on
> HV_STATUS_INVALID_CONNECTION_ID
>
> Dexuan Cui <decui@microsoft.com> writes:
>
> > I got the hypercall error code on Hyper-V 2008 R2 when keeping running
> > "rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils; modprobe hv_utils"
> > in a Linux guest.
> >
> > Without the patch, the driver can occasionally fail to load.
> >
> > CC: "K. Y. Srinivasan" <kys@microsoft.com>
> > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > ---
> > arch/x86/include/uapi/asm/hyperv.h | 1 +
> > drivers/hv/connection.c | 9 +++++++++
> > 2 files changed, 10 insertions(+)
> >
> > diff --git a/arch/x86/include/uapi/asm/hyperv.h
> b/arch/x86/include/uapi/asm/hyperv.h
> > index 90c458e..b9daffb 100644
> > --- a/arch/x86/include/uapi/asm/hyperv.h
> > +++ b/arch/x86/include/uapi/asm/hyperv.h
> > @@ -225,6 +225,7 @@
> > #define HV_STATUS_INVALID_HYPERCALL_CODE 2
> > #define HV_STATUS_INVALID_HYPERCALL_INPUT 3
> > #define HV_STATUS_INVALID_ALIGNMENT 4
> > +#define HV_STATUS_INVALID_CONNECTION_ID 18
> > #define HV_STATUS_INSUFFICIENT_BUFFERS 19
>
> The gap beween 4 and 18 tells me there are other codes here ;-) Are they
> all 'permanent failures'?
It looks we only need to care about these error codes here.
BTW, you can get all the hypercall error codes in the top level functional spec:
http://blogs.msdn.com/b/virtual_pc_guy/archive/2014/02/17/updated-hypervisor-top-level-functional-specification.aspx
For this hypercall (0x005c), see "14.9.7 HvPostMessage".
> >
> > typedef struct _HV_REFERENCE_TSC_PAGE {
> > diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
> > index c4acd1c..8bd05f3 100644
> > --- a/drivers/hv/connection.c
> > +++ b/drivers/hv/connection.c
> > @@ -440,6 +440,15 @@ int vmbus_post_msg(void *buffer, size_t buflen)
> > ret = hv_post_message(conn_id, 1, buffer, buflen);
> >
> > switch (ret) {
> > + case HV_STATUS_INVALID_CONNECTION_ID:
> > + /*
> > + * We could get this if we send messages too
> > + * frequently or the host is under low resource
> > + * conditions: let's wait 1 more second before
> > + * retrying the hypercall.
> > + */
> > + msleep(1000);
> > + break;
>
> In case it is our last try (No. 10) we will return '18' from the
> function. I suggest we set ret = -ENOMEM here as well.
Thanks for the suggestion!
I think it would be better to add this to the case
HV_STATUS_INVALID_CONNECTION_ID:
ret = -EAGAIN;
?
> > case HV_STATUS_INSUFFICIENT_BUFFERS:
> > ret = -ENOMEM;
>
> Or should we treat these two equally? There is a smaller (100ms) sleep
> between tries already, we can consider changing it instead.
>
> > case -ENOMEM:
>
> --
> Vitaly
In my experiments, in the HV_STATUS_INVALID_CONNECTION_ID case,
waiting 100ms is not enough sometimes, so I'd like to wait more time.
I agree with you both cases can wait 1000ms. I'll update my patch.
BTW, the " case -ENOMEM:" is not reachable(the hypervisor itself doesn't
return -ENOMEM), I think. I can remove it.
Thanks,
-- Dexuan
^ permalink raw reply [flat|nested] 15+ messages in thread
* RE: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID
@ 2015-01-30 5:30 ` Dexuan Cui
0 siblings, 0 replies; 15+ messages in thread
From: Dexuan Cui @ 2015-01-30 5:30 UTC (permalink / raw)
To: Vitaly Kuznetsov
Cc: olaf, gregkh, jasowang, driverdev-devel, linux-kernel, apw,
Haiyang Zhang
> -----Original Message-----
> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
> Sent: Thursday, January 29, 2015 21:31 PM
> To: Dexuan Cui
> Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; driverdev-
> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com;
> jasowang@redhat.com; KY Srinivasan; Haiyang Zhang
> Subject: Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on
> HV_STATUS_INVALID_CONNECTION_ID
>
> Dexuan Cui <decui@microsoft.com> writes:
>
> > I got the hypercall error code on Hyper-V 2008 R2 when keeping running
> > "rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils; modprobe hv_utils"
> > in a Linux guest.
> >
> > Without the patch, the driver can occasionally fail to load.
> >
> > CC: "K. Y. Srinivasan" <kys@microsoft.com>
> > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > ---
> > arch/x86/include/uapi/asm/hyperv.h | 1 +
> > drivers/hv/connection.c | 9 +++++++++
> > 2 files changed, 10 insertions(+)
> >
> > diff --git a/arch/x86/include/uapi/asm/hyperv.h
> b/arch/x86/include/uapi/asm/hyperv.h
> > index 90c458e..b9daffb 100644
> > --- a/arch/x86/include/uapi/asm/hyperv.h
> > +++ b/arch/x86/include/uapi/asm/hyperv.h
> > @@ -225,6 +225,7 @@
> > #define HV_STATUS_INVALID_HYPERCALL_CODE 2
> > #define HV_STATUS_INVALID_HYPERCALL_INPUT 3
> > #define HV_STATUS_INVALID_ALIGNMENT 4
> > +#define HV_STATUS_INVALID_CONNECTION_ID 18
> > #define HV_STATUS_INSUFFICIENT_BUFFERS 19
>
> The gap beween 4 and 18 tells me there are other codes here ;-) Are they
> all 'permanent failures'?
It looks we only need to care about these error codes here.
