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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v16 10/11] common: add a new mappable resource type: XENMEM_resource_grant_table
This patch allows grant table frames to be mapped using the
XENMEM_acquire_resource memory op.
NOTE: This patch expands the on-stack mfn_list array in acquire_resource()
but it is still small enough to remain on-stack.
Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Cc: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Tim Deegan <tim@xxxxxxx>
Cc: Wei Liu <wei.liu2@xxxxxxxxxx>
v13:
- Re-work the internals to avoid using the XENMAPIDX_grant_table_status
hack.
v12:
- Dropped limit checks as requested by Jan.
v10:
- Addressed comments from Jan.
v8:
- The functionality was originally incorporated into the earlier patch
"x86/mm: add HYPERVISOR_memory_op to acquire guest resources".
---
xen/common/grant_table.c | 63 +++++++++++++++++++++++++++++++++++++------
xen/common/memory.c | 45 ++++++++++++++++++++++++++++++-
xen/include/public/memory.h | 6 +++++
xen/include/xen/grant_table.h | 4 +++
4 files changed, 109 insertions(+), 9 deletions(-)
diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
index 250450bdda..c4fee21347 100644
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -3770,21 +3770,21 @@ int mem_sharing_gref_to_gfn(struct grant_table *gt,
grant_ref_t ref,
}
#endif
-int gnttab_map_frame(struct domain *d, unsigned long idx, gfn_t gfn,
- mfn_t *mfn)
+/* Caller must hold write lock as version may change and table may grow */
+static int gnttab_get_frame(struct domain *d, bool is_status,
+ unsigned long idx, mfn_t *mfn)
{
- int rc = 0;
struct grant_table *gt = d->grant_table;
-
- grant_write_lock(gt);
+ int rc = 0;
if ( gt->gt_version == 0 )
gt->gt_version = 1;
- if ( gt->gt_version == 2 &&
- (idx & XENMAPIDX_grant_table_status) )
+ if ( is_status )
{
- idx &= ~XENMAPIDX_grant_table_status;
+ if ( gt->gt_version != 2 )
+ return -EINVAL;
+
if ( idx < nr_status_frames(gt) )
*mfn = _mfn(virt_to_mfn(gt->status[idx]));
else
@@ -3801,6 +3801,25 @@ int gnttab_map_frame(struct domain *d, unsigned long
idx, gfn_t gfn,
rc = -EINVAL;
}
+ return rc;
+}
+
+int gnttab_map_frame(struct domain *d, unsigned long idx, gfn_t gfn,
+ mfn_t *mfn)
+{
+ struct grant_table *gt = d->grant_table;
+ bool is_status = false;
+ int rc;
+
+ grant_write_lock(gt);
+
+ if ( idx & XENMAPIDX_grant_table_status )
+ {
+ is_status = true;
+ idx &= ~XENMAPIDX_grant_table_status;
+ }
+
+ rc = gnttab_get_frame(d, is_status, idx, mfn);
if ( !rc )
gnttab_set_frame_gfn(gt, idx, gfn);
@@ -3809,6 +3828,34 @@ int gnttab_map_frame(struct domain *d, unsigned long
idx, gfn_t gfn,
return rc;
}
+int gnttab_get_grant_frame(struct domain *d, unsigned long idx,
+ mfn_t *mfn)
+{
+ struct grant_table *gt = d->grant_table;
+ int rc;
+
+ /* write lock required as version may change and/or table may grow */
+ grant_write_lock(gt);
+ rc = gnttab_get_frame(d, false, idx, mfn);
+ grant_write_unlock(gt);
+
+ return rc;
+}
+
+int gnttab_get_status_frame(struct domain *d, unsigned long idx,
+ mfn_t *mfn)
+{
+ struct grant_table *gt = d->grant_table;
+ int rc;
+
+ /* write lock required as version may change and/or table may grow */
+ grant_write_lock(gt);
+ rc = gnttab_get_frame(d, true, idx, mfn);
+ grant_write_unlock(gt);
+
+ return rc;
+}
