From: David Vrabel <david.vrabel@citrix.com>
To: Roger Pau Monne <roger.pau@citrix.com>, Wei Liu <wei.liu2@citrix.com>
Cc: andrew.cooper3@citrix.com,
Ian Jackson <ian.jackson@eu.citrix.com>,
xen-devel@lists.xenproject.org, JBeulich@suse.com,
Ross Lagerwall <ross.lagerwall@citrix.com>
Subject: Re: Returning errno values inside of hypercall structs (was: Re: [PATCH for-4.7 3/4] tools/xsplice: fix mixing system)
Date: Tue, 3 May 2016 11:49:19 +0100 [thread overview]
Message-ID: <5728822F.5010209@citrix.com> (raw)
In-Reply-To: <20160429161619.hy57yirgq7xzwdhd@mac>
On 29/04/16 17:16, Roger Pau Monne wrote:
>
> It has also been suggested that the privcmd driver simply doesn't translate
> error codes at all, and then let the applications figure out if the error
> code comes from Xen or from the OS. IMHO, this is impossible to achieve,
> because the ioctl syscall can return an error code that's been forwarded
> by Xen or a native one, and the application has no way of knowing where is
> it coming from.
The privcmd driver could return the hypercall error in a parameter and
the ioctl return value is for driver errors. For example:
IOCTL_PRIVCMD_HYPERCALL_V2 takes a
struct xen_privcmd_hypercall_v2 {
uint64_t op
uint64_t arg[5]
int64_t ret;
};
This moves all the error code translation into userspace.
David
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prev parent reply other threads:[~2016-05-03 10:49 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-29 16:16 Returning errno values inside of hypercall structs (was: Re: [PATCH for-4.7 3/4] tools/xsplice: fix mixing system) Roger Pau Monne
2016-04-29 16:22 ` Konrad Rzeszutek Wilk
2016-04-29 16:31 ` Roger Pau Monne
2016-04-29 16:59 ` Konrad Rzeszutek Wilk
2016-04-29 17:07 ` Roger Pau Monne
2016-04-29 17:25 ` Konrad Rzeszutek Wilk
2016-04-29 16:26 ` Jan Beulich
2016-05-03 10:49 ` David Vrabel [this message]
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