On Fri, 16 Dec 2022, Julien Grall wrote:
> From: Wei Liu <wei.l...@citrix.com>
>
> After the direct map removal, pages from the boot allocator are not
> mapped at all in the direct map. Although we have map_domain_page, they
> are ephemeral and are less helpful for mappings that are more than a
> page, so we want a mechanism to globally map a range of pages, which is
> what vmap is for. Therefore, we bring vm_init into early boot stage.
>
> To allow vmap to be initialised and used in early boot, we need to
> modify vmap to receive pages from the boot allocator during early boot
> stage.
>
> Signed-off-by: Wei Liu <wei.l...@citrix.com>
> Signed-off-by: David Woodhouse <dw...@amazon.com>
> Signed-off-by: Hongyan Xia <hongy...@amazon.com>
> Signed-off-by: Julien Grall <jgr...@amazon.com>
For the arm and common parts:
Reviewed-by: Stefano Stabellini <sstabell...@kernel.org>
> ---
> xen/arch/arm/setup.c | 4 ++--
> xen/arch/x86/setup.c | 31 ++++++++++++++++++++-----------
> xen/common/vmap.c | 37 +++++++++++++++++++++++++++++--------
> 3 files changed, 51 insertions(+), 21 deletions(-)
>
> diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
> index 1f26f67b90e3..2311726f5ddd 100644
> --- a/xen/arch/arm/setup.c
> +++ b/xen/arch/arm/setup.c
> @@ -1028,6 +1028,8 @@ void __init start_xen(unsigned long boot_phys_offset,
>
> setup_mm();
>
> + vm_init();
> +
> /* Parse the ACPI tables for possible boot-time configuration */
> acpi_boot_table_init();
>
> @@ -1039,8 +1041,6 @@ void __init start_xen(unsigned long boot_phys_offset,
> */
> system_state = SYS_STATE_boot;
>
> - vm_init();
> -
> if ( acpi_disabled )
> {
> printk("Booting using Device Tree\n");
> diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
> index 6bb5bc7c84be..1c2e09711eb0 100644
> --- a/xen/arch/x86/setup.c
> +++ b/xen/arch/x86/setup.c
> @@ -870,6 +870,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
> unsigned long eb_start, eb_end;
> bool acpi_boot_table_init_done = false, relocated = false;
> int ret;
> + bool vm_init_done = false;
> struct ns16550_defaults ns16550 = {
> .data_bits = 8,
> .parity = 'n',
> @@ -1442,12 +1443,23 @@ void __init noreturn __start_xen(unsigned long mbi_p)
> continue;
>
> if ( !acpi_boot_table_init_done &&
> - s >= (1ULL << 32) &&
> - !acpi_boot_table_init() )
> + s >= (1ULL << 32) )
> {
> - acpi_boot_table_init_done = true;
> - srat_parse_regions(s);
> - setup_max_pdx(raw_max_page);
> + /*
> + * We only initialise vmap and acpi after going through the
> bottom
> + * 4GiB, so that we have enough pages in the boot allocator.
> + */
> + if ( !vm_init_done )
> + {
> + vm_init();
> + vm_init_done = true;
> + }
> + if ( !acpi_boot_table_init() )
> + {
> + acpi_boot_table_init_done = true;
> + srat_parse_regions(s);
> + setup_max_pdx(raw_max_page);
> + }
> }
>
> if ( pfn_to_pdx((e - 1) >> PAGE_SHIFT) >= max_pdx )
> @@ -1624,6 +1636,9 @@ void __init noreturn __start_xen(unsigned long mbi_p)
>
> init_frametable();
>
> + if ( !vm_init_done )
> + vm_init();
> +
> if ( !acpi_boot_table_init_done )
> acpi_boot_table_init();
>
> @@ -1661,12 +1676,6 @@ void __init noreturn __start_xen(unsigned long mbi_p)
> end_boot_allocator();
>
> system_state = SYS_STATE_boot;
> - /*
> - * No calls involving ACPI code should go between the setting of
> - * SYS_STATE_boot and vm_init() (or else acpi_os_{,un}map_memory()
> - * will break).
> - */
> - vm_init();
>
> bsp_stack = cpu_alloc_stack(0);
> if ( !bsp_stack )
> diff --git a/xen/common/vmap.c b/xen/common/vmap.c
> index 4fd6b3067ec1..1340c7c6faf6 100644
> --- a/xen/common/vmap.c
> +++ b/xen/common/vmap.c
> @@ -34,9 +34,20 @@ void __init vm_init_type(enum vmap_region type, void
> *start, void *end)
>
> for ( i = 0, va = (unsigned long)vm_bitmap(type); i < nr; ++i, va +=
> PAGE_SIZE )
> {
> - struct page_info *pg = alloc_domheap_page(NULL, 0);
> + mfn_t mfn;
> + int rc;
>
> - map_pages_to_xen(va, page_to_mfn(pg), 1, PAGE_HYPERVISOR);
> + if ( system_state == SYS_STATE_early_boot )
> + mfn = alloc_boot_pages(1, 1);
> + else
> + {
> + struct page_info *pg = alloc_domheap_page(NULL, 0);
> +
> + BUG_ON(!pg);
> + mfn = page_to_mfn(pg);
> + }
> + rc = map_pages_to_xen(va, mfn, 1, PAGE_HYPERVISOR);
> + BUG_ON(rc);
> clear_page((void *)va);
> }
> bitmap_fill(vm_bitmap(type), vm_low[type]);
> @@ -62,7 +73,7 @@ static void *vm_alloc(unsigned int nr, unsigned int align,
> spin_lock(&vm_lock);
> for ( ; ; )
> {
> - struct page_info *pg;
> + mfn_t mfn;
>
> ASSERT(vm_low[t] == vm_top[t] || !test_bit(vm_low[t], vm_bitmap(t)));
> for ( start = vm_low[t]; start < vm_top[t]; )
> @@ -97,9 +108,16 @@ static void *vm_alloc(unsigned int nr, unsigned int align,
> if ( vm_top[t] >= vm_end[t] )
> return NULL;
>
> - pg = alloc_domheap_page(NULL, 0);
> - if ( !pg )
> - return NULL;
> + if ( system_state == SYS_STATE_early_boot )
> + mfn = alloc_boot_pages(1, 1);
> + else
> + {
> + struct page_info *pg = alloc_domheap_page(NULL, 0);
> +
> + if ( !pg )
> + return NULL;
> + mfn = page_to_mfn(pg);
> + }
>
> spin_lock(&vm_lock);
>
> @@ -107,7 +125,7 @@ static void *vm_alloc(unsigned int nr, unsigned int align,
> {
> unsigned long va = (unsigned long)vm_bitmap(t) + vm_top[t] / 8;
>
> - if ( !map_pages_to_xen(va, page_to_mfn(pg), 1, PAGE_HYPERVISOR) )
> + if ( !map_pages_to_xen(va, mfn, 1, PAGE_HYPERVISOR) )
> {
> clear_page((void *)va);
> vm_top[t] += PAGE_SIZE * 8;
> @@ -117,7 +135,10 @@ static void *vm_alloc(unsigned int nr, unsigned int
> align,
> }
> }
>
> - free_domheap_page(pg);
> + if ( system_state == SYS_STATE_early_boot )
> + init_boot_pages(mfn_to_maddr(mfn), mfn_to_maddr(mfn) +
> PAGE_SIZE);
> + else
> + free_domheap_page(mfn_to_page(mfn));
>
> if ( start >= vm_top[t] )
> {
> --
> 2.38.1
>