BTW, you can get all the hypercall error codes in the top level functional spec:
http://blogs.msdn.com/b/virtual_pc_guy/archive/2014/02/17/updated-hypervisor-top-level-functional-specification.aspx
For this hypercall (0x005c), see "14.9.7 HvPostMessage".
> >
> > typedef struct _HV_REFERENCE_TSC_PAGE {
> > diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
> > index c4acd1c..8bd05f3 100644
> > --- a/drivers/hv/connection.c
> > +++ b/drivers/hv/connection.c
> > @@ -440,6 +440,15 @@ int vmbus_post_msg(void *buffer, size_t buflen)
> > ret = hv_post_message(conn_id, 1, buffer, buflen);
> >
> > switch (ret) {
> > + case HV_STATUS_INVALID_CONNECTION_ID:
> > + /*
> > + * We could get this if we send messages too
> > + * frequently or the host is under low resource
> > + * conditions: let's wait 1 more second before
> > + * retrying the hypercall.
> > + */
> > + msleep(1000);
> > + break;
>
> In case it is our last try (No. 10) we will return '18' from the
> function. I suggest we set ret = -ENOMEM here as well.
Thanks for the suggestion!
I think it would be better to add this to the case
HV_STATUS_INVALID_CONNECTION_ID:
ret = -EAGAIN;
?
> > case HV_STATUS_INSUFFICIENT_BUFFERS:
> > ret = -ENOMEM;
>
> Or should we treat these two equally? There is a smaller (100ms) sleep
> between tries already, we can consider changing it instead.
>
> > case -ENOMEM:
>
> --
> Vitaly
In my experiments, in the HV_STATUS_INVALID_CONNECTION_ID case,
waiting 100ms is not enough sometimes, so I'd like to wait more time.
I agree with you both cases can wait 1000ms. I'll update my patch.
BTW, the " case -ENOMEM:" is not reachable(the hypervisor itself doesn't
return -ENOMEM), I think. I can remove it.
Thanks,
-- Dexuan
_______________________________________________
devel mailing list
devel@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
^ permalink raw reply [flat|nested] 15+ messages in thread
* RE: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID
2015-01-30 2:47 ` Jason Wang
@ 2015-01-30 5:34 ` Dexuan Cui
0 siblings, 0 replies; 15+ messages in thread
From: Dexuan Cui @ 2015-01-30 5:34 UTC (permalink / raw)
To: Jason Wang
Cc: gregkh, linux-kernel, driverdev-devel, olaf, apw, KY Srinivasan,
Haiyang Zhang
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 2776 bytes --]
> -----Original Message-----
> From: Jason Wang [mailto:jasowang@redhat.com]
> Sent: Friday, January 30, 2015 10:47 AM
> To: Dexuan Cui
> Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; driverdev-
> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com; KY
> Srinivasan; Haiyang Zhang
> Subject: Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on
> HV_STATUS_INVALID_CONNECTION_ID
>
>
>
> On Thu, Jan 29, 2015 at 7:02 PM, Dexuan Cui <decui@microsoft.com> wrote:
> > I got the hypercall error code on Hyper-V 2008 R2 when keeping running
> > "rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils; modprobe
> > hv_utils"
> > in a Linux guest.
> >
> > Without the patch, the driver can occasionally fail to load.
> >
> > CC: "K. Y. Srinivasan" <kys@microsoft.com>
> > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > ---
> > arch/x86/include/uapi/asm/hyperv.h | 1 +
> > drivers/hv/connection.c | 9 +++++++++
> > 2 files changed, 10 insertions(+)
> >
> > diff --git a/arch/x86/include/uapi/asm/hyperv.h
> > b/arch/x86/include/uapi/asm/hyperv.h
> > index 90c458e..b9daffb 100644
> > --- a/arch/x86/include/uapi/asm/hyperv.h
> > +++ b/arch/x86/include/uapi/asm/hyperv.h
> > @@ -225,6 +225,7 @@
> > #define HV_STATUS_INVALID_HYPERCALL_CODE 2
> > #define HV_STATUS_INVALID_HYPERCALL_INPUT 3
> > #define HV_STATUS_INVALID_ALIGNMENT 4
> > +#define HV_STATUS_INVALID_CONNECTION_ID 18
> > #define HV_STATUS_INSUFFICIENT_BUFFERS 19
> >
> > typedef struct _HV_REFERENCE_TSC_PAGE {
> > diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
> > index c4acd1c..8bd05f3 100644
> > --- a/drivers/hv/connection.c
> > +++ b/drivers/hv/connection.c
> > @@ -440,6 +440,15 @@ int vmbus_post_msg(void *buffer, size_t buflen)
> > ret = hv_post_message(conn_id, 1, buffer, buflen);
> >
> > switch (ret) {
> > + case HV_STATUS_INVALID_CONNECTION_ID:
> > + /*
> > + * We could get this if we send messages too
> > + * frequently or the host is under low resource
> > + * conditions: let's wait 1 more second before
> > + * retrying the hypercall.
> > + */
>
> The name HV_STATUS_INVALID_CONNECTION_ID is really confusing in this
> case. Since it does not show any meaning of lacking resources.
The description about the 'low host resource condition' might be not accurate.
I'll remove this part.
> > + msleep(1000);
> > + break;
> > case HV_STATUS_INSUFFICIENT_BUFFERS:
> > ret = -ENOMEM;
>
> I thought host should return this error value when lacking resources?
This should be correct.
