From f13968b5693d5316f4904cdc32b4327b3974fcc6 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Mon, 12 Aug 2013 15:59:39 +0200 Subject: dump: populate guest_phys_blocks RH-Author: Laszlo Ersek Message-id: <1376323180-12863-10-git-send-email-lersek@redhat.com> Patchwork-id: 53167 O-Subject: [RHEL-7 qemu-kvm PATCH 09/10] dump: populate guest_phys_blocks Bugzilla: 981582 RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Radim Krcmar RH-Acked-by: Miroslav Rezanina While the machine is paused, in guest_phys_blocks_append() we register a one-shot MemoryListener, solely for the initial collection of the valid guest-physical memory ranges that happens at listener registration time. For each range that is reported to guest_phys_blocks_region_add(), we attempt to merge the range with the preceding one. Ranges can only be joined if they are contiguous in both guest-physical address space, and contiguous in host virtual address space. The "maximal" ranges that remain in the end constitute the guest-physical memory map that the dump will be based on. Related RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=981582 Signed-off-by: Laszlo Ersek Signed-off-by: Luiz Capitulino (cherry picked from commit c5d7f60f0614250bd925071e25220ce5958f75d0) Conflicts: memory_mapping.c The conflicts are due to RHEL-7 not having: - upstream commit 182735ef ("cpu: Make first_cpu and next_cpu CPUState"), whose backport I rejected due to its many dependencies, - upstream commit 052e87b0 ("memory: make section size a 128-bit integer"), which seems quite intrusive, and to belong to the middle of a series. diff --git a/dump.c b/dump.c index 351233b..e6b7a00 100644 --- a/dump.c +++ b/dump.c @@ -750,7 +750,7 @@ static int dump_init(DumpState *s, int fd, bool paging, bool has_filter, s->length = length; guest_phys_blocks_init(&s->guest_phys_blocks); - /* FILL LIST */ + guest_phys_blocks_append(&s->guest_phys_blocks); s->start = get_start_block(s); if (s->start == -1) { diff --git a/include/sysemu/memory_mapping.h b/include/sysemu/memory_mapping.h index d2d06cd..b2d7d85 100644 --- a/include/sysemu/memory_mapping.h +++ b/include/sysemu/memory_mapping.h @@ -66,6 +66,7 @@ void memory_mapping_list_init(MemoryMappingList *list); void guest_phys_blocks_free(GuestPhysBlockList *list); void guest_phys_blocks_init(GuestPhysBlockList *list); +void guest_phys_blocks_append(GuestPhysBlockList *list); void qemu_get_guest_memory_mapping(MemoryMappingList *list, Error **errp); diff --git a/memory_mapping.c b/memory_mapping.c index 78a9829..411aba6 100644 --- a/memory_mapping.c +++ b/memory_mapping.c @@ -11,9 +11,15 @@ * */ +#include + #include "cpu.h" #include "exec/cpu-all.h" #include "sysemu/memory_mapping.h" +#include "exec/memory.h" +#include "exec/address-spaces.h" + +//#define DEBUG_GUEST_PHYS_REGION_ADD static void memory_mapping_list_add_mapping_sorted(MemoryMappingList *list, MemoryMapping *mapping) @@ -182,6 +188,84 @@ void guest_phys_blocks_init(GuestPhysBlockList *list) QTAILQ_INIT(&list->head); } +typedef struct GuestPhysListener { + GuestPhysBlockList *list; + MemoryListener listener; +} GuestPhysListener; + +static void guest_phys_blocks_region_add(MemoryListener *listener, + MemoryRegionSection *section) +{ + GuestPhysListener *g; + uint64_t section_size; + hwaddr target_start, target_end; + uint8_t *host_addr; + GuestPhysBlock *predecessor; + + /* we only care about RAM */ + if (!memory_region_is_ram(section->mr)) { + return; + } + + g = container_of(listener, GuestPhysListener, listener); + section_size = section->size; + target_start = section->offset_within_address_space; + target_end = target_start + section_size; + host_addr = memory_region_get_ram_ptr(section->mr) + + section->offset_within_region; + predecessor = NULL; + + /* find continuity in guest physical address space */ + if (!QTAILQ_EMPTY(&g->list->head)) { + hwaddr predecessor_size; + + predecessor = QTAILQ_LAST(&g->list->head, GuestPhysBlockHead); + predecessor_size = predecessor->target_end - predecessor->target_start; + + /* the memory API guarantees monotonically increasing traversal */ + g_assert(predecessor->target_end <= target_start); + + /* we want continuity in both guest-physical and host-virtual memory */ + if (predecessor->target_end < target_start || + predecessor->host_addr + predecessor_size != host_addr) { + predecessor = NULL; + } + } + + if (predecessor == NULL) { + /* isolated mapping, allocate it and add it to the list */ + GuestPhysBlock *block = g_malloc0(sizeof *block); + + block->target_start = target_start; + block->target_end = target_end; + block->host_addr = host_addr; + + QTAILQ_INSERT_TAIL(&g->list->head, block, next); + ++g->list->num; + } else { + /* expand predecessor until @target_end; predecessor's start doesn't + * change + */ + predecessor->target_end = target_end; + } + +#ifdef DEBUG_GUEST_PHYS_REGION_ADD + fprintf(stderr, "%s: target_start=" TARGET_FMT_plx " target_end=" + TARGET_FMT_plx ": %s (count: %u)\n", __FUNCTION__, target_start, + target_end, predecessor ? "joined" : "added", g->list->num); +#endif +} + +void guest_phys_blocks_append(GuestPhysBlockList *list) +{ + GuestPhysListener g = { 0 }; + + g.list = list; + g.listener.region_add = &guest_phys_blocks_region_add; + memory_listener_register(&g.listener, &address_space_memory); + memory_listener_unregister(&g.listener); +} + static CPUArchState *find_paging_enabled_cpu(CPUArchState *start_cpu) { CPUArchState *env;