From: Julien Grall <julien@xen.org>
To: xen-devel@lists.xenproject.org
Cc: Wei.Chen@arm.com, Henry.Wang@arm.com, Penny.Zheng@arm.com,
Bertrand.Marquis@arm.com, Julien Grall <julien.grall@arm.com>,
Stefano Stabellini <sstabellini@kernel.org>,
Julien Grall <julien@xen.org>,
Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>,
Julien Grall <jgrall@amazon.com>
Subject: [PATCH RFCv2 14/15] xen/arm: mm: Rework setup_xenheap_mappings()
Date: Sun, 25 Apr 2021 21:13:17 +0100 [thread overview]
Message-ID: <20210425201318.15447-15-julien@xen.org> (raw)
In-Reply-To: <20210425201318.15447-1-julien@xen.org>
From: Julien Grall <julien.grall@arm.com>
A few issues have been reported with setup_xenheap_mappings() over the
last couple of years. The main ones are:
- It will break on platform supporting more than 512GB of RAM
because the memory allocated by the boot allocator is not yet
mapped.
- Aligning all the regions to 1GB may lead to unexpected result
because we may alias non-cacheable region (such as device or reserved
regions).
map_pages_to_xen() was recently reworked to allow superpage mappings and
deal with the use of page-tables before they are mapped.
Most of the code in setup_xenheap_mappings() is now replaced with a
single call to map_pages_to_xen().
This also require to re-order the steps setup_mm() so the regions are
given to the boot allocator first and then we setup the xenheap
mappings.
Note that the 1GB alignment is not yet removed.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Julien Grall <jgrall@amazon.com>
---
Changes in v2:
- New patch
TODO:
- Remove the 1GB alignment
- Add support for setting the contiguous bit
---
xen/arch/arm/mm.c | 60 ++++----------------------------------------
xen/arch/arm/setup.c | 10 ++++++--
2 files changed, 13 insertions(+), 57 deletions(-)
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index f5768f2d4a81..c49403b687f5 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -143,17 +143,6 @@ static DEFINE_PAGE_TABLE(cpu0_pgtable);
static DEFINE_PAGE_TABLES(cpu0_dommap, DOMHEAP_SECOND_PAGES);
#endif
-#ifdef CONFIG_ARM_64
-/* The first page of the first level mapping of the xenheap. The
- * subsequent xenheap first level pages are dynamically allocated, but
- * we need this one to bootstrap ourselves. */
-static DEFINE_PAGE_TABLE(xenheap_first_first);
-/* The zeroeth level slot which uses xenheap_first_first. Used because
- * setup_xenheap_mappings otherwise relies on mfn_to_virt which isn't
- * valid for a non-xenheap mapping. */
-static __initdata int xenheap_first_first_slot = -1;
-#endif
-
/* Common pagetable leaves */
/* Second level page tables.
*
@@ -818,9 +807,9 @@ void __init setup_xenheap_mappings(unsigned long base_mfn,
void __init setup_xenheap_mappings(unsigned long base_mfn,
unsigned long nr_mfns)
{
- lpae_t *first, pte;
unsigned long mfn, end_mfn;
vaddr_t vaddr;
+ int rc;
/* Align to previous 1GB boundary */
mfn = base_mfn & ~((FIRST_SIZE>>PAGE_SHIFT)-1);
@@ -846,49 +835,10 @@ void __init setup_xenheap_mappings(unsigned long base_mfn,
*/
vaddr = (vaddr_t)__mfn_to_virt(base_mfn) & FIRST_MASK;
- while ( mfn < end_mfn )
- {
- int slot = zeroeth_table_offset(vaddr);
- lpae_t *p = &xen_pgtable[slot];
-
- if ( p->pt.valid )
- {
- /* mfn_to_virt is not valid on the 1st 1st mfn, since it
- * is not within the xenheap. */
- first = slot == xenheap_first_first_slot ?
- xenheap_first_first : mfn_to_virt(lpae_get_mfn(*p));
- }
- else if ( xenheap_first_first_slot == -1)
- {
- /* Use xenheap_first_first to bootstrap the mappings */
- first = xenheap_first_first;
-
- pte = pte_of_xenaddr((vaddr_t)xenheap_first_first);
- pte.pt.table = 1;
- write_pte(p, pte);
-
- xenheap_first_first_slot = slot;
- }
- else
- {
- mfn_t first_mfn = alloc_boot_pages(1, 1);
-
- clear_page(mfn_to_virt(first_mfn));
- pte = mfn_to_xen_entry(first_mfn, MT_NORMAL);
- pte.pt.table = 1;
- write_pte(p, pte);
- first = mfn_to_virt(first_mfn);
- }
-
- pte = mfn_to_xen_entry(_mfn(mfn), MT_NORMAL);
- /* TODO: Set pte.pt.contig when appropriate. */
- write_pte(&first[first_table_offset(vaddr)], pte);
-
- mfn += FIRST_SIZE>>PAGE_SHIFT;
- vaddr += FIRST_SIZE;
- }
-
- flush_xen_tlb_local();
+ rc = map_pages_to_xen(vaddr, _mfn(mfn), end_mfn - mfn,
+ PAGE_HYPERVISOR_RW | _PAGE_BLOCK);
+ if ( rc )
+ panic("Unable to setup the xenheap mappings.\n");
}
#endif
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index 00aad1c194b9..0993a4bb52d4 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -761,8 +761,11 @@ static void __init setup_mm(void)
ram_start = min(ram_start,bank_start);
ram_end = max(ram_end,bank_end);
- setup_xenheap_mappings(bank_start>>PAGE_SHIFT, bank_size>>PAGE_SHIFT);
-
+ /*
+ * Add the region to the boot allocator first, so we can use
+ * some to allocate page-tables for setting up the xenheap
+ * mappings.
