Messages in this thread | | | From | Vitaly Kuznetsov <> | Subject | Re: [PATCH 2/3] hv: vmbus_post_msg: retry the hypercall on HV_STATUS_INVALID_CONNECTION_ID | Date | Thu, 29 Jan 2015 14:30:57 +0100 |
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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
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