On 09/16/20 11:56, Daniel P. Berrangé wrote: > On Wed, Sep 16, 2020 at 11:52:41AM +0200, Laszlo Ersek wrote: >> Hi Erich, >> >> (1) this patch is really not trivial; please do not continue CC'ing >> qemu-trivial >> >> (2) Please do CC people that have given you feedback previously. I >> primarily mean Daniel and David. >> >> (3) Generally speaking, please post new versions of a patch stand-alone >> (not in reply to another message) on the list. >> >> (4) Please use git-send-email (or suitable wrapper utilities) for >> sending your patch. >> >> https://wiki.qemu.org/Contribute/SubmitAPatch >> >> >> One non-meta comment below: >> >> On 09/15/20 21:10, McMillan, Erich via wrote: >>> Apologies, ignore previous patch. The relevant patch is below: >>> >>> From 473daf6129debf8d158a9ae1aff788c5bdbbc799 Mon Sep 17 00:00:00 2001 >>> From: Erich McMillan <erich.mcmil...@hp.com> >>> Date: Tue, 15 Sep 2020 13:23:25 -0500 >>> Subject: [PATCH 2/2] Add max firmware size as optional parameter >>> >>> Signed-off-by: Erich McMillan <erich.mcmil...@hp.com> >>> --- >>> hw/i386/pc_sysfw.c | 13 ++----------- >>> include/hw/loader.h | 9 +++++++++ >>> qemu-options.hx | 8 ++++++++ >>> softmmu/vl.c | 40 ++++++++++++++++++++++++++++++++++++++++ >>> 4 files changed, 59 insertions(+), 11 deletions(-) >>> >>> diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c >>> index b6c0822..ba6c99d 100644 >>> --- a/hw/i386/pc_sysfw.c >>> +++ b/hw/i386/pc_sysfw.c >>> @@ -39,15 +39,6 @@ >>> #include "hw/block/flash.h" >>> #include "sysemu/kvm.h" >>> >>> -/* >>> - * We don't have a theoretically justifiable exact lower bound on the base >>> - * address of any flash mapping. In practice, the IO-APIC MMIO range is >>> - * [0xFEE00000..0xFEE01000] -- see IO_APIC_DEFAULT_ADDRESS --, leaving free >>> - * only 18MB-4KB below 4G. For now, restrict the cumulative mapping to 8MB >>> in >>> - * size. >>> - */ >>> -#define FLASH_SIZE_LIMIT (8 * MiB) >>> - >>> #define FLASH_SECTOR_SIZE 4096 >>> >>> static void pc_isa_bios_init(MemoryRegion *rom_memory, >>> @@ -182,10 +173,10 @@ static void pc_system_flash_map(PCMachineState *pcms, >>> } >>> if ((hwaddr)size != size >>> || total_size > HWADDR_MAX - size >>> - || total_size + size > FLASH_SIZE_LIMIT) { >>> + || total_size + size > MaxCombinedFirmwareSize) { >>> error_report("combined size of system firmware exceeds " >>> "%" PRIu64 " bytes", >>> - FLASH_SIZE_LIMIT); >>> + MaxCombinedFirmwareSize); >>> exit(1); >>> } >>> >>> diff --git a/include/hw/loader.h b/include/hw/loader.h >>> index a9eeea3..7898b63 100644 >>> --- a/include/hw/loader.h >>> +++ b/include/hw/loader.h >>> @@ -318,4 +318,13 @@ int rom_add_option(const char *file, int32_t >>> bootindex); >>> * overflow on real hardware too. */ >>> #define UBOOT_MAX_GUNZIP_BYTES (64 << 20) >>> >>> +/* >>> + * We don't have a theoretically justifiable exact lower bound on the base >>> + * address of any flash mapping. In practice, the IO-APIC MMIO range is >>> + * [0xFEE00000..0xFEE01000] -- see IO_APIC_DEFAULT_ADDRESS --, leaving free >>> + * only 18MB-4KB below 4G. For now, restrict the cumulative mapping to 8MB >>> in >>> + * size, but allow user to specify larger size via command line. >>> + */ >>> +extern uint64_t MaxCombinedFirmwareSize; >>> + >>> #endif >>> diff --git a/qemu-options.hx b/qemu-options.hx >>> index b0f0205..32eed3a 100644 >>> --- a/qemu-options.hx >>> +++ b/qemu-options.hx >>> @@ -1377,6 +1377,14 @@ SRST >>> |qemu_system_x86| -hda a -hdb b >>> ERST >>> >>> +DEF("maxfirmwaresize", HAS_ARG, QEMU_OPTION_maxfirmwaresize, >>> + "-maxfirmwaresize [size=]megs specify maximum combined firmware size, >>> default is 8MiB. Known issues if value exceeds 16MiB.