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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v3 02/10] xen: reduce number of global variables in xen loader
On Wed, Feb 17, 2016 at 06:19:29PM +0100, Juergen Gross wrote:
> The loader for xen paravirtualized environment is using lots of global
> variables. Reduce the number by making them either local or by putting
> them into a single state structure.
>
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Just two nitpicks but in general...
Reviewed-by: Daniel Kiper <daniel.kiper@xxxxxxxxxx>
> ---
> grub-core/loader/i386/xen.c | 259
> +++++++++++++++++++++++---------------------
> 1 file changed, 138 insertions(+), 121 deletions(-)
>
> diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c
> index ff7c553..d5fe168 100644
> --- a/grub-core/loader/i386/xen.c
> +++ b/grub-core/loader/i386/xen.c
> @@ -42,16 +42,20 @@
>
> GRUB_MOD_LICENSE ("GPLv3+");
>
> -static struct grub_relocator *relocator = NULL;
> -static grub_uint64_t max_addr;
> +struct xen_loader_state {
> + struct grub_relocator *relocator;
> + struct start_info next_start;
> + struct grub_xen_file_info xen_inf;
> + grub_uint64_t max_addr;
> + struct xen_multiboot_mod_list *module_info_page;
> + grub_uint64_t modules_target_start;
> + grub_size_t n_modules;
> + int loaded;
> +};
> +
> +static struct xen_loader_state xen_state;
> +
> static grub_dl_t my_mod;
> -static int loaded = 0;
> -static struct start_info next_start;
> -static void *kern_chunk_src;
> -static struct grub_xen_file_info xen_inf;
> -static struct xen_multiboot_mod_list *xen_module_info_page;
> -static grub_uint64_t modules_target_start;
> -static grub_size_t n_modules;
>
> #define PAGE_SIZE 4096
> #define MAX_MODULES (PAGE_SIZE / sizeof (struct xen_multiboot_mod_list))
> @@ -225,50 +229,55 @@ grub_xen_boot (void)
> if (grub_xen_n_allocated_shared_pages)
> return grub_error (GRUB_ERR_BUG, "active grants");
>
> - state.mfn_list = max_addr;
> - next_start.mfn_list = max_addr + xen_inf.virt_base;
> - next_start.first_p2m_pfn = max_addr >> PAGE_SHIFT; /* Is this right? */
> + state.mfn_list = xen_state.max_addr;
> + xen_state.next_start.mfn_list =
> + xen_state.max_addr + xen_state.xen_inf.virt_base;
> + xen_state.next_start.first_p2m_pfn = xen_state.max_addr >> PAGE_SHIFT;
> pgtsize = sizeof (grub_xen_mfn_t) * grub_xen_start_page_addr->nr_pages;
> - err = grub_relocator_alloc_chunk_addr (relocator, &ch, max_addr, pgtsize);
> - next_start.nr_p2m_frames = (pgtsize + PAGE_SIZE - 1) >> PAGE_SHIFT;
> + err = grub_relocator_alloc_chunk_addr (xen_state.relocator, &ch,
> + xen_state.max_addr, pgtsize);
> + xen_state.next_start.nr_p2m_frames = (pgtsize + PAGE_SIZE - 1) >>
> PAGE_SHIFT;
> if (err)
> return err;
> new_mfn_list = get_virtual_current_address (ch);
> grub_memcpy (new_mfn_list,
> (void *) grub_xen_start_page_addr->mfn_list, pgtsize);
> - max_addr = ALIGN_UP (max_addr + pgtsize, PAGE_SIZE);
> + xen_state.max_addr = ALIGN_UP (xen_state.max_addr + pgtsize, PAGE_SIZE);
>
> - err = grub_relocator_alloc_chunk_addr (relocator, &ch,
> - max_addr, sizeof (next_start));
> + err = grub_relocator_alloc_chunk_addr (xen_state.relocator, &ch,
> + xen_state.max_addr,
> + sizeof (xen_state.next_start));
