This is a preparation for the proposal "allow setting up shared memory areas
between VMs from xl config file". See:
V2: https://lists.xen.org/archives/html/xen-devel/2017-06/msg02256.html
V1: https://lists.xen.org/archives/html/xen-devel/2017-05/msg01288.html
The plan is to use XENMEM_add_to_physmap_batch in xl to map foregin pages from
one DomU to another so that the page could be shared. But currently there is no
wrapper for XENMEM_add_to_physmap_batch in libxc, so we just add a wrapper for
it.
Signed-off-by: Zhongze Liu <blacksk...@gmail.com>
---
Changed Since v2:
* fix coding style issue
* let rc = 1 on buffer bouncing failures
Changed Since v1:
* explain why such a sudden wrapper
* change the parameters' types
Cc: Ian Jackson <ian.jack...@eu.citrix.com>,
Cc: Wei Liu <wei.l...@citrix.com>,
Cc: Stefano Stabellini <sstabell...@kernel.org>
Cc: Julien Grall <julien.gr...@arm.com>
Cc: Jan Beulich <jbeul...@suse.com
---
tools/libxc/include/xenctrl.h | 9 +++++++++
tools/libxc/xc_domain.c | 45 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 54 insertions(+)
diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index 1629f412dd..9501818558 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -1372,6 +1372,15 @@ int xc_domain_add_to_physmap(xc_interface *xch,
unsigned long idx,
xen_pfn_t gpfn);
+int xc_domain_add_to_physmap_batch(xc_interface *xch,
+ domid_t domid,
+ domid_t foreign_domid,
+ unsigned int space,
+ unsigned int size,
+ xen_ulong_t *idxs,
+ xen_pfn_t *gfpns,
+ int *errs);
+
int xc_domain_populate_physmap(xc_interface *xch,
uint32_t domid,
unsigned long nr_extents,
diff --git a/tools/libxc/xc_domain.c b/tools/libxc/xc_domain.c
index 5d192ea0e4..3bab4e8bab 100644
--- a/tools/libxc/xc_domain.c
+++ b/tools/libxc/xc_domain.c
@@ -1032,6 +1032,51 @@ int xc_domain_add_to_physmap(xc_interface *xch,
return do_memory_op(xch, XENMEM_add_to_physmap, &xatp, sizeof(xatp));
}
+int xc_domain_add_to_physmap_batch(xc_interface *xch,
+ domid_t domid,
+ domid_t foreign_domid,
+ unsigned int space,
+ unsigned int size,
+ xen_ulong_t *idxs,
+ xen_pfn_t *gpfns,
+ int *errs)
+{
+ int rc;
+ DECLARE_HYPERCALL_BOUNCE(idxs, size * sizeof(*idxs),
XC_HYPERCALL_BUFFER_BOUNCE_IN);
+ DECLARE_HYPERCALL_BOUNCE(gpfns, size * sizeof(*gpfns),
XC_HYPERCALL_BUFFER_BOUNCE_IN);
+ DECLARE_HYPERCALL_BOUNCE(errs, size * sizeof(*errs),
XC_HYPERCALL_BUFFER_BOUNCE_OUT);
+
+ struct xen_add_to_physmap_batch xatp_batch = {
+ .domid = domid,
+ .space = space,
+ .size = size,
+ .u = { .foreign_domid = foreign_domid }
+ };
+
+ if ( xc_hypercall_bounce_pre(xch, idxs) ||
+ xc_hypercall_bounce_pre(xch, gpfns) ||
+ xc_hypercall_bounce_pre(xch, errs) )
+ {
+ PERROR("Could not bounce memory for XENMEM_add_to_physmap_batch");
+ rc = -1;
+ goto out;
+ }
+
+ set_xen_guest_handle(xatp_batch.idxs, idxs);
+ set_xen_guest_handle(xatp_batch.gpfns, gpfns);
+ set_xen_guest_handle(xatp_batch.errs, errs);
+
+ rc = do_memory_op(xch, XENMEM_add_to_physmap_batch,
+ &xatp_batch, sizeof(xatp_batch));
+
+out:
+ xc_hypercall_bounce_post(xch, idxs);
+ xc_hypercall_bounce_post(xch, gpfns);
+ xc_hypercall_bounce_post(xch, errs);
+
+ return rc;
+}
+
int xc_domain_claim_pages(xc_interface *xch,
uint32_t domid,
unsigned long nr_pages)
--
2.13.1
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