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Re: [PATCH v3 02/10] xen: reduce number of global variables in xen loade
From: |
Juergen Gross |
Subject: |
Re: [PATCH v3 02/10] xen: reduce number of global variables in xen loader |
Date: |
Thu, 18 Feb 2016 11:34:49 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 |
On 18/02/16 11:22, Daniel Kiper wrote:
> 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 <address@hidden>
>
> Just two nitpicks but in general...
>
> Reviewed-by: Daniel Kiper <address@hidden>
>
>> ---
>> 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.
Really? Common indentation style seams to be to use tabs where possible.
And this is a tab.
>
>> + 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.
Yep. tab again.
Juergen
[PATCH v3 06/10] xen: factor out allocation of special pages into separate function, Juergen Gross, 2016/02/17
[PATCH v3 03/10] xen: add elfnote.h to avoid using numbers instead of constants, Juergen Gross, 2016/02/17