> >
> > case -ENOMEM:
> > --
Thanks,
-- Dexuan
ÿôèº{.nÇ+·®+%Ëÿ±éݶ\x17¥wÿº{.nÇ+·¥{±þG«éÿ{ayº\x1dÊÚë,j\a¢f£¢·hïêÿêçz_è®\x03(éÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?¨èÚ&£ø§~á¶iOæ¬z·vØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?I¥
^ permalink raw reply [flat|nested] 15+ messages in thread
* RE: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID
@ 2015-01-30 5:34 ` Dexuan Cui
0 siblings, 0 replies; 15+ messages in thread
From: Dexuan Cui @ 2015-01-30 5:34 UTC (permalink / raw)
To: Jason Wang
Cc: olaf, gregkh, Haiyang Zhang, driverdev-devel, linux-kernel, apw
> -----Original Message-----
> From: Jason Wang [mailto:jasowang@redhat.com]
> Sent: Friday, January 30, 2015 10:47 AM
> To: Dexuan Cui
> Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; driverdev-
> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com; KY
> Srinivasan; Haiyang Zhang
> Subject: Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on
> HV_STATUS_INVALID_CONNECTION_ID
>
>
>
> On Thu, Jan 29, 2015 at 7:02 PM, Dexuan Cui <decui@microsoft.com> wrote:
> > I got the hypercall error code on Hyper-V 2008 R2 when keeping running
> > "rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils; modprobe
> > hv_utils"
> > in a Linux guest.
> >
> > Without the patch, the driver can occasionally fail to load.
> >
> > CC: "K. Y. Srinivasan" <kys@microsoft.com>
> > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > ---
> > arch/x86/include/uapi/asm/hyperv.h | 1 +
> > drivers/hv/connection.c | 9 +++++++++
> > 2 files changed, 10 insertions(+)
> >
> > diff --git a/arch/x86/include/uapi/asm/hyperv.h
> > b/arch/x86/include/uapi/asm/hyperv.h
> > index 90c458e..b9daffb 100644
> > --- a/arch/x86/include/uapi/asm/hyperv.h
> > +++ b/arch/x86/include/uapi/asm/hyperv.h
> > @@ -225,6 +225,7 @@
> > #define HV_STATUS_INVALID_HYPERCALL_CODE 2
> > #define HV_STATUS_INVALID_HYPERCALL_INPUT 3
> > #define HV_STATUS_INVALID_ALIGNMENT 4
> > +#define HV_STATUS_INVALID_CONNECTION_ID 18
> > #define HV_STATUS_INSUFFICIENT_BUFFERS 19
> >
> > typedef struct _HV_REFERENCE_TSC_PAGE {
> > diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
> > index c4acd1c..8bd05f3 100644
> > --- a/drivers/hv/connection.c
> > +++ b/drivers/hv/connection.c
> > @@ -440,6 +440,15 @@ int vmbus_post_msg(void *buffer, size_t buflen)
> > ret = hv_post_message(conn_id, 1, buffer, buflen);
> >
> > switch (ret) {
> > + case HV_STATUS_INVALID_CONNECTION_ID:
> > + /*
> > + * We could get this if we send messages too
> > + * frequently or the host is under low resource
> > + * conditions: let's wait 1 more second before
> > + * retrying the hypercall.
> > + */
>
> The name HV_STATUS_INVALID_CONNECTION_ID is really confusing in this
> case. Since it does not show any meaning of lacking resources.
The description about the 'low host resource condition' might be not accurate.
I'll remove this part.
> > + msleep(1000);
> > + break;
> > case HV_STATUS_INSUFFICIENT_BUFFERS:
> > ret = -ENOMEM;
>
> I thought host should return this error value when lacking resources?
This should be correct.
> >
> > case -ENOMEM:
> > --
Thanks,
-- Dexuan
_______________________________________________
devel mailing list
devel@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID
2015-01-30 5:30 ` Dexuan Cui
@ 2015-01-30 17:29 ` Vitaly Kuznetsov
-1 siblings, 0 replies; 15+ messages in thread
From: Vitaly Kuznetsov @ 2015-01-30 17:29 UTC (permalink / raw)
To: Dexuan Cui
Cc: gregkh, linux-kernel, driverdev-devel, olaf, apw, jasowang,
KY Srinivasan, Haiyang Zhang
Dexuan Cui <decui@microsoft.com> writes:
>> -----Original Message-----
>> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
>> Sent: Thursday, January 29, 2015 21:31 PM
>> To: Dexuan Cui
>> Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; driverdev-
>> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com;
>> jasowang@redhat.com; KY Srinivasan; Haiyang Zhang
>> Subject: Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on
>> HV_STATUS_INVALID_CONNECTION_ID
>>
>> Dexuan Cui <decui@microsoft.com> writes:
>>
>> > I got the hypercall error code on Hyper-V 2008 R2 when keeping running
>> > "rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils; modprobe hv_utils"
>> > in a Linux guest.
>> >
>> > Without the patch, the driver can occasionally fail to load.
>> >
>> > CC: "K. Y. Srinivasan" <kys@microsoft.com>
>> > Signed-off-by: Dexuan Cui <decui@microsoft.com>
>> > ---
>> > arch/x86/include/uapi/asm/hyperv.h | 1 +
>> > drivers/hv/connection.c | 9 +++++++++
>> > 2 files changed, 10 insertions(+)
>> >
>> > diff --git a/arch/x86/include/uapi/asm/hyperv.h
>> b/arch/x86/include/uapi/asm/hyperv.h
>> > index 90c458e..b9daffb 100644
>> > --- a/arch/x86/include/uapi/asm/hyperv.h
>> > +++ b/arch/x86/include/uapi/asm/hyperv.h
>> > @@ -225,6 +225,7 @@
>> > #define HV_STATUS_INVALID_HYPERCALL_CODE 2
>> > #define HV_STATUS_INVALID_HYPERCALL_INPUT 3
>> > #define HV_STATUS_INVALID_ALIGNMENT 4
>> > +#define HV_STATUS_INVALID_CONNECTION_ID 18
>> > #define HV_STATUS_INSUFFICIENT_BUFFERS 19
>>
>> The gap beween 4 and 18 tells me there are other codes here ;-) Are they
>> all 'permanent failures'?
> It looks we only need to care about these error codes here.
