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* [PATCH 0/2] Move RSDP address out of setup_header
@ 2018-11-20  7:25 Juergen Gross
  2018-11-20  7:25 ` [PATCH 1/2] x86/boot: revert commit ae7e1238e68f2a (Add ACPI RSDP address to setup_header) Juergen Gross
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Juergen Gross @ 2018-11-20  7:25 UTC (permalink / raw)
  To: linux-kernel, xen-devel, x86
  Cc: boris.ostrovsky, sstabellini, hpa, tglx, mingo, bp, daniel.kiper,
	Juergen Gross

Resend with Daniel's mailo address corrected

Instead of passing the RSDP address for Xen PVH guests from grub2 to
the kernel in setup_header move it into the non-legacy part of the
boot_params structure.

This patch series should be applied rather sooner than later in order
to avoid shipping linux 4.20 with a corky boot protocol.

Juergen Gross (2):
  x86/boot: revert commit ae7e1238e68f2a (Add ACPI RSDP address to
    setup_header)
  x86/acpi, x86/boot: Take RSDP address from boot params if available

 Documentation/x86/boot.txt            | 32 +-------------------------------
 arch/x86/boot/header.S                |  6 +-----
 arch/x86/include/asm/x86_init.h       |  2 --
 arch/x86/include/uapi/asm/bootparam.h |  7 ++-----
 arch/x86/kernel/acpi/boot.c           |  2 +-
 arch/x86/kernel/head32.c              |  1 -
 arch/x86/kernel/head64.c              |  2 --
 arch/x86/kernel/setup.c               | 17 -----------------
 8 files changed, 5 insertions(+), 64 deletions(-)

-- 
2.16.4


^ permalink raw reply	[flat|nested] 6+ messages in thread
* [PATCH 1/2] x86/boot: revert commit ae7e1238e68f2a (Add ACPI RSDP address to setup_header)
  2018-11-20  7:25 [PATCH 0/2] Move RSDP address out of setup_header Juergen Gross
@ 2018-11-20  7:25 ` Juergen Gross
  2018-11-20  9:59   ` [tip:x86/urgent] x86/boot: Mostly revert commit ae7e1238e68f2a ("Add ACPI RSDP address to setup_header") tip-bot for Juergen Gross
  2018-11-20  7:25 ` [PATCH 2/2] x86/acpi, x86/boot: Take RSDP address from boot params if available Juergen Gross
  2018-11-29  1:05 ` [Xen-devel] [PATCH 0/2] Move RSDP address out of setup_header Hans van Kranenburg
  2 siblings, 1 reply; 6+ messages in thread
From: Juergen Gross @ 2018-11-20  7:25 UTC (permalink / raw)
  To: linux-kernel, xen-devel, x86
  Cc: boris.ostrovsky, sstabellini, hpa, tglx, mingo, bp, daniel.kiper,
	Juergen Gross

Peter Anvin pointed out that commit ae7e1238e68f2a ("x86/boot: Add
ACPI RSDP address to setup_header") should be reverted as setup_header
should contain only items set by legacy BIOS.

So revert said commit. Instead of fully reverting the depending
commit e7b66d16fe4172 ("x86/acpi, x86/boot: Take RSDP address for boot
params if available") just remove the setup_header reference in order
to replace it by a boot_params in a followup patch.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 Documentation/x86/boot.txt            | 32 +-------------------------------
 arch/x86/boot/header.S                |  6 +-----
 arch/x86/include/asm/x86_init.h       |  2 --
 arch/x86/include/uapi/asm/bootparam.h |  4 ----
 arch/x86/kernel/acpi/boot.c           |  2 +-
 arch/x86/kernel/head32.c              |  1 -
 arch/x86/kernel/head64.c              |  2 --
 arch/x86/kernel/setup.c               | 17 -----------------
 8 files changed, 3 insertions(+), 63 deletions(-)

diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt
index 7727db8f94bc..5e9b826b5f62 100644
--- a/Documentation/x86/boot.txt
+++ b/Documentation/x86/boot.txt
@@ -61,18 +61,6 @@ Protocol 2.12:	(Kernel 3.8) Added the xloadflags field and extension fields
 	 	to struct boot_params for loading bzImage and ramdisk
 		above 4G in 64bit.
 
