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authorJanosch Frank <frankja@linux.ibm.com>2022-10-17 08:38:22 +0000
committerMarc-André Lureau <marcandre.lureau@redhat.com>2022-10-26 12:54:59 +0400
commit113d8f4e95cf0450bea421263de6ec016c779ad0 (patch)
treee8765ff222d0cb028300aefe855fca592c520646 /target/s390x
parent753ca06f4706cd6e57750a606afb08c5c5299643 (diff)
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s390x: pv: Add dump support
Sometimes dumping a guest from the outside is the only way to get the data that is needed. This can be the case if a dumping mechanism like KDUMP hasn't been configured or data needs to be fetched at a specific point. Dumping a protected guest from the outside without help from fw/hw doesn't yield sufficient data to be useful. Hence we now introduce PV dump support. The PV dump support works by integrating the firmware into the dump process. New Ultravisor calls are used to initiate the dump process, dump cpu data, dump memory state and lastly complete the dump process. The UV calls are exposed by KVM via the new KVM_PV_DUMP command and its subcommands. The guest's data is fully encrypted and can only be decrypted by the entity that owns the customer communication key for the dumped guest. Also dumping needs to be allowed via a flag in the SE header. On the QEMU side of things we store the PV dump data in the newly introduced architecture ELF sections (storage state and completion data) and the cpu notes (for cpu dump data). Users can use the zgetdump tool to convert the encrypted QEMU dump to an unencrypted one. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Message-Id: <20221017083822.43118-11-frankja@linux.ibm.com>
Diffstat (limited to 'target/s390x')
-rw-r--r--target/s390x/arch_dump.c262
1 files changed, 235 insertions, 27 deletions
diff --git a/target/s390x/arch_dump.c b/target/s390x/arch_dump.c
index f60a149..a232914 100644
--- a/target/s390x/arch_dump.c
+++ b/target/s390x/arch_dump.c
@@ -12,11 +12,13 @@
*/
#include "qemu/osdep.h"
+#include "qemu/units.h"
#include "cpu.h"
#include "s390x-internal.h"
#include "elf.h"
#include "sysemu/dump.h"
-
+#include "hw/s390x/pv.h"
+#include "kvm/kvm_s390x.h"
struct S390xUserRegsStruct {
uint64_t psw[2];
@@ -76,9 +78,16 @@ typedef struct noteStruct {
uint64_t todcmp;
uint32_t todpreg;
uint64_t ctrs[16];
+ uint8_t dynamic[1]; /*
+ * Would be a flexible array member, if
+ * that was legal inside a union. Real
+ * size comes from PV info interface.
+ */
} contents;
} QEMU_PACKED Note;
+static bool pv_dump_initialized;
+
static void s390x_write_elf64_prstatus(Note *note, S390CPU *cpu, int id)
{
int i;
@@ -177,28 +186,39 @@ static void s390x_write_elf64_prefix(Note *note, S390CPU *cpu, int id)
note->contents.prefix = cpu_to_be32((uint32_t)(cpu->env.psa));
}
+static void s390x_write_elf64_pv(Note *note, S390CPU *cpu, int id)
+{
+ note->hdr.n_type = cpu_to_be32(NT_S390_PV_CPU_DATA);
+ if (!pv_dump_initialized) {
+ return;
+ }
+ kvm_s390_dump_cpu(cpu, &note->contents.dynamic);
+}
typedef struct NoteFuncDescStruct {
int contents_size;
+ uint64_t (*note_size_func)(void); /* NULL for non-dynamic sized contents */
void (*note_contents_func)(Note *note, S390CPU *cpu, int id);
+ bool pvonly;
} NoteFuncDesc;
static const NoteFuncDesc note_core[] = {
- {sizeof_field(Note, contents.prstatus), s390x_write_elf64_prstatus},
- {sizeof_field(Note, contents.fpregset), s390x_write_elf64_fpregset},
- { 0, NULL}
+ {sizeof_field(Note, contents.prstatus), NULL, s390x_write_elf64_prstatus, false},
+ {sizeof_field(Note, contents.fpregset), NULL, s390x_write_elf64_fpregset, false},
+ { 0, NULL, NULL, false}
};
static const NoteFuncDesc note_linux[] = {
- {sizeof_field(Note, contents.prefix), s390x_write_elf64_prefix},
- {sizeof_field(Note, contents.ctrs), s390x_write_elf64_ctrs},
- {sizeof_field(Note, contents.timer), s390x_write_elf64_timer},
- {sizeof_field(Note, contents.todcmp), s390x_write_elf64_todcmp},
- {sizeof_field(Note, contents.todpreg), s390x_write_elf64_todpreg},
- {sizeof_field(Note, contents.vregslo), s390x_write_elf64_vregslo},
- {sizeof_field(Note, contents.vregshi), s390x_write_elf64_vregshi},
- {sizeof_field(Note, contents.gscb), s390x_write_elf64_gscb},
- { 0, NULL}
+ {sizeof_field(Note, contents.prefix), NULL, s390x_write_elf64_prefix, false},
+ {sizeof_field(Note, contents.ctrs), NULL, s390x_write_elf64_ctrs, false},
+ {sizeof_field(Note, contents.timer), NULL, s390x_write_elf64_timer, false},
+ {sizeof_field(Note, contents.todcmp), NULL, s390x_write_elf64_todcmp, false},
+ {sizeof_field(Note, contents.todpreg), NULL, s390x_write_elf64_todpreg, false},