>
> BTW, you can get all the hypercall error codes in the top level functional spec:
> http://blogs.msdn.com/b/virtual_pc_guy/archive/2014/02/17/updated-hypervisor-top-level-functional-specification.aspx
> For this hypercall (0x005c), see "14.9.7 HvPostMessage".
Thanks, interesting!
Btw, HV_STATUS_INSUFFICIENT_MEMORY looks suspicious, looks like we can
hit it as well...
I suggest we split all failures here in 2 classes:
1) permanent
2) worth retrying
and treat them accordingly (no big changes, just maybe group them within
hv_post_message() together as it is the only place where these codes are
being used).
>
>> >
>> > typedef struct _HV_REFERENCE_TSC_PAGE {
>> > diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
>> > index c4acd1c..8bd05f3 100644
>> > --- a/drivers/hv/connection.c
>> > +++ b/drivers/hv/connection.c
>> > @@ -440,6 +440,15 @@ int vmbus_post_msg(void *buffer, size_t buflen)
>> > ret = hv_post_message(conn_id, 1, buffer, buflen);
>> >
>> > switch (ret) {
>> > + case HV_STATUS_INVALID_CONNECTION_ID:
>> > + /*
>> > + * We could get this if we send messages too
>> > + * frequently or the host is under low resource
>> > + * conditions: let's wait 1 more second before
>> > + * retrying the hypercall.
>> > + */
>> > + msleep(1000);
>> > + break;
>>
>> In case it is our last try (No. 10) we will return '18' from the
>> function. I suggest we set ret = -ENOMEM here as well.
> Thanks for the suggestion!
>
> I think it would be better to add this to the case
> HV_STATUS_INVALID_CONNECTION_ID:
> ret = -EAGAIN;
> ?
Yes, like fallthrough
>
>> > case HV_STATUS_INSUFFICIENT_BUFFERS:
>> > ret = -ENOMEM;
>>
>> Or should we treat these two equally? There is a smaller (100ms) sleep
>> between tries already, we can consider changing it instead.
>>
>> > case -ENOMEM:
>>
>> --
>> Vitaly
> In my experiments, in the HV_STATUS_INVALID_CONNECTION_ID case,
> waiting 100ms is not enough sometimes, so I'd like to wait more time.
> I agree with you both cases can wait 1000ms. I'll update my patch.
>
> BTW, the " case -ENOMEM:" is not reachable(the hypervisor itself doesn't
> return -ENOMEM), I think. I can remove it.
hv_post_message() can return -EMSGSIZE or do_hypercall() return value
(which becomes u16 in hv_post_message()). So yes, I agree, -ENOMEM is
not possible.
>
> Thanks,
> -- Dexuan
--
Vitaly
^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID
@ 2015-01-30 17:29 ` Vitaly Kuznetsov
0 siblings, 0 replies; 15+ messages in thread
From: Vitaly Kuznetsov @ 2015-01-30 17:29 UTC (permalink / raw)
To: Dexuan Cui
Cc: gregkh, linux-kernel, driverdev-devel, olaf, apw, jasowang,
KY Srinivasan, Haiyang Zhang
Dexuan Cui <decui@microsoft.com> writes:
>> -----Original Message-----
>> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
>> Sent: Thursday, January 29, 2015 21:31 PM
>> To: Dexuan Cui
>> Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; driverdev-
>> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com;
>> jasowang@redhat.com; KY Srinivasan; Haiyang Zhang
>> Subject: Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on
>> HV_STATUS_INVALID_CONNECTION_ID
>>
>> Dexuan Cui <decui@microsoft.com> writes:
>>
>> > I got the hypercall error code on Hyper-V 2008 R2 when keeping running
>> > "rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils; modprobe hv_utils"
>> > in a Linux guest.
>> >
>> > Without the patch, the driver can occasionally fail to load.
>> >
>> > CC: "K. Y. Srinivasan" <kys@microsoft.com>
>> > Signed-off-by: Dexuan Cui <decui@microsoft.com>
>> > ---
>> > arch/x86/include/uapi/asm/hyperv.h | 1 +
>> > drivers/hv/connection.c | 9 +++++++++
>> > 2 files changed, 10 insertions(+)
>> >
>> > diff --git a/arch/x86/include/uapi/asm/hyperv.h
>> b/arch/x86/include/uapi/asm/hyperv.h
>> > index 90c458e..b9daffb 100644
>> > --- a/arch/x86/include/uapi/asm/hyperv.h
>> > +++ b/arch/x86/include/uapi/asm/hyperv.h
>> > @@ -225,6 +225,7 @@
>> > #define HV_STATUS_INVALID_HYPERCALL_CODE 2
>> > #define HV_STATUS_INVALID_HYPERCALL_INPUT 3
>> > #define HV_STATUS_INVALID_ALIGNMENT 4
>> > +#define HV_STATUS_INVALID_CONNECTION_ID 18
>> > #define HV_STATUS_INSUFFICIENT_BUFFERS 19
>>
>> The gap beween 4 and 18 tells me there are other codes here ;-) Are they
>> all 'permanent failures'?
> It looks we only need to care about these error codes here.
>
> BTW, you can get all the hypercall error codes in the top level functional spec:
> http://blogs.msdn.com/b/virtual_pc_guy/archive/2014/02/17/updated-hypervisor-top-level-functional-specification.aspx
> For this hypercall (0x005c), see "14.9.7 HvPostMessage".
Thanks, interesting!
Btw, HV_STATUS_INSUFFICIENT_MEMORY looks suspicious, looks like we can
hit it as well...
I suggest we split all failures here in 2 classes:
1) permanent
2) worth retrying
and treat them accordingly (no big changes, just maybe group them within
hv_post_message() together as it is the only place where these codes are
being used).
