diff options
| -rw-r--r-- | hw/i386/kvm/meson.build | 1 | ||||
| -rw-r--r-- | hw/i386/kvm/xen_evtchn.c | 1 | ||||
| -rw-r--r-- | hw/i386/kvm/xen_xenstore.c | 252 | ||||
| -rw-r--r-- | hw/i386/kvm/xen_xenstore.h | 20 | ||||
| -rw-r--r-- | hw/i386/pc.c | 2 | ||||
| -rw-r--r-- | target/i386/kvm/xen-emu.c | 12 |
6 files changed, 288 insertions, 0 deletions
diff --git a/hw/i386/kvm/meson.build b/hw/i386/kvm/meson.build index 067ff52..82dd6ae 100644 --- a/hw/i386/kvm/meson.build +++ b/hw/i386/kvm/meson.build @@ -8,6 +8,7 @@ i386_kvm_ss.add(when: 'CONFIG_XEN_EMU', if_true: files( 'xen_overlay.c', 'xen_evtchn.c', 'xen_gnttab.c', + 'xen_xenstore.c', )) i386_ss.add_all(when: 'CONFIG_KVM', if_true: i386_kvm_ss) diff --git a/hw/i386/kvm/xen_evtchn.c b/hw/i386/kvm/xen_evtchn.c index 601fbee..6c39627 100644 --- a/hw/i386/kvm/xen_evtchn.c +++ b/hw/i386/kvm/xen_evtchn.c @@ -34,6 +34,7 @@ #include "xen_evtchn.h" #include "xen_overlay.h" +#include "xen_xenstore.h" #include "sysemu/kvm.h" #include "sysemu/kvm_xen.h" diff --git a/hw/i386/kvm/xen_xenstore.c b/hw/i386/kvm/xen_xenstore.c new file mode 100644 index 0000000..e8abdda --- /dev/null +++ b/hw/i386/kvm/xen_xenstore.c @@ -0,0 +1,252 @@ +/* + * QEMU Xen emulation: Shared/overlay pages support + * + * Copyright © 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved. + * + * Authors: David Woodhouse <dwmw2@infradead.org> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" + +#include "qemu/host-utils.h" +#include "qemu/module.h" +#include "qemu/main-loop.h" +#include "qemu/cutils.h" +#include "qapi/error.h" +#include "qom/object.h" +#include "migration/vmstate.h" + +#include "hw/sysbus.h" +#include "hw/xen/xen.h" +#include "xen_overlay.h" +#include "xen_evtchn.h" +#include "xen_xenstore.h" + +#include "sysemu/kvm.h" +#include "sysemu/kvm_xen.h" + +#include "hw/xen/interface/io/xs_wire.h" +#include "hw/xen/interface/event_channel.h" + +#define TYPE_XEN_XENSTORE "xen-xenstore" +OBJECT_DECLARE_SIMPLE_TYPE(XenXenstoreState, XEN_XENSTORE) + +#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)) + +#define XENSTORE_HEADER_SIZE ((unsigned int)sizeof(struct xsd_sockmsg)) + +struct XenXenstoreState { + /*< private >*/ + SysBusDevice busdev; + /*< public >*/ + + MemoryRegion xenstore_page; + struct xenstore_domain_interface *xs; + uint8_t req_data[XENSTORE_HEADER_SIZE + XENSTORE_PAYLOAD_MAX]; + uint8_t rsp_data[XENSTORE_HEADER_SIZE + XENSTORE_PAYLOAD_MAX]; + uint32_t req_offset; + uint32_t rsp_offset; + bool rsp_pending; + bool fatal_error; + + evtchn_port_t guest_port; + evtchn_port_t be_port; + struct xenevtchn_handle *eh; +}; + +struct XenXenstoreState *xen_xenstore_singleton; + +static void xen_xenstore_event(void *opaque); + +static void xen_xenstore_realize(DeviceState *dev, Error **errp) +{ + XenXenstoreState *s = XEN_XENSTORE(dev); + + if (xen_mode != XEN_EMULATE) { + error_setg(errp, "Xen xenstore support is for Xen emulation"); + return; + } + memory_region_init_ram(&s->xenstore_page, OBJECT(dev), "xen:xenstore_page", + XEN_PAGE_SIZE, &error_abort); + memory_region_set_enabled(&s->xenstore_page, true); + s->xs = memory_region_get_ram_ptr(&s->xenstore_page); + memset(s->xs, 0, XEN_PAGE_SIZE); + + /* We can't