> if (err)
> return err;
> - state.start_info = max_addr + xen_inf.virt_base;
> + state.start_info = xen_state.max_addr + xen_state.xen_inf.virt_base;
> nst = get_virtual_current_address (ch);
> - max_addr = ALIGN_UP (max_addr + sizeof (next_start), PAGE_SIZE);
> + xen_state.max_addr =
> + ALIGN_UP (xen_state.max_addr + sizeof (xen_state.next_start), PAGE_SIZE);
>
> - next_start.nr_pages = grub_xen_start_page_addr->nr_pages;
> - grub_memcpy (next_start.magic, grub_xen_start_page_addr->magic,
> - sizeof (next_start.magic));
> - next_start.store_mfn = grub_xen_start_page_addr->store_mfn;
> - next_start.store_evtchn = grub_xen_start_page_addr->store_evtchn;
> - next_start.console.domU = grub_xen_start_page_addr->console.domU;
> - next_start.shared_info = grub_xen_start_page_addr->shared_info;
> + xen_state.next_start.nr_pages = grub_xen_start_page_addr->nr_pages;
> + grub_memcpy (xen_state.next_start.magic, grub_xen_start_page_addr->magic,
> + sizeof (xen_state.next_start.magic));
> + xen_state.next_start.store_mfn = grub_xen_start_page_addr->store_mfn;
> + xen_state.next_start.store_evtchn = grub_xen_start_page_addr->store_evtchn;
> + xen_state.next_start.console.domU = grub_xen_start_page_addr->console.domU;
> + xen_state.next_start.shared_info = grub_xen_start_page_addr->shared_info;
>
> - err = set_mfns (new_mfn_list, max_addr >> PAGE_SHIFT);
> + err = set_mfns (new_mfn_list, xen_state.max_addr >> PAGE_SHIFT);
> if (err)
> return err;
> - max_addr += 2 * PAGE_SIZE;
> + xen_state.max_addr += 2 * PAGE_SIZE;
>
> - next_start.pt_base = max_addr + xen_inf.virt_base;
> - state.paging_start = max_addr >> PAGE_SHIFT;
> + xen_state.next_start.pt_base =
> + xen_state.max_addr + xen_state.xen_inf.virt_base;
> + state.paging_start = xen_state.max_addr >> PAGE_SHIFT;
>
> - nr_info_pages = max_addr >> PAGE_SHIFT;
> + nr_info_pages = xen_state.max_addr >> PAGE_SHIFT;
> nr_pages = nr_info_pages;
>
> while (1)
> {
> nr_pages = ALIGN_UP (nr_pages, (ALIGN_SIZE >> PAGE_SHIFT));
> - nr_pt_pages = get_pgtable_size (nr_pages, xen_inf.virt_base);
> + nr_pt_pages = get_pgtable_size (nr_pages, xen_state.xen_inf.virt_base);
> nr_need_pages =
> nr_info_pages + nr_pt_pages +
> ((ADDITIONAL_SIZE + STACK_SIZE) >> PAGE_SHIFT);
> @@ -278,27 +287,28 @@ grub_xen_boot (void)
> }
>
> grub_dprintf ("xen", "bootstrap domain %llx+%llx\n",
> - (unsigned long long) xen_inf.virt_base,
> + (unsigned long long) xen_state.xen_inf.virt_base,
> (unsigned long long) page2offset (nr_pages));
>
> - err = grub_relocator_alloc_chunk_addr (relocator, &ch,
> - max_addr, page2offset (nr_pt_pages));
> + err = grub_relocator_alloc_chunk_addr (xen_state.relocator, &ch,
> + xen_state.max_addr,
> + page2offset (nr_pt_pages));
> if (err)
> return err;
>
> generate_page_table (get_virtual_current_address (ch),
> - max_addr >> PAGE_SHIFT, nr_pages,
> - xen_inf.virt_base, new_mfn_list);
> + xen_state.max_addr >> PAGE_SHIFT, nr_pages,
> + xen_state.xen_inf.virt_base, new_mfn_list);
>
> - max_addr += page2offset (nr_pt_pages);
> - state.stack = max_addr + STACK_SIZE + xen_inf.virt_base;
> - state.entry_point = xen_inf.entry_point;
> + xen_state.max_addr += page2offset (nr_pt_pages);
> + state.stack = xen_state.max_addr + STACK_SIZE +