+ */
s = bank_start;
while ( s < bank_end )
{
@@ -781,6 +784,9 @@ static void __init setup_mm(void)
fw_unreserved_regions(s, e, init_boot_pages, 0);
s = n;
}
+
+ setup_xenheap_mappings(bank_start >> PAGE_SHIFT,
+ bank_size >> PAGE_SHIFT);
}
total_pages += ram_size >> PAGE_SHIFT;
--
2.17.1
next prev parent reply other threads:[~2021-04-25 20:32 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-25 20:13 [PATCH RFCv2 00/15] xen/arm: mm: Remove open-coding mappings Julien Grall
2021-04-25 20:13 ` [PATCH RFCv2 01/15] xen/arm: lpae: Rename LPAE_ENTRIES_MASK_GS to LPAE_ENTRY_MASK_GS Julien Grall
2021-05-11 22:12 ` Stefano Stabellini
2021-04-25 20:13 ` [PATCH RFCv2 02/15] xen/arm: lpae: Use the generic helpers to defined the Xen PT helpers Julien Grall
2021-05-11 22:26 ` Stefano Stabellini
2021-05-12 14:26 ` Julien Grall
2021-05-12 21:30 ` Stefano Stabellini
2021-05-12 22:16 ` Julien Grall
2021-05-13 22:44 ` Stefano Stabellini
2021-07-03 17:32 ` Julien Grall
2021-07-13 20:53 ` Stefano Stabellini
2021-07-14 17:40 ` Julien Grall
2021-04-25 20:13 ` [PATCH RFCv2 03/15] xen/arm: p2m: Replace level_{orders, masks} arrays with LEVEL_{ORDER, MASK} Julien Grall
2021-05-11 22:33 ` Stefano Stabellini
2021-05-12 14:39 ` Julien Grall
2021-04-25 20:13 ` [PATCH RFCv2 04/15] xen/arm: mm: Allow other mapping size in xen_pt_update_entry() Julien Grall
2021-05-11 22:42 ` Stefano Stabellini
2021-04-25 20:13 ` [PATCH RFCv2 05/15] xen/arm: mm: Avoid flushing the TLBs when mapping are inserted Julien Grall
2021-05-11 22:51 ` Stefano Stabellini
2021-04-25 20:13 ` [PATCH RFCv2 06/15] xen/arm: mm: Don't open-code Xen PT update in remove_early_mappings() Julien Grall
2021-05-11 22:58 ` Stefano Stabellini
2021-04-25 20:13 ` [PATCH RFCv2 07/15] xen/arm: mm: Re-implement early_fdt_map() using map_pages_to_xen() Julien Grall
2021-05-12 21:41 ` Stefano Stabellini
2021-05-12 22:18 ` Julien Grall
2021-04-25 20:13 ` [PATCH RFCv2 08/15] xen/arm32: mm: Check if the virtual address is shared before updating it Julien Grall
2021-05-12 22:00 ` Stefano Stabellini
2021-05-12 22:23 ` Julien Grall
2021-05-13 22:32 ` Stefano Stabellini
2021-05-13 22:59 ` Julien Grall
2021-05-14 1:04 ` Stefano Stabellini
2021-04-25 20:13 ` [PATCH RFCv2 09/15] xen/arm32: mm: Re-implement setup_xenheap_mappings() using map_pages_to_xen() Julien Grall
2021-05-12 22:07 ` Stefano Stabellini
2021-05-13 17:55 ` Julien Grall
2021-04-25 20:13 ` [PATCH RFCv2 10/15] xen/arm: mm: Allocate xen page tables in domheap rather than xenheap Julien Grall
2021-05-12 22:44 ` Stefano Stabellini
2021-05-13 18:09 ` Julien Grall
2021-05-13 22:27 ` Stefano Stabellini
2021-05-15 8:48 ` Julien Grall
2021-05-18 0:37 ` Stefano Stabellini
2021-04-25 20:13 ` [PATCH RFCv2 11/15] xen/arm: mm: Allow page-table allocation from the boot allocator Julien Grall
2021-05-13 22:58 ` Stefano Stabellini
2021-04-25 20:13 ` [PATCH RFCv2 12/15] xen/arm: add Persistent Map (PMAP) infrastructure Julien Grall
2021-04-26 9:41 ` Xia, Hongyan
2021-07-03 17:57 ` Julien Grall
2021-04-28 21:47 ` Wei Liu
2021-05-14 23:25 ` Stefano Stabellini
2021-05-15 8:54 ` Julien Grall
2021-04-25 20:13 ` [PATCH RFCv2 13/15] xen/arm: mm: Use the PMAP helpers in xen_{,un}map_table() Julien Grall
2021-05-14 23:35 ` Stefano Stabellini
2021-05-15 9:03 ` Julien Grall
2021-04-25 20:13 ` Julien Grall [this message]
2021-05-14 23:51 ` [PATCH RFCv2 14/15] xen/arm: mm: Rework setup_xenheap_mappings() Stefano Stabellini
2021-05-15 9:21 ` Julien Grall
2021-05-18 0:50 ` Stefano Stabellini
2022-02-12 19:16 ` Julien Grall
2021-04-25 20:13 ` [PATCH RFCv2 15/15] xen/arm: mm: Re-implement setup_frame_table_mappings() with map_pages_to_xen() Julien Grall
2021-05-15 0:02 ` Stefano Stabellini
2021-05-15 9:25 ` Julien Grall
2021-05-18 0:51 ` Stefano Stabellini
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