From: David Woodhouse <d...@amazon.co.uk>
Signed-off-by: David Woodhouse <d...@amazon.co.uk>
---
hw/i386/kvm/xen_gnttab.c | 83 ++++++++++++++++++++++++++++++++++++++-
hw/i386/kvm/xen_overlay.c | 2 +-
hw/i386/kvm/xen_overlay.h | 2 +
3 files changed, 85 insertions(+), 2 deletions(-)
diff --git a/hw/i386/kvm/xen_gnttab.c b/hw/i386/kvm/xen_gnttab.c
index 7a441445cd..00627648ef 100644
--- a/hw/i386/kvm/xen_gnttab.c
+++ b/hw/i386/kvm/xen_gnttab.c
@@ -9,6 +9,8 @@
* See the COPYING file in the top-level directory.
*/
+#define __XEN_INTERFACE_VERSION__ 0x00040e00
+
#include "qemu/osdep.h"
#include "qemu/host-utils.h"
#include "qemu/module.h"
@@ -36,20 +38,36 @@ OBJECT_DECLARE_SIMPLE_TYPE(XenGnttabState, XEN_GNTTAB)
#define XEN_PAGE_SHIFT 12
#define XEN_PAGE_SIZE (1ULL << XEN_PAGE_SHIFT)
+#define ENTRIES_PER_FRAME_V1 (XEN_PAGE_SIZE / sizeof(grant_entry_v1_t))
+#define ENTRIES_PER_FRAME_V2 (XEN_PAGE_SIZE / sizeof(grant_entry_v2_t))
+
struct XenGnttabState {
/*< private >*/
SysBusDevice busdev;
/*< public >*/
+ QemuMutex gnt_lock;
+
uint32_t nr_frames;
uint32_t max_frames;
+
+ union {
+ grant_entry_v1_t *v1;
+ grant_entry_v2_t *v2;
+ } entries;
+
+ MemoryRegion gnt_frames;
+ MemoryRegion *gnt_aliases;
+ uint64_t *gnt_frame_gpas;
};
struct XenGnttabState *xen_gnttab_singleton;
+
static void xen_gnttab_realize(DeviceState *dev, Error **errp)
{
XenGnttabState *s = XEN_GNTTAB(dev);
+ int i;
if (xen_mode != XEN_EMULATE) {
error_setg(errp, "Xen grant table support is for Xen emulation");
@@ -57,6 +75,39 @@ static void xen_gnttab_realize(DeviceState *dev, Error
**errp)
}
s->nr_frames = 0;
s->max_frames = kvm_xen_get_gnttab_max_frames();
+ memory_region_init_ram(&s->gnt_frames, OBJECT(dev), "xen:grant_table",
+ XEN_PAGE_SIZE * s->max_frames, &error_abort);
+ memory_region_set_enabled(&s->gnt_frames, true);
+ s->entries.v1 = memory_region_get_ram_ptr(&s->gnt_frames);
+ memset(s->entries.v1, 0, XEN_PAGE_SIZE * s->max_frames);
+
+ /* Create individual page-sizes aliases for overlays */
+ s->gnt_aliases = (void *)g_new0(MemoryRegion, s->max_frames);
+ s->gnt_frame_gpas = (void *)g_new(uint64_t, s->max_frames);
+ for (i = 0; i < s->max_frames; i++) {
+ memory_region_init_alias(&s->gnt_aliases[i], OBJECT(dev),
+ NULL, &s->gnt_frames,
+ i * XEN_PAGE_SIZE, XEN_PAGE_SIZE);
+ s->gnt_frame_gpas[i] = INVALID_GPA;
+ }
+
+ qemu_mutex_init(&s->gnt_lock);
+
+ xen_gnttab_singleton = s;
+}
+
+static int xen_gnttab_post_load(void *opaque, int version_id)
+{
+ XenGnttabState *s = XEN_GNTTAB(opaque);
+ uint32_t i;
+
+ for (i = 0; i < s->nr_frames; i++) {
+ if (s->gnt_frame_gpas[i] != INVALID_GPA) {
+ xen_overlay_map_page_locked(&s->gnt_aliases[i],
+ s->gnt_frame_gpas[i]);
+ }
+ }
+ return 0;
}
static bool xen_gnttab_is_needed(void *opaque)
@@ -69,8 +120,11 @@ static const VMStateDescription xen_gnttab_vmstate = {
.version_id = 1,
.minimum_version_id = 1,
.needed = xen_gnttab_is_needed,
+ .post_load = xen_gnttab_post_load,
.fields = (VMStateField[]) {
VMSTATE_UINT32(nr_frames, XenGnttabState),
+ VMSTATE_VARRAY_UINT32(gnt_frame_gpas, XenGnttabState, nr_frames, 0,
+ vmstate_info_uint64, uint64_t),
VMSTATE_END_OF_LIST()
}
};
@@ -105,6 +159,33 @@ type_init(xen_gnttab_register_types)
int xen_gnttab_map_page(uint64_t idx, uint64_t gfn)
{
- return -ENOSYS;
+ XenGnttabState *s = xen_gnttab_singleton;
+ uint64_t gpa = gfn << XEN_PAGE_SHIFT;
+
+ if (!s) {
+ return -ENOTSUP;
+ }
+
+ if (idx >= s->max_frames) {
+ return -EINVAL;
+ }
+
+ qemu_mutex_lock(&s->gnt_lock);
+
+ qemu_mutex_lock_iothread();
+
+ xen_overlay_map_page_locked(&s->gnt_aliases[idx], gpa);
+
+ qemu_mutex_unlock_iothread();
+
+ s->gnt_frame_gpas[idx] = gpa;
+
+ if (s->nr_frames <= idx) {
+ s->nr_frames = idx + 1;
+ }
+
+ qemu_mutex_unlock(&s->gnt_lock);
+
+ return 0;
}
diff --git a/hw/i386/kvm/xen_overlay.c b/hw/i386/kvm/xen_overlay.c
index 7046bd55f1..2b88d846ac 100644
--- a/hw/i386/kvm/xen_overlay.c
+++ b/hw/i386/kvm/xen_overlay.c
@@ -49,7 +49,7 @@ struct XenOverlayState {
struct XenOverlayState *xen_overlay_singleton;
-static void xen_overlay_map_page_locked(MemoryRegion *page, uint64_t gpa)
+void xen_overlay_map_page_locked(MemoryRegion *page, uint64_t gpa)
{
/*
* Xen allows guests to map the same page as many times as it likes
diff --git a/hw/i386/kvm/xen_overlay.h b/hw/i386/kvm/xen_overlay.h
index 5c46a0b036..594d2cba59 100644
--- a/hw/i386/kvm/xen_overlay.h
+++ b/hw/i386/kvm/xen_overlay.h
@@ -21,4 +21,6 @@ int xen_sync_long_mode(void);
int xen_set_long_mode(bool long_mode);
bool xen_is_long_mode(void);
+void xen_overlay_map_page_locked(MemoryRegion *page, uint64_t gpa);
+
#endif /* QEMU_XEN_OVERLAY_H */
--
2.35.3