>
>> >
>> > typedef struct _HV_REFERENCE_TSC_PAGE {
>> > diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
>> > index c4acd1c..8bd05f3 100644
>> > --- a/drivers/hv/connection.c
>> > +++ b/drivers/hv/connection.c
>> > @@ -440,6 +440,15 @@ int vmbus_post_msg(void *buffer, size_t buflen)
>> > ret = hv_post_message(conn_id, 1, buffer, buflen);
>> >
>> > switch (ret) {
>> > + case HV_STATUS_INVALID_CONNECTION_ID:
>> > + /*
>> > + * We could get this if we send messages too
>> > + * frequently or the host is under low resource
>> > + * conditions: let's wait 1 more second before
>> > + * retrying the hypercall.
>> > + */
>> > + msleep(1000);
>> > + break;
>>
>> In case it is our last try (No. 10) we will return '18' from the
>> function. I suggest we set ret = -ENOMEM here as well.
> Thanks for the suggestion!
>
> I think it would be better to add this to the case
> HV_STATUS_INVALID_CONNECTION_ID:
> ret = -EAGAIN;
> ?
Yes, like fallthrough
>
>> > case HV_STATUS_INSUFFICIENT_BUFFERS:
>> > ret = -ENOMEM;
>>
>> Or should we treat these two equally? There is a smaller (100ms) sleep
>> between tries already, we can consider changing it instead.
>>
>> > case -ENOMEM:
>>
>> --
>> Vitaly
> In my experiments, in the HV_STATUS_INVALID_CONNECTION_ID case,
> waiting 100ms is not enough sometimes, so I'd like to wait more time.
> I agree with you both cases can wait 1000ms. I'll update my patch.
>
> BTW, the " case -ENOMEM:" is not reachable(the hypervisor itself doesn't
> return -ENOMEM), I think. I can remove it.
hv_post_message() can return -EMSGSIZE or do_hypercall() return value
(which becomes u16 in hv_post_message()). So yes, I agree, -ENOMEM is
not possible.
>
> Thanks,
> -- Dexuan
--
Vitaly
^ permalink raw reply [flat|nested] 15+ messages in thread
* RE: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID
2015-01-30 17:29 ` Vitaly Kuznetsov
@ 2015-02-01 3:37 ` Dexuan Cui
-1 siblings, 0 replies; 15+ messages in thread
From: Dexuan Cui @ 2015-02-01 3:37 UTC (permalink / raw)
To: Vitaly Kuznetsov
Cc: gregkh, linux-kernel, driverdev-devel, olaf, apw, jasowang,
KY Srinivasan, Haiyang Zhang
> -----Original Message-----
> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
> Sent: Saturday, January 31, 2015 1:29 AM
> To: Dexuan Cui
> Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; driverdev-
> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com;
> jasowang@redhat.com; KY Srinivasan; Haiyang Zhang
> Subject: Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on
> HV_STATUS_INVALID_CONNECTION_ID
>
> Dexuan Cui <decui@microsoft.com> writes:
>
> >> -----Original Message-----
> >> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
> >> Sent: Thursday, January 29, 2015 21:31 PM
> >> To: Dexuan Cui
> >> Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; driverdev-
> >> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com;
> >> jasowang@redhat.com; KY Srinivasan; Haiyang Zhang
> >> Subject: Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on
> >> HV_STATUS_INVALID_CONNECTION_ID
> >>
> >> Dexuan Cui <decui@microsoft.com> writes:
> >>
> >> > I got the hypercall error code on Hyper-V 2008 R2 when keeping running
> >> > "rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils; modprobe
> hv_utils"
> >> > in a Linux guest.
> >> >
> >> > Without the patch, the driver can occasionally fail to load.
> >> >
> >> > CC: "K. Y. Srinivasan" <kys@microsoft.com>
> >> > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> >> > ---
> >> > arch/x86/include/uapi/asm/hyperv.h | 1 +
> >> > drivers/hv/connection.c | 9 +++++++++
> >> > 2 files changed, 10 insertions(+)
> >> >
> >> > diff --git a/arch/x86/include/uapi/asm/hyperv.h
> >> b/arch/x86/include/uapi/asm/hyperv.h
> >> > index 90c458e..b9daffb 100644
> >> > --- a/arch/x86/include/uapi/asm/hyperv.h
> >> > +++ b/arch/x86/include/uapi/asm/hyperv.h
> >> > @@ -225,6 +225,7 @@
> >> > #define HV_STATUS_INVALID_HYPERCALL_CODE 2
> >> > #define HV_STATUS_INVALID_HYPERCALL_INPUT 3
> >> > #define HV_STATUS_INVALID_ALIGNMENT 4
> >> > +#define HV_STATUS_INVALID_CONNECTION_ID 18
> >> > #define HV_STATUS_INSUFFICIENT_BUFFERS 19
> >>
> >> The gap beween 4 and 18 tells me there are other codes here ;-) Are they
> >> all 'permanent failures'?
> > It looks we only need to care about these error codes here.
> >
> > BTW, you can get all the hypercall error codes in the top level functional spec:
> > http://blogs.msdn.com/b/virtual_pc_guy/archive/2014/02/17/updated-
> hypervisor-top-level-functional-specification.aspx
> > For this hypercall (0x005c), see "14.9.7 HvPostMessage".
>
> Thanks, interesting!
>
> Btw, HV_STATUS_INSUFFICIENT_MEMORY looks suspicious, looks like we can
> hit it as well...
>
> I suggest we split all failures here in 2 classes:
> 1) permanent
> 2) worth retrying
>
> and treat them accordingly (no big changes, just maybe group them within
> hv_post_message() together as it is the only place where these codes are
> being used).
Thanks for the suggestion, Vitaly!
I'll send out v2.
-- Dexuan
> >
> >> >
> >> > typedef struct _HV_REFERENCE_TSC_PAGE {
> >> > diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
> >> > index c4acd1c..8bd05f3 100644
> >> > --- a/drivers/hv/connection.c
> >> > +++ b/drivers/hv/connection.c
> >> > @@ -440,6 +440,15 @@ int vmbus_post_msg(void *buffer, size_t buflen)
> >> > ret = hv_post_message(conn_id, 1, buffer, buflen);
> >> >
> >> > switch (ret) {
> >> > + case HV_STATUS_INVALID_CONNECTION_ID:
> >> > + /*
> >> > + * We could get this if we send messages too
> >> > + * frequently or the host is under low resource
> >> > + * conditions: let's wait 1 more second before
> >> > + * retrying the hypercall.
