From 8350ad9c0f54519a06ec396c2997330615f4b470 Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Fri, 29 May 2020 05:53:58 -0400 Subject: [PATCH 16/42] pc-bios: s390x: Save iplb location in lowcore RH-Author: Thomas Huth Message-id: <20200529055420.16855-17-thuth@redhat.com> Patchwork-id: 97027 O-Subject: [RHEL-8.3.0 qemu-kvm PATCH v2 16/38] pc-bios: s390x: Save iplb location in lowcore Bugzilla: 1828317 RH-Acked-by: Claudio Imbrenda RH-Acked-by: Cornelia Huck RH-Acked-by: David Hildenbrand From: Janosch Frank The POP states that for a list directed IPL the IPLB is stored into memory by the machine loader and its address is stored at offset 0x14 of the lowcore. ZIPL currently uses the address in offset 0x14 to access the IPLB and acquire flags about secure boot. If the IPLB address points into memory which has an unsupported mix of flags set, ZIPL will panic instead of booting the OS. As the lowcore can have quite a high entropy for a guest that did drop out of protected mode (i.e. rebooted) we encountered the ZIPL panic quite often. Signed-off-by: Janosch Frank Tested-by: Marc Hartmayer Message-Id: <20200304114231.23493-19-frankja@linux.ibm.com> Reviewed-by: Christian Borntraeger Reviewed-by: David Hildenbrand Signed-off-by: Christian Borntraeger (cherry picked from commit 9bfc04f9ef6802fff0fc77130ff345a541783363) Signed-off-by: Danilo C. L. de Paula --- pc-bios/s390-ccw/jump2ipl.c | 1 + pc-bios/s390-ccw/main.c | 8 +++++++- pc-bios/s390-ccw/netmain.c | 1 + pc-bios/s390-ccw/s390-arch.h | 10 ++++++++-- pc-bios/s390-ccw/s390-ccw.h | 1 + 5 files changed, 18 insertions(+), 3 deletions(-) diff --git a/pc-bios/s390-ccw/jump2ipl.c b/pc-bios/s390-ccw/jump2ipl.c index da13c43cc0..4eba2510b0 100644 --- a/pc-bios/s390-ccw/jump2ipl.c +++ b/pc-bios/s390-ccw/jump2ipl.c @@ -35,6 +35,7 @@ void jump_to_IPL_code(uint64_t address) { /* store the subsystem information _after_ the bootmap was loaded */ write_subsystem_identification(); + write_iplb_location(); /* prevent unknown IPL types in the guest */ if (iplb.pbt == S390_IPL_TYPE_QEMU_SCSI) { diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c index a21b386280..4e65b411e1 100644 --- a/pc-bios/s390-ccw/main.c +++ b/pc-bios/s390-ccw/main.c @@ -9,6 +9,7 @@ */ #include "libc.h" +#include "helper.h" #include "s390-arch.h" #include "s390-ccw.h" #include "cio.h" @@ -22,7 +23,7 @@ QemuIplParameters qipl; IplParameterBlock iplb __attribute__((__aligned__(PAGE_SIZE))); static bool have_iplb; static uint16_t cutype; -LowCore const *lowcore; /* Yes, this *is* a pointer to address 0 */ +LowCore *lowcore; /* Yes, this *is* a pointer to address 0 */ #define LOADPARM_PROMPT "PROMPT " #define LOADPARM_EMPTY " " @@ -42,6 +43,11 @@ void write_subsystem_identification(void) *zeroes = 0; } +void write_iplb_location(void) +{ + lowcore->ptr_iplb = ptr2u32(&iplb); +} + void panic(const char *string) { sclp_print(string); diff --git a/pc-bios/s390-ccw/netmain.c b/pc-bios/s390-ccw/netmain.c index f2dcc01e27..309ffa30d9 100644 --- a/pc-bios/s390-ccw/netmain.c +++ b/pc-bios/s390-ccw/netmain.c @@ -40,6 +40,7 @@ #define DEFAULT_TFTP_RETRIES 20 extern char _start[]; +void write_iplb_location(void) {} #define KERNEL_ADDR ((void *)0L) #define KERNEL_MAX_SIZE ((long)_start) diff --git a/pc-bios/s390-ccw/s390-arch.h b/pc-bios/s390-ccw/s390-arch.h index 504fc7c2f0..5f36361c02 100644 --- a/pc-bios/s390-ccw/s390-arch.h +++ b/pc-bios/s390-ccw/s390-arch.h @@ -36,7 +36,13 @@ typedef struct LowCore { /* prefix area: defined by architecture */ PSWLegacy ipl_psw; /* 0x000 */ uint32_t ccw1[2]; /* 0x008 */ - uint32_t ccw2[2]; /* 0x010 */ + union { + uint32_t ccw2[2]; /* 0x010 */ + struct { + uint32_t reserved10; + uint32_t ptr_iplb; + }; + }; uint8_t pad1[0x80 - 0x18]; /* 0x018 */ uint32_t ext_params; /* 0x080 */ uint16_t cpu_addr; /* 0x084 */ @@ -85,7 +91,7 @@ typedef struct LowCore { PSW io_new_psw; /* 0x1f0 */ } __attribute__((packed, aligned(8192))) LowCore; -extern LowCore const *lowcore; +extern LowCore *lowcore; static inline void set_prefix(uint32_t address) { diff --git a/pc-bios/s390-ccw/s390-ccw.h b/pc-bios/s390-ccw/s390-ccw.h index 11bce7d73c..21f27e7990 100644 --- a/pc-bios/s390-ccw/s390-ccw.h +++ b/pc-bios/s390-ccw/s390-ccw.h @@ -57,6 +57,7 @@ void consume_io_int(void); /* main.c */ void panic(const char *string); void write_subsystem_identification(void); +void write_iplb_location(void); extern char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE))); unsigned int get_loadparm_index(void); -- 2.27.0