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". Please look at the object_class_property_add() calls in pc_machine_class_init() [hw/i386/pc.c]. I think the PC_MACHINE_MAX_RAM_BELOW_4G property is a good example to imitate: - It has type "size". - It comes with a getter and a setter, and an associated field in PCMachineState ("max_ram_below_4g"). - It has a nice description. Then in pc_system_flash_map() [hw/i386/pc_sysfw.c], I suggest replacing FLASH_SIZE_LIMIT with "pcms->firmware_max_size". (On a tangent: if the new property mattered for the recently added "microvm" machine type too, i.e., not just i440fx (=pc) and q35, then the function to modify would be the more abstract x86_machine_class_init() [hw/i386/x86.c], rather than pc_machine_class_init(). But the new property does not seem to matter for "microvm".) Thanks Laszlo
