Paul Durrant
2011-Dec-14 09:31 UTC
[PATCH 0 of 2] Support for VM generation ID save/restore and migrate
This patch series adds support for preservation of the VM generation ID buffer address in xenstore across save/restore and migrate, and also code to increment the value in all cases except for migration. The vast majority of the code is in second patch. The first patch merely changes the xenstore key name used by hvmloader to store the buffer address.
Paul Durrant
2011-Dec-14 09:31 UTC
[PATCH 1 of 2] Re-name xenstore key used to save VM generation ID buffer address
# HG changeset patch # User Paul Durrant <paul.durrant@citrix.com> # Date 1323854952 0 # Node ID fded65be5d82461e87de54960db14ce8feb4625f # Parent 03138a08366b895d79e143119d4c9c72833cdbcd Re-name xenstore key used to save VM generation ID buffer address. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> diff -r 03138a08366b -r fded65be5d82 tools/firmware/hvmloader/acpi/build.c --- a/tools/firmware/hvmloader/acpi/build.c Fri Dec 09 16:19:36 2011 +0000 +++ b/tools/firmware/hvmloader/acpi/build.c Wed Dec 14 09:29:12 2011 +0000 @@ -309,7 +309,7 @@ unsigned long new_vm_gid(void) if ( snprintf(addr, sizeof(addr), "0x%lx", virt_to_phys(buf)) >= sizeof(addr) ) return 0; - xenstore_write("data/generation-id", addr); + xenstore_write("data/generation-id-address", addr); gid = strtoll(xenstore_read("platform/generation-id", "0"), NULL, 0); *(uint64_t *)buf = gid;
Paul Durrant
2011-Dec-14 09:31 UTC
[PATCH 2 of 2] VM generation ID save/restore and migrate
# HG changeset patch # User Paul Durrant <paul.durrant@citrix.com> # Date 1323854955 0 # Node ID 972927dc84c7e22520f4771d58d4770bf2726816 # Parent fded65be5d82461e87de54960db14ce8feb4625f VM generation ID save/restore and migrate. Add code to track the address of the VM generation ID buffer across a save/restore or migrate, and increment it as necessary. The address of the buffer is written into xenstore by hvmloader at boot time. It must be read from xenstore by the caller of xc_domain_save() and then written back again by the caller of xc_domain_restore(). Signed-off-by: Paul Durrant <paul.durrant@citrix.com> diff -r fded65be5d82 -r 972927dc84c7 tools/libxc/ia64/xc_ia64_linux_restore.c --- a/tools/libxc/ia64/xc_ia64_linux_restore.c Wed Dec 14 09:29:12 2011 +0000 +++ b/tools/libxc/ia64/xc_ia64_linux_restore.c Wed Dec 14 09:29:15 2011 +0000 @@ -548,7 +548,8 @@ int xc_domain_restore(xc_interface *xch, int io_fd, uint32_t dom, unsigned int store_evtchn, unsigned long *store_mfn, unsigned int console_evtchn, unsigned long *console_mfn, - unsigned int hvm, unsigned int pae, int superpages) + unsigned int hvm, unsigned int pae, int superpages, + int no_incr_generationid, unsigned long *vm_generationid_addr) { DECLARE_DOMCTL; int rc = 1; diff -r fded65be5d82 -r 972927dc84c7 tools/libxc/ia64/xc_ia64_linux_save.c --- a/tools/libxc/ia64/xc_ia64_linux_save.c Wed Dec 14 09:29:12 2011 +0000 +++ b/tools/libxc/ia64/xc_ia64_linux_save.c Wed Dec 14 09:29:15 2011 +0000 @@ -382,7 +382,8 @@ out: int xc_domain_save(xc_interface *xch, int io_fd, uint32_t dom, uint32_t max_iters, uint32_t max_factor, uint32_t flags, - struct save_callbacks* callbacks, int hvm) + struct save_callbacks* callbacks, int hvm, + unsigned long vm_generationid_addr) { DECLARE_DOMCTL; xc_dominfo_t info; diff -r fded65be5d82 -r 972927dc84c7 tools/libxc/xc_domain_restore.c --- a/tools/libxc/xc_domain_restore.c Wed Dec 14 09:29:12 2011 +0000 +++ b/tools/libxc/xc_domain_restore.c Wed Dec 14 09:29:15 2011 +0000 @@ -681,6 +681,7 @@ typedef struct { uint64_t console_pfn; uint64_t acpi_ioport_location; uint64_t viridian; + uint64_t vm_generationid_addr; } pagebuf_t; static int pagebuf_init(pagebuf_t* buf) @@ -860,6 +861,17 @@ static int pagebuf_get_one(xc_interface } return compbuf_size; + case XC_SAVE_ID_HVM_GENERATION_ID_ADDR: + /* Skip padding 4 bytes then read the generation id buffer location. */ + if ( RDEXACT(fd, &buf->vm_generationid_addr, sizeof(uint32_t)) || + RDEXACT(fd, &buf->vm_generationid_addr, sizeof(uint64_t)) ) + { + PERROR("error