-Protocol 2.13:	(Kernel 3.14) Support 32- and 64-bit flags being set in
-		xloadflags to support booting a 64-bit kernel from 32-bit
-		EFI
-
-Protocol 2.14:	(Kernel 4.20) Added acpi_rsdp_addr holding the physical
-		address of the ACPI RSDP table.
-		The bootloader updates version with:
-		0x8000 | min(kernel-version, bootloader-version)
-		kernel-version being the protocol version supported by
-		the kernel and bootloader-version the protocol version
-		supported by the bootloader.
-
 **** MEMORY LAYOUT
 
 The traditional memory map for the kernel loader, used for Image or
@@ -209,7 +197,6 @@ Offset	Proto	Name		Meaning
 0258/8	2.10+	pref_address	Preferred loading address
 0260/4	2.10+	init_size	Linear memory required during initialization
 0264/4	2.11+	handover_offset	Offset of handover entry point
-0268/8	2.14+	acpi_rsdp_addr	Physical address of RSDP table
 
 (1) For backwards compatibility, if the setup_sects field contains 0, the
     real value is 4.
@@ -322,7 +309,7 @@ Protocol:	2.00+
   Contains the magic number "HdrS" (0x53726448).
 
 Field name:	version
-Type:		modify
+Type:		read
 Offset/size:	0x206/2
 Protocol:	2.00+
 
@@ -330,12 +317,6 @@ Protocol:	2.00+
   e.g. 0x0204 for version 2.04, and 0x0a11 for a hypothetical version
   10.17.
 
-  Up to protocol version 2.13 this information is only read by the
-  bootloader. From protocol version 2.14 onwards the bootloader will
-  write the used protocol version or-ed with 0x8000 to the field. The
-  used protocol version will be the minimum of the supported protocol
-  versions of the bootloader and the kernel.
-
 Field name:	realmode_swtch
 Type:		modify (optional)
 Offset/size:	0x208/4
@@ -763,17 +744,6 @@ Offset/size:	0x264/4
 
   See EFI HANDOVER PROTOCOL below for more details.
 
-Field name:	acpi_rsdp_addr
-Type:		write
-Offset/size:	0x268/8
-Protocol:	2.14+
-
-  This field can be set by the boot loader to tell the kernel the
-  physical address of the ACPI RSDP table.
-
-  A value of 0 indicates the kernel should fall back to the standard
-  methods to locate the RSDP.
-
 
 **** THE IMAGE CHECKSUM
 
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 4c881c850125..850b8762e889 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -300,7 +300,7 @@ _start:
 	# Part 2 of the header, from the old setup.S
 
 		.ascii	"HdrS"		# header signature
-		.word	0x020e		# header version number (>= 0x0105)
+		.word	0x020d		# header version number (>= 0x0105)
 					# or else old loadlin-1.5 will fail)
 		.globl realmode_swtch
 realmode_swtch:	.word	0, 0		# default_switch, SETUPSEG
@@ -558,10 +558,6 @@ pref_address:		.quad LOAD_PHYSICAL_ADDR	# preferred load addr
 init_size:		.long INIT_SIZE		# kernel initialization size
 handover_offset:	.long 0			# Filled in by build.c
 
-acpi_rsdp_addr:		.quad 0			# 64-bit physical pointer to the
-						# ACPI RSDP table, added with
-						# version 2.14
-
 # End of setup header #####################################################
 
 	.section ".entrytext", "ax"
diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index 0f842104862c..b85a7c54c6a1 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -303,6 +303,4 @@ extern void x86_init_noop(void);
 extern void x86_init_uint_noop(unsigned int unused);
 extern bool x86_pnpbios_disabled(void);
 
-void x86_verify_bootdata_version(void);
-
 #endif
diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
index 22f89d040ddd..a06cbf019744 100644
--- a/arch/x86/include/uapi/asm/bootparam.h
+++ b/arch/x86/include/uapi/asm/bootparam.h
@@ -16,9 +16,6 @@
 #define RAMDISK_PROMPT_FLAG		0x8000
 #define RAMDISK_LOAD_FLAG		0x4000
 