> >> > + */
> >> > + msleep(1000);
> >> > + break;
> >>
> >> In case it is our last try (No. 10) we will return '18' from the
> >> function. I suggest we set ret = -ENOMEM here as well.
> > Thanks for the suggestion!
> >
> > I think it would be better to add this to the case
> > HV_STATUS_INVALID_CONNECTION_ID:
> > ret = -EAGAIN;
> > ?
>
> Yes, like fallthrough
>
> >
> >> > case HV_STATUS_INSUFFICIENT_BUFFERS:
> >> > ret = -ENOMEM;
> >>
> >> Or should we treat these two equally? There is a smaller (100ms) sleep
> >> between tries already, we can consider changing it instead.
> >>
> >> > case -ENOMEM:
> >>
> >> --
> >> Vitaly
> > In my experiments, in the HV_STATUS_INVALID_CONNECTION_ID case,
> > waiting 100ms is not enough sometimes, so I'd like to wait more time.
> > I agree with you both cases can wait 1000ms. I'll update my patch.
> >
> > BTW, the " case -ENOMEM:" is not reachable(the hypervisor itself doesn't
> > return -ENOMEM), I think. I can remove it.
>
> hv_post_message() can return -EMSGSIZE or do_hypercall() return value
> (which becomes u16 in hv_post_message()). So yes, I agree, -ENOMEM is
> not possible.
>
> >
> > Thanks,
> > -- Dexuan
>
> --
> Vitaly
^ permalink raw reply [flat|nested] 15+ messages in thread
* RE: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID
@ 2015-02-01 3:37 ` Dexuan Cui
0 siblings, 0 replies; 15+ messages in thread
From: Dexuan Cui @ 2015-02-01 3:37 UTC (permalink / raw)
To: Vitaly Kuznetsov
Cc: gregkh, linux-kernel, driverdev-devel, olaf, apw, jasowang,
KY Srinivasan, Haiyang Zhang
> -----Original Message-----
> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
> Sent: Saturday, January 31, 2015 1:29 AM
> To: Dexuan Cui
> Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; driverdev-
> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com;
> jasowang@redhat.com; KY Srinivasan; Haiyang Zhang
> Subject: Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on
> HV_STATUS_INVALID_CONNECTION_ID
>
> Dexuan Cui <decui@microsoft.com> writes:
>
> >> -----Original Message-----
> >> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
> >> Sent: Thursday, January 29, 2015 21:31 PM
> >> To: Dexuan Cui
> >> Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; driverdev-
> >> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com;
> >> jasowang@redhat.com; KY Srinivasan; Haiyang Zhang
> >> Subject: Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on
> >> HV_STATUS_INVALID_CONNECTION_ID
> >>
> >> Dexuan Cui <decui@microsoft.com> writes:
> >>
> >> > I got the hypercall error code on Hyper-V 2008 R2 when keeping running
> >> > "rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils; modprobe
> hv_utils"
> >> > in a Linux guest.
> >> >
> >> > Without the patch, the driver can occasionally fail to load.
> >> >
> >> > CC: "K. Y. Srinivasan" <kys@microsoft.com>
> >> > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> >> > ---
> >> > arch/x86/include/uapi/asm/hyperv.h | 1 +
> >> > drivers/hv/connection.c | 9 +++++++++
> >> > 2 files changed, 10 insertions(+)
> >> >
> >> > diff --git a/arch/x86/include/uapi/asm/hyperv.h
> >> b/arch/x86/include/uapi/asm/hyperv.h
> >> > index 90c458e..b9daffb 100644
> >> > --- a/arch/x86/include/uapi/asm/hyperv.h
> >> > +++ b/arch/x86/include/uapi/asm/hyperv.h
> >> > @@ -225,6 +225,7 @@
> >> > #define HV_STATUS_INVALID_HYPERCALL_CODE 2
> >> > #define HV_STATUS_INVALID_HYPERCALL_INPUT 3
> >> > #define HV_STATUS_INVALID_ALIGNMENT 4
> >> > +#define HV_STATUS_INVALID_CONNECTION_ID 18
> >> > #define HV_STATUS_INSUFFICIENT_BUFFERS 19
> >>
> >> The gap beween 4 and 18 tells me there are other codes here ;-) Are they
> >> all 'permanent failures'?
> > It looks we only need to care about these error codes here.
> >
> > BTW, you can get all the hypercall error codes in the top level functional spec:
> > http://blogs.msdn.com/b/virtual_pc_guy/archive/2014/02/17/updated-
> hypervisor-top-level-functional-specification.aspx
> > For this hypercall (0x005c), see "14.9.7 HvPostMessage".
>
> Thanks, interesting!
>
> Btw, HV_STATUS_INSUFFICIENT_MEMORY looks suspicious, looks like we can
> hit it as well...
>
> I suggest we split all failures here in 2 classes:
> 1) permanent
> 2) worth retrying
>
> and treat them accordingly (no big changes, just maybe group them within
> hv_post_message() together as it is the only place where these codes are
> being used).
Thanks for the suggestion, Vitaly!
I'll send out v2.
-- Dexuan
> >
> >> >
> >> > typedef struct _HV_REFERENCE_TSC_PAGE {
> >> > diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
> >> > index c4acd1c..8bd05f3 100644
> >> > --- a/drivers/hv/connection.c
> >> > +++ b/drivers/hv/connection.c
> >> > @@ -440,6 +440,15 @@ int vmbus_post_msg(void *buffer, size_t buflen)
> >> > ret = hv_post_message(conn_id, 1, buffer, buflen);
> >> >
> >> > switch (ret) {
> >> > + case HV_STATUS_INVALID_CONNECTION_ID:
> >> > + /*
> >> > + * We could get this if we send messages too
> >> > + * frequently or the host is under low resource
> >> > + * conditions: let's wait 1 more second before
> >> > + * retrying the hypercall.