read the generation id buffer location"); + return -1; + } + DPRINTF("read generation id buffer address"); + return pagebuf_get_one(xch, ctx, buf, fd, dom); + default: if ( (count > MAX_BATCH_SIZE) || (count < 0) ) { ERROR("Max batch size exceeded (%d). Giving up.", count); @@ -1248,7 +1260,8 @@ static int apply_batch(xc_interface *xch int xc_domain_restore(xc_interface *xch, int io_fd, uint32_t dom, unsigned int store_evtchn, unsigned long *store_mfn, unsigned int console_evtchn, unsigned long *console_mfn, - unsigned int hvm, unsigned int pae, int superpages) + unsigned int hvm, unsigned int pae, int superpages, + int no_incr_generationid, unsigned long *vm_generationid_addr) { DECLARE_DOMCTL; int rc = 1, frc, i, j, n, m, pae_extended_cr3 = 0, ext_vcpucontext = 0; @@ -1449,6 +1462,39 @@ int xc_domain_restore(xc_interface *xch, xc_set_hvm_param(xch, dom, HVM_PARAM_VM86_TSS, pagebuf.vm86_tss); if ( pagebuf.console_pfn ) console_pfn = pagebuf.console_pfn; + if ( pagebuf.vm_generationid_addr ) { + if ( !no_incr_generationid ) { + unsigned int offset; + unsigned char *buf; + unsigned long long generationid; + + /* + * Map the VM generation id buffer and inject the new value. + */ + + pfn = pagebuf.vm_generationid_addr >> PAGE_SHIFT; + offset = pagebuf.vm_generationid_addr & (PAGE_SIZE - 1); + + if ( (pfn >= dinfo->p2m_size) || + (pfn_type[pfn] != XEN_DOMCTL_PFINFO_NOTAB) ) + { + ERROR("generation id buffer frame is bad"); + goto out; + } + + mfn = ctx->p2m[pfn]; + buf = xc_map_foreign_range(xch, dom, PAGE_SIZE, + PROT_READ | PROT_WRITE, mfn); + + generationid = *(unsigned long long *)(buf + offset); + *(unsigned long long *)(buf + offset) = generationid + 1; + + munmap(buf, PAGE_SIZE); + } + + *vm_generationid_addr = pagebuf.vm_generationid_addr; + } + break; /* our work here is done */ } diff -r fded65be5d82 -r 972927dc84c7 tools/libxc/xc_domain_save.c --- a/tools/libxc/xc_domain_save.c Wed Dec 14 09:29:12 2011 +0000 +++ b/tools/libxc/xc_domain_save.c Wed Dec 14 09:29:15 2011 +0000 @@ -804,7 +804,8 @@ static int save_tsc_info(xc_interface *x int xc_domain_save(xc_interface *xch, int io_fd, uint32_t dom, uint32_t max_iters, uint32_t max_factor, uint32_t flags, - struct save_callbacks* callbacks, int hvm) + struct save_callbacks* callbacks, int hvm, + unsigned long vm_generationid_addr) { xc_dominfo_t info; DECLARE_DOMCTL; @@ -1616,6 +1617,16 @@ int xc_domain_save(xc_interface *xch, in uint64_t data; } chunk = { 0, }; + chunk.id = XC_SAVE_ID_HVM_GENERATION_ID_ADDR; + chunk.data = vm_generationid_addr; + + if ( (chunk.data != 0) && + wrexact(io_fd, &chunk, sizeof(chunk)) ) + { + PERROR("Error when writing the generation id buffer location for guest"); + goto out; + } + chunk.id = XC_SAVE_ID_HVM_IDENT_PT; chunk.data = 0; xc_get_hvm_param(xch, dom, HVM_PARAM_IDENT_PT, diff -r fded65be5d82 -r 972927dc84c7 tools/libxc/xenguest.h --- a/tools/libxc/xenguest.h Wed Dec 14 09:29:12 2011 +0000 +++ b/tools/libxc/xenguest.h Wed Dec 14 09:29:15 2011 +0000 @@ -58,7 +58,8 @@ struct save_callbacks { */ int xc_domain_save(xc_interface *xch, int io_fd, uint32_t dom, uint32_t max_iters, uint32_t max_factor, uint32_t flags /* XCFLAGS_xxx */, - struct save_callbacks* callbacks, int hvm); + struct save_callbacks* callbacks, int hvm, + unsigned long vm_generationid_addr); /** @@ -72,12 +73,15 @@ int xc_domain_save(xc_interface *xch, in * @parm hvm non-zero if this is a HVM restore * @parm pae non-zero if this HVM domain has PAE support enabled * @parm superpages non-zero to allocate guest memory with superpages + * @parm no_incr_generationid non-zero if generation id is NOT to be incremented + * @parm vm_generationid_addr returned with the address of the generation id buffer * @return 0 on success, -1 on failure */ int xc_domain_restore(xc_interface *xch, int io_fd, uint32_t dom, unsigned int store_evtchn, unsigned long *store_mfn, unsigned int console_evtchn, unsigned long *console_mfn, - unsigned int hvm, unsigned int pae, int superpages); + unsigned int