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Re: [PATCH v2 1/6] xen: factor out p2m list allocation into separate fun
From: |
Daniel Kiper |
Subject: |
Re: [PATCH v2 1/6] xen: factor out p2m list allocation into separate function |
Date: |
Thu, 11 Feb 2016 13:19:54 +0100 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Thu, Feb 11, 2016 at 08:53:21AM +0100, Juergen Gross wrote:
> Do the p2m list allocation of the to be loaded kernel in a separate
> function. This will allow doing the p2m list allocation at different
> times of the boot preparations depending on the features the kernel
> is supporting.
>
> While at this remove superfluous setting of first_p2m_pfn and
> nr_p2m_frames as those are needed only in case of the p2m list not
> being mapped by the initial kernel mapping.
>
> Signed-off-by: Juergen Gross <address@hidden>
> ---
> grub-core/loader/i386/xen.c | 70
> ++++++++++++++++++++++++++-------------------
> 1 file changed, 40 insertions(+), 30 deletions(-)
>
> diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c
> index c4d9689..42ed7c7 100644
> --- a/grub-core/loader/i386/xen.c
> +++ b/grub-core/loader/i386/xen.c
> @@ -52,6 +52,8 @@ 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;
> +static struct grub_relocator_xen_state state;
> +static grub_xen_mfn_t *virt_mfn_list;
Do we strongly need this as globals? I suppose that
both of them could be local to grub_xen_boot.
> #define PAGE_SIZE 4096
> #define MAX_MODULES (PAGE_SIZE / sizeof (struct xen_multiboot_mod_list))
> @@ -166,7 +168,7 @@ generate_page_table (grub_uint64_t *where, grub_uint64_t
> paging_start,
> }
>
> static grub_err_t
> -set_mfns (grub_xen_mfn_t * new_mfn_list, grub_xen_mfn_t pfn)
> +set_mfns (grub_xen_mfn_t pfn)
> {
> grub_xen_mfn_t i, t;
> grub_xen_mfn_t cn_pfn = -1, st_pfn = -1;
> @@ -175,32 +177,32 @@ set_mfns (grub_xen_mfn_t * new_mfn_list, grub_xen_mfn_t
> pfn)
>
> for (i = 0; i < grub_xen_start_page_addr->nr_pages; i++)
> {
> - if (new_mfn_list[i] == grub_xen_start_page_addr->console.domU.mfn)
> + if (virt_mfn_list[i] == grub_xen_start_page_addr->console.domU.mfn)
> cn_pfn = i;
> - if (new_mfn_list[i] == grub_xen_start_page_addr->store_mfn)
> + if (virt_mfn_list[i] == grub_xen_start_page_addr->store_mfn)
> st_pfn = i;
> }
> if (cn_pfn == (grub_xen_mfn_t)-1)
> return grub_error (GRUB_ERR_BUG, "no console");
> if (st_pfn == (grub_xen_mfn_t)-1)
> return grub_error (GRUB_ERR_BUG, "no store");
> - t = new_mfn_list[pfn];
> - new_mfn_list[pfn] = new_mfn_list[cn_pfn];
> - new_mfn_list[cn_pfn] = t;
> - t = new_mfn_list[pfn + 1];
> - new_mfn_list[pfn + 1] = new_mfn_list[st_pfn];
> - new_mfn_list[st_pfn] = t;
> -
> - m2p_updates[0].ptr = page2offset (new_mfn_list[pfn]) | MMU_MACHPHYS_UPDATE;
> + t = virt_mfn_list[pfn];
> + virt_mfn_list[pfn] = virt_mfn_list[cn_pfn];
> + virt_mfn_list[cn_pfn] = t;
> + t = virt_mfn_list[pfn + 1];
> + virt_mfn_list[pfn + 1] = virt_mfn_list[st_pfn];
> + virt_mfn_list[st_pfn] = t;
> +
> + m2p_updates[0].ptr = page2offset (virt_mfn_list[pfn]) |
> MMU_MACHPHYS_UPDATE;
> m2p_updates[0].val = pfn;
> m2p_updates[1].ptr =
> - page2offset (new_mfn_list[pfn + 1]) | MMU_MACHPHYS_UPDATE;
> + page2offset (virt_mfn_list[pfn + 1]) | MMU_MACHPHYS_UPDATE;
> m2p_updates[1].val = pfn + 1;
> m2p_updates[2].ptr =
> - page2offset (new_mfn_list[cn_pfn]) | MMU_MACHPHYS_UPDATE;
> + page2offset (virt_mfn_list[cn_pfn]) | MMU_MACHPHYS_UPDATE;
> m2p_updates[2].val = cn_pfn;
> m2p_updates[3].ptr =
> - page2offset (new_mfn_list[st_pfn]) | MMU_MACHPHYS_UPDATE;
> + page2offset (virt_mfn_list[st_pfn]) | MMU_MACHPHYS_UPDATE;
> m2p_updates[3].val = st_pfn;
>
> grub_xen_mmu_update (m2p_updates, 4, NULL, DOMID_SELF);
> @@ -209,34 +211,43 @@ set_mfns (grub_xen_mfn_t * new_mfn_list, grub_xen_mfn_t
> pfn)
> }
>
> static grub_err_t
> +grub_xen_p2m_alloc (void)
> +{
> + grub_relocator_chunk_t ch;
> + grub_size_t p2msize;
> + grub_err_t err;
> +
> + state.mfn_list = max_addr;
> + next_start.mfn_list = max_addr + xen_inf.virt_base;
> + p2msize = sizeof (grub_xen_mfn_t) * grub_xen_start_page_addr->nr_pages;
> + err = grub_relocator_alloc_chunk_addr (relocator, &ch, max_addr, p2msize);
Hmmm.... Where relocator is defined?
> + if (err)
> + return err;
> + virt_mfn_list = get_virtual_current_address (ch);
> + grub_memcpy (virt_mfn_list,
> + (void *) grub_xen_start_page_addr->mfn_list, p2msize);
> + max_addr = ALIGN_UP (max_addr + p2msize, PAGE_SIZE);
> +
> + return GRUB_ERR_NONE;
> +}
> +
> +static grub_err_t
> grub_xen_boot (void)
> {
> - struct grub_relocator_xen_state state;
> grub_relocator_chunk_t ch;
> grub_err_t err;
> - grub_size_t pgtsize;
> struct start_info *nst;
> grub_uint64_t nr_info_pages;
> grub_uint64_t nr_pages, nr_pt_pages, nr_need_pages;
> struct gnttab_set_version gnttab_setver;
> - grub_xen_mfn_t *new_mfn_list;
> grub_size_t i;
>
> 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? */
> - 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_xen_p2m_alloc ();
> 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);
>
> err = grub_relocator_alloc_chunk_addr (relocator, &ch,
Ditto. I think that this could be passed as a grub_xen_boot() argument.
Otherwise this appear from nowhere and reading/understanding is more
difficult.
Daniel
- [PATCH v2 6/6] xen: add capability to load p2m list outside of kernel mapping, (continued)
[PATCH v2 1/6] xen: factor out p2m list allocation into separate function, Juergen Gross, 2016/02/11
- Re: [PATCH v2 1/6] xen: factor out p2m list allocation into separate function,
Daniel Kiper <=
[PATCH v2 3/6] xen: factor out allocation of page tables into separate function, Juergen Gross, 2016/02/11
[PATCH v2 5/6] xen: modify page table construction, Juergen Gross, 2016/02/11