qemu/target/ppc/arch_dump.c
Narayana Murty N 93c691a003 target: ppc: Use MSR_HVB bit to get the target endianness for memory dump
Currently on PPC64 qemu always dumps the guest memory in
Big Endian (BE) format even though the guest running in Little Endian
(LE) mode. So crash tool fails to load the dump as illustrated below:

Log :
$ virsh dump DOMAIN --memory-only dump.file

Domain 'DOMAIN' dumped to dump.file

$ crash vmlinux dump.file

<snip>
crash 8.0.2-1.el9

WARNING: endian mismatch:
          crash utility: little-endian
          dump.file: big-endian

WARNING: machine type mismatch:
          crash utility: PPC64
          dump.file: (unknown)

crash: dump.file: not a supported file format
<snip>

This happens because cpu_get_dump_info() passes cpu->env->has_hv_mode
to function ppc_interrupts_little_endian(), the cpu->env->has_hv_mode
always set for powerNV even though the guest is not running in hv mode.
The hv mode should be taken from msr_mask MSR_HVB bit
(cpu->env.msr_mask & MSR_HVB). This patch fixes the issue by passing
MSR_HVB value to ppc_interrupts_little_endian() in order to determine
the guest endianness.

The crash tool also expects guest kernel endianness should match the
endianness of the dump.

The patch was tested on POWER9 box booted with Linux as host in
following cases:

Host-Endianess Qemu-Target-Machine                Qemu-Generated-Guest
                                                  Memory-Dump-Format
BE             powernv(OPAL/PowerNV)                   LE
BE             powernv(OPAL/PowerNV)                   BE
LE             powernv(OPAL/PowerNV)                   LE
LE             powernv(OPAL/PowerNV)                   BE
LE             pseries(OPAL/PowerNV/pSeries) KVMHV     LE
LE             pseries TCG                             LE

Fixes: 5609400a42 ("target/ppc: Set the correct endianness for powernv memory
dumps")
Signed-off-by: Narayana Murty N <nnmlinux@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Message-ID: <20230623072506.34713-1-nnmlinux@linux.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2023-07-07 04:46:12 -03:00