hvm, unsigned int pae, int superpages, + int no_incr_generationid, unsigned long *vm_generationid_addr); /** * xc_domain_restore writes a file to disk that contains the device * model saved state. diff -r fded65be5d82 -r 972927dc84c7 tools/libxc/xg_save_restore.h --- a/tools/libxc/xg_save_restore.h Wed Dec 14 09:29:12 2011 +0000 +++ b/tools/libxc/xg_save_restore.h Wed Dec 14 09:29:15 2011 +0000 @@ -253,6 +253,7 @@ #define XC_SAVE_ID_HVM_VIRIDIAN -11 #define XC_SAVE_ID_COMPRESSED_DATA -12 /* Marker to indicate arrival of compressed data */ #define XC_SAVE_ID_ENABLE_COMPRESSION -13 /* Marker to enable compression logic at receiver side */ +#define XC_SAVE_ID_HVM_GENERATION_ID_ADDR -14 /* ** We process save/restore/migrate in batches of pages; the below diff -r fded65be5d82 -r 972927dc84c7 tools/libxl/libxl_create.c --- a/tools/libxl/libxl_create.c Wed Dec 14 09:29:12 2011 +0000 +++ b/tools/libxl/libxl_create.c Wed Dec 14 09:29:15 2011 +0000 @@ -99,6 +99,7 @@ int libxl_init_build_info(libxl_ctx *ctx b_info->u.hvm.vpt_align = 1; b_info->u.hvm.timer_mode = 1; b_info->u.hvm.nested_hvm = 0; + b_info->u.hvm.no_incr_generationid = 0; break; case LIBXL_DOMAIN_TYPE_PV: b_info->u.pv.slack_memkb = 8 * 1024; diff -r fded65be5d82 -r 972927dc84c7 tools/libxl/libxl_dom.c --- a/tools/libxl/libxl_dom.c Wed Dec 14 09:29:12 2011 +0000 +++ b/tools/libxl/libxl_dom.c Wed Dec 14 09:29:15 2011 +0000 @@ -124,7 +124,7 @@ int libxl__build_post(libxl__gc *gc, uin if (info->cpuid != NULL) libxl_cpuid_set(ctx, domid, info->cpuid); - ents = libxl__calloc(gc, 12 + (info->max_vcpus * 2) + 2, sizeof(char *)); + ents = libxl__calloc(gc, 14 + (info->max_vcpus * 2) + 2, sizeof(char *)); ents[0] = "memory/static-max"; ents[1] = libxl__sprintf(gc, "%d", info->max_memkb); ents[2] = "memory/target"; @@ -137,9 +137,11 @@ int libxl__build_post(libxl__gc *gc, uin ents[9] = libxl__sprintf(gc, "%"PRIu32, state->store_port); ents[10] = "store/ring-ref"; ents[11] = libxl__sprintf(gc, "%lu", state->store_mfn); + ents[12] = "data/generation-id-address"; + ents[13] = libxl__sprintf(gc, "0x%lx", state->vm_generationid_addr); for (i = 0; i < info->max_vcpus; i++) { - ents[12+(i*2)] = libxl__sprintf(gc, "cpu/%d/availability", i); - ents[12+(i*2)+1] = (i && info->cur_vcpus && !(info->cur_vcpus & (1 << i))) + ents[14+(i*2)] = libxl__sprintf(gc, "cpu/%d/availability", i); + ents[14+(i*2)+1] = (i && info->cur_vcpus && !(info->cur_vcpus & (1 << i))) ? "offline" : "online"; } @@ -356,16 +358,19 @@ int libxl__domain_restore_common(libxl__ /* read signature */ int rc; int hvm, pae, superpages; + int no_incr_generationid; switch (info->type) { case LIBXL_DOMAIN_TYPE_HVM: hvm = 1; superpages = 1; pae = info->u.hvm.pae; + no_incr_generationid = info->u.hvm.no_incr_generationid; break; case LIBXL_DOMAIN_TYPE_PV: hvm = 0; superpages = 0; pae = 1; + no_incr_generationid = 0; break; default: return ERROR_INVAL; @@ -373,7 +378,8 @@ int libxl__domain_restore_common(libxl__ rc = xc_domain_restore(ctx->xch, fd, domid, state->store_port, &state->store_mfn, state->console_port, &state->console_mfn, - hvm, pae, superpages); + hvm, pae, superpages, no_incr_generationid, + &state->vm_generationid_addr); if ( rc ) { LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "restoring domain"); return ERROR_FAIL; @@ -539,12 +545,22 @@ int libxl__domain_suspend_common(libxl__ struct save_callbacks callbacks; struct suspendinfo si; int hvm, rc = ERROR_FAIL; + unsigned long vm_generationid_addr; switch (type) { - case LIBXL_DOMAIN_TYPE_HVM: + case LIBXL_DOMAIN_TYPE_HVM: { + char *path; + char *addr; + + path = libxl__sprintf(gc, "%s/data/generation-id-address", libxl__xs_get_dompath(gc, domid)); + addr = libxl__xs_read(gc, XBT_NULL, path); + + vm_generationid_addr = (addr) ? strtoul(addr, NULL, 0) : 0; hvm = 1; break; + } case LIBXL_DOMAIN_TYPE_PV: + vm_generationid_addr = 0; hvm = 0; break; default: @@ -582,7 +598,8 @@ int libxl__domain_suspend_common(libxl__ callbacks.switch_qemu_logdirty = libxl__domain_suspend_common_switch_qemu_logdirty; callbacks.data = &si; - rc = xc_domain_save(ctx->xch, fd, domid, 0, 0, flags, &callbacks, hvm); + rc = xc_domain_save(ctx->xch, fd, domid, 0, 0, flags, &callbacks, + hvm, vm_generationid_addr); if ( rc ) { LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "saving domain: %s", si.guest_responded ? diff -r fded65be5d82 -r 972927dc84c7 tools/libxl/libxl_internal.h --- a/tools/libxl/libxl_internal.h Wed Dec 14 09:29:12 2011 +0000 +++ b/tools/libxl/libxl_internal.h Wed Dec 14 09:29:15 2011 +0000 @@ -218,6 +218,7 @@ typedef struct { uint32_t console_port; unsigned long console_mfn; + unsigned long vm_generationid_addr; } libxl__domain_build_state; _hidden int libxl__build_pre(libxl__gc *gc, uint32_t domid, diff -r fded65be5d82 -r 972927dc84c7 tools/libxl/libxl_types.idl --- a/tools/libxl/libxl_types.idl Wed Dec 14 09:29:12 2011 +0000 +++ b/tools/libxl/libxl_types.idl Wed Dec 14 09:29:15 2011 +0000 @@ -184,6 +184,7 @@ libxl_domain_build_info = Struct("domain ("vpt_align", bool), ("timer_mode", integer), ("nested_hvm", bool), + ("no_incr_generationid", bool), ])), ("pv", Struct(None, [("kernel", libxl_file_reference), ("slack_memkb", uint32), diff -r fded65be5d82 -r 972927dc84c7 tools/libxl/xl_cmdimpl.c --- a/tools/libxl/xl_cmdimpl.c Wed Dec 14 09:29:12 2011 +0000 +++ b/tools/libxl/xl_cmdimpl.c Wed Dec 14 09:29:15 2011 +0000 @@ -360,6 +360,7 @@ static void printf_info(int domid, printf("\t\t\t(vpt_align %d)\n", b_info->u.hvm.vpt_align); printf("\t\t\t(timer_mode %d)\n", b_info->u.hvm.timer_mode); printf("\t\t\t(nestedhvm %d)\n", b_info->u.hvm.nested_hvm); + printf("\t\t\t(no_incr_generationid %d)\n", b_info->u.hvm.no_incr_generationid); printf("\t\t\t(device_model %s)\n", dm_info->device_model ? : "default"); printf("\t\t\t(videoram %d)\n", dm_info->videoram); @@ -1362,6 +1363,7 @@ struct domain_create { const char *restore_file; int migrate_fd; /* -1 means none */ char **migration_domname_r; /* from malloc */ + int no_incr_generationid; }; static int freemem(libxl_domain_build_info *b_info, libxl_device_model_info *dm_info) @@ -1575,6 +1577,8 @@ static int create_domain(struct domain_c } } + d_config.b_info.u.hvm.no_incr_generationid = dom_info->no_incr_generationid; + if (debug || dom_info->dryrun) printf_info(-1, &d_config, &d_config.dm_info); @@ -2800,6 +2804,7 @@ static void migrate_receive(int debug, i dom_info.restore_file = "incoming migration stream"; dom_info.migrate_fd = 0; /* stdin */ dom_info.migration_domname_r = &migration_domname; + dom_info.no_incr_generationid = 1; rc = create_domain(&dom_info); if (rc < 0) { diff -r fded65be5d82 -r 972927dc84c7 tools/python/xen/lowlevel/checkpoint/libcheckpoint.c --- a/tools/python/xen/lowlevel/checkpoint/libcheckpoint.c Wed Dec 14 09:29:12 2011 +0000 +++ b/tools/python/xen/lowlevel/checkpoint/libcheckpoint.c Wed Dec 14 09:29:15 2011 +0000 @@ -175,6 +175,7 @@ int checkpoint_start(checkpoint_state* s { int hvm, rc; int flags = XCFLAGS_LIVE; + unsigned long vm_generationid_addr; if (!s->domid) { s->errstr = "checkpoint state not opened"; @@ -185,16 +186,27 @@ int checkpoint_start(checkpoint_state* s hvm = s->domtype > dt_pv; if (hvm) { + char path[128]; + char *addr; + + sprintf(path, "/local/domain/%u/data/generation-id-address", s->domid); + addr = xs_read(s->xsh, XBT_NULL, path, NULL); + + vm_generationid_addr = (addr) ? strtoul(addr, NULL, 0) : 0; + free(addr); + flags |= XCFLAGS_HVM; if (switch_qemu_logdirty(s, 1)) return -1; + } else { + vm_generationid_addr = 0; } if (remus_flags & CHECKPOINT_FLAGS_COMPRESSION) flags |= XCFLAGS_CHECKPOINT_COMPRESS; callbacks->switch_qemu_logdirty = noop_switch_logdirty; - rc = xc_domain_save(s->xch, fd, s->domid, 0, 0, flags, callbacks, hvm); + rc = xc_domain_save(s->xch, fd, s->domid, 0, 0, flags, callbacks, hvm, vm_generationid_addr); if (hvm) switch_qemu_logdirty(s, 0); diff -r fded65be5d82 -r 972927dc84c7 tools/xcutils/xc_restore.c --- a/tools/xcutils/xc_restore.c Wed Dec 14 09:29:12 2011 +0000 +++ b/tools/xcutils/xc_restore.c Wed Dec 14 09:29:15 2011 +0000 @@ -23,11 +23,12 @@ main(int argc, char **argv) xc_interface *xch; int io_fd, ret; int superpages; - unsigned long store_mfn, console_mfn; + unsigned long store_mfn, console_mfn, vm_generationid_addr; + int no_incr_generationid; - if ( (argc != 8) && (argc != 9) ) + if ( (argc < 8) || (argc > 10) ) errx(1, "usage: %s iofd domid store_evtchn " - "console_evtchn hvm pae apic [superpages]", argv[0]); + "console_evtchn hvm pae apic [superpages [no_incr_generationid]]", argv[0]); xch = xc_interface_open(0,0,0); if ( !xch ) @@ -40,19 +41,25 @@ main(int argc, char **argv) hvm = atoi(argv[5]); pae = atoi(argv[6]); apic = atoi(argv[7]); - if ( argc == 9 ) + if ( argc >= 9 ) superpages = atoi(argv[8]); else superpages = !!hvm; + if ( argc == 10 ) + no_incr_generationid = !atoi(argv[9]); + else + no_incr_generationid = 0; ret = xc_domain_restore(xch, io_fd, domid, store_evtchn, &store_mfn, - console_evtchn, &console_mfn, hvm, pae, superpages); + console_evtchn, &console_mfn, hvm, pae, superpages, + no_incr_generationid, &vm_generationid_addr); if ( ret == 0 ) { printf("store-mfn %li\n", store_mfn); if ( !hvm ) printf("console-mfn %li\n", console_mfn); + printf("vm-gid-addr %lx\n", vm_generationid_addr); fflush(stdout); } diff -r fded65be5d82 -r 972927dc84c7 tools/xcutils/xc_save.c --- a/tools/xcutils/xc_save.c Wed Dec 14 09:29:12 2011 +0000 +++ b/tools/xcutils/xc_save.c Wed Dec 14 09:29:15 2011 +0000 @@ -169,6 +169,10 @@ main(int argc, char **argv) unsigned int maxit, max_f; int io_fd, ret, port; struct save_callbacks callbacks; + char path[128]; + struct xs_handle *xs; + char *addr; + unsigned long vm_generationid_addr; if (argc != 6) errx(1, "usage: %s iofd domid maxit maxf flags", argv[0]); @@ -207,8 +211,21 @@ main(int argc, char **argv) memset(&callbacks, 0, sizeof(callbacks)); callbacks.suspend = suspend; callbacks.switch_qemu_logdirty = switch_qemu_logdirty; + + sprintf(path, "/local/domain/%d/data/generation-id-address", si.domid); + + if ((xs = xs_daemon_open()) == NULL) + errx(1, "Couldn''t contact xenstore"); + + addr = xs_read(xs, XBT_NULL, path, NULL); + + xs_daemon_close(xs); + + vm_generationid_addr = (addr) ? strtoul(addr, NULL, 0) : 0; + free(addr); + ret = xc_domain_save(si.xch, io_fd, si.domid, maxit, max_f, si.flags, - &callbacks, !!(si.flags & XCFLAGS_HVM)); + &callbacks, !!(si.flags & XCFLAGS_HVM), vm_generationid_addr); if (si.suspend_evtchn > 0) xc_suspend_evtchn_release(si.xch, si.xce, si.domid, si.suspend_evtchn);
Ian Campbell
2011-Dec-14 10:11 UTC
Re: [PATCH 1 of 2] Re-name xenstore key used to save VM generation ID buffer address
On Wed, 2011-12-14 at 09:31 +0000, Paul Durrant wrote:> # HG changeset patch > # User Paul Durrant <paul.durrant@citrix.com> > # Date 1323854952 0 > # Node ID fded65be5d82461e87de54960db14ce8feb4625f > # Parent 03138a08366b895d79e143119d4c9c72833cdbcd > Re-name xenstore key used to save VM generation ID buffer address. > > Signed-off-by: Paul Durrant <paul.durrant@citrix.com> > > diff -r 03138a08366b -r fded65be5d82 tools/firmware/hvmloader/acpi/build.c > --- a/tools/firmware/hvmloader/acpi/build.c Fri Dec 09 16:19:36 2011 +0000 > +++ b/tools/firmware/hvmloader/acpi/build.c Wed Dec 14 09:29:12 2011 +0000 > @@ -309,7 +309,7 @@ unsigned long new_vm_gid(void) > if ( snprintf(addr, sizeof(addr), "0x%lx", virt_to_phys(buf)) > >= sizeof(addr) ) > return 0; > - xenstore_write("data/generation-id", addr); > + xenstore_write("data/generation-id-address", addr);data/ seems like an odd home for this, isn''t that the area where guests can expect to store their own bits and bobs, agent stuff etc? Although this key is going to be guest writeable (so hvmloader can write it) it really ought to be off somewhere out of the way. We select the bios with /local/domain/<domid>/hvmloader/bios so perhaps something under there or /local/domain/<domid>/platform? (/me adds "do archaeology and document valid/best-practice xenstore paths to TODO list) Ian.> > gid = strtoll(xenstore_read("platform/generation-id", "0"), NULL, 0); > *(uint64_t *)buf = gid; > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel
Paul Durrant
2011-Dec-14 11:17 UTC
Re: [PATCH 1 of 2] Re-name xenstore key used to save VM generation ID buffer address
> -----Original Message----- > From: Ian Campbell > Sent: 14 December 2011 10:12 > To: Paul Durrant > Cc: xen-devel@lists.xensource.com > Subject: Re: [Xen-devel] [PATCH 1 of 2] Re-name xenstore key used to > save VM generation ID buffer address > > On Wed, 2011-12-14 at 09:31 +0000, Paul Durrant wrote: > > # HG changeset patch > > # User Paul Durrant <paul.durrant@citrix.com> # Date 1323854952 0 > # > > Node ID fded65be5d82461e87de54960db14ce8feb4625f > > # Parent 03138a08366b895d79e143119d4c9c72833cdbcd > > Re-name xenstore key used to save VM generation ID buffer address. > > > > Signed-off-by: Paul Durrant <paul.durrant@citrix.com> > > > > diff -r 03138a08366b -r fded65be5d82 > tools/firmware/hvmloader/acpi/build.c > > --- a/tools/firmware/hvmloader/acpi/build.c Fri Dec 09 16:19:36 > 2011 +0000 > > +++ b/tools/firmware/hvmloader/acpi/build.c Wed Dec 14 09:29:12 > 2011 +0000 > > @@ -309,7 +309,7 @@ unsigned long new_vm_gid(void) > > if ( snprintf(addr, sizeof(addr), "0x%lx", virt_to_phys(buf)) > > >= sizeof(addr) ) > > return 0; > > - xenstore_write("data/generation-id", addr); > > + xenstore_write("data/generation-id-address", addr); > > data/ seems like an odd home for this, isn''t that the area where > guests can expect to store their own bits and bobs, agent stuff etc? >No what data is ''for'' as such. It seemed like a reasonable place to put something created by the guest and for the tools'' consumption. I could move it under hvmloader, but is that the right place? hvmloader/bios is *read* by hvmloader, not written by it. Paul> Although this key is going to be guest writeable (so hvmloader can > write > it) it really ought to be off somewhere out of the way. We select > the bios with /local/domain/<domid>/hvmloader/bios so perhaps > something under there or /local/domain/<domid>/platform? > > (/me adds "do archaeology and document valid/best-practice xenstore > paths to TODO list) > > Ian. > > > > > gid = strtoll(xenstore_read("platform/generation-id", "0"), > NULL, 0); > > *(uint64_t *)buf = gid; > > > > _______________________________________________ > > Xen-devel mailing list > > Xen-devel@lists.xensource.com > > http://lists.xensource.com/xen-devel >
Ian Campbell
2011-Dec-14 11:38 UTC
Re: [PATCH 1 of 2] Re-name xenstore key used to save VM generation ID buffer address
On Wed, 2011-12-14 at 11:17 +0000, Paul Durrant wrote:> > > -----Original Message----- > > From: Ian Campbell > > Sent: 14 December 2011 10:12 > > To: Paul Durrant > > Cc: xen-devel@lists.xensource.com > > Subject: Re: [Xen-devel] [PATCH 1 of 2] Re-name xenstore key used to > > save VM generation ID buffer address > > > > On Wed, 2011-12-14 at 09:31 +0000, Paul Durrant wrote: > > > # HG changeset patch > > > # User Paul Durrant <paul.durrant@citrix.com> # Date 1323854952 0 > > # > > > Node ID fded65be5d82461e87de54960db14ce8feb4625f > > > # Parent 03138a08366b895d79e143119d4c9c72833cdbcd > > > Re-name xenstore key used to save VM generation ID buffer address. > > > > > > Signed-off-by: Paul Durrant <paul.durrant@citrix.com> > > > > > > diff -r 03138a08366b -r fded65be5d82 > > tools/firmware/hvmloader/acpi/build.c > > > --- a/tools/firmware/hvmloader/acpi/build.c Fri Dec 09 16:19:36 > > 2011 +0000 > > > +++ b/tools/firmware/hvmloader/acpi/build.c Wed Dec 14 09:29:12 > > 2011 +0000 > > > @@ -309,7 +309,7 @@ unsigned long new_vm_gid(void) > > > if ( snprintf(addr, sizeof(addr), "0x%lx", virt_to_phys(buf)) > > > >= sizeof(addr) ) > > > return 0; > > > - xenstore_write("data/generation-id", addr); > > > + xenstore_write("data/generation-id-address", addr); > > > > data/ seems like an odd home for this, isn''t that the area where > > guests can expect to store their own bits and bobs, agent stuff etc? > > > > No what data is ''for'' as such. It seemed like a reasonable place to > put something created by the guest and for the tools'' consumption.Although it runs in guest context hvmloader should really be considered an extension of the tools and not part of the guest.