diff options
author | David Woodhouse <dwmw@amazon.co.uk> | 2022-12-16 18:33:49 +0000 |
---|---|---|
committer | David Woodhouse <dwmw@amazon.co.uk> | 2023-03-01 09:07:52 +0000 |
commit | e33cb789afd3aedbe181b78fd75d04a5c48f7cba (patch) | |
tree | 5e140abf2a1e88595432bd1246d2c4080989bc2c /hw/i386/kvm | |
parent | a28b0fc0345b1ddc12109de807e6d4ce566c1914 (diff) |
hw/xen: Support mapping grant frames
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
Diffstat (limited to 'hw/i386/kvm')
-rw-r--r-- | hw/i386/kvm/xen_gnttab.c | 73 | ||||
-rw-r--r-- | hw/i386/kvm/xen_overlay.c | 2 | ||||
-rw-r--r-- | hw/i386/kvm/xen_overlay.h | 2 |
3 files changed, 75 insertions, 2 deletions
diff --git a/hw/i386/kvm/xen_gnttab.c b/hw/i386/kvm/xen_gnttab.c index ef8857e50c..72e87aea6a 100644 --- a/hw/i386/kvm/xen_gnttab.c +++ b/hw/i386/kvm/xen_gnttab.c @@ -37,13 +37,26 @@ 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)) + struct XenGnttabState { /*< private >*/ SysBusDevice busdev; /*< public >*/ + QemuMutex gnt_lock; + uint32_t nr_frames; uint32_t max_frames; + + union { + grant_entry_v1_t *v1; + /* Theoretically, v2 support could be added here. */ + } entries; + + MemoryRegion gnt_frames; + MemoryRegion *gnt_aliases; + uint64_t *gnt_frame_gpas; }; struct XenGnttabState *xen_gnttab_singleton; @@ -51,6 +64,7 @@ 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"); @@ -58,6 +72,38 @@ 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_do_map_page(&s->gnt_aliases[i], s->gnt_frame_gpas[i]); + } + } + return 0; } static bool xen_gnttab_is_needed(void *opaque) @@ -70,8 +116,11 @@ 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() } }; @@ -106,6 +155,28 @@ 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_IOTHREAD_LOCK_GUARD(); + QEMU_LOCK_GUARD(&s->gnt_lock); + + xen_overlay_do_map_page(&s->gnt_aliases[idx], gpa); + + s->gnt_frame_gpas[idx] = gpa; + + if (s->nr_frames <= idx) { + s->nr_frames = idx + 1; + } + + return 0; } diff --git a/hw/i386/kvm/xen_overlay.c b/hw/i386/kvm/xen_overlay.c index 8685d87959..39fda1b72c 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_do_map_page(MemoryRegion *page, uint64_t gpa) +void xen_overlay_do_map_page(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..75ecb6b359 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_do_map_page(MemoryRegion *page, uint64_t gpa); + #endif /* QEMU_XEN_OVERLAY_H */ |