New subject: [PATCH] kexec/x86: Always try to fill acpi_rsdp_addr in boot params

25 Jun 2019

This patch sync the behavior of user space kexec and kexec_file_load,
they will both fill the boot_params.acpi_rsdp_addr with a valid RSDP
value, to make sure second kernel can always get the RSDP consistently.
This will make it effortless to boot newer version of kernel (5.0+)
without specifying acpi_rsdp= cmdline on EFI system even with EFI
service disabled. Should not change any behavior with older kernels.
Backport the following commits from upstream:
commit 40805e393b2fc84551a6705e1890e995e3ee8320
Author: Kairui Song kasong@redhat.com
crashdump/x86: Use new introduce helper for getting RSDP
commit b071fc084bdafd4674cd776581cab2bf2b44a004
Author: Kairui Song kasong@redhat.com
x86: Always try to fill acpi_rsdp_addr in boot params
commit cedeee0a30075030632a18e419419371ddf3fca3
Author: Kairui Song kasong@redhat.com
x86: Introduce helpers for getting RSDP address
commit 402351390f31b2db0768eef4ced375d00bff9e17
Author: Kairui Song kasong@redhat.com
x86: Update boot parameters defination
Signed-off-by: Kairui Song kasong@redhat.com
---
 ...o-fill-acpi_rsdp_addr-in-boot-params.patch | 272 ++++++++++++++++++
 kexec-tools.spec                              |   4 +-
 2 files changed, 275 insertions(+), 1 deletion(-)
 create mode 100644 kexec-tools-2.0.19-always-try-to-fill-acpi_rsdp_addr-in-boot-params.patch

diff --git a/kexec-tools-2.0.19-always-try-to-fill-acpi_rsdp_addr-in-boot-params.patch b/kexec-tools-2.0.19-always-try-to-fill-acpi_rsdp_addr-in-boot-params.patch
new file mode 100644
index 0000000..c9f6459
--- /dev/null
+++ b/kexec-tools-2.0.19-always-try-to-fill-acpi_rsdp_addr-in-boot-params.patch
@@ -0,0 +1,272 @@
+From f9bfb3d112ee4ba7566bc07d744cb356e4383254 Mon Sep 17 00:00:00 2001
+From: Kairui Song kasong@redhat.com
+Date: Fri, 24 May 2019 14:23:18 +0800
+Subject: [PATCH] x86: Always try to fill acpi_rsdp_addr in boot params
+
+This is squash of following commits:
+
+commit 40805e393b2fc84551a6705e1890e995e3ee8320
+Author: Kairui Song kasong@redhat.com
+Date:   Fri May 24 14:23:21 2019 +0800
+
+    crashdump/x86: Use new introduce helper for getting RSDP
+
+    Use the new introduce helper for getting RSDP, this ensures RSDP is
+    always accessible and avoid code duplication.
+
+    Signed-off-by: Kairui Song kasong@redhat.com
+    Signed-off-by: Simon Horman horms@verge.net.au
+
+commit b071fc084bdafd4674cd776581cab2bf2b44a004
+Author: Kairui Song kasong@redhat.com
+Date:   Fri May 24 14:23:20 2019 +0800
+
+    x86: Always try to fill acpi_rsdp_addr in boot params
+
+    Since kernel commit e6e094e053af75 ("x86/acpi, x86/boot: Take RSDP address
+    from boot params if available"), kernel accept an acpi_rsdp_addr param in
+    boot_params. So fill in this parameter unconditionally, ensure second
+    kernel always get the right RSDP address consistently, and boot well on
+    EFI system even with EFI service disabled. User no longer need to change
+    the kernel cmdline to workaround the missing RSDP issue.
+
+    For older version of kernels (Before 5.0), there won't be any change of
+    behavior.
