From 394f0f72fd94595e656af62f079b7680cdbe8add Mon Sep 17 00:00:00 2001 From: Shameer Kolothum Date: Fri, 3 Apr 2020 11:18:26 +0100 Subject: [PATCH] fw_cfg: Migrate ACPI table mr sizes separately Any sub-page size update to ACPI MRs will be lost during migration, as we use aligned size in ram_load_precopy() -> qemu_ram_resize() path. This will result in inconsistency in FWCfgEntry sizes between source and destination. In order to avoid this, save and restore them separately during migration. Up until now, this problem may not be that relevant for x86 as both ACPI table and Linker MRs gets padded and aligned. Also at present, qemu_ram_resize() doesn't invoke callback to update FWCfgEntry for unaligned size changes. But since we are going to fix the qemu_ram_resize() in the subsequent patch, the issue may become more serious especially for RSDP MR case. Moreover, the issue will soon become prominent in arm/virt as well where the MRs are not padded or aligned at all and eventually have acpi table changes as part of future additions like NVDIMM hot-add feature. Suggested-by: David Hildenbrand Signed-off-by: Shameer Kolothum Acked-by: David Hildenbrand Message-Id: <20200403101827.30664-3-shameerali.kolothum.thodi@huawei.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/core/machine.c | 1 + hw/nvram/fw_cfg.c | 91 ++++++++++++++++++++++++++++++++++++++- include/hw/nvram/fw_cfg.h | 6 +++ 3 files changed, 97 insertions(+), 1 deletion(-) diff --git a/hw/core/machine.c b/hw/core/machine.c index de0c425605..c1a444cb75 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -39,6 +39,7 @@ GlobalProperty hw_compat_4_2[] = { { "usb-redir", "suppress-remote-wake", "off" }, { "qxl", "revision", "4" }, { "qxl-vga", "revision", "4" }, + { "fw_cfg", "acpi-mr-restore", "false" }, }; const size_t hw_compat_4_2_len = G_N_ELEMENTS(hw_compat_4_2); diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c index 179b302f01..4be6c9d9fd 100644 --- a/hw/nvram/fw_cfg.c +++ b/hw/nvram/fw_cfg.c @@ -39,6 +39,7 @@ #include "qemu/config-file.h" #include "qemu/cutils.h" #include "qapi/error.h" +#include "hw/acpi/aml-build.h" #define FW_CFG_FILE_SLOTS_DFLT 0x20 @@ -610,6 +611,55 @@ bool fw_cfg_dma_enabled(void *opaque) return s->dma_enabled; } +static bool fw_cfg_acpi_mr_restore(void *opaque) +{ + FWCfgState *s = opaque; + bool mr_aligned; + + mr_aligned = QEMU_IS_ALIGNED(s->table_mr_size, qemu_real_host_page_size) && + QEMU_IS_ALIGNED(s->linker_mr_size, qemu_real_host_page_size) && + QEMU_IS_ALIGNED(s->rsdp_mr_size, qemu_real_host_page_size); + return s->acpi_mr_restore && !mr_aligned; +} + +static void fw_cfg_update_mr(FWCfgState *s, uint16_t key, size_t size) +{ + MemoryRegion *mr; + ram_addr_t offset; + int arch = !!(key & FW_CFG_ARCH_LOCAL); + void *ptr; + + key &= FW_CFG_ENTRY_MASK; + assert(key < fw_cfg_max_entry(s)); + + ptr = s->entries[arch][key].data; + mr = memory_region_from_host(ptr, &offset); + + memory_region_ram_resize(mr, size, &error_abort); +} + +static int fw_cfg_acpi_mr_restore_post_load(void *opaque, int version_id) +{ + FWCfgState *s = opaque; + int i, index; + + assert(s->files); + + index = be32_to_cpu(s->files->count); + + for (i = 0; i < index; i++) { + if (!strcmp(s->files->f[i].name, ACPI_BUILD_TABLE_FILE)) { + fw_cfg_update_mr(s, FW_CFG_FILE_FIRST + i, s->table_mr_size); + } else if (!strcmp(s->files->f[i].name, ACPI_BUILD_LOADER_FILE)) { + fw_cfg_update_mr(s, FW_CFG_FILE_FIRST + i, s->linker_mr_size); + } else if (!strcmp(s->files->f[i].name, ACPI_BUILD_RSDP_FILE)) { + fw_cfg_update_mr(s, FW_CFG_FILE_FIRST + i, s->rsdp_mr_size); + } + } + + return 0; +} + static const VMStateDescription vmstate_fw_cfg_dma = { .name = "fw_cfg/dma", .needed = fw_cfg_dma_enabled, @@ -619,6 +669,20 @@ static const VMStateDescription vmstate_fw_cfg_dma = { }, }; +static const VMStateDescription vmstate_fw_cfg_acpi_mr = { + .name = "fw_cfg/acpi_mr", + .version_id = 1, + .minimum_version_id = 1, + .needed = fw_cfg_acpi_mr_restore, + .post_load = fw_cfg_acpi_mr_restore_post_load, + .fields = (VMStateField[]) { + VMSTATE_UINT64(table_mr_size, FWCfgState), + VMSTATE_UINT64(linker_mr_size, FWCfgState), + VMSTATE_UINT64(rsdp_mr_size, FWCfgState), + VMSTATE_END_OF_LIST() + }, +}; + static const VMStateDescription vmstate_fw_cfg = { .name = "fw_cfg", .version_id = 2, @@ -631,6 +695,7 @@ static const VMStateDescription vmstate_fw_cfg = { }, .subsections = (const VMStateDescription*[]) { &vmstate_fw_cfg_dma, + &vmstate_fw_cfg_acpi_mr, NULL, } }; @@ -815,6 +880,23 @@ static struct { #define FW_CFG_ORDER_OVERRIDE_LAST 200 }; +/* + * Any sub-page size update to these table MRs will be lost during migration, + * as we use aligned size in ram_load_precopy() -> qemu_ram_resize() path. + * In order to avoid the inconsistency in sizes save them seperately and + * migrate over in vmstate post_load(). + */ +static void fw_cfg_acpi_mr_save(FWCfgState *s, const char *filename, size_t len) +{ + if (!strcmp(filename, ACPI_BUILD_TABLE_FILE)) { + s->table_mr_size = len; + } else if (!strcmp(filename, ACPI_BUILD_LOADER_FILE)) { + s->linker_mr_size = len; + } else if (!strcmp(filename, ACPI_BUILD_RSDP_FILE)) { + s->rsdp_mr_size = len; + } +} + static int get_fw_cfg_order(FWCfgState *s, const char *name) { int i; @@ -914,6 +996,7 @@ void fw_cfg_add_file_callback(FWCfgState *s, const char *filename, trace_fw_cfg_add_file(s, index, s->files->f[index].name, len); s->files->count = cpu_to_be32(count+1); + fw_cfg_acpi_mr_save(s, filename, len); } void fw_cfg_add_file(FWCfgState *s, const char *filename, @@ -937,6 +1020,7 @@ void *fw_cfg_modify_file(FWCfgState *s, const char *filename, ptr = fw_cfg_modify_bytes_read(s, FW_CFG_FILE_FIRST + i, data, len); s->files->f[i].size = cpu_to_be32(len); + fw_cfg_acpi_mr_save(s, filename, len); return ptr; } } @@ -973,7 +1057,10 @@ static void fw_cfg_machine_ready(struct Notifier *n, void *data) qemu_register_reset(fw_cfg_machine_reset, s); } - +static Property fw_cfg_properties[] = { + DEFINE_PROP_BOOL("acpi-mr-restore", FWCfgState, acpi_mr_restore, true), + DEFINE_PROP_END_OF_LIST(), +}; static void fw_cfg_common_realize(DeviceState *dev, Error **errp) { @@ -1097,6 +1184,8 @@ static void fw_cfg_class_init(ObjectClass *klass, void *data) dc->reset = fw_cfg_reset; dc->vmsd = &vmstate_fw_cfg; + + device_class_set_props(dc, fw_cfg_properties); } static const TypeInfo fw_cfg_info = { diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h index b5291eefad..25d9307018 100644 --- a/include/hw/nvram/fw_cfg.h +++ b/include/hw/nvram/fw_cfg.h @@ -53,6 +53,12 @@ struct FWCfgState { dma_addr_t dma_addr; AddressSpace *dma_as; MemoryRegion dma_iomem; + + /* restore during migration */ + bool acpi_mr_restore; + uint64_t table_mr_size; + uint64_t linker_mr_size; + uint64_t rsdp_mr_size; }; struct FWCfgIoState {