309 lines
8 KiB
C

/*
* writing ELF notes for ppc{64,} arch
*
*
* Copyright IBM, Corp. 2013
*
* Authors:
* Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "elf.h"
#include "sysemu/dump.h"
#include "sysemu/kvm.h"
#ifdef TARGET_PPC64
#define ELFCLASS ELFCLASS64
#define cpu_to_dump_reg cpu_to_dump64
typedef uint64_t reg_t;
typedef Elf64_Nhdr Elf_Nhdr;
#else
#define ELFCLASS ELFCLASS32
#define cpu_to_dump_reg cpu_to_dump32
typedef uint32_t reg_t;
typedef Elf32_Nhdr Elf_Nhdr;
#endif /* TARGET_PPC64 */
struct PPCUserRegStruct {
reg_t gpr[32];
reg_t nip;
reg_t msr;
reg_t orig_gpr3;
reg_t ctr;
reg_t link;
reg_t xer;
reg_t ccr;
reg_t softe;
reg_t trap;
reg_t dar;
reg_t dsisr;
reg_t result;
} QEMU_PACKED;
struct PPCElfPrstatus {
char pad1[112];
struct PPCUserRegStruct pr_reg;
char pad2[40];
} QEMU_PACKED;
struct PPCElfFpregset {
uint64_t fpr[32];
reg_t fpscr;
} QEMU_PACKED;
struct PPCElfVmxregset {
ppc_avr_t avr[32];
ppc_avr_t vscr;
union {
ppc_avr_t unused;
uint32_t value;
} vrsave;
} QEMU_PACKED;
struct PPCElfVsxregset {
uint64_t vsr[32];
} QEMU_PACKED;
struct PPCElfSperegset {
uint32_t evr[32];
uint64_t spe_acc;
uint32_t spe_fscr;
} QEMU_PACKED;
typedef struct noteStruct {
Elf_Nhdr hdr;
char name[5];
char pad3[3];
union {
struct PPCElfPrstatus prstatus;
struct PPCElfFpregset fpregset;
struct PPCElfVmxregset vmxregset;
struct PPCElfVsxregset vsxregset;
struct PPCElfSperegset speregset;
} contents;
} QEMU_PACKED Note;
typedef struct NoteFuncArg {
Note note;
DumpState *state;
} NoteFuncArg;
static void ppc_write_elf_prstatus(NoteFuncArg *arg, PowerPCCPU *cpu)
{
int i;
reg_t cr;
struct PPCElfPrstatus *prstatus;
struct PPCUserRegStruct *reg;
Note *note = &arg->note;
DumpState *s = arg->state;
note->hdr.n_type = cpu_to_dump32(s, NT_PRSTATUS);
prstatus = &note->contents.prstatus;
memset(prstatus, 0, sizeof(*prstatus));
reg = &prstatus->pr_reg;
for (i = 0; i < 32; i++) {
reg->gpr[i] = cpu_to_dump_reg(s, cpu->env.gpr[i]);
}
reg->nip = cpu_to_dump_reg(s, cpu->env.nip);
reg->msr = cpu_to_dump_reg(s, cpu->env.msr);
reg->ctr = cpu_to_dump_reg(s, cpu->env.ctr);
reg->link = cpu_to_dump_reg(s, cpu->env.lr);
reg->xer = cpu_to_dump_reg(s, cpu_read_xer(&cpu->env));
cr = 0;
for (i = 0; i < 8; i++) {
cr |= (cpu->env.crf[i] & 15) << (4 * (7 - i));
}
reg->ccr = cpu_to_dump_reg(s, cr);
}
static void ppc_write_elf_fpregset(NoteFuncArg *arg, PowerPCCPU *cpu)
{
int i;
struct PPCElfFpregset *fpregset;
Note *note = &arg->note;
DumpState *s = arg->state;
note->hdr.n_type = cpu_to_dump32(s, NT_PRFPREG);
fpregset = &note->contents.fpregset;
memset(fpregset, 0, sizeof(*fpregset));
for (i = 0; i < 32; i++) {
uint64_t *fpr = cpu_fpr_ptr(&cpu->env, i);
fpregset->fpr[i] = cpu_to_dump64(s, *fpr);
}
fpregset->fpscr = cpu_to_dump_reg(s, cpu->env.fpscr);
}
static void ppc_write_elf_vmxregset(NoteFuncArg *arg, PowerPCCPU *cpu)
{
int i;
struct PPCElfVmxregset *vmxregset;
Note *note = &arg->note;
DumpState *s = arg->state;
note->hdr.n_type = cpu_to_dump32(s, NT_PPC_VMX);
vmxregset = &note->contents.vmxregset;
memset(vmxregset, 0, sizeof(*vmxregset));
for (i = 0; i < 32; i++) {
bool needs_byteswap;
ppc_avr_t *avr = cpu_avr_ptr(&cpu->env, i);
#if HOST_BIG_ENDIAN
needs_byteswap = s->dump_info.d_endian == ELFDATA2LSB;
#else
needs_byteswap = s->dump_info.d_endian == ELFDATA2MSB;
#endif
if (needs_byteswap) {
vmxregset->avr[i].u64[0] = bswap64(avr->u64[1]);
vmxregset->avr[i].u64[1] = bswap64(avr->u64[0]);
} else {
vmxregset->avr[i].u64[0] = avr->u64[0];