-/* version flags */
-#define VERSION_WRITTEN	0x8000
-
 /* loadflags */
 #define LOADED_HIGH	(1<<0)
 #define KASLR_FLAG	(1<<1)
@@ -89,7 +86,6 @@ struct setup_header {
 	__u64	pref_address;
 	__u32	init_size;
 	__u32	handover_offset;
-	__u64	acpi_rsdp_addr;
 } __attribute__((packed));
 
 struct sys_desc_table {
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 92c76bf97ad8..fb3b1f3a5aba 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1776,5 +1776,5 @@ void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size)
 
 u64 x86_default_get_root_pointer(void)
 {
-	return boot_params.hdr.acpi_rsdp_addr;
+	return 0;
 }
diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c
index 76fa3b836598..ec6fefbfd3c0 100644
--- a/arch/x86/kernel/head32.c
+++ b/arch/x86/kernel/head32.c
@@ -37,7 +37,6 @@ asmlinkage __visible void __init i386_start_kernel(void)
 	cr4_init_shadow();
 
 	sanitize_boot_params(&boot_params);
-	x86_verify_bootdata_version();
 
 	x86_early_init_platform_quirks();
 
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 7663a8eb602b..16b1cbd3a61e 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -457,8 +457,6 @@ void __init x86_64_start_reservations(char *real_mode_data)
 	if (!boot_params.hdr.version)
 		copy_bootdata(__va(real_mode_data));
 
-	x86_verify_bootdata_version();
-
 	x86_early_init_platform_quirks();
 
 	switch (boot_params.hdr.hardware_subarch) {
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index b74e7bfed6ab..d494b9bfe618 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1280,23 +1280,6 @@ void __init setup_arch(char **cmdline_p)
 	unwind_init();
 }
 
-/*
- * From boot protocol 2.14 onwards we expect the bootloader to set the
- * version to "0x8000 | <used version>". In case we find a version >= 2.14
- * without the 0x8000 we assume the boot loader supports 2.13 only and
- * reset the version accordingly. The 0x8000 flag is removed in any case.
- */
-void __init x86_verify_bootdata_version(void)
-{
-	if (boot_params.hdr.version & VERSION_WRITTEN)
-		boot_params.hdr.version &= ~VERSION_WRITTEN;
-	else if (boot_params.hdr.version >= 0x020e)
-		boot_params.hdr.version = 0x020d;
-
-	if (boot_params.hdr.version < 0x020e)
-		boot_params.hdr.acpi_rsdp_addr = 0;
-}
-
 #ifdef CONFIG_X86_32
 
 static struct resource video_ram_resource = {
-- 
2.16.4


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH 2/2] x86/acpi, x86/boot: Take RSDP address from boot params if available
  2018-11-20  7:25 [PATCH 0/2] Move RSDP address out of setup_header Juergen Gross
  2018-11-20  7:25 ` [PATCH 1/2] x86/boot: revert commit ae7e1238e68f2a (Add ACPI RSDP address to setup_header) Juergen Gross
@ 2018-11-20  7:25 ` Juergen Gross
  2018-11-20  9:59   ` [tip:x86/urgent] " tip-bot for Juergen Gross
  2018-11-29  1:05 ` [Xen-devel] [PATCH 0/2] Move RSDP address out of setup_header Hans van Kranenburg
  2 siblings, 1 reply; 6+ messages in thread
From: Juergen Gross @ 2018-11-20  7:25 UTC (permalink / raw)
  To: linux-kernel, xen-devel, x86
  Cc: boris.ostrovsky, sstabellini, hpa, tglx, mingo, bp, daniel.kiper,
	Juergen Gross

