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Re: [PATCH v3 02/10] xen: reduce number of global variables in xen loade
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From: |
Lennart Sorensen |
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Subject: |
Re: [PATCH v3 02/10] xen: reduce number of global variables in xen loader |
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Date: |
Thu, 18 Feb 2016 12:00:06 -0500 |
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User-agent: |
Mutt/1.5.23 (2014-03-12) |
On Thu, Feb 18, 2016 at 11:34:49AM +0100, Juergen Gross wrote:
> 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.
But your line continuation is indented LESS than the line it is
continuing, which is clearly NOT the style.
--
len Sorensen
[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
[PATCH v3 10/10] xen: add capability to load p2m list outside of kernel mapping, Juergen Gross, 2016/02/17