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Re: [PATCH] x86: initialize initial_page_table before paravirt jumps

Previous thread: hey by bayogirl29 on Tuesday, December 21, 2010 - 6:30 pm. (1 message)

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From: Rusty Russell
Subject: [PATCH] x86: initialize initial_page_table before paravirt jumps
Date: Tuesday, December 21, 2010 - 7:29 pm

v2.6.36-rc8-54-gb40827f (x86-32, mm: Add an initial page table for
core bootstrapping) made x86 boot using initial_page_table and broke
lguest.

For 2.6.37 we simply cut & paste the initialization code into lguest
(da32dac10126 "lguest: populate initial_page_table"), now we fix it
properly by doing that initialization before the paravirt jump.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
---
 arch/x86/kernel/head_32.S   |   77 ++++++++++++++++----------------
 arch/x86/lguest/i386_head.S |  105 --------------------------------------------
 2 files changed, 39 insertions(+), 143 deletions(-)

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -139,39 +139,6 @@ 1:
 	movl %eax, pa(olpc_ofw_pgd)
 #endif
 
-#ifdef CONFIG_PARAVIRT
-	/* This is can only trip for a broken bootloader... */
-	cmpw $0x207, pa(boot_params + BP_version)
-	jb default_entry
-
-	/* Paravirt-compatible boot parameters.  Look to see what architecture
-		we're booting under. */
-	movl pa(boot_params + BP_hardware_subarch), %eax
-	cmpl $num_subarch_entries, %eax
-	jae bad_subarch
-
-	movl pa(subarch_entries)(,%eax,4), %eax
-	subl $__PAGE_OFFSET, %eax
-	jmp *%eax
-
-bad_subarch:
-WEAK(lguest_entry)
-WEAK(xen_entry)
-	/* Unknown implementation; there's really
-	   nothing we can do at this point. */
-	ud2a
-
-	__INITDATA
-
-subarch_entries:
-	.long default_entry		/* normal x86/PC */
-	.long lguest_entry		/* lguest hypervisor */
-	.long xen_entry			/* Xen hypervisor */
-	.long default_entry		/* Moorestown MID */
-num_subarch_entries = (. - subarch_entries) / 4
-.previous
-#endif /* CONFIG_PARAVIRT */
-
 /*
  * Initialize page tables.  This creates a PDE and a set of page
  * tables, which are located immediately beyond __brk_base.  The variable
@@ -181,7 +148,6 @@ num_subarch_entries = (. - subarch_entri
  *
  * Note that the stack is not yet set up!
 ...
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[view original message]
From: Rusty Russell
Subject: Re: [PATCH] x86: initialize initial_page_table before paravirt jumps
Date: Monday, January 3, 2011 - 11:50 pm

Ping?  Ingo?  I don't see this in -tip...

Thanks,
Rusty.

Subject: x86: initialize initial_page_table before paravirt jumps

v2.6.36-rc8-54-gb40827f (x86-32, mm: Add an initial page table for
core bootstrapping) made x86 boot using initial_page_table and broke
lguest.

For 2.6.37 we simply cut & paste the initialization code into lguest
(da32dac10126 "lguest: populate initial_page_table"), now we fix it
properly by doing that initialization before the paravirt jump.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
---
 arch/x86/kernel/head_32.S   |   77 ++++++++++++++++----------------
 arch/x86/lguest/i386_head.S |  105 --------------------------------------------
 2 files changed, 39 insertions(+), 143 deletions(-)

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -139,39 +139,6 @@ 1:
 	movl %eax, pa(olpc_ofw_pgd)
 #endif
 
-#ifdef CONFIG_PARAVIRT
-	/* This is can only trip for a broken bootloader... */
-	cmpw $0x207, pa(boot_params + BP_version)
-	jb default_entry
-
-	/* Paravirt-compatible boot parameters.  Look to see what architecture
-		we're booting under. */
-	movl pa(boot_params + BP_hardware_subarch), %eax
-	cmpl $num_subarch_entries, %eax
-	jae bad_subarch
-
-	movl pa(subarch_entries)(,%eax,4), %eax
-	subl $__PAGE_OFFSET, %eax
-	jmp *%eax
-
-bad_subarch:
-WEAK(lguest_entry)
-WEAK(xen_entry)
-	/* Unknown implementation; there's really
-	   nothing we can do at this point. */
-	ud2a
-
-	__INITDATA
-
-subarch_entries:
-	.long default_entry		/* normal x86/PC */
-	.long lguest_entry		/* lguest hypervisor */
-	.long xen_entry			/* Xen hypervisor */
-	.long default_entry		/* Moorestown MID */
-num_subarch_entries = (. - subarch_entries) / 4
-.previous
-#endif /* CONFIG_PARAVIRT */
-
 /*
  * Initialize page tables.  This creates a PDE and a set of page
  * tables, which are located immediately beyond ...
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From: tip-bot for Rusty Russell
Subject: [tip:x86/mm] x86, mm: Initialize initial_page_table before paravirt jumps
Date: Tuesday, January 4, 2011 - 2:25 am

Commit-ID:  d50d8fe192428090790e7178e9507e981e0b005b
Gitweb:     http://git.kernel.org/tip/d50d8fe192428090790e7178e9507e981e0b005b
Author:     Rusty Russell <rusty@rustcorp.com.au>
AuthorDate: Tue, 4 Jan 2011 17:20:54 +1030
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Tue, 4 Jan 2011 09:53:50 +0100

x86, mm: Initialize initial_page_table before paravirt jumps

v2.6.36-rc8-54-gb40827f (x86-32, mm: Add an initial page table
for core bootstrapping) made x86 boot using initial_page_table
and broke lguest.

For 2.6.37 we simply cut & paste the initialization code into
lguest (da32dac10126 "lguest: populate initial_page_table"), now
we fix it properly by doing that initialization before the
paravirt jump.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: lguest <lguest@ozlabs.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <201101041720.54535.rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/head_32.S   |   77 ++++++++++++++++---------------
 arch/x86/lguest/i386_head.S |  105 -------------------------------------------
 2 files changed, 39 insertions(+), 143 deletions(-)

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index c0dbd9a..e3a8bb9 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -139,39 +139,6 @@ ENTRY(startup_32)
 	movl %eax, pa(olpc_ofw_pgd)
 #endif
 
-#ifdef CONFIG_PARAVIRT
-	/* This is can only trip for a broken bootloader... */
-	cmpw $0x207, pa(boot_params + BP_version)
-	jb default_entry
-
-	/* Paravirt-compatible boot parameters.  Look to see what architecture
-		we're booting under. */
-	movl pa(boot_params + BP_hardware_subarch), %eax
-	cmpl $num_subarch_entries, %eax
-	jae bad_subarch
-
-	movl pa(subarch_entries)(,%eax,4), %eax
-	subl $__PAGE_OFFSET, %eax
-	jmp ...
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Previous thread: hey by bayogirl29 on Tuesday, December 21, 2010 - 6:30 pm. (1 message)

Next thread: [RFC 1/3] mm, Make __get_user_pages return -EHWPOISON for HWPOISON page optionally by Huang Ying on Tuesday, December 21, 2010 - 7:51 pm. (4 messages)