> xen_state.xen_inf.virt_base;
> + state.entry_point = xen_state.xen_inf.entry_point;
>
> - next_start.nr_p2m_frames += nr_pt_pages;
> - next_start.nr_pt_frames = nr_pt_pages;
> + xen_state.next_start.nr_p2m_frames += nr_pt_pages;
> + xen_state.next_start.nr_pt_frames = nr_pt_pages;
> state.paging_size = nr_pt_pages;
>
> - *nst = next_start;
> + *nst = xen_state.next_start;
>
> grub_memset (&gnttab_setver, 0, sizeof (gnttab_setver));
>
> @@ -308,24 +318,20 @@ grub_xen_boot (void)
> for (i = 0; i < ARRAY_SIZE (grub_xen_shared_info->evtchn_pending); i++)
> grub_xen_shared_info->evtchn_pending[i] = 0;
>
> - return grub_relocator_xen_boot (relocator, state, nr_pages,
> - xen_inf.virt_base <
> + return grub_relocator_xen_boot (xen_state.relocator, state, nr_pages,
> + xen_state.xen_inf.virt_base <
> PAGE_SIZE ? page2offset (nr_pages) : 0,
> nr_pages - 1,
> page2offset (nr_pages - 1) +
> - xen_inf.virt_base);
> + xen_state.xen_inf.virt_base);
> }
>
> static void
> grub_xen_reset (void)
> {
> - grub_memset (&next_start, 0, sizeof (next_start));
> - xen_module_info_page = NULL;
> - n_modules = 0;
> + grub_relocator_unload (xen_state.relocator);
>
> - grub_relocator_unload (relocator);
> - relocator = NULL;
> - loaded = 0;
> + grub_memset (&xen_state, 0, sizeof (xen_state));
> }
>
> static grub_err_t
> @@ -409,17 +415,22 @@ grub_cmd_xen (grub_command_t cmd __attribute__
> ((unused)),
> grub_file_t file;
> grub_elf_t elf;
> grub_err_t err;
> + void *kern_chunk_src;
> + grub_relocator_chunk_t ch;
> + grub_addr_t kern_start;
> + grub_addr_t kern_end;
>
> if (argc == 0)
> return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));
>
> + /* Call grub_loader_unset early to avoid it being called by
> grub_loader_set */
> grub_loader_unset ();
>
> grub_xen_reset ();
>
> grub_create_loader_cmdline (argc - 1, argv + 1,
> - (char *) next_start.cmd_line,
> - sizeof (next_start.cmd_line) - 1);
> + (char *) xen_state.next_start.cmd_line,
> + sizeof (xen_state.next_start.cmd_line) - 1);
>
> file = grub_file_open (argv[0]);
> if (!file)
> @@ -429,85 +440,82 @@ grub_cmd_xen (grub_command_t cmd __attribute__
> ((unused)),
> if (!elf)
> goto fail;
>
> - err = grub_xen_get_info (elf, &xen_inf);
> + err = grub_xen_get_info (elf, &xen_state.xen_inf);
> if (err)
> goto fail;
> #ifdef __x86_64__
> - if (xen_inf.arch != GRUB_XEN_FILE_X86_64)
> + if (xen_state.xen_inf.arch != GRUB_XEN_FILE_X86_64)
> #else
> - if (xen_inf.arch != GRUB_XEN_FILE_I386_PAE
> - && xen_inf.arch != GRUB_XEN_FILE_I386_PAE_BIMODE)
> + if (xen_state.xen_inf.arch != GRUB_XEN_FILE_I386_PAE
> + && xen_state.xen_inf.arch != GRUB_XEN_FILE_I386_PAE_BIMODE)
> #endif
> {
> grub_error (GRUB_ERR_BAD_OS, "incompatible architecture: %d",
> - xen_inf.arch);
> + xen_state.xen_inf.arch);
> goto fail;
> }
>
> - if (xen_inf.virt_base & (PAGE_SIZE - 1))
> + if (xen_state.xen_inf.virt_base & (PAGE_SIZE - 1))
> {
> grub_error (GRUB_ERR_BAD_OS, "unaligned virt_base");
> goto fail;
> }
> grub_dprintf ("xen", "virt_base = %llx, entry = %llx\n",
> - (unsigned long long) xen_inf.virt_base,
> - (unsigned long long) xen_inf.entry_point);
> + (unsigned long long) xen_state.xen_inf.virt_base,
> + (unsigned long long) xen_state.xen_inf.entry_point);
>
> - relocator = grub_relocator_new ();
