[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v12 06/10] x86: change default load address from 1 MiB to 2 MiB
Subsequent patches introducing relocatable early boot code play with page tables using 2 MiB huge pages. If load address is not aligned at 2 MiB then code touching such page tables must have special cases for start and end of Xen image memory region. So, let's make life easier and move default load address from 1 MiB to 2 MiB. This way page table code will be nice and easy. Hence, there is a chance that it will be less error prone too... :-))) Additionally, drop first 2 MiB mapping from Xen image mapping. It is no longer needed. Signed-off-by: Daniel Kiper <daniel.kiper@xxxxxxxxxx> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> Reviewed-by: Doug Goldstein <cardoe@xxxxxxxxxx> --- v8 - suggestions/fixes: - drop first 2 MiB mapping from Xen image mapping (suggested by Jan Beulich), - improve commit message. v7 - suggestions/fixes: - minor cleanups (suggested by Jan Beulich). --- xen/arch/x86/Makefile | 2 +- xen/arch/x86/Rules.mk | 3 +++ xen/arch/x86/boot/head.S | 8 -------- xen/arch/x86/boot/x86_64.S | 5 +++-- xen/arch/x86/setup.c | 3 ++- xen/arch/x86/xen.lds.S | 2 +- 6 files changed, 10 insertions(+), 13 deletions(-) diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile index 08e9f7b..e5b840e 100644 --- a/xen/arch/x86/Makefile +++ b/xen/arch/x86/Makefile @@ -90,7 +90,7 @@ all_symbols = endif $(TARGET): $(TARGET)-syms $(efi-y) boot/mkelf32 - ./boot/mkelf32 $(notes_phdrs) $(TARGET)-syms $(TARGET) 0x100000 \ + ./boot/mkelf32 $(notes_phdrs) $(TARGET)-syms $(TARGET) $(XEN_IMG_OFFSET) \ `$(NM) $(TARGET)-syms | sed -ne 's/^\([^ ]*\) . __2M_rwdata_end$$/0x\1/p'` ALL_OBJS := $(BASEDIR)/arch/x86/boot/built_in.o $(BASEDIR)/arch/x86/efi/built_in.o $(ALL_OBJS) diff --git a/xen/arch/x86/Rules.mk b/xen/arch/x86/Rules.mk index 42be4bc..36e6386 100644 --- a/xen/arch/x86/Rules.mk +++ b/xen/arch/x86/Rules.mk @@ -1,9 +1,12 @@ ######################################## # x86-specific definitions +XEN_IMG_OFFSET := 0x200000 + CFLAGS += -I$(BASEDIR)/include CFLAGS += -I$(BASEDIR)/include/asm-x86/mach-generic CFLAGS += -I$(BASEDIR)/include/asm-x86/mach-default +CFLAGS += -DXEN_IMG_OFFSET=$(XEN_IMG_OFFSET) CFLAGS += '-D__OBJECT_LABEL__=$(subst /,$$,$(subst -,_,$(subst $(BASEDIR)/,,$(CURDIR))/$@))' # Prevent floating-point variables from creeping into Xen. diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S index b8f727a..22bd68d 100644 --- a/xen/arch/x86/boot/head.S +++ b/xen/arch/x86/boot/head.S @@ -482,14 +482,6 @@ trampoline_setup: mov %eax,sym_phys(boot_tsc_stamp) mov %edx,sym_phys(boot_tsc_stamp+4) - /* - * During boot, hook 4kB mappings of first 2MB of memory into L2. - * This avoids mixing cachability for the legacy VGA region, and is - * corrected when Xen relocates itself. - */ - mov $sym_phys(l1_identmap)+__PAGE_HYPERVISOR,%edi - mov %edi,sym_phys(l2_xenmap) - /* Apply relocations to bootstrap trampoline. */ mov sym_phys(trampoline_phys),%edx mov $sym_phys(__trampoline_rel_start),%edi diff --git a/xen/arch/x86/boot/x86_64.S b/xen/arch/x86/boot/x86_64.S index 139b2ca..7890374 100644 --- a/xen/arch/x86/boot/x86_64.S +++ b/xen/arch/x86/boot/x86_64.S @@ -121,8 +121,9 @@ GLOBAL(l2_identmap) * page. */ GLOBAL(l2_xenmap) - idx = 0 - .rept 8 + .quad 0 + idx = 1 + .rept 7 .quad sym_phys(__image_base__) + (idx << L2_PAGETABLE_SHIFT) + (PAGE_HYPERVISOR | _PAGE_PSE) idx = idx + 1 .endr diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c index d4b7d25..e6f6ef1 100644 --- a/xen/arch/x86/setup.c +++ b/xen/arch/x86/setup.c @@ -999,7 +999,8 @@ void __init noreturn __start_xen(unsigned long mbi_p) * Undo the temporary-hooking of the l1_identmap. __2M_text_start * is contained in this PTE. */ - BUG_ON(l2_table_offset((unsigned long)_erodata) == + BUG_ON(using_2M_mapping() && + l2_table_offset((unsigned long)_erodata) == l2_table_offset((unsigned long)_stext)); *pl2e++ = l2e_from_pfn(xen_phys_start >> PAGE_SHIFT, PAGE_HYPERVISOR_RX | _PAGE_PSE); diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S index 3a02b2b..f9cdfc1 100644 --- a/xen/arch/x86/xen.lds.S +++ b/xen/arch/x86/xen.lds.S @@ -55,7 +55,7 @@ SECTIONS __2M_text_start = .; /* Start of 2M superpages, mapped RX. */ #endif - . = __XEN_VIRT_START + MB(1); + . = __XEN_VIRT_START + XEN_IMG_OFFSET; _start = .; .text : { _stext = .; /* Text and read-only data */ -- 1.7.10.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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