From dbb3c4d0a458f4bca91ec50ac81f5f7a739f8729 Mon Sep 17 00:00:00 2001 From: Ian Jackson Date: Fri, 4 May 2018 16:00:42 +0100 Subject: [PATCH] libxc: Provide access to internal handles MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit In order to support auditing of qemu depriv, my audit tool wants to know the fd of a privcmd handle on which it can easily make hypercalls. xencall provides such a handle, but has no cooked facilities for making hypercalls. So I open a libxc handle. That means I need to get the privcmd fd out of the libxc handle. ISTM that it is best to do this by providing an interface to get the underlying library handles for a libxc handle. This kind of interface is quite common elsewhere and has not caused problems. libxc is not a stable API so the downside risk of providing this access is not significant. Signed-off-by: Ian Jackson Acked-by: Wei Liu Reviewed-by: Roger Pau Monné --- tools/libxc/include/xenctrl.h | 10 ++++++++++ tools/libxc/xc_private.c | 15 +++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h index 580d2cdb06..5520c942d1 100644 --- a/tools/libxc/include/xenctrl.h +++ b/tools/libxc/include/xenctrl.h @@ -183,6 +183,16 @@ enum xc_open_flags { */ int xc_interface_close(xc_interface *xch); +/** + * Return the handles which xch has opened and will use for + * hypercalls, foreign memory accesses and device model operations. + * These may be used with the corresponding libraries so long as the + * xch itself remains open. + */ +struct xencall_handle *xc_interface_xcall_handle(xc_interface *xch); +struct xenforeignmemory_handle *xc_interface_fmem_handle(xc_interface *xch); +struct xendevicemodel_handle *xc_interface_dmod_handle(xc_interface *xch); + /* * HYPERCALL SAFE MEMORY BUFFER * diff --git a/tools/libxc/xc_private.c b/tools/libxc/xc_private.c index e6e3d9913c..90974d572e 100644 --- a/tools/libxc/xc_private.c +++ b/tools/libxc/xc_private.c @@ -104,6 +104,21 @@ int xc_interface_close(xc_interface *xch) return rc; } +xencall_handle *xc_interface_xcall_handle(xc_interface *xch) +{ + return xch->xcall; +} + +struct xenforeignmemory_handle *xc_interface_fmem_handle(xc_interface *xch) +{ + return xch->fmem; +} + +struct xendevicemodel_handle *xc_interface_dmod_handle(xc_interface *xch) +{ + return xch->dmod; +} + static pthread_key_t errbuf_pkey; static pthread_once_t errbuf_pkey_once = PTHREAD_ONCE_INIT; -- 2.30.2