Re: [PATCH 3/9] factor out xen-specific bootstrap

[Samuel Thibault]

Applied, thanks!

Luca Dariz, le dim. 12 févr. 2023 18:28:12 +0100, a ecrit:
> * i386/intel/pmap.c: move it to pmap_bootstrap_xen()
> ---
>  i386/intel/pmap.c | 107 ++++++++++++++++++++++++----------------------
>  1 file changed, 56 insertions(+), 51 deletions(-)
> 
> diff --git a/i386/intel/pmap.c b/i386/intel/pmap.c
> index 9fe16368..15577a09 100644
> --- a/i386/intel/pmap.c
> +++ b/i386/intel/pmap.c
> @@ -581,6 +581,61 @@ vm_offset_t pmap_map_bd(
>       return(virt);
>  }
>  
> +#ifdef       MACH_PV_PAGETABLES
> +void pmap_bootstrap_xen()
> +{
> +     /* We don't actually deal with the CR3 register content at all */
> +     hyp_vm_assist(VMASST_CMD_enable, VMASST_TYPE_pae_extended_cr3);
> +     /*
> +      * Xen may only provide as few as 512KB extra bootstrap linear memory,
> +      * which is far from enough to map all available memory, so we need to
> +      * map more bootstrap linear memory. We here map 1 (resp. 4 for PAE)
> +      * other L1 table(s), thus 4MiB extra memory (resp. 8MiB), which is
> +      * enough for a pagetable mapping 4GiB.
> +      */
> +#ifdef PAE
> +#define NSUP_L1 4
> +#else
> +#define NSUP_L1 1
> +#endif
> +     pt_entry_t *l1_map[NSUP_L1];
> +     vm_offset_t la;
> +     int n_l1map;
> +     for (n_l1map = 0, la = VM_MIN_KERNEL_ADDRESS; la >= 
> VM_MIN_KERNEL_ADDRESS; la += NPTES * PAGE_SIZE) {
> +             pt_entry_t *base = (pt_entry_t*) boot_info.pt_base;
> +#ifdef       PAE
> +#ifdef __x86_64__
> +             base = (pt_entry_t*) ptetokv(base[0]);
> +#endif /* x86_64 */
> +             pt_entry_t *l2_map = (pt_entry_t*) 
> ptetokv(base[lin2pdpnum(la)]);
> +#else        /* PAE */
> +             pt_entry_t *l2_map = base;
> +#endif       /* PAE */
> +             /* Like lin2pdenum, but works with non-contiguous boot L3 */
> +             l2_map += (la >> PDESHIFT) & PDEMASK;
> +             if (!(*l2_map & INTEL_PTE_VALID)) {
> +                     struct mmu_update update;
> +                     unsigned j, n;
> +
> +                     l1_map[n_l1map] = (pt_entry_t*) 
> phystokv(pmap_grab_page());
> +                     for (j = 0; j < NPTES; j++)
> +                             l1_map[n_l1map][j] = 
> (((pt_entry_t)pfn_to_mfn(lin2pdenum(la - VM_MIN_KERNEL_ADDRESS) * NPTES + j)) 
> << PAGE_SHIFT) | INTEL_PTE_VALID | INTEL_PTE_WRITE;
> +                     pmap_set_page_readonly_init(l1_map[n_l1map]);
> +                     if (!hyp_mmuext_op_mfn (MMUEXT_PIN_L1_TABLE, kv_to_mfn 
> (l1_map[n_l1map])))
> +                             panic("couldn't pin page %p(%lx)", 
> l1_map[n_l1map], (vm_offset_t) kv_to_ma (l1_map[n_l1map]));
> +                     update.ptr = kv_to_ma(l2_map);
> +                     update.val = kv_to_ma(l1_map[n_l1map]) | 
> INTEL_PTE_VALID | INTEL_PTE_WRITE;
> +                     hyp_mmu_update(kv_to_la(&update), 1, kv_to_la(&n), 
> DOMID_SELF);
> +                     if (n != 1)
> +                             panic("couldn't complete bootstrap map");
> +                     /* added the last L1 table, can stop */
> +                     if (++n_l1map >= NSUP_L1)
> +                             break;
> +             }
> +     }
> +}
> +#endif       /* MACH_PV_PAGETABLES */
> +
>  /*