+
+    Signed-off-by: Kairui Song kasong@redhat.com
+    Signed-off-by: Simon Horman horms@verge.net.au
+
+commit cedeee0a30075030632a18e419419371ddf3fca3
+Author: Kairui Song kasong@redhat.com
+Date:   Fri May 24 14:23:19 2019 +0800
+
+    x86: Introduce helpers for getting RSDP address
+
+    On x86 RSDP is fundamental for booting the machine. When second kernel
+    is incapable of parsing the RSDP address (eg. kexec next kernel on an EFI
+    system with EFI service disabled), kexec should prepare the RSDP address
+    for second kernel.
+
+    Introduce helpers for getting RSDP from multiple sources, including boot
+    params and EFI firmware.
+
+    For legacy BIOS interface, there is no better way to find the RSDP address
+    rather than scanning the memory region and search for it, and this will
+    always be done by the kernel as a fallback, so this is no need to try to
+    get the RSDP address for that case.
+
+    Signed-off-by: Kairui Song kasong@redhat.com
+    Signed-off-by: Simon Horman horms@verge.net.au
+
+commit 402351390f31b2db0768eef4ced375d00bff9e17
+Author: Kairui Song kasong@redhat.com
+Date:   Fri May 24 14:23:18 2019 +0800
+
+    x86: Update boot parameters defination
+
+    Since kernel commit e6e094e053af75 ("x86/acpi, x86/boot: Take RSDP address
+    from boot params if available"), kernel accept a acpi_rsdp_addr param in
+    boot_params. Sync the x86_linux_param_header to support this param.
+
+    Signed-off-by: Kairui Song kasong@redhat.com
+    Signed-off-by: Simon Horman horms@verge.net.au
+---
+ include/x86/x86-linux.h            |  6 +++--
+ kexec/arch/i386/crashdump-x86.c    | 34 +++++++----------------
+ kexec/arch/i386/kexec-x86-common.c | 43 ++++++++++++++++++++++++++++++
+ kexec/arch/i386/kexec-x86.h        |  1 +
+ kexec/arch/i386/x86-linux-setup.c  |  6 +++--
+ kexec/arch/i386/x86-linux-setup.h  |  1 +
+ 6 files changed, 62 insertions(+), 29 deletions(-)
+
+diff --git a/include/x86/x86-linux.h b/include/x86/x86-linux.h
+index 352ea02..9646102 100644
+--- a/include/x86/x86-linux.h
++++ b/include/x86/x86-linux.h
+@@ -45,7 +45,6 @@ struct apm_bios_info {
+ 	uint16_t cseg_len;	/* 0x4e */
+ 	uint16_t cseg_16_len;	/* 0x50 */
+ 	uint16_t dseg_len;	/* 0x52 */
+-	uint8_t  reserved[44];	/* 0x54 */
+ };
+ 
+ /*
+@@ -113,12 +112,15 @@ struct x86_linux_param_header {
+ 	uint8_t  reserved4[2];			/* 0x3e -- 0x3f reserved for future expansion */
+ 
+ 	struct apm_bios_info apm_bios_info;	/* 0x40 */
++	uint8_t  reserved4_1[28];		/* 0x54 */
++	uint64_t acpi_rsdp_addr;		/* 0x70 */
++	uint8_t  reserved4_2[8];		/* 0x78 */
+ 	struct drive_info_struct drive_info;	/* 0x80 */
+ 	struct sys_desc_table sys_desc_table;	/* 0xa0 */
+ 	uint32_t ext_ramdisk_image;		/* 0xc0 */
+ 	uint32_t ext_ramdisk_size;		/* 0xc4 */
+ 	uint32_t ext_cmd_line_ptr;		/* 0xc8 */
+-	uint8_t reserved4_1[0x1c0 - 0xcc];	/* 0xe4 */