map it this early as KVM isn't ready */ + xen_xenstore_singleton = s; + + s->eh = xen_be_evtchn_open(); + if (!s->eh) { + error_setg(errp, "Xenstore evtchn port init failed"); + return; + } + aio_set_fd_handler(qemu_get_aio_context(), xen_be_evtchn_fd(s->eh), true, + xen_xenstore_event, NULL, NULL, NULL, s); +} + +static bool xen_xenstore_is_needed(void *opaque) +{ + return xen_mode == XEN_EMULATE; +} + +static int xen_xenstore_pre_save(void *opaque) +{ + XenXenstoreState *s = opaque; + + if (s->eh) { + s->guest_port = xen_be_evtchn_get_guest_port(s->eh); + } + return 0; +} + +static int xen_xenstore_post_load(void *opaque, int ver) +{ + XenXenstoreState *s = opaque; + + /* + * As qemu/dom0, rebind to the guest's port. The Windows drivers may + * unbind the XenStore evtchn and rebind to it, having obtained the + * "remote" port through EVTCHNOP_status. In the case that migration + * occurs while it's unbound, the "remote" port needs to be the same + * as before so that the guest can find it, but should remain unbound. + */ + if (s->guest_port) { + int be_port = xen_be_evtchn_bind_interdomain(s->eh, xen_domid, + s->guest_port); + if (be_port < 0) { + return be_port; + } + s->be_port = be_port; + } + return 0; +} + +static const VMStateDescription xen_xenstore_vmstate = { + .name = "xen_xenstore", + .version_id = 1, + .minimum_version_id = 1, + .needed = xen_xenstore_is_needed, + .pre_save = xen_xenstore_pre_save, + .post_load = xen_xenstore_post_load, + .fields = (VMStateField[]) { + VMSTATE_UINT8_ARRAY(req_data, XenXenstoreState, + sizeof_field(XenXenstoreState, req_data)), + VMSTATE_UINT8_ARRAY(rsp_data, XenXenstoreState, + sizeof_field(XenXenstoreState, rsp_data)), + VMSTATE_UINT32(req_offset, XenXenstoreState), + VMSTATE_UINT32(rsp_offset, XenXenstoreState), + VMSTATE_BOOL(rsp_pending, XenXenstoreState), + VMSTATE_UINT32(guest_port, XenXenstoreState), + VMSTATE_BOOL(fatal_error, XenXenstoreState), + VMSTATE_END_OF_LIST() + } +}; + +static void xen_xenstore_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->realize = xen_xenstore_realize; + dc->vmsd = &xen_xenstore_vmstate; +} + +static const TypeInfo xen_xenstore_info = { + .name = TYPE_XEN_XENSTORE, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(XenXenstoreState), + .class_init = xen_xenstore_class_init, +}; + +void xen_xenstore_create(void) +{ + DeviceState *dev = sysbus_create_simple(TYPE_XEN_XENSTORE, -1, NULL); + + xen_xenstore_singleton = XEN_XENSTORE(dev); + + /* + * Defer the init (xen_xenstore_reset()) until KVM is set up and the + * overlay page can be mapped. + */ +} + +static void xen_xenstore_register_types(void) +{ + type_register_static(&xen_xenstore_info); +} + +type_init(xen_xenstore_register_types) + +uint16_t xen_xenstore_get_port(void) +{ + XenXenstoreState *s = xen_xenstore_singleton; + if (!s) { + return 0; + } + return s->guest_port; +} + +static void xen_xenstore_event(void *opaque) +{ + XenXenstoreState *s = opaque; + evtchn_port_t port = xen_be_evtchn_pending(s->eh); + if (port != s->be_port) { + return; + } + printf("xenstore event\n"); + /* We know this is a no-op. */ + xen_be_evtchn_unmask(s->eh, port); + qemu_hexdump(stdout, "", s->xs, sizeof(*s->xs)); + xen_be_evtchn_notify(s->eh, s->be_port); +} + +static