vmxregset->avr[i].u64[1] = avr->u64[1];
}
}
vmxregset->vscr.u32[3] = cpu_to_dump32(s, ppc_get_vscr(&cpu->env));
}
static void ppc_write_elf_vsxregset(NoteFuncArg *arg, PowerPCCPU *cpu)
{
int i;
struct PPCElfVsxregset *vsxregset;
Note *note = &arg->note;
DumpState *s = arg->state;
note->hdr.n_type = cpu_to_dump32(s, NT_PPC_VSX);
vsxregset = &note->contents.vsxregset;
memset(vsxregset, 0, sizeof(*vsxregset));
for (i = 0; i < 32; i++) {
uint64_t *vsrl = cpu_vsrl_ptr(&cpu->env, i);
vsxregset->vsr[i] = cpu_to_dump64(s, *vsrl);
}
}
static void ppc_write_elf_speregset(NoteFuncArg *arg, PowerPCCPU *cpu)
{
struct PPCElfSperegset *speregset;
Note *note = &arg->note;
DumpState *s = arg->state;
note->hdr.n_type = cpu_to_dump32(s, NT_PPC_SPE);
speregset = &note->contents.speregset;
memset(speregset, 0, sizeof(*speregset));
speregset->spe_acc = cpu_to_dump64(s, cpu->env.spe_acc);
speregset->spe_fscr = cpu_to_dump32(s, cpu->env.spe_fscr);
}
static const struct NoteFuncDescStruct {
int contents_size;
void (*note_contents_func)(NoteFuncArg *arg, PowerPCCPU *cpu);
} note_func[] = {
{sizeof_field(Note, contents.prstatus), ppc_write_elf_prstatus},
{sizeof_field(Note, contents.fpregset), ppc_write_elf_fpregset},
{sizeof_field(Note, contents.vmxregset), ppc_write_elf_vmxregset},
{sizeof_field(Note, contents.vsxregset), ppc_write_elf_vsxregset},
{sizeof_field(Note, contents.speregset), ppc_write_elf_speregset},
{ 0, NULL}
};
typedef struct NoteFuncDescStruct NoteFuncDesc;
int cpu_get_dump_info(ArchDumpInfo *info,
const struct GuestPhysBlockList *guest_phys_blocks)
{
PowerPCCPU *cpu;
if (first_cpu == NULL) {
return -1;
}
cpu = POWERPC_CPU(first_cpu);
info->d_machine = PPC_ELF_MACHINE;
info->d_class = ELFCLASS;
if (ppc_interrupts_little_endian(cpu, !!(cpu->env.msr_mask & MSR_HVB))) {
info->d_endian = ELFDATA2LSB;
} else {
info->d_endian = ELFDATA2MSB;
}
/* 64KB is the max page size for pseries kernel */
if (strncmp(object_get_typename(qdev_get_machine()),
"pseries-", 8) == 0) {
info->page_size = (1U << 16);
}
return 0;
}
ssize_t cpu_get_note_size(int class, int machine, int nr_cpus)
{
int name_size = 8; /* "CORE" or "QEMU" rounded */
size_t elf_note_size = 0;
int note_head_size;
const NoteFuncDesc *nf;
note_head_size = sizeof(Elf_Nhdr);
for (nf = note_func; nf->note_contents_func; nf++) {
elf_note_size = elf_note_size + note_head_size + name_size +
nf->contents_size;
}
return (elf_note_size) * nr_cpus;
}
static int ppc_write_all_elf_notes(const char *note_name,
WriteCoreDumpFunction f,
PowerPCCPU *cpu, int id,
DumpState *s)
{
NoteFuncArg arg = { .state = s };
int ret = -1;
int note_size;
const NoteFuncDesc *nf;
for (nf = note_func; nf->note_contents_func; nf++) {
arg.note.hdr.n_namesz = cpu_to_dump32(s, sizeof(arg.note.name));
arg.note.hdr.n_descsz = cpu_to_dump32(s, nf->contents_size);
strncpy(arg.note.name, note_name, sizeof(arg.note.name));
(*nf->note_contents_func)(&arg, cpu);
note_size =
sizeof(arg.note) - sizeof(arg.note.contents) + nf->contents_size;
ret = f(&arg.note, note_size, s);
if (ret < 0) {
return -1;
}
}
return 0;
}
int ppc64_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
int cpuid, DumpState *s)
{
PowerPCCPU *cpu = POWERPC_CPU(cs);
return ppc_write_all_elf_notes("CORE", f, cpu, cpuid, s);
}
int ppc32_cpu_write_elf32_note(WriteCoreDumpFunction f, CPUState *cs,
int cpuid, DumpState *s)
{
PowerPCCPU *cpu = POWERPC_CPU(cs);
return ppc_write_all_elf_notes("CORE", f, cpu, cpuid, s);
}