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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH RFC 17/55] x86/mm: drop lXe_to_lYe invocations in map_pages_to_xen
On Thu, 2019-02-07 at 16:44 +0000, Wei Liu wrote:
> Map and unmap page tables where necessary.
>
> Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
> ---
> xen/arch/x86/mm.c | 40 +++++++++++++++++++++++++++++-----------
> 1 file changed, 29 insertions(+), 11 deletions(-)
>
> diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
> index c4cb6fbb60..1ea2974c1f 100644
> --- a/xen/arch/x86/mm.c
> +++ b/xen/arch/x86/mm.c
> @@ -5014,8 +5014,10 @@ int map_pages_to_xen(
> else
> {
> l2_pgentry_t *l2t;
> + mfn_t l2t_mfn = l3e_get_mfn(ol3e);
> +
> + l2t = map_xen_pagetable_new(l2t_mfn);
>
> - l2t = l3e_to_l2e(ol3e);
> for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ )
> {
> ol2e = l2t[i];
> @@ -5027,10 +5029,12 @@ int map_pages_to_xen(
> {
> unsigned int j;
> l1_pgentry_t *l1t;
> + mfn_t l1t_mfn = l2e_get_mfn(ol2e);
>
> - l1t = l2e_to_l1e(ol2e);
> + l1t = map_xen_pagetable_new(l1t_mfn);
> for ( j = 0; j < L1_PAGETABLE_ENTRIES;
> j++ )
> flush_flags(l1e_get_flags(l1t[j]));
> + UNMAP_XEN_PAGETABLE_NEW(l1t);
> }
> }
> flush_area(virt, flush_flags);
> @@ -5039,9 +5043,9 @@ int map_pages_to_xen(
> ol2e = l2t[i];
> if ( (l2e_get_flags(ol2e) & _PAGE_PRESENT)
> &&
> !(l2e_get_flags(ol2e) & _PAGE_PSE) )
> - free_xen_pagetable(l2e_to_l1e(ol2e));
> + free_xen_pagetable_new(l2e_get_mfn(ol2e)
> );
> }
> - free_xen_pagetable(l2t);
> + free_xen_pagetable_new(l2t_mfn);
> }
> }
>
> @@ -5146,12 +5150,14 @@ int map_pages_to_xen(
> else
> {
> l1_pgentry_t *l1t;
> + mfn_t l1t_mfn = l2e_get_mfn(ol2e);
>
> - l1t = l2e_to_l1e(ol2e);
> + l1t = map_xen_pagetable_new(l1t_mfn);
> for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ )
> flush_flags(l1e_get_flags(l1t[i]));
> flush_area(virt, flush_flags);
> - free_xen_pagetable(l1t);
> + UNMAP_XEN_PAGETABLE_NEW(l1t);
> + free_xen_pagetable_new(l1t_mfn);
> }
> }
>
> @@ -5165,12 +5171,14 @@ int map_pages_to_xen(
> /* Normal page mapping. */
> if ( !(l2e_get_flags(*pl2e) & _PAGE_PRESENT) )
> {
> + /* XXX This forces page table to be populated */
> pl1e = virt_to_xen_l1e(virt);
> if ( pl1e == NULL )
> {
> ASSERT(rc == -ENOMEM);
> goto out;
> }
> + UNMAP_XEN_PAGETABLE_NEW(pl1e);
This should be part of patch 15/55 "x86/mm: rewrite virt_to_xen_l1e"
where you adapt the callers of virt_to_xen_l1e to free the returned
pointer.
- Stefan
> }
> else if ( l2e_get_flags(*pl2e) & _PAGE_PSE )
> {
> @@ -5234,9 +5242,11 @@ int map_pages_to_xen(
> }
> }
>
> - pl1e = l2e_to_l1e(*pl2e) + l1_table_offset(virt);
> + pl1e = map_xen_pagetable_new(l2e_get_mfn((*pl2e)));
> + pl1e += l1_table_offset(virt);
> ol1e = *pl1e;
> l1e_write_atomic(pl1e, l1e_from_mfn(mfn, flags));
> + UNMAP_XEN_PAGETABLE_NEW(pl1e);
> if ( (l1e_get_flags(ol1e) & _PAGE_PRESENT) )
> {
> unsigned int flush_flags = FLUSH_TLB |
> FLUSH_ORDER(0);
> @@ -5257,6 +5267,7 @@ int map_pages_to_xen(
> {
> unsigned long base_mfn;
> l1_pgentry_t *l1t;
> + mfn_t l1t_mfn;
>
> if ( locking )
> spin_lock(&map_pgdir_lock);
> @@ -5280,12 +5291,15 @@ int map_pages_to_xen(
> goto check_l3;
> }
>
> - l1t = l2e_to_l1e(ol2e);
> + l1t_mfn = l2e_get_mfn(ol2e);
> + l1t = map_xen_pagetable_new(l1t_mfn);
> +
> base_mfn = l1e_get_pfn(l1t[0]) &
> ~(L1_PAGETABLE_ENTRIES - 1);
> for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ )
> if ( (l1e_get_pfn(l1t[i]) != (base_mfn + i)) ||
> (l1e_get_flags(l1t[i]) != flags) )
> break;
> + UNMAP_XEN_PAGETABLE_NEW(l1t);
> if ( i == L1_PAGETABLE_ENTRIES )
> {
> l2e_write_atomic(pl2e, l2e_from_pfn(base_mfn,
> @@ -5295,7 +5309,7 @@ int map_pages_to_xen(
> flush_area(virt - PAGE_SIZE,
> FLUSH_TLB_GLOBAL |
> FLUSH_ORDER(PAGETABLE_ORDER));
> - free_xen_pagetable(l2e_to_l1e(ol2e));
> + free_xen_pagetable_new(l1t_mfn);
> }
> else if ( locking )
> spin_unlock(&map_pgdir_lock);
> @@ -5311,6 +5325,7 @@ int map_pages_to_xen(
> {
> unsigned long base_mfn;
> l2_pgentry_t *l2t;
> + mfn_t l2t_mfn;
>
> if ( locking )
> spin_lock(&map_pgdir_lock);
> @@ -5328,7 +5343,9 @@ int map_pages_to_xen(
> goto end_of_loop;
> }
>
> - l2t = l3e_to_l2e(ol3e);
> + l2t_mfn = l3e_get_mfn(ol3e);
> + l2t = map_xen_pagetable_new(l2t_mfn);
> +
> base_mfn = l2e_get_pfn(l2t[0]) & ~(L2_PAGETABLE_ENTRIES
> *
> L1_PAGETABLE_ENTRIES -
> 1);
> for ( i = 0; i < L2_PAGETABLE_ENTRIES; i++ )
> @@ -5336,6 +5353,7 @@ int map_pages_to_xen(
> (base_mfn + (i << PAGETABLE_ORDER))) ||
> (l2e_get_flags(l2t[i]) != l1f_to_lNf(flags)) )
> break;
> + UNMAP_XEN_PAGETABLE_NEW(l2t);
> if ( i == L2_PAGETABLE_ENTRIES )
> {
> l3e_write_atomic(pl3e, l3e_from_pfn(base_mfn,
> @@ -5345,7 +5363,7 @@ int map_pages_to_xen(
> flush_area(virt - PAGE_SIZE,
> FLUSH_TLB_GLOBAL |
> FLUSH_ORDER(2*PAGETABLE_ORDER));
> - free_xen_pagetable(l3e_to_l2e(ol3e));
> + free_xen_pagetable_new(l2t_mfn);
> }
> else if ( locking )
> spin_unlock(&map_pgdir_lock);
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