[Qemu-devel] [PULL 08/11] target-arm: dump-guest-memory: add prfpreg notes for aarch64

[Peter Maydell <peter.maydell@linaro.org>]

From: Andrew Jones <drjones@redhat.com>

Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1452542185-10914-7-git-send-email-drjones@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target-arm/arch_dump.c | 79 +++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 71 insertions(+), 8 deletions(-)

diff --git a/target-arm/arch_dump.c b/target-arm/arch_dump.c
index f7a4873..d7b63a0 100644
--- a/target-arm/arch_dump.c
+++ b/target-arm/arch_dump.c
@@ -45,13 +45,36 @@ struct aarch64_elf_prstatus {
 
 QEMU_BUILD_BUG_ON(sizeof(struct aarch64_elf_prstatus) != 392);
 
+/* struct user_fpsimd_state from arch/arm64/include/uapi/asm/ptrace.h
+ *
+ * While the vregs member of user_fpsimd_state is of type __uint128_t,
+ * QEMU uses an array of uint64_t, where the high half of the 128-bit
+ * value is always in the 2n+1'th index. Thus we also break the 128-
+ * bit values into two halves in this reproduction of user_fpsimd_state.
+ */
+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 aarch64_note {
     Elf64_Nhdr hdr;
     char name[8]; /* align_up(sizeof("CORE"), 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_PRFPREG_NOTE_SIZE \
+            (AARCH64_NOTE_HEADER_SIZE + sizeof(struct aarch64_user_vfp_state))
 
 static void aarch64_note_init(struct aarch64_note *note, DumpState *s,
                               const char *name, Elf64_Word namesz,
@@ -66,6 +89,42 @@ static void aarch64_note_init(struct aarch64_note *note, DumpState *s,
     memcpy(note->name, name, namesz);
 }
 
+static int aarch64_write_elf64_prfpreg(WriteCoreDumpFunction f,
+                                       CPUARMState *env, int cpuid,
+                                       DumpState *s)
+{
+    struct aarch64_note note;
+    int ret, i;
+
+    aarch64_note_init(&note, s, "CORE", 5, NT_PRFPREG, sizeof(note.vfp));
+
+    for (i = 0; i < 64; ++i) {
+        note.vfp.vregs[i] = cpu_to_dump64(s, float64_val(env->vfp.regs[i]));
+    }
+
+    if (s->dump_info.d_endian == ELFDATA2MSB) {
+        /* For AArch64 we must always swap the 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 < 32; ++i) {
+            uint64_t tmp = note.vfp.vregs[2*i];
+            note.vfp.vregs[2*i] = note.vfp.vregs[2*i+1];
+            note.vfp.vregs[2*i+1] = tmp;
+        }
+    }
+
+    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_PRFPREG_NOTE_SIZE, s);
+    if (ret < 0) {
+        return -1;
+    }
+
+    return 0;
+}
+
 int arm_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
                              int cpuid, void *opaque)
 {
@@ -78,6 +137,7 @@ int arm_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
     aarch64_note_init(&note, s, "CORE", 5, NT_PRSTATUS, sizeof(note.prstatus));
 
     note.prstatus.pr_pid = cpu_to_dump32(s, cpuid);
+    note.prstatus.pr_fpvalid = cpu_to_dump32(s, 1);
 
     if (!is_a64(env)) {
         aarch64_sync_32_to_64(env);
@@ -95,12 +155,12 @@ int arm_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
     note.prstatus.pr_reg.pc = cpu_to_dump64(s, env->pc);
     note.prstatus.pr_reg.pstate = cpu_to_dump64(s, pstate);
 
-    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_prfpreg(f, env, cpuid, s);
 }
 
 /* struct pt_regs from arch/arm/include/asm/ptrace.h */
@@ -129,7 +189,9 @@ struct arm_note {
     struct arm_elf_prstatus prstatus;
 } 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))
 
 static void arm_note_init(struct arm_note *note, DumpState *s,
                           const char *name, Elf32_Word namesz,
@@ -161,7 +223,7 @@ int arm_cpu_write_elf32_note(WriteCoreDumpFunction f, CPUState *cs,
     }
     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;
     }
@@ -221,9 +283,10 @@ 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_PRFPREG_NOTE_SIZE;
     } else {
-        note_size = sizeof(struct arm_note);
+        note_size = ARM_PRSTATUS_NOTE_SIZE;
     }
 
     return note_size * nr_cpus;
-- 
1.9.1