[Qemu-devel] [PATCH v2 6/6] target-arm: dump-guest-memory: add fpregset notes

[Andrew Jones]

Also refactors note init code to avoid code duplication.

Signed-off-by: Andrew Jones <address@hidden>
---
 target-arm/arch_dump.c | 161 ++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 139 insertions(+), 22 deletions(-)

diff --git a/target-arm/arch_dump.c b/target-arm/arch_dump.c
index 5debe549d721d..8d74788411d79 100644
--- a/target-arm/arch_dump.c
+++ b/target-arm/arch_dump.c
@@ -35,6 +35,16 @@ struct aarch64_user_regs {
 
 QEMU_BUILD_BUG_ON(sizeof(struct aarch64_user_regs) != 272);
 
+/* struct user_fpsimd_state from arch/arm64/include/uapi/asm/ptrace.h */
+struct aarch64_user_vfp_state {
+    uint64_t vregs[64];
+    uint32_t fpsr;
+    uint32_t fpcr;
+    char pad[8];
+} QEMU_PACKED;
+
+QEMU_BUILD_BUG_ON(sizeof(struct aarch64_user_vfp_state) != 528);
+
 /* struct elf_prstatus from include/uapi/linux/elfcore.h */
 struct aarch64_elf_prstatus {
     char pad1[32]; /* 32 == offsetof(struct elf_prstatus, pr_pid) */
@@ -51,10 +61,77 @@ QEMU_BUILD_BUG_ON(sizeof(struct aarch64_elf_prstatus) != 
392);
 struct aarch64_note {
     Elf64_Nhdr hdr;
     char name[QEMU_ALIGN_UP(NOTE_NAMESZ, 4)];
-    struct aarch64_elf_prstatus prstatus;
+    union {
+        struct aarch64_elf_prstatus prstatus;
+        struct aarch64_user_vfp_state vfp;
+    };
 } QEMU_PACKED;
 
-QEMU_BUILD_BUG_ON(sizeof(struct aarch64_note) != 412);
+#define AARCH64_NOTE_HEADER_SIZE offsetof(struct aarch64_note, prstatus)
+#define AARCH64_PRSTATUS_NOTE_SIZE \
+            (AARCH64_NOTE_HEADER_SIZE + sizeof(struct aarch64_elf_prstatus))
+#define AARCH64_FPREGSET_NOTE_SIZE \
+            (AARCH64_NOTE_HEADER_SIZE + sizeof(struct aarch64_user_vfp_state))
+
+static void aarch64_note_init(struct aarch64_note *note, DumpState *s,
+                              Elf64_Word type, Elf64_Word descsz)
+{
+    memset(note, 0, sizeof(*note));
+
+    note->hdr.n_namesz = cpu_to_dump32(s, NOTE_NAMESZ);
+    note->hdr.n_descsz = cpu_to_dump32(s, descsz);
+    note->hdr.n_type = cpu_to_dump32(s, type);
+
+    memcpy(note->name, NOTE_NAME, NOTE_NAMESZ);
+}
+
+static void arm_write_vregs(uint64_t *vregs, int num_regs,
+                            CPUARMState *env, DumpState *s)
+{
+    int i;
+
+    for (i = 0; i < num_regs; ++i) {
+        vregs[i] = cpu_to_dump64(s, env->vfp.regs[i]);
+    }
+
+    if (s->dump_info.d_endian == ELFDATA2MSB) {
+        /* We must always swap vfp.regs's 2n and 2n+1 entries when
+         * generating BE notes, because even big endian hosts use
+         * 2n+1 for the high half.
+         */
+        for (i = 0; i < num_regs/2; ++i) {
+            uint64_t tmp = vregs[2*i];
+            vregs[2*i] = vregs[2*i+1];
+            vregs[2*i+1] = tmp;
+        }
+    }
+}
+
+static int
+aarch64_write_elf64_fpregset(WriteCoreDumpFunction f, CPUARMState *env,
+                             int id, DumpState *s)
+{
+    struct aarch64_note note;
+    int ret;
+
+    aarch64_note_init(&note, s, NT_FPREGSET, sizeof(note.vfp));
+
+    if (is_a64(env)) {
+        arm_write_vregs(note.vfp.vregs, 64, env, s);
+    } else {
+        arm_write_vregs(note.vfp.vregs, 32, env, s);
+    }
+
+    note.vfp.fpsr = cpu_to_dump32(s, vfp_get_fpsr(env));
+    note.vfp.fpcr = cpu_to_dump32(s, vfp_get_fpcr(env));
+
+    ret = f(&note, AARCH64_FPREGSET_NOTE_SIZE, s);
+    if (ret < 0) {
+        return -1;
+    }
+
+    return 0;
+}
 
 static int
 aarch64_write_elf64_note(WriteCoreDumpFunction f, CPUARMState *env,
@@ -63,13 +140,8 @@ aarch64_write_elf64_note(WriteCoreDumpFunction f, 
CPUARMState *env,
     struct aarch64_note note;
     int ret, i;
 
-    memset(&note, 0, sizeof(note));
-
-    note.hdr.n_namesz = cpu_to_dump32(s, NOTE_NAMESZ);
-    note.hdr.n_descsz = cpu_to_dump32(s, sizeof(note.prstatus));
-    note.hdr.n_type = cpu_to_dump32(s, NT_PRSTATUS);
+    aarch64_note_init(&note, s, NT_PRSTATUS, sizeof(note.prstatus));
 