\n", >>> + QEMU_ARCH_ALL) >>> +SRST >>> +``-maxfirmwaresize [size=]megs`` >>> + Specify maximum combined firmware size, default is 8MiB. Known issues >>> if value exceeds 16MiB. >>> +ERST >>> + >>> DEF("mtdblock", HAS_ARG, QEMU_OPTION_mtdblock, >>> "-mtdblock file use 'file' as on-board Flash memory image\n", >>> QEMU_ARCH_ALL) >>> diff --git a/softmmu/vl.c b/softmmu/vl.c >>> index 0cc86b0..fcf41d2 100644 >>> --- a/softmmu/vl.c >>> +++ b/softmmu/vl.c >>> @@ -116,6 +116,8 @@ >>> >>> #define MAX_VIRTIO_CONSOLES 1 >>> >>> +uint64_t MaxCombinedFirmwareSize = 8 * MiB; >>> + >>> static const char *data_dir[16]; >>> static int data_dir_idx; >>> const char *bios_name = NULL; >>> @@ -448,6 +450,20 @@ static QemuOptsList qemu_mem_opts = { >>> }, >>> }; >>> >>> +static QemuOptsList qemu_max_fw_size_opts = { >>> + .name = "maxfirmwaresize", >>> + .implied_opt_name = "size", >>> + .head = QTAILQ_HEAD_INITIALIZER(qemu_max_fw_size_opts.head), >>> + .merge_lists = true, >>> + .desc = { >>> + { >>> + .name = "size", >>> + .type = QEMU_OPT_SIZE, >>> + }, >>> + { /* end of list */ } >>> + }, >>> +}; >>> + >>> static QemuOptsList qemu_icount_opts = { >>> .name = "icount", >>> .implied_opt_name = "shift", >>> @@ -2576,6 +2592,23 @@ static bool object_create_delayed(const char *type, >>> QemuOpts *opts) >>> return !object_create_initial(type, opts); >>> } >>> >>> +static void set_max_firmware_size(uint64_t *maxfwsize) >>> +{ >>> + const char *max_fw_size_str; >>> + QemuOpts *opts = qemu_find_opts_singleton("maxfirmwaresize"); >>> + >>> + max_fw_size_str = qemu_opt_get(opts, "size"); >>> + >>> + if (max_fw_size_str) { >>> + if (!*max_fw_size_str) { >>> + error_report("missing 'size' option value"); >>> + exit(EXIT_FAILURE); >>> + } >>> + >>> + *maxfwsize = qemu_opt_get_size(opts, "size", 8 * MiB); >>> + } >>> +} >>> + >>> >>> static bool set_memory_options(uint64_t *ram_slots, ram_addr_t >>> *maxram_size, >>> MachineClass *mc) >>> @@ -2904,6 +2937,7 @@ void qemu_init(int argc, char **argv, char **envp) >>> qemu_add_opts(&qemu_machine_opts); >>> qemu_add_opts(&qemu_accel_opts); >>> qemu_add_opts(&qemu_mem_opts); >>> + qemu_add_opts(&qemu_max_fw_size_opts); >>> qemu_add_opts(&qemu_smp_opts); >>> qemu_add_opts(&qemu_boot_opts); >>> qemu_add_opts(&qemu_add_fd_opts); >>> @@ -3160,6 +3194,10 @@ void qemu_init(int argc, char **argv, char **envp) >>> exit(EXIT_FAILURE); >>> } >>> break; >>> + case QEMU_OPTION_maxfirmwaresize: >>> + opts = >>> qemu_opts_parse_noisily(qemu_find_opts("maxfirmwaresize"), >>> + optarg, true); >>> + break; >>> #ifdef CONFIG_TPM >>> case QEMU_OPTION_tpmdev: >>> if (tpm_config_parse(qemu_find_opts("tpmdev"), optarg) < >>> 0) { >>> @@ -3845,6 +3883,8 @@ void qemu_init(int argc, char **argv, char **envp) >>> have_custom_ram_size = set_memory_options(&ram_slots, &maxram_size, >>> machine_class); >>> >>> + set_max_firmware_size(&MaxCombinedFirmwareSize); >>> + >>> os_daemonize(); >>> rcu_disable_atfork(); >>> >> >> (5) In my opinion (which could be wrong of course), we shouldn't >> introduce a new command line option for this, but a new PC machine type >> property called "x-firmware-max-size". > > Yeah, we definitely do not want a new top level CLI arg, just a > machine type property. We don't need any "x-" prefix on it > though, just a plain "firmware-max-size" prop is fine.
According to the previous discussion, I'd like to request that we add the x- prefix (showing that either the property is experimental, or that it is intended in support of experimental use cases). If you disagree, I'll accept that though. Thanks Laszlo
