Re: [Xen-devel] [PATCH 09/25] errno: add POSIX error codes EMSGSIZE, ECONNREFUSED to the ABI
>>> On 04.12.18 at 10:10, wrote: > On Mon, Dec 3, 2018 at 7:42 AM Jan Beulich wrote: >> >> >>> On 01.12.18 at 02:32, wrote: >> > http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/errno.h.html >> > describes these codes thus: >> > EMSGSIZE : "Message too large" >> > ECONNREFUSED : "Connection refused". >> >> If you were to go solely by what POSIX mandates to have, more >> additions would be necessary afaict. We had limited ourselves to >> some basic set, so selective additions need further rationale put >> here. The more that for both added error codes the use case in >> the hypervisor isn't immediately obvious. > > Thanks for reviewing the series and the previous iterations of this work. > > I note your other message indicating a preference for including these > changes at point of first use and I will do so in the next revision. Actually, for the error code additions here I wouldn't insist on them getting folded into patches using them, as long as it is explained well here why the additions are desired. > An aside before the rationales below: part of the motivation for > selection of these error codes is to continue alignment with the > modern v4v implementation in uxen where possible. > > EMSGSIZE: > > This series proposes to return EMSGSIZE for a sendv operation (patch > #15) where an excess amount of data, across all iovs, has been > supplied, exceeding either the statically configured maximum size of a > transmittable message, or the (variable) size of the ring registered > by another domain. Ah yes, for a send-like operation I can see its use. > ECONNREFUSED: > > This series proposes to return ECONNREFUSED whenever a remote domain > is specified that either does not exist or is not argo-enabled. > This affects both the ring registration and sending data operations. > (register op, patch #13; sendv op, patch #15) > > ECONNREFUSED seems plausible for this use as it is determined by the > remote domain state within the hypervisor. Makes sense for the not argo-enabled case. The domain not existing case, however, is nothing argo-specific, and we use a pretty consistent -ESRCH in such cases, I think. Jan ___ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
Re: [Xen-devel] [PATCH 09/25] errno: add POSIX error codes EMSGSIZE, ECONNREFUSED to the ABI
On Mon, Dec 3, 2018 at 7:42 AM Jan Beulich wrote: > > >>> On 01.12.18 at 02:32, wrote: > > http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/errno.h.html > > describes these codes thus: > > EMSGSIZE : "Message too large" > > ECONNREFUSED : "Connection refused". > > If you were to go solely by what POSIX mandates to have, more > additions would be necessary afaict. We had limited ourselves to > some basic set, so selective additions need further rationale put > here. The more that for both added error codes the use case in > the hypervisor isn't immediately obvious. Thanks for reviewing the series and the previous iterations of this work. I note your other message indicating a preference for including these changes at point of first use and I will do so in the next revision. An aside before the rationales below: part of the motivation for selection of these error codes is to continue alignment with the modern v4v implementation in uxen where possible. EMSGSIZE: This series proposes to return EMSGSIZE for a sendv operation (patch #15) where an excess amount of data, across all iovs, has been supplied, exceeding either the statically configured maximum size of a transmittable message, or the (variable) size of the ring registered by another domain. If the new code EMSGSIZE is not wanted, an alternative error code could be EINVAL, though that is returned for other errors in the same operation, such as supplying incorrectly sized individual iovs. ECONNREFUSED: This series proposes to return ECONNREFUSED whenever a remote domain is specified that either does not exist or is not argo-enabled. This affects both the ring registration and sending data operations. (register op, patch #13; sendv op, patch #15) ECONNREFUSED seems plausible for this use as it is determined by the remote domain state within the hypervisor. Elsewhere, ENODEV is already used to indicate that the local sending domain cannot perform the operation due to its own state. ENOENT is used in the unregister operation to indicate that the domain's own ring that it is attempting to unregister is not present. ENXIO could work; ECONNREFUSED just seems more descriptive. Are you OK with these new codes if they are used as described here, and melded into the patches which first use them? Christopher ___ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
Re: [Xen-devel] [PATCH 09/25] errno: add POSIX error codes EMSGSIZE, ECONNREFUSED to the ABI
>>> On 01.12.18 at 02:32, wrote: > http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/errno.h.html > describes these codes thus: > EMSGSIZE : "Message too large" > ECONNREFUSED : "Connection refused". If you were to go solely by what POSIX mandates to have, more additions would be necessary afaict. We had limited ourselves to some basic set, so selective additions need further rationale put here. The more that for both added error codes the use case in the hypervisor isn't immediately obvious. Jan ___ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