++	uint8_t reserved4_3[0x1c0 - 0xcc];	/* 0xe4 */
+ 	uint8_t efi_info[32];			/* 0x1c0 */
+ 	uint32_t alt_mem_k;			/* 0x1e0 */
+ 	uint8_t  reserved5[4];			/* 0x1e4 */
+diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
+index 140f45b..a2aea31 100644
+--- a/kexec/arch/i386/crashdump-x86.c
++++ b/kexec/arch/i386/crashdump-x86.c
+@@ -787,35 +787,19 @@ static int sysfs_efi_runtime_map_exist(void)
+ /* Appends 'acpi_rsdp=' commandline for efi boot crash dump */
+ static void cmdline_add_efi(char *cmdline)
+ {
+-	FILE *fp;
+-	int cmdlen, len;
+-	char line[MAX_LINE], *s;
+-	const char *acpis = " acpi_rsdp=";
++	uint64_t acpi_rsdp;
++	char acpi_rsdp_buf[MAX_LINE];
+ 
+-	fp = fopen("/sys/firmware/efi/systab", "r");
+-	if (!fp)
+-		return;
++	acpi_rsdp = get_acpi_rsdp();
+ 
+-	while(fgets(line, sizeof(line), fp) != 0) {
+-		/* ACPI20= always goes before ACPI= */
+-		if ((strstr(line, "ACPI20=")) || (strstr(line, "ACPI="))) {
+-		        line[strlen(line) - 1] = '\0';
+-			s = strchr(line, '=');
+-			s += 1;
+-			len = strlen(s) + strlen(acpis);
+-			cmdlen = strlen(cmdline) + len;
+-			if (cmdlen > (COMMAND_LINE_SIZE - 1))
+-				die("Command line overflow\n");
+-			strcat(cmdline, acpis);
+-			strcat(cmdline, s);
+-			dbgprintf("Command line after adding efi\n");
+-			dbgprintf("%s\n", cmdline);
++	if (!acpi_rsdp)
++		return;
+ 
+-			break;
+-		}
+-	}
++	sprintf(acpi_rsdp_buf, " acpi_rsdp=0x%lx", acpi_rsdp);
++	if (strlen(cmdline) + strlen(acpi_rsdp_buf) > (COMMAND_LINE_SIZE - 1))
++		die("Command line overflow\n");
+ 
+-	fclose(fp);
++	strcat(cmdline, acpi_rsdp_buf);
+ }
+ 
+ static void get_backup_area(struct kexec_info *info,
+diff --git a/kexec/arch/i386/kexec-x86-common.c b/kexec/arch/i386/kexec-x86-common.c
+index de99758..5c55ec8 100644
+--- a/kexec/arch/i386/kexec-x86-common.c
++++ b/kexec/arch/i386/kexec-x86-common.c
+@@ -39,6 +39,7 @@
+ #include "../../firmware_memmap.h"
+ #include "../../crashdump.h"
+ #include "kexec-x86.h"
++#include "x86-linux-setup.h"
+ #include "../../kexec-xen.h"
+ 
+ /* Used below but not present in (older?) xenctrl.h */
+@@ -392,4 +393,46 @@ int get_memory_ranges(struct memory_range **range, int *ranges,
+ 	return ret;
+ }
+ 
++static uint64_t bootparam_get_acpi_rsdp(void) {
++	uint64_t acpi_rsdp = 0;
++	off_t offset = offsetof(struct x86_linux_param_header, acpi_rsdp_addr);
+ 
++	if (get_bootparam(&acpi_rsdp, offset, sizeof(acpi_rsdp)))
++		return 0;
++
++	return acpi_rsdp;
++}
++
++static uint64_t efi_get_acpi_rsdp(void) {
++	FILE *fp;
++	char line[MAX_LINE], *s;
++	uint64_t acpi_rsdp = 0;
++
++	fp = fopen("/sys/firmware/efi/systab", "r");
++	if (!fp)
++		return acpi_rsdp;
++
++	while(fgets(line, sizeof(line), fp) != 0) {
++		/* ACPI20= always goes before ACPI= */
++		if ((strstr(line, "ACPI20=")) || (strstr(line, "ACPI="))) {
++			s = strchr(line, '=') + 1;
++			sscanf(s, "0x%lx", &acpi_rsdp);
++			break;