+
static void gnttab_usage_print(struct domain *rd)
{
int first = 1;
diff --git a/xen/common/memory.c b/xen/common/memory.c
index 0167d9788b..40d4264d5f 100644
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -23,6 +23,7 @@
#include <xen/numa.h>
#include <xen/mem_access.h>
#include <xen/trace.h>
+#include <xen/grant_table.h>
#include <asm/current.h>
#include <asm/hardirq.h>
#include <asm/p2m.h>
@@ -970,6 +971,43 @@ static long xatp_permission_check(struct domain *d,
unsigned int space)
return xsm_add_to_physmap(XSM_TARGET, current->domain, d);
}
+static int acquire_grant_table(struct domain *d, unsigned int id,
+ unsigned long frame,
+ unsigned int nr_frames,
+ xen_pfn_t mfn_list[])
+{
+ unsigned int i = nr_frames;
+
+ /* Iterate backwards in case table needs to grow */
+ while ( i-- != 0 )
+ {
+ mfn_t mfn = INVALID_MFN;
+ int rc;
+
+ switch ( id )
+ {
+ case XENMEM_resource_grant_table_id_grant:
+ rc = gnttab_get_grant_frame(d, frame + i, &mfn);
+ break;
+
+ case XENMEM_resource_grant_table_id_status:
+ rc = gnttab_get_status_frame(d, frame + i, &mfn);
+ break;
+
+ default:
+ rc = -EINVAL;
+ break;
+ }
+
+ if ( rc )
+ return rc;
+
+ mfn_list[i] = mfn_x(mfn);
+ }
+
+ return 0;
+}
+
static int acquire_resource(
XEN_GUEST_HANDLE_PARAM(xen_mem_acquire_resource_t) arg)
{
@@ -980,7 +1018,7 @@ static int acquire_resource(
* moment since they are small, but if they need to grow in future
* use-cases then per-CPU arrays or heap allocations may be required.
*/
- xen_pfn_t mfn_list[2];
+ xen_pfn_t mfn_list[32];
int rc;
if ( copy_from_guest(&xmar, arg, 1) )
@@ -1015,6 +1053,11 @@ static int acquire_resource(
switch ( xmar.type )
{
+ case XENMEM_resource_grant_table:
+ rc = acquire_grant_table(d, xmar.id, xmar.frame, xmar.nr_frames,
+ mfn_list);
+ break;
+
default:
rc = arch_acquire_resource(d, xmar.type, xmar.id, xmar.frame,
xmar.nr_frames, mfn_list);
diff --git a/xen/include/public/memory.h b/xen/include/public/memory.h
index 838f248a59..d4ed8ba889 100644
--- a/xen/include/public/memory.h
+++ b/xen/include/public/memory.h
@@ -611,14 +611,20 @@ struct xen_mem_acquire_resource {
uint16_t type;
#define XENMEM_resource_ioreq_server 0
+#define XENMEM_resource_grant_table 1
/*
* IN - a type-specific resource identifier, which must be zero
* unless stated otherwise.
*
* type == XENMEM_resource_ioreq_server -> id == ioreq server id
+ * type == XENMEM_resource_grant_table -> id defined below
*/
uint32_t id;
+
+#define XENMEM_resource_grant_table_id_grant 0
+#define XENMEM_resource_grant_table_id_status 1
+
/* IN/OUT - As an IN parameter number of frames of the resource
* to be mapped. However, if the specified value is 0 and
* frame_list is NULL then this field will be set to the
diff --git a/xen/include/xen/grant_table.h b/xen/include/xen/grant_table.h
index b3a95fda58..e9125e43e7 100644
--- a/xen/include/xen/grant_table.h
+++ b/xen/include/xen/grant_table.h
@@ -55,6 +55,10 @@ int mem_sharing_gref_to_gfn(struct grant_table *gt,
grant_ref_t ref,
int gnttab_map_frame(struct domain *d, unsigned long idx, gfn_t gfn,
mfn_t *mfn);
+int gnttab_get_grant_frame(struct domain *d, unsigned long idx,
+ mfn_t *mfn);
+int gnttab_get_status_frame(struct domain *d, unsigned long idx,
+ mfn_t *mfn);
unsigned int gnttab_dom0_frames(void);
--
2.11.0
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