SeaBIOS

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3783 discussions

Re: [SeaBIOS] [PATCH v4 2/3] romfile-loader: Switch to using named structs
by Laszlo Ersek 17 Feb '17

17 Feb '17

On 02/17/17 07:26, ben(a)skyportsystems.com wrote: > From: Ben Warren <ben(a)skyportsystems.com> > > This is a little cleaner and matches how the command structures are > defined in QEMU. > > Signed-off-by: Ben Warren <ben(a)skyportsystems.com> > --- > src/fw/romfile_loader.c | 34 +++++++++++++++++----------------- > src/fw/romfile_loader.h | 40 ++++++++++++++++++++-------------------- > 2 files changed, 37 insertions(+), 37 deletions(-) Reviewed-by: Laszlo Ersek <lersek(a)redhat.com> Thanks Laszlo > diff --git a/src/fw/romfile_loader.c b/src/fw/romfile_loader.c > index f4b17ff..7737453 100644 > --- a/src/fw/romfile_loader.c > +++ b/src/fw/romfile_loader.c > @@ -35,12 +35,12 @@ static void romfile_loader_allocate(struct romfile_loader_entry_s *entry, > struct romfile_loader_file *file = &files->files[files->nfiles]; > void *data; > int ret; > - unsigned alloc_align = le32_to_cpu(entry->alloc_align); > + unsigned alloc_align = le32_to_cpu(entry->alloc.align); > > if (alloc_align & (alloc_align - 1)) > goto err; > > - switch (entry->alloc_zone) { > + switch (entry->alloc.zone) { > case ROMFILE_LOADER_ALLOC_ZONE_HIGH: > zone = &ZoneHigh; > break; > @@ -52,9 +52,9 @@ static void romfile_loader_allocate(struct romfile_loader_entry_s *entry, > } > if (alloc_align < MALLOC_MIN_ALIGN) > alloc_align = MALLOC_MIN_ALIGN; > - if (entry->alloc_file[ROMFILE_LOADER_FILESZ - 1]) > + if (entry->alloc.file[ROMFILE_LOADER_FILESZ - 1]) > goto err; > - file->file = romfile_find(entry->alloc_file); > + file->file = romfile_find(entry->alloc.file); > if (!file->file || !file->file->size) > return; > data = _malloc(zone, file->file->size, alloc_align); > @@ -80,24 +80,24 @@ static void romfile_loader_add_pointer(struct romfile_loader_entry_s *entry, > { > struct romfile_loader_file *dest_file; > struct romfile_loader_file *src_file; > - unsigned offset = le32_to_cpu(entry->pointer_offset); > + unsigned offset = le32_to_cpu(entry->pointer.offset); > u64 pointer = 0; > > - dest_file = romfile_loader_find(entry->pointer_dest_file, files); > - src_file = romfile_loader_find(entry->pointer_src_file, files); > + dest_file = romfile_loader_find(entry->pointer.dest_file, files); > + src_file = romfile_loader_find(entry->pointer.src_file, files); > > if (!dest_file || !src_file || !dest_file->data || !src_file->data || > - offset + entry->pointer_size < offset || > - offset + entry->pointer_size > dest_file->file->size || > - entry->pointer_size < 1 || entry->pointer_size > 8 || > - entry->pointer_size & (entry->pointer_size - 1)) > + offset + entry->pointer.size < offset || > + offset + entry->pointer.size > dest_file->file->size || > + entry->pointer.size < 1 || entry->pointer.size > 8 || > + entry->pointer.size & (entry->pointer.size - 1)) > goto err; > > - memcpy(&pointer, dest_file->data + offset, entry->pointer_size); > + memcpy(&pointer, dest_file->data + offset, entry->pointer.size); > pointer = le64_to_cpu(pointer); > pointer += (unsigned long)src_file->data; > pointer = cpu_to_le64(pointer); > - memcpy(dest_file->data + offset, &pointer, entry->pointer_size); > + memcpy(dest_file->data + offset, &pointer, entry->pointer.size); > > return; > err: > @@ -108,12 +108,12 @@ static void romfile_loader_add_checksum(struct romfile_loader_entry_s *entry, > struct romfile_loader_files *files) > { > struct romfile_loader_file *file; > - unsigned offset = le32_to_cpu(entry->cksum_offset); > - unsigned start = le32_to_cpu(entry->cksum_start); > - unsigned len = le32_to_cpu(entry->cksum_length); > + unsigned offset = le32_to_cpu(entry->cksum.offset); > + unsigned start = le32_to_cpu(entry->cksum.start); > + unsigned len = le32_to_cpu(entry->cksum.length); > u8 *data; > > - file = romfile_loader_find(entry->cksum_file, files); > + file = romfile_loader_find(entry->cksum.file, files); > > if (!file || !file->data || offset >= file->file->size || > start + len < start || start + len > file->file->size) > diff --git a/src/fw/romfile_loader.h b/src/fw/romfile_loader.h > index 15eab2a..bce3719 100644 > --- a/src/fw/romfile_loader.h > +++ b/src/fw/romfile_loader.h > @@ -11,45 +11,45 @@ struct romfile_loader_entry_s { > u32 command; > union { > /* > - * COMMAND_ALLOCATE - allocate a table from @alloc_file > - * subject to @alloc_align alignment (must be power of 2) > - * and @alloc_zone (can be HIGH or FSEG) requirements. > + * COMMAND_ALLOCATE - allocate a table from @alloc.file > + * subject to @alloc.align alignment (must be power of 2) > + * and @alloc.zone (can be HIGH or FSEG) requirements. > * > * Must appear exactly once for each file, and before > * this file is referenced by any other command. > */ > struct { > - char alloc_file[ROMFILE_LOADER_FILESZ]; > - u32 alloc_align; > - u8 alloc_zone; > - }; > + char file[ROMFILE_LOADER_FILESZ]; > + u32 align; > + u8 zone; > + } alloc; > > /* > * COMMAND_ADD_POINTER - patch the table (originating from > - * @dest_file) at @pointer_offset, by adding a pointer to the table > + * @dest_file) at @pointer.offset, by adding a pointer to the table > * originating from @src_file. 1,2,4 or 8 byte unsigned > - * addition is used depending on @pointer_size. > + * addition is used depending on @pointer.size. > */ > struct { > - char pointer_dest_file[ROMFILE_LOADER_FILESZ]; > - char pointer_src_file[ROMFILE_LOADER_FILESZ]; > - u32 pointer_offset; > - u8 pointer_size; > - }; > + char dest_file[ROMFILE_LOADER_FILESZ]; > + char src_file[ROMFILE_LOADER_FILESZ]; > + u32 offset; > + u8 size; > + } pointer; > > /* > * COMMAND_ADD_CHECKSUM - calculate checksum of the range specified by > - * @cksum_start and @cksum_length fields, > + * @cksum.start and @cksum.length fields, > * and then add the value at @cksum_offset. > * Checksum simply sums -X for each byte X in the range > * using 8-bit math. > */ > struct { > - char cksum_file[ROMFILE_LOADER_FILESZ]; > - u32 cksum_offset; > - u32 cksum_start; > - u32 cksum_length; > - }; > + char file[ROMFILE_LOADER_FILESZ]; > + u32 offset; > + u32 start; > + u32 length; > + } cksum; > > /* padding */ > char pad[124]; >