> >> > + */
> >> > + msleep(1000);
> >> > + break;
> >>
> >> In case it is our last try (No. 10) we will return '18' from the
> >> function. I suggest we set ret = -ENOMEM here as well.
> > Thanks for the suggestion!
> >
> > I think it would be better to add this to the case
> > HV_STATUS_INVALID_CONNECTION_ID:
> > ret = -EAGAIN;
> > ?
>
> Yes, like fallthrough
>
> >
> >> > case HV_STATUS_INSUFFICIENT_BUFFERS:
> >> > ret = -ENOMEM;
> >>
> >> Or should we treat these two equally? There is a smaller (100ms) sleep
> >> between tries already, we can consider changing it instead.
> >>
> >> > case -ENOMEM:
> >>
> >> --
> >> Vitaly
> > In my experiments, in the HV_STATUS_INVALID_CONNECTION_ID case,
> > waiting 100ms is not enough sometimes, so I'd like to wait more time.
> > I agree with you both cases can wait 1000ms. I'll update my patch.
> >
> > BTW, the " case -ENOMEM:" is not reachable(the hypervisor itself doesn't
> > return -ENOMEM), I think. I can remove it.
>
> hv_post_message() can return -EMSGSIZE or do_hypercall() return value
> (which becomes u16 in hv_post_message()). So yes, I agree, -ENOMEM is
> not possible.
>
> >
> > Thanks,
> > -- Dexuan
>
> --
> Vitaly
^ permalink raw reply [flat|nested] 15+ messages in thread
* RE: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID
2015-02-01 3:37 ` Dexuan Cui
@ 2015-02-01 19:48 ` KY Srinivasan
-1 siblings, 0 replies; 15+ messages in thread
From: KY Srinivasan @ 2015-02-01 19:48 UTC (permalink / raw)
To: Dexuan Cui, Vitaly Kuznetsov
Cc: gregkh, linux-kernel, driverdev-devel, olaf, apw, jasowang,
Haiyang Zhang
> -----Original Message-----
> From: Dexuan Cui
> Sent: Saturday, January 31, 2015 7:38 PM
> To: Vitaly Kuznetsov
> Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; driverdev-
> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com;
> jasowang@redhat.com; KY Srinivasan; Haiyang Zhang
> Subject: RE: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on
> HV_STATUS_INVALID_CONNECTION_ID
>
> > -----Original Message-----
> > From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
> > Sent: Saturday, January 31, 2015 1:29 AM
> > To: Dexuan Cui
> > Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org;
> > driverdev- devel@linuxdriverproject.org; olaf@aepfle.de;
> > apw@canonical.com; jasowang@redhat.com; KY Srinivasan; Haiyang Zhang
> > Subject: Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on
> > HV_STATUS_INVALID_CONNECTION_ID
> >
> > Dexuan Cui <decui@microsoft.com> writes:
> >
> > >> -----Original Message-----
> > >> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
> > >> Sent: Thursday, January 29, 2015 21:31 PM
> > >> To: Dexuan Cui
> > >> Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org;
> > >> driverdev- devel@linuxdriverproject.org; olaf@aepfle.de;
> > >> apw@canonical.com; jasowang@redhat.com; KY Srinivasan; Haiyang
> > >> Zhang
> > >> Subject: Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on
> > >> HV_STATUS_INVALID_CONNECTION_ID
> > >>
> > >> Dexuan Cui <decui@microsoft.com> writes:
> > >>
> > >> > I got the hypercall error code on Hyper-V 2008 R2 when keeping
> > >> > running "rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils;
> > >> > modprobe
> > hv_utils"
> > >> > in a Linux guest.
> > >> >
> > >> > Without the patch, the driver can occasionally fail to load.
> > >> >
> > >> > CC: "K. Y. Srinivasan" <kys@microsoft.com>
> > >> > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > >> > ---
> > >> > arch/x86/include/uapi/asm/hyperv.h | 1 +
> > >> > drivers/hv/connection.c | 9 +++++++++
> > >> > 2 files changed, 10 insertions(+)
> > >> >
> > >> > diff --git a/arch/x86/include/uapi/asm/hyperv.h
> > >> b/arch/x86/include/uapi/asm/hyperv.h
> > >> > index 90c458e..b9daffb 100644
> > >> > --- a/arch/x86/include/uapi/asm/hyperv.h
> > >> > +++ b/arch/x86/include/uapi/asm/hyperv.h
> > >> > @@ -225,6 +225,7 @@
> > >> > #define HV_STATUS_INVALID_HYPERCALL_CODE 2
> > >> > #define HV_STATUS_INVALID_HYPERCALL_INPUT 3
> > >> > #define HV_STATUS_INVALID_ALIGNMENT 4
> > >> > +#define HV_STATUS_INVALID_CONNECTION_ID 18
> > >> > #define HV_STATUS_INSUFFICIENT_BUFFERS 19
> > >>
> > >> The gap beween 4 and 18 tells me there are other codes here ;-) Are
> > >> they all 'permanent failures'?
> > > It looks we only need to care about these error codes here.
> > >
> > > BTW, you can get all the hypercall error codes in the top level functional
> spec:
> > > http://blogs.msdn.com/b/virtual_pc_guy/archive/2014/02/17/updated-
> > hypervisor-top-level-functional-specification.aspx
> > > For this hypercall (0x005c), see "14.9.7 HvPostMessage".
> >
> > Thanks, interesting!
> >
> > Btw, HV_STATUS_INSUFFICIENT_MEMORY looks suspicious, looks like we
> can
> > hit it as well...