In case the RSDP address in struct boot_params is specified don't try
to find the table by searching, but take the address directly as set
by the boot loader.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 arch/x86/include/uapi/asm/bootparam.h | 3 ++-
 arch/x86/kernel/acpi/boot.c           | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
index a06cbf019744..60733f137e9a 100644
--- a/arch/x86/include/uapi/asm/bootparam.h
+++ b/arch/x86/include/uapi/asm/bootparam.h
@@ -155,7 +155,8 @@ struct boot_params {
 	__u8  _pad2[4];					/* 0x054 */
 	__u64  tboot_addr;				/* 0x058 */
 	struct ist_info ist_info;			/* 0x060 */
-	__u8  _pad3[16];				/* 0x070 */
+	__u64 acpi_rsdp_addr;				/* 0x070 */
+	__u8  _pad3[8];					/* 0x078 */
 	__u8  hd0_info[16];	/* obsolete! */		/* 0x080 */
 	__u8  hd1_info[16];	/* obsolete! */		/* 0x090 */
 	struct sys_desc_table sys_desc_table; /* obsolete! */	/* 0x0a0 */
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index fb3b1f3a5aba..06635fbca81c 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1776,5 +1776,5 @@ void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size)
 
 u64 x86_default_get_root_pointer(void)
 {
-	return 0;
+	return boot_params.acpi_rsdp_addr;
 }
-- 
2.16.4


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [tip:x86/urgent] x86/boot: Mostly revert commit ae7e1238e68f2a ("Add ACPI RSDP address to setup_header")
  2018-11-20  7:25 ` [PATCH 1/2] x86/boot: revert commit ae7e1238e68f2a (Add ACPI RSDP address to setup_header) Juergen Gross
@ 2018-11-20  9:59   ` tip-bot for Juergen Gross
  0 siblings, 0 replies; 6+ messages in thread
From: tip-bot for Juergen Gross @ 2018-11-20  9:59 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: hpa, mingo, linux-kernel, torvalds, tglx, jgross, peterz

Commit-ID:  3841840449817ba6cf3e636008bc4e1061a03388
Gitweb:     https://git.kernel.org/tip/3841840449817ba6cf3e636008bc4e1061a03388
Author:     Juergen Gross <jgross@suse.com>
AuthorDate: Tue, 20 Nov 2018 08:25:28 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 20 Nov 2018 09:43:10 +0100

x86/boot: Mostly revert commit ae7e1238e68f2a ("Add ACPI RSDP address to setup_header")

Peter Anvin pointed out that commit:

  ae7e1238e68f2a ("x86/boot: Add ACPI RSDP address to setup_header")

should be reverted as setup_header should only contain items set by the
legacy BIOS.

So revert said commit. Instead of fully reverting the dependent commit
of:

  e7b66d16fe4172 ("x86/acpi, x86/boot: Take RSDP address for boot params if available")

just remove the setup_header reference in order to replace it by
a boot_params in a followup patch.

Suggested-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boris.ostrovsky@oracle.com
Cc: bp@alien8.de
Cc: daniel.kiper@oracle.com
Cc: sstabellini@kernel.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20181120072529.5489-2-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 Documentation/x86/boot.txt            | 32 +-------------------------------
 arch/x86/boot/header.S                |  6 +-----
 arch/x86/include/asm/x86_init.h       |  2 --
 arch/x86/include/uapi/asm/bootparam.h |  4 ----
 arch/x86/kernel/acpi/boot.c           |  2 +-
 arch/x86/kernel/head32.c              |  1 -
 arch/x86/kernel/head64.c              |  2 --
 arch/x86/kernel/setup.c               | 17 -----------------
 8 files changed, 3 insertions(+), 63 deletions(-)

diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt
index 7727db8f94bc..5e9b826b5f62 100644
--- a/Documentation/x86/boot.txt
+++ b/Documentation/x86/boot.txt
@@ -61,18 +61,6 @@ Protocol 2.12:	(Kernel 3.8) Added the xloadflags field and extension fields
 	 	to struct boot_params for loading bzImage and ramdisk
 		above 4G in 64bit.
 
-Protocol 2.13:	(Kernel 3.14) Support 32- and 64-bit flags being set in
-		xloadflags to support booting a 64-bit kernel from 32-bit
-		EFI
-
-Protocol 2.14:	(Kernel 4.20) Added acpi_rsdp_addr holding the physical
-		address of the ACPI RSDP table.
-		The bootloader updates version with:
-		0x8000 | min(kernel-version, bootloader-version)
-		kernel-version being the protocol version supported by
-		the kernel and bootloader-version the protocol version
-		supported by the bootloader.
-
 **** MEMORY LAYOUT
 
 The traditional memory map for the kernel loader, used for Image or
@@ -209,7 +197,6 @@ Offset	Proto	Name		Meaning
 0258/8	2.10+	pref_address	Preferred loading address
 0260/4	2.10+	init_size	Linear memory required during initialization
 0264/4	2.11+	handover_offset	Offset of handover entry point
-0268/8	2.14+	acpi_rsdp_addr	Physical address of RSDP table
 
 (1) For backwards compatibility, if the setup_sects field contains 0, the
     real value is 4.
@@ -322,7 +309,7 @@ Protocol:	2.00+
   Contains the magic number "HdrS" (0x53726448).
 
