Merge pull request #2732 from jongwu/plugin

qemu: prepare to upgrade qemu version to 6.1.0 for arm
This commit is contained in:
Fabiano Fidêncio
2021-09-28 12:12:48 +02:00
committed by GitHub
2 changed files with 96 additions and 0 deletions

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@@ -0,0 +1,94 @@
From 5745513881520f48401ac40306ac8cd6ef35beaf Mon Sep 17 00:00:00 2001
From: Sudarshan Rajagopalan <sudaraja@codeaurora.org>
Date: Sun, 26 Sep 2021 13:10:41 +0800
Subject: [PATCH] arm64/sparsemem: reduce SECTION_SIZE_BITS
memory_block_size_bytes() determines the memory hotplug granularity i.e the
amount of memory which can be hot added or hot removed from the kernel. The
generic value here being MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS)
for memory_block_size_bytes() on platforms like arm64 that does not override.
Current SECTION_SIZE_BITS is 30 i.e 1GB which is large and a reduction here
increases memory hotplug granularity, thus improving its agility. A reduced
section size also reduces memory wastage in vmemmmap mapping for sections
with large memory holes. So we try to set the least section size as possible.
A section size bits selection must follow:
(MAX_ORDER - 1 + PAGE_SHIFT) <= SECTION_SIZE_BITS
CONFIG_FORCE_MAX_ZONEORDER is always defined on arm64 and so just following it
would help achieve the smallest section size.
SECTION_SIZE_BITS = (CONFIG_FORCE_MAX_ZONEORDER - 1 + PAGE_SHIFT)
SECTION_SIZE_BITS = 22 (11 - 1 + 12) i.e 4MB for 4K pages
SECTION_SIZE_BITS = 24 (11 - 1 + 14) i.e 16MB for 16K pages without THP
SECTION_SIZE_BITS = 25 (12 - 1 + 14) i.e 32MB for 16K pages with THP
SECTION_SIZE_BITS = 26 (11 - 1 + 16) i.e 64MB for 64K pages without THP
SECTION_SIZE_BITS = 29 (14 - 1 + 16) i.e 512MB for 64K pages with THP
But there are other problems in reducing SECTION_SIZE_BIT. Reducing it by too
much would over populate /sys/devices/system/memory/ and also consume too many
page->flags bits in the !vmemmap case. Also section size needs to be multiple
of 128MB to have PMD based vmemmap mapping with CONFIG_ARM64_4K_PAGES.
Given these constraints, lets just reduce the section size to 128MB for 4K
Signed-off-by: Sudarshan Rajagopalan <sudaraja@codeaurora.org>
Suggested-by: Anshuman Khandual <anshuman.khandual@arm.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/43843c5e092bfe3ec4c41e3c8c78a7ee35b69bb0.1611206601.git.sudaraja@codeaurora.org
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/include/asm/sparsemem.h | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/sparsemem.h b/arch/arm64/include/asm/sparsemem.h
index 1f43fcc79738..eb4a75d720ed 100644
--- a/arch/arm64/include/asm/sparsemem.h
+++ b/arch/arm64/include/asm/sparsemem.h
@@ -7,7 +7,26 @@
#ifdef CONFIG_SPARSEMEM
#define MAX_PHYSMEM_BITS CONFIG_ARM64_PA_BITS
-#define SECTION_SIZE_BITS 30
-#endif
+
+/*
+ * Section size must be at least 512MB for 64K base
+ * page size config. Otherwise it will be less than
+ * (MAX_ORDER - 1) and the build process will fail.
+ */
+#ifdef CONFIG_ARM64_64K_PAGES
+#define SECTION_SIZE_BITS 29
+
+#else
+
+/*
+ * Section size must be at least 128MB for 4K base
+ * page size config. Otherwise PMD based huge page
+ * entries could not be created for vmemmap mappings.
+ * 16K follows 4K for simplicity.
+ */
+#define SECTION_SIZE_BITS 27
+#endif /* CONFIG_ARM64_64K_PAGES */
+
+#endif /* CONFIG_SPARSEMEM*/
#endif
--
2.17.1

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@@ -437,6 +437,8 @@ generate_qemu_options() {
# aarch64 need to explictly set --enable-pie
if [ -z "${static}" ] && [ "${arch}" = "aarch64" ]; then
qemu_options+=(arch:"--enable-pie")
# pie is conflict with plugins build for qemu 6.1.0
[ "${qemu_version}" == "6.1.0" ] && qemu_options+=(arch:"--disable-plugins")
fi
_qemu_cflags=""