> - if (!relocator)
> + xen_state.relocator = grub_relocator_new ();
> + if (!xen_state.relocator)
> goto fail;
>
> - grub_relocator_chunk_t ch;
> - grub_addr_t kern_start = xen_inf.kern_start - xen_inf.paddr_offset;
> - grub_addr_t kern_end = xen_inf.kern_end - xen_inf.paddr_offset;
> + kern_start = xen_state.xen_inf.kern_start - xen_state.xen_inf.paddr_offset;
> + kern_end = xen_state.xen_inf.kern_end - xen_state.xen_inf.paddr_offset;
>
> - if (xen_inf.has_hypercall_page)
> + if (xen_state.xen_inf.has_hypercall_page)
> {
> grub_dprintf ("xen", "hypercall page at 0x%llx\n",
> - (unsigned long long) xen_inf.hypercall_page);
> - if (xen_inf.hypercall_page - xen_inf.virt_base < kern_start)
> - kern_start = xen_inf.hypercall_page - xen_inf.virt_base;
> -
> - if (xen_inf.hypercall_page - xen_inf.virt_base + PAGE_SIZE > kern_end)
> - kern_end = xen_inf.hypercall_page - xen_inf.virt_base + PAGE_SIZE;
> + (unsigned long long) xen_state.xen_inf.hypercall_page);
> + kern_start = grub_min (kern_start, xen_state.xen_inf.hypercall_page -
> + xen_state.xen_inf.virt_base);
> + kern_end = grub_max (kern_end, xen_state.xen_inf.hypercall_page -
> + xen_state.xen_inf.virt_base + PAGE_SIZE);
> }
>
> - max_addr = ALIGN_UP (kern_end, PAGE_SIZE);
> + xen_state.max_addr = ALIGN_UP (kern_end, PAGE_SIZE);
>
> - err = grub_relocator_alloc_chunk_addr (relocator, &ch, kern_start,
> + err = grub_relocator_alloc_chunk_addr (xen_state.relocator, &ch,
> kern_start,
> kern_end - kern_start);
> if (err)
> goto fail;
> kern_chunk_src = get_virtual_current_address (ch);
>
> grub_dprintf ("xen", "paddr_offset = 0x%llx\n",
> - (unsigned long long) xen_inf.paddr_offset);
> + (unsigned long long) xen_state.xen_inf.paddr_offset);
> grub_dprintf ("xen", "kern_start = 0x%llx, kern_end = 0x%llx\n",
> - (unsigned long long) xen_inf.kern_start,
> - (unsigned long long) xen_inf.kern_end);
> + (unsigned long long) xen_state.xen_inf.kern_start,
> + (unsigned long long) xen_state.xen_inf.kern_end);
>
> err = grub_elfXX_load (elf, argv[0],
> (grub_uint8_t *) kern_chunk_src - kern_start
> - - xen_inf.paddr_offset, 0, 0, 0);
> + - xen_state.xen_inf.paddr_offset, 0, 0, 0);
>
> - if (xen_inf.has_hypercall_page)
> + if (xen_state.xen_inf.has_hypercall_page)
> {
> unsigned i;
> for (i = 0; i < PAGE_SIZE / HYPERCALL_INTERFACE_SIZE; i++)
> set_hypercall_interface ((grub_uint8_t *) kern_chunk_src +
> i * HYPERCALL_INTERFACE_SIZE +
> - xen_inf.hypercall_page - xen_inf.virt_base -
> - kern_start, i);
> + xen_state.xen_inf.hypercall_page -
> + xen_state.xen_inf.virt_base - kern_start, i);
> }
>
> if (err)
> goto fail;
>
> grub_dl_ref (my_mod);
> - loaded = 1;
> + xen_state.loaded = 1;
>
> grub_loader_set (grub_xen_boot, grub_xen_unload, 0);
> - loaded = 1;
>
> goto fail;
>
> @@ -540,14 +548,14 @@ grub_cmd_initrd (grub_command_t cmd __attribute__
> ((unused)),
> goto fail;
> }
>
> - if (!loaded)
> + if (!xen_state.loaded)
> {
> grub_error (GRUB_ERR_BAD_ARGUMENT,
> N_("you need to load the kernel first"));
> goto fail;
> }
>
> - if (next_start.mod_start || next_start.mod_len)
> + if (xen_state.next_start.mod_start || xen_state.next_start.mod_len)
> {
> grub_error (GRUB_ERR_BAD_ARGUMENT, N_("initrd already loaded"));