++		}
++	}
++	fclose(fp);
++
++	return acpi_rsdp;
++}
++
++uint64_t get_acpi_rsdp(void)
++{
++	uint64_t acpi_rsdp = 0;
++
++	acpi_rsdp = bootparam_get_acpi_rsdp();
++
++	if (!acpi_rsdp)
++		acpi_rsdp = efi_get_acpi_rsdp();
++
++	return acpi_rsdp;
++}
+diff --git a/kexec/arch/i386/kexec-x86.h b/kexec/arch/i386/kexec-x86.h
+index c2bcd37..1b58c3b 100644
+--- a/kexec/arch/i386/kexec-x86.h
++++ b/kexec/arch/i386/kexec-x86.h
+@@ -86,4 +86,5 @@ int nbi_load(int argc, char **argv, const char *buf, off_t len,
+ void nbi_usage(void);
+ 
+ extern unsigned xen_e820_to_kexec_type(uint32_t type);
++extern uint64_t get_acpi_rsdp(void);
+ #endif /* KEXEC_X86_H */
+diff --git a/kexec/arch/i386/x86-linux-setup.c b/kexec/arch/i386/x86-linux-setup.c
+index b643c8b..057ee14 100644
+--- a/kexec/arch/i386/x86-linux-setup.c
++++ b/kexec/arch/i386/x86-linux-setup.c
+@@ -123,7 +123,6 @@ void setup_linux_bootloader_parameters_high(
+ 	cmdline_ptr[cmdline_len - 1] = '\0';
+ }
+ 
+-static int get_bootparam(void *buf, off_t offset, size_t size);
+ static int setup_linux_vesafb(struct x86_linux_param_header *real_mode)
+ {
+ 	struct fb_fix_screeninfo fix;
+@@ -460,7 +459,7 @@ char *find_mnt_by_type(char *type)
+ 	return mntdir;
+ }
+ 
+-static int get_bootparam(void *buf, off_t offset, size_t size)
++int get_bootparam(void *buf, off_t offset, size_t size)
+ {
+ 	int data_file;
+ 	char *debugfs_mnt, *sysfs_mnt;
+@@ -910,4 +909,7 @@ void setup_linux_system_parameters(struct kexec_info *info,
+ 
+ 	/* fill the EDD information */
+ 	setup_edd_info(real_mode);
++
++	/* Always try to fill acpi_rsdp_addr */
++	real_mode->acpi_rsdp_addr = get_acpi_rsdp();
+ }
+diff --git a/kexec/arch/i386/x86-linux-setup.h b/kexec/arch/i386/x86-linux-setup.h
+index f5d23d3..0c651e5 100644
+--- a/kexec/arch/i386/x86-linux-setup.h
++++ b/kexec/arch/i386/x86-linux-setup.h
+@@ -21,6 +21,7 @@ static inline void setup_linux_bootloader_parameters(
+ }
+ void setup_linux_system_parameters(struct kexec_info *info,
+ 	struct x86_linux_param_header *real_mode);
++int get_bootparam(void *buf, off_t offset, size_t size);
+ 
+ 
+ #define SETUP_BASE    0x90000
+-- 
+2.21.0
+
diff --git a/kexec-tools.spec b/kexec-tools.spec
index b642543..5a050e8 100644
--- a/kexec-tools.spec
+++ b/kexec-tools.spec
@@ -76,6 +76,7 @@ Obsoletes: diskdumputils netdump kexec-tools-eppic
 # Patches 101 through 200 are meant for x86_64 kexec-tools enablement
 #
 Patch101: kexec-tools-2.0.19-makedumpfiles-x86_64-Add-support-for-AMD-Secure-Memory-Encry.patch
+Patch102: kexec-tools-2.0.19-always-try-to-fill-acpi_rsdp_addr-in-boot-params.patch
#
 # Patches 301 through 400 are meant for ppc64 kexec-tools enablement
@@ -107,8 +108,9 @@ mkdir -p -m755 kcp
 tar -z -x -v -f %{SOURCE9}
 tar -z -x -v -f %{SOURCE19}
-%patch601 -p1
 %patch101 -p1
+%patch102 -p1
+%patch601 -p1
%ifarch ppc
 %define archdef ARCH=ppc
-- 
2.21.0

    