Eric Biederman complained that lguest doesn't use the Linux standard boot header format. He's got a good point.
This also simplifies the code: the example launcher writes the header directly, rather than lguest writing into it during boot. While we're touching this code, we also fix the problem of initrd's which don't have a page-aligned size. This anticipates changing the paravirt-finding routines to use a "platform type" field from %esi, rather than a "probe all until one succeeds" routine, but doesn't actually change that code. Signed-off-by: Rusty Russell <[EMAIL PROTECTED]> --- Documentation/lguest/lguest.c | 50 ++++++++++++++++++++++++--------------- drivers/lguest/lguest.c | 22 +++++++---------- drivers/lguest/lguest_asm.S | 5 +++ drivers/lguest/lguest_user.c | 4 --- include/linux/lguest.h | 5 --- include/linux/lguest_launcher.h | 8 ------ 6 files changed, 46 insertions(+), 48 deletions(-) =================================================================== --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -30,10 +30,12 @@ #include <termios.h> #include <getopt.h> #include <zlib.h> +typedef unsigned long long u64; typedef uint32_t u32; typedef uint16_t u16; typedef uint8_t u8; #include "../../include/linux/lguest_launcher.h" +#include "../../include/asm-i386/e820.h" #define PAGE_PRESENT 0x7 /* Present, RW, Execute */ #define NET_PEERNUM 1 @@ -241,31 +243,33 @@ static unsigned long load_kernel(int fd, return load_bzimage(fd, page_offset); } +static inline unsigned long page_align(unsigned long addr) +{ + return ((addr + getpagesize()-1) & ~(getpagesize()-1)); +} + /* initrd gets loaded at top of memory: return length. */ static unsigned long load_initrd(const char *name, unsigned long mem) { int ifd; struct stat st; + unsigned long len; void *iaddr; ifd = open_or_die(name, O_RDONLY); if (fstat(ifd, &st) < 0) err(1, "fstat() on initrd '%s'", name); - iaddr = mmap((void *)mem - st.st_size, st.st_size, + len = page_align(st.st_size); + iaddr = mmap((void *)mem - len, st.st_size, PROT_READ|PROT_EXEC|PROT_WRITE, MAP_FIXED|MAP_PRIVATE, ifd, 0); - if (iaddr != (void *)mem - st.st_size) + if (iaddr != (void *)mem - len) err(1, "Mmaping initrd '%s' returned %p not %p", - name, iaddr, (void *)mem - st.st_size); + name, iaddr, (void *)mem - len); close(ifd); verbose("mapped initrd %s size=%lu @ %p\n", name, st.st_size, iaddr); - return st.st_size; -} - -static inline unsigned long page_align(unsigned long addr) -{ - return ((addr + getpagesize()-1) & ~(getpagesize()-1)); + return len; } static unsigned long setup_pagetables(unsigned long mem, @@ -933,10 +937,10 @@ static void usage(void) int main(int argc, char *argv[]) { - unsigned long mem, pgdir, start, page_offset; + unsigned long mem, pgdir, start, page_offset, initrd_size = 0; int c, lguest_fd, waker_fd; struct device_list device_list; - struct lguest_boot_info *boot = (void *)0; + void *boot = (void *)0; const char *initrd_name = NULL; device_list.max_infd = -1; @@ -984,15 +988,25 @@ int main(int argc, char *argv[]) map_device_descriptors(&device_list, mem); /* Map the initrd image if requested */ - if (initrd_name) - boot->initrd_size = load_initrd(initrd_name, mem); + if (initrd_name) { + initrd_size = load_initrd(initrd_name, mem); + *(unsigned long *)(boot+0x218) = mem - initrd_size; + *(unsigned long *)(boot+0x21c) = initrd_size; + *(unsigned char *)(boot+0x210) = 0xFF; + } /* Set up the initial linar pagetables. */ - pgdir = setup_pagetables(mem, boot->initrd_size, page_offset); - - /* Give the guest the boot information it needs. */ - concat(boot->cmdline, argv+optind+2); - boot->max_pfn = mem/getpagesize(); + pgdir = setup_pagetables(mem, initrd_size, page_offset); + + /* E820 memory map: ours is a simple, single region. */ + *(char*)(boot+E820NR) = 1; + *((struct e820entry *)(boot+E820MAP)) + = ((struct e820entry) { 0, mem, E820_RAM }); + /* Command line pointer and command line (at 4096) */ + *(void **)(boot + 0x228) = boot + 4096; + concat(boot + 4096, argv+optind+2); + /* Paravirt type: 1 == lguest */ + *(int *)(boot + 0x23c) = 1; lguest_fd = tell_kernel(pgdir, start, page_offset); waker_fd = setup_waker(&device_list); =================================================================== --- a/drivers/lguest/lguest.c +++ b/drivers/lguest/lguest.c @@ -52,7 +52,6 @@ struct lguest_data lguest_data = { .blocked_interrupts = { 1 }, /* Block timer interrupts */ }; struct lguest_device_desc *lguest_devices; -static __initdata const struct lguest_boot_info *boot = __va(0); static enum paravirt_lazy_mode lazy_mode; static void lguest_lazy_mode(enum paravirt_lazy_mode mode) @@ -377,8 +376,7 @@ static __init char *lguest_memory_setup( /* We do this here because lockcheck barfs if before start_kernel */ atomic_notifier_chain_register(&panic_notifier_list, &paniced); - e820.nr_map = 0; - add_memory_region(0, PFN_PHYS(boot->max_pfn), E820_RAM); + add_memory_region(E820_MAP->addr, E820_MAP->size, E820_MAP->type); return "LGUEST"; } @@ -409,8 +407,14 @@ static unsigned lguest_patch(u8 type, u1 return insn_len; } -__init void lguest_init(void) -{ +__init void lguest_init(void *boot) +{ + /* Copy boot parameters first. */ + memcpy(boot_params, boot, PARAM_SIZE); + memcpy(boot_command_line, + __va(*(unsigned long *)(boot_params + NEW_CL_POINTER)), + COMMAND_LINE_SIZE); + paravirt_ops.name = "lguest"; paravirt_ops.paravirt_enabled = 1; paravirt_ops.kernel_rpl = 1; @@ -459,7 +463,6 @@ __init void lguest_init(void) paravirt_ops.wbinvd = lguest_wbinvd; hcall(LHCALL_LGUEST_INIT, __pa(&lguest_data), 0, 0); - strncpy(boot_command_line, boot->cmdline, COMMAND_LINE_SIZE); /* We use top of mem for initial pagetables. */ init_pg_tables_end = __pa(pg0); @@ -485,13 +488,6 @@ __init void lguest_init(void) add_preferred_console("hvc", 0, NULL); - if (boot->initrd_size) { - /* We stash this at top of memory. */ - INITRD_START = boot->max_pfn*PAGE_SIZE - boot->initrd_size; - INITRD_SIZE = boot->initrd_size; - LOADER_TYPE = 0xFF; - } - pm_power_off = lguest_power_off; start_kernel(); } =================================================================== --- a/drivers/lguest/lguest_asm.S +++ b/drivers/lguest/lguest_asm.S @@ -10,7 +10,8 @@ * This is where we begin: we have a magic signature which the launcher looks * for. The plan is that the Linux boot protocol will be extended with a * "platform type" field which will guide us here from the normal entry point, - * but for the moment this suffices. + * but for the moment this suffices. We pass the virtual address of the boot + * info to lguest_init(). * * We put it in .init.text will be discarded after boot. */ @@ -18,6 +19,8 @@ .ascii "GenuineLguest" /* Set up initial stack. */ movl $(init_thread_union+THREAD_SIZE),%esp + movl %esi, %eax + addl $__PAGE_OFFSET, %eax jmp lguest_init /* The templates for inline patching. */ =================================================================== --- a/drivers/lguest/lguest_user.c +++ b/drivers/lguest/lguest_user.c @@ -7,13 +7,11 @@ static void setup_regs(struct lguest_reg static void setup_regs(struct lguest_regs *regs, unsigned long start) { /* Write out stack in format lguest expects, so we can switch to it. */ - regs->edi = LGUEST_MAGIC_EDI; - regs->ebp = LGUEST_MAGIC_EBP; - regs->esi = LGUEST_MAGIC_ESI; regs->ds = regs->es = regs->ss = __KERNEL_DS|GUEST_PL; regs->cs = __KERNEL_CS|GUEST_PL; regs->eflags = 0x202; /* Interrupts enabled. */ regs->eip = start; + /* esi points to our boot information (physical address 0) */ } /* + addr */ =================================================================== --- a/include/linux/lguest.h +++ b/include/linux/lguest.h @@ -2,11 +2,6 @@ * this is subject to wild and random change between versions. */ #ifndef _ASM_LGUEST_H #define _ASM_LGUEST_H - -/* These are randomly chosen numbers which indicate we're an lguest at boot */ -#define LGUEST_MAGIC_EBP 0x4C687970 -#define LGUEST_MAGIC_EDI 0x652D4D65 -#define LGUEST_MAGIC_ESI 0xFFFFFFFF #ifndef __ASSEMBLY__ #include <asm/irq.h> =================================================================== --- a/include/linux/lguest_launcher.h +++ b/include/linux/lguest_launcher.h @@ -15,14 +15,6 @@ struct lguest_dma u32 used_len; u32 addr[LGUEST_MAX_DMA_SECTIONS]; u16 len[LGUEST_MAX_DMA_SECTIONS]; -}; - -/* This is found at address 0. */ -struct lguest_boot_info -{ - u32 max_pfn; - u32 initrd_size; - char cmdline[256]; }; struct lguest_block_page - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/