This is a note to let you know that I've just added the patch titled xen: move max_pfn in xen_memory_setup() out of function scope to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: xen-move-max_pfn-in-xen_memory_setup-out-of-function.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit bd83746529b2e5643edb183620b3e154f1cb17fe Author: Juergen Gross <jgross@xxxxxxxx> Date: Tue Aug 6 10:24:41 2024 +0200 xen: move max_pfn in xen_memory_setup() out of function scope [ Upstream commit 43dc2a0f479b9cd30f6674986d7a40517e999d31 ] Instead of having max_pfn as a local variable of xen_memory_setup(), make it a static variable in setup.c instead. This avoids having to pass it to subfunctions, which will be needed in more cases in future. Rename it to ini_nr_pages, as the value denotes the currently usable number of memory pages as passed from the hypervisor at boot time. Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Tested-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Stable-dep-of: be35d91c8880 ("xen: tolerate ACPI NVS memory overlapping with Xen allocated memory") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 96fb245d901b3..af18bd7e0700d 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -46,6 +46,9 @@ unsigned long xen_released_pages; /* E820 map used during setting up memory. */ static struct e820_table xen_e820_table __initdata; +/* Number of initially usable memory pages. */ +static unsigned long ini_nr_pages __initdata; + /* * Buffer used to remap identity mapped pages. We only need the virtual space. * The physical page behind this address is remapped as needed to different @@ -253,7 +256,7 @@ static int __init xen_free_mfn(unsigned long mfn) * as a fallback if the remapping fails. */ static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn, - unsigned long end_pfn, unsigned long nr_pages) + unsigned long end_pfn) { unsigned long pfn, end; int ret; @@ -261,7 +264,7 @@ static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn, WARN_ON(start_pfn > end_pfn); /* Release pages first. */ - end = min(end_pfn, nr_pages); + end = min(end_pfn, ini_nr_pages); for (pfn = start_pfn; pfn < end; pfn++) { unsigned long mfn = pfn_to_mfn(pfn); @@ -382,15 +385,14 @@ static void __init xen_do_set_identity_and_remap_chunk( * to Xen and not remapped. */ static unsigned long __init xen_set_identity_and_remap_chunk( - unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages, - unsigned long remap_pfn) + unsigned long start_pfn, unsigned long end_pfn, unsigned long remap_pfn) { unsigned long pfn; unsigned long i = 0; unsigned long n = end_pfn - start_pfn; if (remap_pfn == 0) - remap_pfn = nr_pages; + remap_pfn = ini_nr_pages; while (i < n) { unsigned long cur_pfn = start_pfn + i; @@ -399,19 +401,19 @@ static unsigned long __init xen_set_identity_and_remap_chunk( unsigned long remap_range_size; /* Do not remap pages beyond the current allocation */ - if (cur_pfn >= nr_pages) { + if (cur_pfn >= ini_nr_pages) { /* Identity map remaining pages */ set_phys_range_identity(cur_pfn, cur_pfn + size); break; } - if (cur_pfn + size > nr_pages) - size = nr_pages - cur_pfn; + if (cur_pfn + size > ini_nr_pages) + size = ini_nr_pages - cur_pfn; remap_range_size = xen_find_pfn_range(&remap_pfn); if (!remap_range_size) { pr_warn("Unable to find available pfn range, not remapping identity pages\n"); xen_set_identity_and_release_chunk(cur_pfn, - cur_pfn + left, nr_pages); + cur_pfn + left); break; } /* Adjust size to fit in current e820 RAM region */ @@ -438,18 +440,18 @@ static unsigned long __init xen_set_identity_and_remap_chunk( } static unsigned long __init xen_count_remap_pages( - unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages, + unsigned long start_pfn, unsigned long end_pfn, unsigned long remap_pages) { - if (start_pfn >= nr_pages) + if (start_pfn >= ini_nr_pages) return remap_pages; - return remap_pages + min(end_pfn, nr_pages) - start_pfn; + return remap_pages + min(end_pfn, ini_nr_pages) - start_pfn; } -static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages, +static unsigned long __init xen_foreach_remap_area( unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn, - unsigned long nr_pages, unsigned long last_val)) + unsigned long last_val)) { phys_addr_t start = 0; unsigned long ret_val = 0; @@ -477,8 +479,7 @@ static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages, end_pfn = PFN_UP(entry->addr); if (start_pfn < end_pfn) - ret_val = func(start_pfn, end_pfn, nr_pages, - ret_val); + ret_val = func(start_pfn, end_pfn, ret_val); start = end; } } @@ -741,7 +742,7 @@ static void __init xen_reserve_xen_mfnlist(void) **/ char * __init xen_memory_setup(void) { - unsigned long max_pfn, pfn_s, n_pfns; + unsigned long pfn_s, n_pfns; phys_addr_t mem_end, addr, size, chunk_size; u32 type; int rc; @@ -753,9 +754,8 @@ char * __init xen_memory_setup(void) int op; xen_parse_512gb(); - max_pfn = xen_get_pages_limit(); - max_pfn = min(max_pfn, xen_start_info->nr_pages); - mem_end = PFN_PHYS(max_pfn); + ini_nr_pages = min(xen_get_pages_limit(), xen_start_info->nr_pages); + mem_end = PFN_PHYS(ini_nr_pages); memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries); set_xen_guest_handle(memmap.buffer, xen_e820_table.entries); @@ -799,10 +799,10 @@ char * __init xen_memory_setup(void) max_pages = xen_get_max_pages(); /* How many extra pages do we need due to remapping? */ - max_pages += xen_foreach_remap_area(max_pfn, xen_count_remap_pages); + max_pages += xen_foreach_remap_area(xen_count_remap_pages); - if (max_pages > max_pfn) - extra_pages += max_pages - max_pfn; + if (max_pages > ini_nr_pages) + extra_pages += max_pages - ini_nr_pages; /* * Clamp the amount of extra memory to a EXTRA_MEM_RATIO @@ -811,8 +811,8 @@ char * __init xen_memory_setup(void) * Make sure we have no memory above max_pages, as this area * isn't handled by the p2m management. */ - maxmem_pages = EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)); - extra_pages = min3(maxmem_pages, extra_pages, max_pages - max_pfn); + maxmem_pages = EXTRA_MEM_RATIO * min(ini_nr_pages, PFN_DOWN(MAXMEM)); + extra_pages = min3(maxmem_pages, extra_pages, max_pages - ini_nr_pages); i = 0; addr = xen_e820_table.entries[0].addr; size = xen_e820_table.entries[0].size; @@ -914,7 +914,7 @@ char * __init xen_memory_setup(void) * Set identity map on non-RAM pages and prepare remapping the * underlying RAM. */ - xen_foreach_remap_area(max_pfn, xen_set_identity_and_remap_chunk); + xen_foreach_remap_area(xen_set_identity_and_remap_chunk); pr_info("Released %ld page(s)\n", xen_released_pages);