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Re: [SeaBIOS] [PATCH v4 1/3] QEMU DMA: Add DMA write capability
by Laszlo Ersek 17 Feb '17

17 Feb '17

On 02/17/17 07:26, ben(a)skyportsystems.com wrote: > From: Ben Warren <ben(a)skyportsystems.com> > > This allows BIOS to write data back to QEMU using the DMA interface and > provides a higher-level abstraction to write to a fw_cfg file > > Signed-off-by: Ben Warren <ben(a)skyportsystems.com> > --- > src/fw/paravirt.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ > src/fw/paravirt.h | 3 +++ > 2 files changed, 52 insertions(+) > > diff --git a/src/fw/paravirt.c b/src/fw/paravirt.c > index 6de70f6..75cb992 100644 > --- a/src/fw/paravirt.c > +++ b/src/fw/paravirt.c > @@ -253,6 +253,20 @@ qemu_cfg_read(void *buf, int len) > } > > static void > +qemu_cfg_write(void *buf, int len) > +{ > + if (len == 0) { > + return; > + } > + > + if (qemu_cfg_dma_enabled()) { > + qemu_cfg_dma_transfer(buf, len, QEMU_CFG_DMA_CTL_WRITE); > + } else { > + warn_internalerror(); > + } > +} > + > +static void > qemu_cfg_skip(int len) > { > if (len == 0) { > @@ -280,6 +294,18 @@ qemu_cfg_read_entry(void *buf, int e, int len) > } > } > > +static void > +qemu_cfg_write_entry(void *buf, int e, int len) > +{ > + if (qemu_cfg_dma_enabled()) { > + u32 control = (e << 16) | QEMU_CFG_DMA_CTL_SELECT > + | QEMU_CFG_DMA_CTL_WRITE; > + qemu_cfg_dma_transfer(buf, len, control); > + } else { > + warn_internalerror(); > + } > +} > + > struct qemu_romfile_s { > struct romfile_s file; > int select, skip; > @@ -303,6 +329,29 @@ qemu_cfg_read_file(struct romfile_s *file, void *dst, u32 maxlen) > return file->size; > } > > +int > +qemu_cfg_write_file(void *src, struct romfile_s *file, u32 offset, u32 len) > +{ > + if ((file->size + offset) < len) I think you forgot to fix this up: https://www.seabios.org/pipermail/seabios/2017-February/011130.html The patch is identical to v3 1/2, so other than this, it looks okay to me. Thanks Laszlo > + return -1; > + > + if (!qemu_cfg_dma_enabled() || (file->copy != qemu_cfg_read_file)) { > + warn_internalerror(); > + return -1; > + } > + struct qemu_romfile_s *qfile; > + qfile = container_of(file, struct qemu_romfile_s, file); > + if (offset == 0) { > + /* Do it in one transfer */ > + qemu_cfg_write_entry(src, qfile->select, len); > + } else { > + qemu_cfg_select(qfile->select); > + qemu_cfg_skip(offset); > + qemu_cfg_write(src, len); > + } > + return len; > +} > + > static void > qemu_romfile_add(char *name, int select, int skip, int size) > { > diff --git a/src/fw/paravirt.h b/src/fw/paravirt.h > index d8eb7c4..fb220d8 100644 > --- a/src/fw/paravirt.h > +++ b/src/fw/paravirt.h > @@ -3,6 +3,7 @@ > > #include "config.h" // CONFIG_* > #include "biosvar.h" // GET_GLOBAL > +#include "romfile.h" // struct romfile_s > > // Types of paravirtualized platforms. > #define PF_QEMU (1<<0) > @@ -43,6 +44,7 @@ static inline int runningOnKVM(void) { > #define QEMU_CFG_DMA_CTL_READ 0x02 > #define QEMU_CFG_DMA_CTL_SKIP 0x04 > #define QEMU_CFG_DMA_CTL_SELECT 0x08 > +#define QEMU_CFG_DMA_CTL_WRITE 0x10 > > // QEMU_CFG_DMA ID bit > #define QEMU_CFG_VERSION_DMA 2 > @@ -53,5 +55,6 @@ void qemu_platform_setup(void); > void qemu_cfg_init(void); > > u16 qemu_get_present_cpus_count(void); > +int qemu_cfg_write_file(void *src, struct romfile_s *file, u32 offset, u32 len); > > #endif >

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[PATCH v4 0/3] QEMU: Add capability to write back fw_cfg address to QEMU
by ben＠skyportsystems.com 17 Feb '17