 Field name:	version
-Type:		modify
+Type:		read
 Offset/size:	0x206/2
 Protocol:	2.00+
 
@@ -330,12 +317,6 @@ Protocol:	2.00+
   e.g. 0x0204 for version 2.04, and 0x0a11 for a hypothetical version
   10.17.
 
-  Up to protocol version 2.13 this information is only read by the
-  bootloader. From protocol version 2.14 onwards the bootloader will
-  write the used protocol version or-ed with 0x8000 to the field. The
-  used protocol version will be the minimum of the supported protocol
-  versions of the bootloader and the kernel.
-
 Field name:	realmode_swtch
 Type:		modify (optional)
 Offset/size:	0x208/4
@@ -763,17 +744,6 @@ Offset/size:	0x264/4
 
   See EFI HANDOVER PROTOCOL below for more details.
 
-Field name:	acpi_rsdp_addr
-Type:		write
-Offset/size:	0x268/8
-Protocol:	2.14+
-
-  This field can be set by the boot loader to tell the kernel the
-  physical address of the ACPI RSDP table.
-
-  A value of 0 indicates the kernel should fall back to the standard
-  methods to locate the RSDP.
-
 
 **** THE IMAGE CHECKSUM
 
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 4c881c850125..850b8762e889 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -300,7 +300,7 @@ _start:
 	# Part 2 of the header, from the old setup.S
 
 		.ascii	"HdrS"		# header signature
-		.word	0x020e		# header version number (>= 0x0105)
+		.word	0x020d		# header version number (>= 0x0105)
 					# or else old loadlin-1.5 will fail)
 		.globl realmode_swtch
 realmode_swtch:	.word	0, 0		# default_switch, SETUPSEG
@@ -558,10 +558,6 @@ pref_address:		.quad LOAD_PHYSICAL_ADDR	# preferred load addr
 init_size:		.long INIT_SIZE		# kernel initialization size
 handover_offset:	.long 0			# Filled in by build.c
 
-acpi_rsdp_addr:		.quad 0			# 64-bit physical pointer to the
-						# ACPI RSDP table, added with
-						# version 2.14
-
 # End of setup header #####################################################
 
 	.section ".entrytext", "ax"
diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index 0f842104862c..b85a7c54c6a1 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -303,6 +303,4 @@ extern void x86_init_noop(void);
 extern void x86_init_uint_noop(unsigned int unused);
 extern bool x86_pnpbios_disabled(void);
 
-void x86_verify_bootdata_version(void);
-
 #endif
diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
index 22f89d040ddd..a06cbf019744 100644
--- a/arch/x86/include/uapi/asm/bootparam.h
+++ b/arch/x86/include/uapi/asm/bootparam.h
@@ -16,9 +16,6 @@
 #define RAMDISK_PROMPT_FLAG		0x8000
 #define RAMDISK_LOAD_FLAG		0x4000
 
-/* version flags */
-#define VERSION_WRITTEN	0x8000
-
 /* loadflags */
 #define LOADED_HIGH	(1<<0)
 #define KASLR_FLAG	(1<<1)
@@ -89,7 +86,6 @@ struct setup_header {
 	__u64	pref_address;
 	__u32	init_size;
 	__u32	handover_offset;
-	__u64	acpi_rsdp_addr;
 } __attribute__((packed));
 
 struct sys_desc_table {
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 92c76bf97ad8..fb3b1f3a5aba 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1776,5 +1776,5 @@ void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size)
 
 u64 x86_default_get_root_pointer(void)
 {
-	return boot_params.hdr.acpi_rsdp_addr;
+	return 0;
 }
diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c
index 76fa3b836598..ec6fefbfd3c0 100644
--- a/arch/x86/kernel/head32.c
+++ b/arch/x86/kernel/head32.c
@@ -37,7 +37,6 @@ asmlinkage __visible void __init i386_start_kernel(void)
 	cr4_init_shadow();
 
 	sanitize_boot_params(&boot_params);
-	x86_verify_bootdata_version();
 
 	x86_early_init_platform_quirks();
 