+ {sizeof_field(Note, contents.vregslo), NULL, s390x_write_elf64_vregslo, false},
+ {sizeof_field(Note, contents.vregshi), NULL, s390x_write_elf64_vregshi, false},
+ {sizeof_field(Note, contents.gscb), NULL, s390x_write_elf64_gscb, false},
+ {0, kvm_s390_pv_dmp_get_size_cpu, s390x_write_elf64_pv, true},
+ { 0, NULL, NULL, false}
};
static int s390x_write_elf64_notes(const char *note_name,
@@ -207,22 +227,41 @@ static int s390x_write_elf64_notes(const char *note_name,
DumpState *s,
const NoteFuncDesc *funcs)
{
- Note note;
+ Note note, *notep;
const NoteFuncDesc *nf;
- int note_size;
+ int note_size, content_size;
int ret = -1;
assert(strlen(note_name) < sizeof(note.name));
for (nf = funcs; nf->note_contents_func; nf++) {
- memset(&note, 0, sizeof(note));
- note.hdr.n_namesz = cpu_to_be32(strlen(note_name) + 1);
- note.hdr.n_descsz = cpu_to_be32(nf->contents_size);
- g_strlcpy(note.name, note_name, sizeof(note.name));
- (*nf->note_contents_func)(&note, cpu, id);
+ notep = &note;
+ if (nf->pvonly && !s390_is_pv()) {
+ continue;
+ }
+
+ content_size = nf->note_size_func ? nf->note_size_func() : nf->contents_size;
+ note_size = sizeof(note) - sizeof(notep->contents) + content_size;
+
+ /* Notes with dynamic sizes need to allocate a note */
+ if (nf->note_size_func) {
+ notep = g_malloc(note_size);
+ }
+
+ memset(notep, 0, sizeof(note));
- note_size = sizeof(note) - sizeof(note.contents) + nf->contents_size;
- ret = f(&note, note_size, s);
+ /* Setup note header data */
+ notep->hdr.n_descsz = cpu_to_be32(content_size);
+ notep->hdr.n_namesz = cpu_to_be32(strlen(note_name) + 1);
+ g_strlcpy(notep->name, note_name, sizeof(notep->name));
+
+ /* Get contents and write them out */
+ (*nf->note_contents_func)(notep, cpu, id);
+ ret = f(notep, note_size, s);
+
+ if (nf->note_size_func) {
+ g_free(notep);
+ }
if (ret < 0) {
return -1;
@@ -247,13 +286,179 @@ int s390_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
return s390x_write_elf64_notes("LINUX", f, cpu, cpuid, s, note_linux);
}
+/* PV dump section size functions */
+static uint64_t get_mem_state_size_from_len(uint64_t len)
+{
+ return (len / (MiB)) * kvm_s390_pv_dmp_get_size_mem_state();
+}
+
+static uint64_t get_size_mem_state(DumpState *s)
+{
+ return get_mem_state_size_from_len(s->total_size);
+}
+
+static uint64_t get_size_completion_data(DumpState *s)
+{
+ return kvm_s390_pv_dmp_get_size_completion_data();
+}
+
+/* PV dump section data functions*/
+static int get_data_completion(DumpState *s, uint8_t *buff)
+{
+ int rc;
+
+ if (!pv_dump_initialized) {
+ return 0;
+ }
+ rc = kvm_s390_dump_completion_data(buff);
+ if (!rc) {
+ pv_dump_initialized = false;
+ }
+ return rc;
+}
+
+static int get_mem_state(DumpState *s, uint8_t *buff)
+{
+ int64_t memblock_size, memblock_start;
+ GuestPhysBlock *block;
+ uint64_t off;
+ int rc;
+
+ QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
+ memblock_start = dump_filtered_memblock_start(block, s->filter_area_begin,
+ s->filter_area_length);
+ if (memblock_start == -1) {
+ continue;
+ }
+
+ memblock_size = dump_filtered_memblock_size(block, s->filter_area_begin,
+ s->filter_area_length);
+
+ off = get_mem_state_size_from_len(block->target_start);
+
+ rc = kvm_s390_dump_mem_state(block->target_start,
+ get_mem_state_size_from_len(memblock_size),
+ buff + off);
+ if (rc) {
+ return rc;
+ }
+ }
+
+ return 0;
+}
+
+static struct sections {
+ uint64_t (*sections_size_func)(DumpState *s);
+ int (*sections_contents_func)(DumpState *s, uint8_t *buff);
+ char sctn_str[12];
+} sections[] = {
+ { get_size_mem_state, get_mem_state, "pv_mem_meta"},
+ { get_size_completion_data, get_data_completion, "pv_compl"},
+ {NULL , NULL, ""}
+};
+
+static uint64_t arch_sections_write_hdr(DumpState *s, uint8_t *buff)
+{
+ Elf64_Shdr *shdr = (void *)buff;
+ struct sections *sctn = sections;
+ uint64_t off = s->section_offset;
+
+ if (!pv_dump_initialized) {
+ return 0;
+ }
+
+ for (; sctn->sections_size_func; off += shdr->sh_size, sctn++, shdr++) {
+ memset(shdr, 0, sizeof(*shdr));
+ shdr->sh_type = SHT_PROGBITS;
+ shdr->sh_offset = off;
+ shdr->sh_size = sctn->sections_size_func(s);
+ shdr->sh_name = s->string_table_buf->len;
+ g_array_append_vals(s->string_table_buf, sctn->sctn_str, sizeof(sctn->sctn_str));
+ }
+
+ return (uintptr_t)shdr - (uintptr_t)buff;
+}
+
+
+/* Add arch specific number of sections and their respective sizes */
+static void arch_sections_add(DumpState *s)
+{
+ struct sections *sctn = sections;
+
+ /*
+ * We only do a PV dump if we are running a PV guest, KVM supports
+ * the dump API and we got valid dump length information.