17 Feb '17

From: Ben Warren <ben(a)skyportsystems.com> This patch set adds the capability to write to QEMU across the fw_cfg DMA link. It adds a higher-level command to write the BIOS-allocated address of one fw_cfg file into an arbitrary point within another, writeable fw_cfg file across the above-mentioned link. The initial use case is for Windows VM Generation ID, where QEMU needs to change the contents of fw_cfg data at runtime, while still having BIOS allocate and manage the memory. The final corresponding QEMU patch can be found here: https://www.mail-archive.com/qemu-devel@nongnu.org/msg430490.html v3->v4: - Added a 'src_offset' field in the message so the pointer need not point to the beginning of the file. - Changed the command struct definitions from anonymous to named. v2->v3: - fixed up the qemu_cfg_write* functions to allow writing to an arbitrary offset within the destination file. - Changed function name to COMMAND_WRITE_POINTER and its functionality to not patch memory at all, but write back to a specified offset. v1->v2: - separated patch into two functional units. - changed so writes only occur over the DMA interface. - fixed coding style. - removed change to romfile struct definition (removed new write_back method). Ben Warren (3): QEMU DMA: Add DMA write capability romfile-loader: Switch to using named structs QEMU fw_cfg: Add command to write back address of file src/fw/paravirt.c | 49 ++++++++++++++++++++++++++++++++ src/fw/paravirt.h | 3 ++ src/fw/romfile_loader.c | 74 +++++++++++++++++++++++++++++++++++++------------ src/fw/romfile_loader.h | 63 ++++++++++++++++++++++++++--------------- 4 files changed, 149 insertions(+), 40 deletions(-) -- 2.7.4

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About seabios on ESXi
by Jian LIU/Gmail 16 Feb '17

16 Feb '17

Hi Folks, I try to compile and run seabios on VMware ESXi. However, there is litter document about this target. Any information about this topic is welcome. Thanks, Jian

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Re: [SeaBIOS] [coreboot] How does SeaBIOS transition to Linux?
by Peter Stuge 14 Feb '17

14 Feb '17

Zoran Stojsavljevic wrote: > Did not understand... I must admit! As of my best interpretation > SeaBIOS has 5 functions which makes BIOS legacy: > > get and set variables, get and set real time clock, reset. > > Or maybe, something changed. SeaBIOS implements a whole bunch of legacy BIOS services, including option ROM processing and the BBS. > Where I see e820 table which is to be passed to OS, in order OS to > understand what memory it can use. But I did not find explicitly these > 5 functions. So I need a little help here. Where are these functions? I don't really know what you are refering to, but it doesn't matter.. > Now... How GRUB2 replaces all of these functionalities? It doesn't and is not supposed to. It is only used to load the operating system, not to create a BIOS environment. If you need a legacy BIOS or UEFI then you do not use GRUB2 as (only) payload. > who/what entity is replacing missing SeaBIOS functionalities? None. With GRUB2 as payload, no legacy BIOS environment is present, and that's a good thing. //Peter

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Re: [SeaBIOS] [coreboot] How does SeaBIOS transition to Linux?
by Zoran Stojsavljevic 13 Feb '17