> >
> > I suggest we split all failures here in 2 classes:
> > 1) permanent
> > 2) worth retrying
> >
> > and treat them accordingly (no big changes, just maybe group them
> > within
> > hv_post_message() together as it is the only place where these codes
> > are being used).
> Thanks for the suggestion, Vitaly!
> I'll send out v2.
Thanks Dexuan.
K. Y
^ permalink raw reply [flat|nested] 15+ messages in thread
* RE: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID
@ 2015-02-01 19:48 ` KY Srinivasan
0 siblings, 0 replies; 15+ messages in thread
From: KY Srinivasan @ 2015-02-01 19:48 UTC (permalink / raw)
To: Dexuan Cui, Vitaly Kuznetsov
Cc: gregkh, linux-kernel, driverdev-devel, olaf, apw, jasowang,
Haiyang Zhang
> -----Original Message-----
> From: Dexuan Cui
> Sent: Saturday, January 31, 2015 7:38 PM
> To: Vitaly Kuznetsov
> Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; driverdev-
> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com;
> jasowang@redhat.com; KY Srinivasan; Haiyang Zhang
> Subject: RE: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on
> HV_STATUS_INVALID_CONNECTION_ID
>
> > -----Original Message-----
> > From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
> > Sent: Saturday, January 31, 2015 1:29 AM
> > To: Dexuan Cui
> > Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org;
> > driverdev- devel@linuxdriverproject.org; olaf@aepfle.de;
> > apw@canonical.com; jasowang@redhat.com; KY Srinivasan; Haiyang Zhang
> > Subject: Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on
> > HV_STATUS_INVALID_CONNECTION_ID
> >
> > Dexuan Cui <decui@microsoft.com> writes:
> >
> > >> -----Original Message-----
> > >> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
> > >> Sent: Thursday, January 29, 2015 21:31 PM
> > >> To: Dexuan Cui
> > >> Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org;
> > >> driverdev- devel@linuxdriverproject.org; olaf@aepfle.de;
> > >> apw@canonical.com; jasowang@redhat.com; KY Srinivasan; Haiyang
> > >> Zhang
> > >> Subject: Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on
> > >> HV_STATUS_INVALID_CONNECTION_ID
> > >>
> > >> Dexuan Cui <decui@microsoft.com> writes:
> > >>
> > >> > I got the hypercall error code on Hyper-V 2008 R2 when keeping
> > >> > running "rmmod hv_netvsc; modprobe hv_netvsc; rmmod hv_utils;
> > >> > modprobe
> > hv_utils"
> > >> > in a Linux guest.
> > >> >
> > >> > Without the patch, the driver can occasionally fail to load.
> > >> >
> > >> > CC: "K. Y. Srinivasan" <kys@microsoft.com>
> > >> > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > >> > ---
> > >> > arch/x86/include/uapi/asm/hyperv.h | 1 +
> > >> > drivers/hv/connection.c | 9 +++++++++
> > >> > 2 files changed, 10 insertions(+)
> > >> >
> > >> > diff --git a/arch/x86/include/uapi/asm/hyperv.h
> > >> b/arch/x86/include/uapi/asm/hyperv.h
> > >> > index 90c458e..b9daffb 100644
> > >> > --- a/arch/x86/include/uapi/asm/hyperv.h
> > >> > +++ b/arch/x86/include/uapi/asm/hyperv.h
> > >> > @@ -225,6 +225,7 @@
> > >> > #define HV_STATUS_INVALID_HYPERCALL_CODE 2
> > >> > #define HV_STATUS_INVALID_HYPERCALL_INPUT 3
> > >> > #define HV_STATUS_INVALID_ALIGNMENT 4
> > >> > +#define HV_STATUS_INVALID_CONNECTION_ID 18
> > >> > #define HV_STATUS_INSUFFICIENT_BUFFERS 19
> > >>
> > >> The gap beween 4 and 18 tells me there are other codes here ;-) Are
> > >> they all 'permanent failures'?
> > > It looks we only need to care about these error codes here.
> > >
> > > BTW, you can get all the hypercall error codes in the top level functional
> spec:
> > > http://blogs.msdn.com/b/virtual_pc_guy/archive/2014/02/17/updated-
> > hypervisor-top-level-functional-specification.aspx
> > > For this hypercall (0x005c), see "14.9.7 HvPostMessage".
> >
> > Thanks, interesting!
> >
> > Btw, HV_STATUS_INSUFFICIENT_MEMORY looks suspicious, looks like we
> can
> > hit it as well...
> >
> > I suggest we split all failures here in 2 classes:
> > 1) permanent
> > 2) worth retrying
> >
> > and treat them accordingly (no big changes, just maybe group them
> > within
> > hv_post_message() together as it is the only place where these codes
> > are being used).
> Thanks for the suggestion, Vitaly!
> I'll send out v2.
Thanks Dexuan.
K. Y
^ permalink raw reply [flat|nested] 15+ messages in thread
end of thread, other threads:[~2015-02-01 19:48 UTC | newest]
Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-01-29 11:02 [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID Dexuan Cui
2015-01-29 11:02 ` Dexuan Cui
2015-01-29 13:30 ` Vitaly Kuznetsov
2015-01-29 13:30 ` Vitaly Kuznetsov
2015-01-30 5:30 ` Dexuan Cui
2015-01-30 5:30 ` Dexuan Cui
2015-01-30 17:29 ` Vitaly Kuznetsov
2015-01-30 17:29 ` Vitaly Kuznetsov
2015-02-01 3:37 ` Dexuan Cui
2015-02-01 3:37 ` Dexuan Cui
2015-02-01 19:48 ` KY Srinivasan
2015-02-01 19:48 ` KY Srinivasan
2015-01-30 2:47 ` Jason Wang
2015-01-30 5:34 ` Dexuan Cui
2015-01-30 5:34 ` Dexuan Cui
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