>   *   Bootstrap the system enough to run with virtual memory.
>   *   Allocate the kernel page directory and page tables,
> @@ -677,57 +732,7 @@ void pmap_bootstrap(void)
>       }
>  
>  #ifdef       MACH_PV_PAGETABLES
> -     /* We don't actually deal with the CR3 register content at all */
> -     hyp_vm_assist(VMASST_CMD_enable, VMASST_TYPE_pae_extended_cr3);
> -     /*
> -      * Xen may only provide as few as 512KB extra bootstrap linear memory,
> -      * which is far from enough to map all available memory, so we need to
> -      * map more bootstrap linear memory. We here map 1 (resp. 4 for PAE)
> -      * other L1 table(s), thus 4MiB extra memory (resp. 8MiB), which is
> -      * enough for a pagetable mapping 4GiB.
> -      */
> -#ifdef PAE
> -#define NSUP_L1 4
> -#else
> -#define NSUP_L1 1
> -#endif
> -     pt_entry_t *l1_map[NSUP_L1];
> -     {
> -             vm_offset_t la;
> -             int n_l1map;
> -             for (n_l1map = 0, la = VM_MIN_KERNEL_ADDRESS; la >= 
> VM_MIN_KERNEL_ADDRESS; la += NPTES * PAGE_SIZE) {
> -                     pt_entry_t *base = (pt_entry_t*) boot_info.pt_base;
> -#ifdef       PAE
> -#ifdef __x86_64__
> -                     base = (pt_entry_t*) ptetokv(base[0]);
> -#endif /* x86_64 */
> -                     pt_entry_t *l2_map = (pt_entry_t*) 
> ptetokv(base[lin2pdpnum(la)]);
> -#else        /* PAE */
> -                     pt_entry_t *l2_map = base;
> -#endif       /* PAE */
> -                     /* Like lin2pdenum, but works with non-contiguous boot 
> L3 */
> -                     l2_map += (la >> PDESHIFT) & PDEMASK;
> -                     if (!(*l2_map & INTEL_PTE_VALID)) {
> -                             struct mmu_update update;
> -                             unsigned j, n;
> -
> -                             l1_map[n_l1map] = (pt_entry_t*) 
> phystokv(pmap_grab_page());
> -                             for (j = 0; j < NPTES; j++)
> -                                     l1_map[n_l1map][j] = 
> (((pt_entry_t)pfn_to_mfn(lin2pdenum(la - VM_MIN_KERNEL_ADDRESS) * NPTES + j)) 
> << PAGE_SHIFT) | INTEL_PTE_VALID | INTEL_PTE_WRITE;
> -                             pmap_set_page_readonly_init(l1_map[n_l1map]);
> -                             if (!hyp_mmuext_op_mfn (MMUEXT_PIN_L1_TABLE, 
> kv_to_mfn (l1_map[n_l1map])))
> -                                     panic("couldn't pin page %p(%lx)", 
> l1_map[n_l1map], (vm_offset_t) kv_to_ma (l1_map[n_l1map]));
> -                             update.ptr = kv_to_ma(l2_map);
> -                             update.val = kv_to_ma(l1_map[n_l1map]) | 
> INTEL_PTE_VALID | INTEL_PTE_WRITE;
> -                             hyp_mmu_update(kv_to_la(&update), 1, 
> kv_to_la(&n), DOMID_SELF);
> -                             if (n != 1)
> -                                     panic("couldn't complete bootstrap 
> map");
> -                             /* added the last L1 table, can stop */
> -                             if (++n_l1map >= NSUP_L1)
> -                                     break;
> -                     }
> -             }
> -     }
> +     pmap_bootstrap_xen()
>  #endif       /* MACH_PV_PAGETABLES */
>  
>       /*
> -- 
> 2.30.2
> 
> 

-- 
Samuel
---
Pour une évaluation indépendante, transparente et rigoureuse !
Je soutiens la Commission d'Évaluation de l'Inria.