13 Feb '17

Hello Peter, Did not understand... I must admit! As of my best interpretation SeaBIOS has 5 functions which makes BIOS legacy: get and set variables, get and set real time clock, reset. Or maybe, something changed. I went back, to inspect CSM code in SeaBIOS, and found the following: # # General Features # # CONFIG_COREBOOT is not set # CONFIG_QEMU is not set *CONFIG_CSM=y <<==================== set CSM ON* # CONFIG_QEMU_HARDWARE is not set CONFIG_THREADS=y CONFIG_RELOCATE_INIT=y CONFIG_BOOTMENU=y CONFIG_BOOTSPLASH=y CONFIG_BOOTORDER=y CONFIG_ENTRY_EXTRASTACK=y CONFIG_MALLOC_UPPERMEMORY=y CONFIG_ROM_SIZE=0 Then make: Compile checking out/src/hw/pcidevice.o Compile checking out/src/hw/ahci.o Compile checking out/src/hw/pvscsi.o Compile checking out/src/hw/usb-xhci.o Compile checking out/src/hw/usb-hub.o Compile checking out/src/hw/sdcard.o Compile checking out/src/fw/coreboot.o Compile checking out/src/fw/lzmadecode.o Compile checking out/src/fw/multiboot.o *Compile checking out/src/fw/csm.o* Compile checking out/src/fw/biostables.o Compile checking out/src/fw/paravirt.o Compile checking out/src/fw/shadow.o Compile checking out/src/fw/pciinit.o Compile checking out/src/fw/smm.o Compile checking out/src/fw/smp.o Compile checking out/src/fw/mtrr.o Compile checking out/src/fw/xen.o Compile checking out/src/fw/acpi.o Compile checking out/src/fw/mptable.o Compile checking out/src/fw/pirtable.o Compile checking out/src/fw/smbios.o Where I see e820 table which is to be passed to OS, in order OS to understand what memory it can use. But I did not find explicitly these 5 functions. So I need a little help here. Where are these functions? Now... How GRUB2 replaces all of these functionalities? I see what you said here (that GRUB2 is directly implemented into FW, thus skipping MBR), but who/what entity is replacing missing SeaBIOS functionalities? Thank you, Zoran On Sat, Feb 11, 2017 at 2:18 PM, Peter Stuge <peter(a)stuge.se> wrote: > Zoran Stojsavljevic wrote: > > crucial question from me: how Coreboot will work if instead SeaBIOS > > GRUB2 is the payload chosen > > Instead of SeaBIOS reading MBR, GRUB2 will read its configuration > file and operate accordingly. > > > //Peter > > -- > coreboot mailing list: coreboot(a)coreboot.org > https://www.coreboot.org/mailman/listinfo/coreboot >

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coreboot and `Timeout at i8042_flush:71!`
by Paul Menzel 12 Feb '17

12 Feb '17

Dear SeaBIOS folks, coreboots board status repository has some SeaBIOS warnings, and I believe the keyboard doesn’t work in that case. ``` $ git grep 'Timeout at i8042_flush' origin/master -- origin/master:amd/lamar/4.0-9540-gae5ab60/2015-04-30T02:12:19Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! origin/master:amd/olivehill/4.0-7005-gb9a0809/2014-10-08T13:44:17Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! origin/master:amd/olivehillplus/4.0-6942-g4177db5/2014-09-19T19:38:48Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! origin/master:amd/thatcher/4.3-102-g380e167/2016-02-04T18_30_40Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! origin/master:aopen/dxplplusu/4.5-485-g52896c6/2016-12-04T02_03_58Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! origin/master:gizmosphere/gizmo/4.0-9564-g58649b0/2015-05-03T07:14:33Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! origin/master:google/panther/4.0-9491-g64c7791/2015-04-23T21:31:14Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! origin/master:google/panther/4.1-340-gb38b0f2/2015-08-25T18:38:10Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! origin/master:google/panther/4.3-777-g4774bb9/2016-04-18T13_11_58Z/coreboot_console.txt:|7f6bc000| WARNING - Timeout at i8042_flush:71! origin/master:hp/2760p/4.5-906-g3fb6e6e-dirty/2017-01-27T03_04_14Z/coreboot_console.txt:|7feca000| WARNING - Timeout at i8042_flush:71! origin/master:hp/2760p/4.5-911-g9510156/2017-01-28T14_47_33Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! origin/master:hp/2760p/4.5-913-g0f70fbd/2017-01-29T02_16_08Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! origin/master:intel/bayleybay_fsp/4.0-6293-g0b4b230/2014-06-25T23:32:28Z/coreboot_console.txt:|7ba9a000| WARNING - Timeout at i8042_flush:71! origin/master:intel/minnowmax/4.2-429-g4013469/2015-11-30T20_21_41Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! origin/master:intel/minnowmax/4.2-429-g4013469/2015-11-30T20_21_41Z/tests/cbmem-console.log:WARNING - Timeout at i8042_flush:71! origin/master:intel/minnowmax/4.5-306-g00ad7ff/2016-11-17T17_00_43Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! origin/master:intel/minnowmax/4.5-306-g00ad7ff/2016-11-17T17_00_43Z/tests/cbmem-console.log:WARNING - Timeout at i8042_flush:71! origin/master:pcengines/alix2d/4.0-6723-ga0a3727-dirty/2014-08-15T23:01:34Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! origin/master:pcengines/alix2d/4.0-6723-ga0a3727/2014-08-15T01:44:46Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! origin/master:pcengines/apu1/4.4-422-g9aba60e/2016-06-05T08_06_37Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! origin/master:pcengines/apu2/4.5-801-gfeb4ef6/2017-01-11T16_15_42Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! origin/master:siemens/mc_tcu3/4.4-108-g0d4e124/2016-05-09T06_14_45Z/coreboot_console.txt:WARNING - Timeout at i8042_flush:71! ``` I also experience this sometimes on a Lenovo X60, when I load the SeaBIOS ELF file from GRUB with the commands below. ``` > chainloader (cbfsdisk)/img/seabios > boot ``` Every time, the keyboard doesn’t work – on the Lenovo X60 it’s connected over the PS/2 port – the error message `Timeout at i8042_flush:71!` can be seen. Note, that it’s unlikely to be a timing issue, as the keyboard works in the GRUB payload *before*. Any idea, what causes the problem, and is there a way to fix it? Thanks, Paul