+ */
+ if (!s390_is_pv() || !kvm_s390_get_protected_dump() ||
+ !kvm_s390_pv_info_basic_valid()) {
+ return;
+ }
+
+ /*
+ * Start the UV dump process by doing the initialize dump call via
+ * KVM as the proxy.
+ */
+ if (!kvm_s390_dump_init()) {
+ pv_dump_initialized = true;
+ } else {
+ /*
+ * Dump init failed, maybe the guest owner disabled dumping.
+ * We'll continue the non-PV dump process since this is no
+ * reason to crash qemu.
+ */
+ return;
+ }
+
+ for (; sctn->sections_size_func; sctn++) {
+ s->shdr_num += 1;
+ s->elf_section_data_size += sctn->sections_size_func(s);
+ }
+}
+
+/*
+ * After the PV dump has been initialized, the CPU data has been
+ * fetched and memory has been dumped, we need to grab the tweak data
+ * and the completion data.
+ */
+static int arch_sections_write(DumpState *s, uint8_t *buff)
+{
+ struct sections *sctn = sections;
+ int rc;
+
+ if (!pv_dump_initialized) {
+ return -EINVAL;
+ }
+
+ for (; sctn->sections_size_func; sctn++) {
+ rc = sctn->sections_contents_func(s, buff);
+ buff += sctn->sections_size_func(s);
+ if (rc) {
+ return rc;
+ }
+ }
+ return 0;
+}
+
int cpu_get_dump_info(ArchDumpInfo *info,
const struct GuestPhysBlockList *guest_phys_blocks)
{
info->d_machine = EM_S390;
info->d_endian = ELFDATA2MSB;
info->d_class = ELFCLASS64;
-
+ /*
+ * This is evaluated for each dump so we can freely switch
+ * between PV and non-PV.
+ */
+ if (s390_is_pv() && kvm_s390_get_protected_dump() &&
+ kvm_s390_pv_info_basic_valid()) {
+ info->arch_sections_add_fn = *arch_sections_add;
+ info->arch_sections_write_hdr_fn = *arch_sections_write_hdr;
+ info->arch_sections_write_fn = *arch_sections_write;
+ } else {
+ info->arch_sections_add_fn = NULL;
+ info->arch_sections_write_hdr_fn = NULL;
+ info->arch_sections_write_fn = NULL;
+ }
return 0;
}
@@ -261,7 +466,7 @@ ssize_t cpu_get_note_size(int class, int machine, int nr_cpus)
{
int name_size = 8; /* "LINUX" or "CORE" + pad */
size_t elf_note_size = 0;
- int note_head_size;
+ int note_head_size, content_size;
const NoteFuncDesc *nf;
assert(class == ELFCLASS64);
@@ -270,12 +475,15 @@ ssize_t cpu_get_note_size(int class, int machine, int nr_cpus)
note_head_size = sizeof(Elf64_Nhdr);
for (nf = note_core; nf->note_contents_func; nf++) {
- elf_note_size = elf_note_size + note_head_size + name_size +
- nf->contents_size;
+ elf_note_size = elf_note_size + note_head_size + name_size + nf->contents_size;
}
for (nf = note_linux; nf->note_contents_func; nf++) {
+ if (nf->pvonly && !s390_is_pv()) {
+ continue;
+ }
+ content_size = nf->contents_size ? nf->contents_size : nf->note_size_func();
elf_note_size = elf_note_size + note_head_size + name_size +
- nf->contents_size;
+ content_size;
}
return (elf_note_size) * nr_cpus;