> goto fail;
> @@ -560,7 +568,8 @@ grub_cmd_initrd (grub_command_t cmd __attribute__
> ((unused)),
>
> if (size)
> {
> - err = grub_relocator_alloc_chunk_addr (relocator, &ch, max_addr, size);
> + err = grub_relocator_alloc_chunk_addr (xen_state.relocator, &ch,
> + xen_state.max_addr, size);
> if (err)
> goto fail;
>
> @@ -569,13 +578,14 @@ grub_cmd_initrd (grub_command_t cmd __attribute__
> ((unused)),
> goto fail;
> }
>
> - next_start.mod_start = max_addr + xen_inf.virt_base;
> - next_start.mod_len = size;
> + xen_state.next_start.mod_start =
> + xen_state.max_addr + xen_state.xen_inf.virt_base;
> + xen_state.next_start.mod_len = size;
>
> - max_addr = ALIGN_UP (max_addr + size, PAGE_SIZE);
> + xen_state.max_addr = ALIGN_UP (xen_state.max_addr + size, PAGE_SIZE);
>
> grub_dprintf ("xen", "Initrd, addr=0x%x, size=0x%x\n",
> - (unsigned) next_start.mod_start, (unsigned) size);
> + (unsigned) xen_state.next_start.mod_start, (unsigned) size);
>
> fail:
> grub_initrd_close (&initrd_ctx);
> @@ -607,45 +617,48 @@ grub_cmd_module (grub_command_t cmd __attribute__
> ((unused)),
> if (argc == 0)
> return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));
>
> - if (!loaded)
> + if (!xen_state.loaded)
> {
> return grub_error (GRUB_ERR_BAD_ARGUMENT,
> N_("you need to load the kernel first"));
> }
>
> - if ((next_start.mod_start || next_start.mod_len) && !xen_module_info_page)
> + if ((xen_state.next_start.mod_start || xen_state.next_start.mod_len) &&
> + !xen_state.module_info_page)
> {
> return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("initrd already loaded"));
> }
>
> /* Leave one space for terminator. */
> - if (n_modules >= MAX_MODULES - 1)
> + if (xen_state.n_modules >= MAX_MODULES - 1)
> {
> return grub_error (GRUB_ERR_BAD_ARGUMENT, "too many modules");
> }
>
> - if (!xen_module_info_page)
> + if (!xen_state.module_info_page)
> {
> - n_modules = 0;
> - max_addr = ALIGN_UP (max_addr, PAGE_SIZE);
> - modules_target_start = max_addr;
> - next_start.mod_start = max_addr + xen_inf.virt_base;
> - next_start.flags |= SIF_MULTIBOOT_MOD;
> + xen_state.n_modules = 0;
> + xen_state.max_addr = ALIGN_UP (xen_state.max_addr, PAGE_SIZE);
> + xen_state.modules_target_start = xen_state.max_addr;
> + xen_state.next_start.mod_start =
> + xen_state.max_addr + xen_state.xen_inf.virt_base;
Lost one space.
> + xen_state.next_start.flags |= SIF_MULTIBOOT_MOD;
>
> - err = grub_relocator_alloc_chunk_addr (relocator, &ch,
> - max_addr, MAX_MODULES
> + err = grub_relocator_alloc_chunk_addr (xen_state.relocator, &ch,
> + xen_state.max_addr, MAX_MODULES
> *
> - sizeof (xen_module_info_page
> + sizeof (xen_state.module_info_page
> [0]));
> if (err)
> return err;
> - xen_module_info_page = get_virtual_current_address (ch);
> - grub_memset (xen_module_info_page, 0, MAX_MODULES
> - * sizeof (xen_module_info_page[0]));
> - max_addr += MAX_MODULES * sizeof (xen_module_info_page[0]);
> + xen_state.module_info_page = get_virtual_current_address (ch);
> + grub_memset (xen_state.module_info_page, 0, MAX_MODULES
> + * sizeof (xen_state.module_info_page[0]));
> + xen_state.max_addr +=
> + MAX_MODULES * sizeof (xen_state.module_info_page[0]);
Ditto.
Daniel
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