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Re: [SeaBIOS] [PATCH v3 2/2] QEMU fw_cfg: Add command to write back address of file
by Laszlo Ersek 09 Feb '17

09 Feb '17

On 02/05/17 18:09, ben(a)skyportsystems.com wrote: > From: Ben Warren <ben(a)skyportsystems.com> > > This command is similar to ADD_POINTER, but instead of patching > memory, it writes the pointer back to QEMU over the DMA interface. > > Signed-off-by: Ben Warren <ben(a)skyportsystems.com> > --- > src/fw/romfile_loader.c | 37 +++++++++++++++++++++++++++++++++++++ > src/fw/romfile_loader.h | 16 ++++++++++------ > 2 files changed, 47 insertions(+), 6 deletions(-) > > diff --git a/src/fw/romfile_loader.c b/src/fw/romfile_loader.c > index f4b17ff..d0ae42b 100644 > --- a/src/fw/romfile_loader.c > +++ b/src/fw/romfile_loader.c > @@ -5,6 +5,7 @@ > #include "romfile.h" // struct romfile_s > #include "malloc.h" // Zone*, _malloc > #include "output.h" // warn_* > +#include "paravirt.h" // qemu_cfg_write_file > > struct romfile_loader_file { > struct romfile_s *file; > @@ -98,7 +99,39 @@ static void romfile_loader_add_pointer(struct romfile_loader_entry_s *entry, > pointer += (unsigned long)src_file->data; > pointer = cpu_to_le64(pointer); > memcpy(dest_file->data + offset, &pointer, entry->pointer_size); > + return; > +err: > + warn_internalerror(); > +} > + > +static void romfile_loader_write_pointer(struct romfile_loader_entry_s *entry, > + struct romfile_loader_files *files) > +{ > + struct romfile_s *dest_file; > + struct romfile_loader_file *src_file; > + unsigned offset = le32_to_cpu(entry->pointer_offset); > + u64 pointer = 0; There's no need to zero-init "pointer" here. It doesn't hurt of course; I just like to avoid initialization if it is useless. > + > + /* Writing back to a file that may not be loaded in RAM */ > + dest_file = romfile_find(entry->pointer_dest_file); > + src_file = romfile_loader_find(entry->pointer_src_file, files); > > + if (!dest_file || !src_file || !src_file->data || > + offset + entry->pointer_size < offset || > + offset + entry->pointer_size > dest_file->size || > + entry->pointer_size < 1 || entry->pointer_size > 8 || > + entry->pointer_size & (entry->pointer_size - 1)) { > + goto err; > + } > + > + pointer = (unsigned long)src_file->data; > + pointer = cpu_to_le64(pointer); > + > + /* Only supported on QEMU */ > + if (qemu_cfg_write_file(&pointer, dest_file, offset, > + entry->pointer_size) != entry->pointer_size) { > + goto err; > + } > return; > err: > warn_internalerror(); > @@ -161,6 +194,10 @@ int romfile_loader_execute(const char *name) > break; > case ROMFILE_LOADER_COMMAND_ADD_CHECKSUM: > romfile_loader_add_checksum(entry, files); > + break; > + case ROMFILE_LOADER_COMMAND_WRITE_POINTER: > + romfile_loader_write_pointer(entry, files); > + break; > default: > /* Skip commands that we don't recognize. */ > break; > diff --git a/src/fw/romfile_loader.h b/src/fw/romfile_loader.h > index 15eab2a..0c0782c 100644 > --- a/src/fw/romfile_loader.h > +++ b/src/fw/romfile_loader.h > @@ -25,10 +25,13 @@ struct romfile_loader_entry_s { > }; > > /* > - * COMMAND_ADD_POINTER - patch the table (originating from > - * @dest_file) at @pointer_offset, by adding a pointer to the table > + * COMMAND_ADD_POINTER & > + * COMMAND_WRITE_POINTER - patch memory (originating from > + * @dest_file) at @pointer.offset, by adding a pointer to the memory > * originating from @src_file. 1,2,4 or 8 byte unsigned > - * addition is used depending on @pointer_size. > + * addition is used depending on @pointer.size. > + * Instead of patching memory, COMMAND_WRITE_POINTER writes the changes > + * to @dest_file back to the host via DMA > */ > struct { > char pointer_dest_file[ROMFILE_LOADER_FILESZ]; In general I think the patch is good, but (similarly to the QEMU case) I quite dislike this kind of repurposing. At the least, please leave the original comment block for COMMAND_ADD_POINTER intact, and add a separate, standalone comment block for COMMAND_WRITE_POINTER. Thanks! Laszlo > @@ -57,9 +60,10 @@ struct romfile_loader_entry_s { > }; > > enum { > - ROMFILE_LOADER_COMMAND_ALLOCATE = 0x1, > - ROMFILE_LOADER_COMMAND_ADD_POINTER = 0x2, > - ROMFILE_LOADER_COMMAND_ADD_CHECKSUM = 0x3, > + ROMFILE_LOADER_COMMAND_ALLOCATE = 0x1, > + ROMFILE_LOADER_COMMAND_ADD_POINTER = 0x2, > + ROMFILE_LOADER_COMMAND_ADD_CHECKSUM = 0x3, > + ROMFILE_LOADER_COMMAND_WRITE_POINTER = 0x4, > }; > > enum { >