void alloc_guest_port(XenXenstoreState *s) +{ + struct evtchn_alloc_unbound alloc = { + .dom = DOMID_SELF, + .remote_dom = DOMID_QEMU, + }; + + if (!xen_evtchn_alloc_unbound_op(&alloc)) { + s->guest_port = alloc.port; + } +} + +int xen_xenstore_reset(void) +{ + XenXenstoreState *s = xen_xenstore_singleton; + int err; + + if (!s) { + return -ENOTSUP; + } + + s->req_offset = s->rsp_offset = 0; + s->rsp_pending = false; + + if (!memory_region_is_mapped(&s->xenstore_page)) { + uint64_t gpa = XEN_SPECIAL_PFN(XENSTORE) << TARGET_PAGE_BITS; + xen_overlay_do_map_page(&s->xenstore_page, gpa); + } + + alloc_guest_port(s); + + /* + * As qemu/dom0, bind to the guest's port. For incoming migration, this + * will be unbound as the guest's evtchn table is overwritten. We then + * rebind to the correct guest port in xen_xenstore_post_load(). + */ + err = xen_be_evtchn_bind_interdomain(s->eh, xen_domid, s->guest_port); + if (err < 0) { + return err; + } + s->be_port = err; + + return 0; +} diff --git a/hw/i386/kvm/xen_xenstore.h b/hw/i386/kvm/xen_xenstore.h new file mode 100644 index 0000000..8c3768e --- /dev/null +++ b/hw/i386/kvm/xen_xenstore.h @@ -0,0 +1,20 @@ +/* + * QEMU Xen emulation: Xenstore emulation + * + * Copyright © 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved. + * + * Authors: David Woodhouse <dwmw2@infradead.org> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#ifndef QEMU_XEN_XENSTORE_H +#define QEMU_XEN_XENSTORE_H + +void xen_xenstore_create(void); +int xen_xenstore_reset(void); + +uint16_t xen_xenstore_get_port(void); + +#endif /* QEMU_XEN_XENSTORE_H */ diff --git a/hw/i386/pc.c b/hw/i386/pc.c index 1cf112e..f4a08cc 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -93,6 +93,7 @@ #include "hw/i386/kvm/xen_overlay.h" #include "hw/i386/kvm/xen_evtchn.h" #include "hw/i386/kvm/xen_gnttab.h" +#include "hw/i386/kvm/xen_xenstore.h" #include "hw/mem/memory-device.h" #include "sysemu/replay.h" #include "target/i386/cpu.h" @@ -1862,6 +1863,7 @@ int pc_machine_kvm_type(MachineState *machine, const char *kvm_type) xen_overlay_create(); xen_evtchn_create(); xen_gnttab_create(); + xen_xenstore_create(); } #endif return 0; diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c index d2c88ef..50965b5 100644 --- a/target/i386/kvm/xen-emu.c +++ b/target/i386/kvm/xen-emu.c @@ -27,6 +27,7 @@ #include "hw/i386/kvm/xen_overlay.h" #include "hw/i386/kvm/xen_evtchn.h" #include "hw/i386/kvm/xen_gnttab.h" +#include "hw/i386/kvm/xen_xenstore.h" #include "hw/xen/interface/version.h" #include "hw/xen/interface/sched.h" @@ -179,6 +180,9 @@ int kvm_xen_init(KVMState *s, uint32_t hypercall_msr) return ret; } + /* The page couldn't be overlaid until KVM was initialized */ + xen_xenstore_reset(); + return 0; } @@ -789,6 +793,9 @@ static bool handle_get_param(struct kvm_xen_exit *exit, X86CPU *cpu, case HVM_PARAM_STORE_PFN: hp.value = XEN_SPECIAL_PFN(XENSTORE); break; + case HVM_PARAM_STORE_EVTCHN: + hp.value = xen_xenstore_get_port(); + break; default: return false; } @@ -1383,6 +1390,11 @@ int kvm_xen_soft_reset(void) return err; } + err = xen_xenstore_reset(); + if (err) { + return err; + } + return 0; } |