-    memcpy(note.name, NOTE_NAME, NOTE_NAMESZ);
     note.prstatus.pr_pid = cpu_to_dump32(s, id);
 
     if (is_a64(env)) {
@@ -89,12 +161,12 @@ aarch64_write_elf64_note(WriteCoreDumpFunction f, 
CPUARMState *env,
         note.prstatus.pr_reg.pstate = cpu_to_dump64(s, cpsr_read(env));
     }
 
-    ret = f(&note, sizeof(note), s);
+    ret = f(&note, AARCH64_PRSTATUS_NOTE_SIZE, s);
     if (ret < 0) {
         return -1;
     }
 
-    return 0;
+    return aarch64_write_elf64_fpregset(f, env, id, s);
 }
 
 /* struct pt_regs from arch/arm/include/asm/ptrace.h */
@@ -105,6 +177,14 @@ struct arm_user_regs {
 
 QEMU_BUILD_BUG_ON(sizeof(struct arm_user_regs) != 72);
 
+/* struct user_vfp from arch/arm/include/asm/user.h */
+struct arm_user_vfp_state {
+    uint64_t vregs[32];
+    uint32_t fpscr;
+} QEMU_PACKED;
+
+QEMU_BUILD_BUG_ON(sizeof(struct arm_user_vfp_state) != 260);
+
 /* struct elf_prstatus from include/uapi/linux/elfcore.h */
 struct arm_elf_prstatus {
     char pad1[24]; /* 24 == offsetof(struct elf_prstatus, pr_pid) */
@@ -120,10 +200,50 @@ QEMU_BUILD_BUG_ON(sizeof(struct arm_elf_prstatus) != 148);
 struct arm_note {
     Elf32_Nhdr hdr;
     char name[QEMU_ALIGN_UP(NOTE_NAMESZ, 4)];
-    struct arm_elf_prstatus prstatus;
+    union {
+        struct arm_elf_prstatus prstatus;
+        struct arm_user_vfp_state vfp;
+    };
 } QEMU_PACKED;
 
-QEMU_BUILD_BUG_ON(sizeof(struct arm_note) != 168);
+#define ARM_NOTE_HEADER_SIZE offsetof(struct arm_note, prstatus)
+#define ARM_PRSTATUS_NOTE_SIZE \
+            (ARM_NOTE_HEADER_SIZE + sizeof(struct arm_elf_prstatus))
+#define ARM_FPREGSET_NOTE_SIZE \
+            (ARM_NOTE_HEADER_SIZE + sizeof(struct arm_user_vfp_state))
+
+static void arm_note_init(struct arm_note *note, DumpState *s,
+                          Elf32_Word type, Elf32_Word descsz)
+{
+    memset(note, 0, sizeof(*note));
+
+    note->hdr.n_namesz = cpu_to_dump32(s, NOTE_NAMESZ);
+    note->hdr.n_descsz = cpu_to_dump32(s, descsz);
+    note->hdr.n_type = cpu_to_dump32(s, type);
+
+    memcpy(note->name, NOTE_NAME, NOTE_NAMESZ);
+}
+
+static int
+arm_write_elf32_fpregset(WriteCoreDumpFunction f, CPUARMState *env,
+                         int id, DumpState *s)
+{
+    struct arm_note note;
+    int ret;
+
+    arm_note_init(&note, s, NT_FPREGSET, sizeof(note.vfp));
+
+    arm_write_vregs(note.vfp.vregs, 32, env, s);
+
+    note.vfp.fpscr = cpu_to_dump32(s, vfp_get_fpscr(env));
+
+    ret = f(&note, ARM_FPREGSET_NOTE_SIZE, s);
+    if (ret < 0) {
+        return -1;
+    }
+
+    return 0;
+}
 
 static int
 arm_write_elf32_note(WriteCoreDumpFunction f, CPUARMState *env,
@@ -132,13 +252,8 @@ arm_write_elf32_note(WriteCoreDumpFunction f, CPUARMState 
*env,
     struct arm_note note;
     int ret, i;
 
-    memset(&note, 0, sizeof(note));
-
-    note.hdr.n_namesz = cpu_to_dump32(s, NOTE_NAMESZ);
-    note.hdr.n_descsz = cpu_to_dump32(s, sizeof(note.prstatus));
-    note.hdr.n_type = cpu_to_dump32(s, NT_PRSTATUS);
+    arm_note_init(&note, s, NT_PRSTATUS, sizeof(note.prstatus));
 
-    memcpy(note.name, NOTE_NAME, NOTE_NAMESZ);
     note.prstatus.pr_pid = cpu_to_dump32(s, id);
 
     for (i = 0; i < 16; ++i) {
@@ -146,12 +261,12 @@ arm_write_elf32_note(WriteCoreDumpFunction f, CPUARMState 
*env,
     }
     note.prstatus.pr_reg.regs[16] = cpu_to_dump32(s, cpsr_read(env));
 
-    ret = f(&note, sizeof(note), s);
+    ret = f(&note, ARM_PRSTATUS_NOTE_SIZE, s);
     if (ret < 0) {
         return -1;
     }
 
-    return 0;
+    return arm_write_elf32_fpregset(f, env, id, s);
 }
 
 int arm_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
@@ -221,9 +336,11 @@ ssize_t cpu_get_note_size(int class, int machine, int 
nr_cpus)
     size_t note_size;
 
     if (class == ELFCLASS64) {
-        note_size = sizeof(struct aarch64_note);
+        note_size = AARCH64_PRSTATUS_NOTE_SIZE;
+        note_size += AARCH64_FPREGSET_NOTE_SIZE;
     } else {
-        note_size = sizeof(struct arm_note);
+        note_size = ARM_PRSTATUS_NOTE_SIZE;
+        note_size += ARM_FPREGSET_NOTE_SIZE;
     }
 
     return note_size * nr_cpus;
-- 
2.4.3