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Re: [SeaBIOS] [PATCH v3 1/2] QEMU DMA: Add DMA write capability
by Laszlo Ersek 09 Feb '17

09 Feb '17

On 02/05/17 18:09, ben(a)skyportsystems.com wrote: > From: Ben Warren <ben(a)skyportsystems.com> > > This allows BIOS to write data back to QEMU using the DMA interface and > provides a higher-level abstraction to write to a fw_cfg file > > Signed-off-by: Ben Warren <ben(a)skyportsystems.com> > --- > src/fw/paravirt.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ > src/fw/paravirt.h | 3 +++ > 2 files changed, 52 insertions(+) > > diff --git a/src/fw/paravirt.c b/src/fw/paravirt.c > index 6de70f6..75cb992 100644 > --- a/src/fw/paravirt.c > +++ b/src/fw/paravirt.c > @@ -253,6 +253,20 @@ qemu_cfg_read(void *buf, int len) > } > > static void > +qemu_cfg_write(void *buf, int len) > +{ > + if (len == 0) { > + return; > + } > + > + if (qemu_cfg_dma_enabled()) { > + qemu_cfg_dma_transfer(buf, len, QEMU_CFG_DMA_CTL_WRITE); > + } else { > + warn_internalerror(); > + } > +} > + > +static void > qemu_cfg_skip(int len) > { > if (len == 0) { > @@ -280,6 +294,18 @@ qemu_cfg_read_entry(void *buf, int e, int len) > } > } > > +static void > +qemu_cfg_write_entry(void *buf, int e, int len) > +{ > + if (qemu_cfg_dma_enabled()) { > + u32 control = (e << 16) | QEMU_CFG_DMA_CTL_SELECT > + | QEMU_CFG_DMA_CTL_WRITE; > + qemu_cfg_dma_transfer(buf, len, control); > + } else { > + warn_internalerror(); > + } > +} > + > struct qemu_romfile_s { > struct romfile_s file; > int select, skip; > @@ -303,6 +329,29 @@ qemu_cfg_read_file(struct romfile_s *file, void *dst, u32 maxlen) > return file->size; > } > > +int > +qemu_cfg_write_file(void *src, struct romfile_s *file, u32 offset, u32 len) > +{ > + if ((file->size + offset) < len) > + return -1; I'm confused about this; mathematically, we want to require offset + len <= size If we want to avoid any possibility for overflow in the addition, we can subtract "len": offset <= size - len However, in this case the subtraction needs to be protected, and we end up with the following condition to proceed: size >= len && offset <= size - len If we want a condition for bailing out early, we got to negate the above: size < len || offset > size - len The rest looks good to me. Thanks Laszlo > + > + if (!qemu_cfg_dma_enabled() || (file->copy != qemu_cfg_read_file)) { > + warn_internalerror(); > + return -1; > + } > + struct qemu_romfile_s *qfile; > + qfile = container_of(file, struct qemu_romfile_s, file); > + if (offset == 0) { > + /* Do it in one transfer */ > + qemu_cfg_write_entry(src, qfile->select, len); > + } else { > + qemu_cfg_select(qfile->select); > + qemu_cfg_skip(offset); > + qemu_cfg_write(src, len); > + } > + return len; > +} > + > static void > qemu_romfile_add(char *name, int select, int skip, int size) > { > diff --git a/src/fw/paravirt.h b/src/fw/paravirt.h > index d8eb7c4..fb220d8 100644 > --- a/src/fw/paravirt.h > +++ b/src/fw/paravirt.h > @@ -3,6 +3,7 @@ > > #include "config.h" // CONFIG_* > #include "biosvar.h" // GET_GLOBAL > +#include "romfile.h" // struct romfile_s > > // Types of paravirtualized platforms. > #define PF_QEMU (1<<0) > @@ -43,6 +44,7 @@ static inline int runningOnKVM(void) { > #define QEMU_CFG_DMA_CTL_READ 0x02 > #define QEMU_CFG_DMA_CTL_SKIP 0x04 > #define QEMU_CFG_DMA_CTL_SELECT 0x08 > +#define QEMU_CFG_DMA_CTL_WRITE 0x10 > > // QEMU_CFG_DMA ID bit > #define QEMU_CFG_VERSION_DMA 2 > @@ -53,5 +55,6 @@ void qemu_platform_setup(void); > void qemu_cfg_init(void); > > u16 qemu_get_present_cpus_count(void); > +int qemu_cfg_write_file(void *src, struct romfile_s *file, u32 offset, u32 len); > > #endif >

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[PATCH v3 0/2] QEMU: Add capability to write back fw_cfg address to QEMU
by ben＠skyportsystems.com 06 Feb '17

06 Feb '17

From: Ben Warren <ben(a)skyportsystems.com> This patch set adds the capability to write to QEMU across the fw_cfg DMA link. It adds a higher-level command to write the BIOS-allocated address of one fw_cfg file into an arbitrary point within another, writeable fw_cfg file across the above-mentioned link. The initial use case is for Windows VM Generation ID, where QEMU needs to change the contents of fw_cfg data at runtime, while still having BIOS allocate and manage the memory. v2->v3: - fixed up the qemu_cfg_write* functions to allow writing to an arbitrary offset within the destination file. - Changed function name to COMMAND_WRITE_POINTER and its functionality to not patch memory at all, but write back to a specified offset. v1->v2: - separated patch into two functional units. - changed so writes only occur over the DMA interface. - fixed coding style. - removed change to romfile struct definition (removed new write_back method). Ben Warren (2): QEMU DMA: Add DMA write capability QEMU fw_cfg: Add command to write back address of file src/fw/paravirt.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ src/fw/paravirt.h | 3 +++ src/fw/romfile_loader.c | 37 +++++++++++++++++++++++++++++++++++++ src/fw/romfile_loader.h | 16 ++++++++++------ 4 files changed, 99 insertions(+), 6 deletions(-) -- 2.7.4

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