Mailing List Archive

[xen stable-4.17] tools/ocaml/xc: Fix binding for xc_domain_assign_device()
commit afdcc108566e5a4ee352b6427c98ebad6885a81d
Author: Edwin Török <edwin.torok@cloud.com>
AuthorDate: Thu Jan 12 11:38:38 2023 +0000
Commit: Andrew Cooper <andrew.cooper3@citrix.com>
CommitDate: Thu Feb 9 15:55:25 2023 +0000

tools/ocaml/xc: Fix binding for xc_domain_assign_device()

The patch adding this binding was plain broken, and unreviewed. It modified
the C stub to add a 4th parameter without an equivalent adjustment in the
Ocaml side of the bindings.

In 64bit builds, this causes us to dereference whatever dead value is in %rcx
when trying to interpret the rflags parameter.

This has gone unnoticed because Xapi doesn't use this binding (it has its
own), but unbreak the binding by passing RDM_RELAXED unconditionally for
now (matching the libxl default behaviour).

Fixes: 9b34056cb4 ("tools: extend xc_assign_device() to support rdm reservation policy")
Signed-off-by: Edwin Török <edwin.torok@cloud.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 4250683842104f02996428f93927a035c8e19266)
---
tools/ocaml/libs/xc/xenctrl_stubs.c | 17 +++++------------
1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/tools/ocaml/libs/xc/xenctrl_stubs.c b/tools/ocaml/libs/xc/xenctrl_stubs.c
index e25367531b..f376d94334 100644
--- a/tools/ocaml/libs/xc/xenctrl_stubs.c
+++ b/tools/ocaml/libs/xc/xenctrl_stubs.c
@@ -1139,17 +1139,12 @@ CAMLprim value stub_xc_domain_test_assign_device(value xch, value domid, value d
CAMLreturn(Val_bool(ret == 0));
}

-static int domain_assign_device_rdm_flag_table[] = {
- XEN_DOMCTL_DEV_RDM_RELAXED,
-};
-
-CAMLprim value stub_xc_domain_assign_device(value xch, value domid, value desc,
- value rflag)
+CAMLprim value stub_xc_domain_assign_device(value xch, value domid, value desc)
{
- CAMLparam4(xch, domid, desc, rflag);
+ CAMLparam3(xch, domid, desc);
int ret;
int domain, bus, dev, func;
- uint32_t sbdf, flag;
+ uint32_t sbdf;

domain = Int_val(Field(desc, 0));
bus = Int_val(Field(desc, 1));
@@ -1157,10 +1152,8 @@ CAMLprim value stub_xc_domain_assign_device(value xch, value domid, value desc,
func = Int_val(Field(desc, 3));
sbdf = encode_sbdf(domain, bus, dev, func);

- ret = Int_val(Field(rflag, 0));
- flag = domain_assign_device_rdm_flag_table[ret];
-
- ret = xc_assign_device(_H(xch), _D(domid), sbdf, flag);
+ ret = xc_assign_device(_H(xch), _D(domid), sbdf,
+ XEN_DOMCTL_DEV_RDM_RELAXED);

if (ret < 0)
failwith_xc(_H(xch));
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.17