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 7663a8eb602b..16b1cbd3a61e 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -457,8 +457,6 @@ void __init x86_64_start_reservations(char *real_mode_data)
 	if (!boot_params.hdr.version)
 		copy_bootdata(__va(real_mode_data));
 
-	x86_verify_bootdata_version();
-
 	x86_early_init_platform_quirks();
 
 	switch (boot_params.hdr.hardware_subarch) {
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index b74e7bfed6ab..d494b9bfe618 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1280,23 +1280,6 @@ void __init setup_arch(char **cmdline_p)
 	unwind_init();
 }
 
-/*
- * From boot protocol 2.14 onwards we expect the bootloader to set the
- * version to "0x8000 | <used version>". In case we find a version >= 2.14
- * without the 0x8000 we assume the boot loader supports 2.13 only and
- * reset the version accordingly. The 0x8000 flag is removed in any case.
- */
-void __init x86_verify_bootdata_version(void)
-{
-	if (boot_params.hdr.version & VERSION_WRITTEN)
-		boot_params.hdr.version &= ~VERSION_WRITTEN;
-	else if (boot_params.hdr.version >= 0x020e)
-		boot_params.hdr.version = 0x020d;
-
-	if (boot_params.hdr.version < 0x020e)
-		boot_params.hdr.acpi_rsdp_addr = 0;
-}
-
 #ifdef CONFIG_X86_32
 
 static struct resource video_ram_resource = {

^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [tip:x86/urgent] x86/acpi, x86/boot: Take RSDP address from boot params if available
  2018-11-20  7:25 ` [PATCH 2/2] x86/acpi, x86/boot: Take RSDP address from boot params if available Juergen Gross
@ 2018-11-20  9:59   ` tip-bot for Juergen Gross
  0 siblings, 0 replies; 6+ messages in thread
From: tip-bot for Juergen Gross @ 2018-11-20  9:59 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: tglx, peterz, torvalds, jgross, mingo, hpa, linux-kernel

Commit-ID:  e6e094e053af75cbc164e950814d3d084fb1e698
Gitweb:     https://git.kernel.org/tip/e6e094e053af75cbc164e950814d3d084fb1e698
Author:     Juergen Gross <jgross@suse.com>
AuthorDate: Tue, 20 Nov 2018 08:25:29 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 20 Nov 2018 09:43:11 +0100

x86/acpi, x86/boot: Take RSDP address from boot params if available

In case the RSDP address in struct boot_params is specified don't try
to find the table by searching, but take the address directly as set
by the boot loader.

Suggested-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boris.ostrovsky@oracle.com
Cc: bp@alien8.de
Cc: daniel.kiper@oracle.com
Cc: sstabellini@kernel.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20181120072529.5489-3-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/include/uapi/asm/bootparam.h | 3 ++-
 arch/x86/kernel/acpi/boot.c           | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
index a06cbf019744..60733f137e9a 100644
--- a/arch/x86/include/uapi/asm/bootparam.h
+++ b/arch/x86/include/uapi/asm/bootparam.h
@@ -155,7 +155,8 @@ struct boot_params {
 	__u8  _pad2[4];					/* 0x054 */
 	__u64  tboot_addr;				/* 0x058 */
 	struct ist_info ist_info;			/* 0x060 */
-	__u8  _pad3[16];				/* 0x070 */
+	__u64 acpi_rsdp_addr;				/* 0x070 */
+	__u8  _pad3[8];					/* 0x078 */
 	__u8  hd0_info[16];	/* obsolete! */		/* 0x080 */
 	__u8  hd1_info[16];	/* obsolete! */		/* 0x090 */
 	struct sys_desc_table sys_desc_table; /* obsolete! */	/* 0x0a0 */
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index fb3b1f3a5aba..06635fbca81c 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1776,5 +1776,5 @@ void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size)
 
 u64 x86_default_get_root_pointer(void)
 {
-	return 0;
+	return boot_params.acpi_rsdp_addr;
 }