> I could move it under hvmloader, but is that the right place? > hvmloader/bios is *read* by hvmloader, not written by it.I think it''s a good as anywhere else. Ian.> > Paul > > > Although this key is going to be guest writeable (so hvmloader can > > write > > it) it really ought to be off somewhere out of the way. We select > > the bios with /local/domain/<domid>/hvmloader/bios so perhaps > > something under there or /local/domain/<domid>/platform? > > > > (/me adds "do archaeology and document valid/best-practice xenstore > > paths to TODO list) > > > > Ian. > > > > > > > > gid = strtoll(xenstore_read("platform/generation-id", "0"), > > NULL, 0); > > > *(uint64_t *)buf = gid; > > > > > > _______________________________________________ > > > Xen-devel mailing list > > > Xen-devel@lists.xensource.com > > > http://lists.xensource.com/xen-devel > > >
Paul Durrant
2011-Dec-14 11:49 UTC
Re: [PATCH 1 of 2] Re-name xenstore key used to save VM generation ID buffer address
> -----Original Message----- > From: Ian Campbell > Sent: 14 December 2011 11:39 > To: Paul Durrant > Cc: xen-devel@lists.xensource.com > Subject: RE: [Xen-devel] [PATCH 1 of 2] Re-name xenstore key used to > save VM generation ID buffer address > > On Wed, 2011-12-14 at 11:17 +0000, Paul Durrant wrote: > > > > > -----Original Message----- > > > From: Ian Campbell > > > Sent: 14 December 2011 10:12 > > > To: Paul Durrant > > > Cc: xen-devel@lists.xensource.com > > > Subject: Re: [Xen-devel] [PATCH 1 of 2] Re-name xenstore key > used to > > > save VM generation ID buffer address > > > > > > On Wed, 2011-12-14 at 09:31 +0000, Paul Durrant wrote: > > > > # HG changeset patch > > > > # User Paul Durrant <paul.durrant@citrix.com> # Date > 1323854952 0 > > > # > > > > Node ID fded65be5d82461e87de54960db14ce8feb4625f > > > > # Parent 03138a08366b895d79e143119d4c9c72833cdbcd > > > > Re-name xenstore key used to save VM generation ID buffer > address. > > > > > > > > Signed-off-by: Paul Durrant <paul.durrant@citrix.com> > > > > > > > > diff -r 03138a08366b -r fded65be5d82 > > > tools/firmware/hvmloader/acpi/build.c > > > > --- a/tools/firmware/hvmloader/acpi/build.c Fri Dec 09 > 16:19:36 > > > 2011 +0000 > > > > +++ b/tools/firmware/hvmloader/acpi/build.c Wed Dec 14 > 09:29:12 > > > 2011 +0000 > > > > @@ -309,7 +309,7 @@ unsigned long new_vm_gid(void) > > > > if ( snprintf(addr, sizeof(addr), "0x%lx", > virt_to_phys(buf)) > > > > >= sizeof(addr) ) > > > > return 0; > > > > - xenstore_write("data/generation-id", addr); > > > > + xenstore_write("data/generation-id-address", addr); > > > > > > data/ seems like an odd home for this, isn''t that the area where > > > guests can expect to store their own bits and bobs, agent stuff > etc? > > > > > > > No what data is ''for'' as such. It seemed like a reasonable place > to > > put something created by the guest and for the tools'' consumption. > > Although it runs in guest context hvmloader should really be > considered an extension of the tools and not part of the guest. > > > I could move it under hvmloader, but is that the right place? > > hvmloader/bios is *read* by hvmloader, not written by it. > > I think it''s a good as anywhere else. >Ok, does that mean that we should create hmvloader as writable by the guest, or should we special-case the generation-id-address key? Paul
Ian Campbell
2011-Dec-14 12:24 UTC
Re: [PATCH 1 of 2] Re-name xenstore key used to save VM generation ID buffer address