^ permalink raw reply related	[flat|nested] 6+ messages in thread
* Re: [Xen-devel] [PATCH 0/2] Move RSDP address out of setup_header
  2018-11-20  7:25 [PATCH 0/2] Move RSDP address out of setup_header Juergen Gross
  2018-11-20  7:25 ` [PATCH 1/2] x86/boot: revert commit ae7e1238e68f2a (Add ACPI RSDP address to setup_header) Juergen Gross
  2018-11-20  7:25 ` [PATCH 2/2] x86/acpi, x86/boot: Take RSDP address from boot params if available Juergen Gross
@ 2018-11-29  1:05 ` Hans van Kranenburg
  2 siblings, 0 replies; 6+ messages in thread
From: Hans van Kranenburg @ 2018-11-29  1:05 UTC (permalink / raw)
  To: Juergen Gross, linux-kernel, xen-devel, x86
  Cc: sstabellini, daniel.kiper, mingo, bp, hpa, boris.ostrovsky, tglx

Hi,

On 11/20/18 8:25 AM, Juergen Gross wrote:
> Resend with Daniel's mailo address corrected
> 
> Instead of passing the RSDP address for Xen PVH guests from grub2 to
> the kernel in setup_header move it into the non-legacy part of the
> boot_params structure.
> 
> This patch series should be applied rather sooner than later in order
> to avoid shipping linux 4.20 with a corky boot protocol.
> 
> Juergen Gross (2):
>   x86/boot: revert commit ae7e1238e68f2a (Add ACPI RSDP address to
>     setup_header)
>   x86/acpi, x86/boot: Take RSDP address from boot params if available
> 
>  Documentation/x86/boot.txt            | 32 +-------------------------------
>  arch/x86/boot/header.S                |  6 +-----
>  arch/x86/include/asm/x86_init.h       |  2 --
>  arch/x86/include/uapi/asm/bootparam.h |  7 ++-----
>  arch/x86/kernel/acpi/boot.c           |  2 +-
>  arch/x86/kernel/head32.c              |  1 -
>  arch/x86/kernel/head64.c              |  2 --
>  arch/x86/kernel/setup.c               | 17 -----------------
>  8 files changed, 5 insertions(+), 64 deletions(-)

FWIW, I can confirm that I can boot a Xen domU in PVH mode with the
following four patches added on top of Linux 4.19.5 (applied in this
order), in combination with grub master branch with patchset v5 for grub
on top:

Date:   Wed Oct 10 08:14:55 2018 +0200
x86/boot: Add ACPI RSDP address to setup_header

Date:   Wed Oct 10 08:14:56 2018 +0200
x86/acpi, x86/boot: Take RSDP address for boot params if available

Date:   Tue Nov 20 08:25:28 2018 +0100
x86/boot: revert commit ae7e1238e68f2a (Add ACPI RSDP address to
setup_header)

Date:   Tue Nov 20 08:25:29 2018 +0100
x86/acpi, x86/boot: Take RSDP address from boot params if available

[    0.205884] Booting paravirtualized kernel on Xen PVH

Thanks,
Hans

^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2018-11-29  1:15 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-11-20  7:25 [PATCH 0/2] Move RSDP address out of setup_header Juergen Gross
2018-11-20  7:25 ` [PATCH 1/2] x86/boot: revert commit ae7e1238e68f2a (Add ACPI RSDP address to setup_header) Juergen Gross
2018-11-20  9:59   ` [tip:x86/urgent] x86/boot: Mostly revert commit ae7e1238e68f2a ("Add ACPI RSDP address to setup_header") tip-bot for Juergen Gross
2018-11-20  7:25 ` [PATCH 2/2] x86/acpi, x86/boot: Take RSDP address from boot params if available Juergen Gross
2018-11-20  9:59   ` [tip:x86/urgent] " tip-bot for Juergen Gross
2018-11-29  1:05 ` [Xen-devel] [PATCH 0/2] Move RSDP address out of setup_header Hans van Kranenburg

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