On Wed, 2011-12-14 at 11:49 +0000, Paul Durrant wrote:> > -----Original Message----- > > From: Ian Campbell > > Sent: 14 December 2011 11:39 > > To: Paul Durrant > > Cc: xen-devel@lists.xensource.com > > Subject: RE: [Xen-devel] [PATCH 1 of 2] Re-name xenstore key used to > > save VM generation ID buffer address > > > > On Wed, 2011-12-14 at 11:17 +0000, Paul Durrant wrote: > > > > > > > -----Original Message----- > > > > From: Ian Campbell > > > > Sent: 14 December 2011 10:12 > > > > To: Paul Durrant > > > > Cc: xen-devel@lists.xensource.com > > > > Subject: Re: [Xen-devel] [PATCH 1 of 2] Re-name xenstore key > > used to > > > > save VM generation ID buffer address > > > > > > > > On Wed, 2011-12-14 at 09:31 +0000, Paul Durrant wrote: > > > > > # HG changeset patch > > > > > # User Paul Durrant <paul.durrant@citrix.com> # Date > > 1323854952 0 > > > > # > > > > > Node ID fded65be5d82461e87de54960db14ce8feb4625f > > > > > # Parent 03138a08366b895d79e143119d4c9c72833cdbcd > > > > > Re-name xenstore key used to save VM generation ID buffer > > address. > > > > > > > > > > Signed-off-by: Paul Durrant <paul.durrant@citrix.com> > > > > > > > > > > diff -r 03138a08366b -r fded65be5d82 > > > > tools/firmware/hvmloader/acpi/build.c > > > > > --- a/tools/firmware/hvmloader/acpi/build.c Fri Dec 09 > > 16:19:36 > > > > 2011 +0000 > > > > > +++ b/tools/firmware/hvmloader/acpi/build.c Wed Dec 14 > > 09:29:12 > > > > 2011 +0000 > > > > > @@ -309,7 +309,7 @@ unsigned long new_vm_gid(void) > > > > > if ( snprintf(addr, sizeof(addr), "0x%lx", > > virt_to_phys(buf)) > > > > > >= sizeof(addr) ) > > > > > return 0; > > > > > - xenstore_write("data/generation-id", addr); > > > > > + xenstore_write("data/generation-id-address", addr); > > > > > > > > data/ seems like an odd home for this, isn''t that the area where > > > > guests can expect to store their own bits and bobs, agent stuff > > etc? > > > > > > > > > > No what data is ''for'' as such. It seemed like a reasonable place > > to > > > put something created by the guest and for the tools'' consumption. > > > > Although it runs in guest context hvmloader should really be > > considered an extension of the tools and not part of the guest. > > > > > I could move it under hvmloader, but is that the right place? > > > hvmloader/bios is *read* by hvmloader, not written by it. > > > > I think it''s a good as anywhere else. > > > > Ok, does that mean that we should create hmvloader as writable by the > guest, or should we special-case the generation-id-address key?Just the specific key. Ian.
Ian Jackson
2011-Dec-15 17:25 UTC
Re: [PATCH 2 of 2] VM generation ID save/restore and migrate
Paul Durrant writes ("[Xen-devel] [PATCH 2 of 2] VM generation ID save/restore and migrate"):> VM generation ID save/restore and migrate. > > Add code to track the address of the VM generation ID buffer across a > save/restore or migrate, and increment it as necessary. > The address of the buffer is written into xenstore by hvmloader at > boot time. It must be read from xenstore by the caller of > xc_domain_save() and then written back again by the caller of > xc_domain_restore().You need to rewrap some of this now I''m afraid. Ian.
Paul Durrant
2011-Dec-15 17:47 UTC
Re: [PATCH 2 of 2] VM generation ID save/restore and migrate
> -----Original Message----- > From: Ian Jackson [mailto:Ian.Jackson@eu.citrix.com] > Sent: 15 December 2011 17:26 > To: Paul Durrant > Cc: xen-devel@lists.xensource.com > Subject: Re: [Xen-devel] [PATCH 2 of 2] VM generation ID > save/restore and migrate > > Paul Durrant writes ("[Xen-devel] [PATCH 2 of 2] VM generation ID > save/restore and migrate"): > > VM generation ID save/restore and migrate. > > > > Add code to track the address of the VM generation ID buffer > across a > > save/restore or migrate, and increment it as necessary. > > The address of the buffer is written into xenstore by hvmloader at > > boot time. It must be read from xenstore by the caller of > > xc_domain_save() and then written back again by the caller of > > xc_domain_restore(). > > You need to rewrap some of this now I''m afraid. ><sigh> OK, I''ll post a new series. Paul
Possibly Parallel Threads
- [PATCH 0 of 3] Support for VM generation ID save/restore and migrate
- [PATCH 0 of 4] Support for VM generation ID save/restore and migrate
- [PATCH 0 of 6] Add support for a VM generation ID virtual device (v2)
- Bug#710650: Bug#718767: transition: ocaml 4.00.1
- [PATCH v4 00/23] Xenstore stub domain